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Ankur's_Chemical_Engg_Blog - How To Write A Plant Operating Manual

July 13, 2013, 4:58 am
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Most Process Engineers, specially the senior process engineers are required to write a plant operating manual for a new greenfield project during their career. Mind you, this is quite different from updating an existing operating manual for a brownfield project where the scope of the project is modification and debottlenecking. Updation of an existing operating manual is a simpler exercise compared to writing a new operating manual where you follow the format of the existing operating manual and only provide an addendum to the existing operating manual related to the scope of the project.
 
The real challenge lies in writing a new operating manual and that is where the experience of the process engineer comes into fore.
 
In this blog entry I have tried to put across general guidelines on preparing a plant operating manual based on my experience of writing a few of them. These guidelines are generic in nature and do not subscribe to any company philosophy for writing an operating manual.
 
Let us begin the exercise with what are the basic minimum requirements to start writing an operating manual
 
Following input documents are required during preparation of Operating Manual:
 
a. Basis of Design – Process Description
b. Process & Utility Flow Diagrams (PFDs and UFDs)
c. Piping & Instrument Diagrams (P&ID’s)
d. Deatiled process description from "Technology Licensor" for proprietary processes if applicable
e. Operating and Miantenance manuals of vendor equipment and packages (e.g. Instrument Air Package, Compressor Systems, Pumps, Water Treatment Plants, Fired Heaters etc.)
f. Function logic narrative provided by Instrumentation
 
Procedure:
 
Operating Manual is generally a Microsoft Word document.
 
Structure:
 The Operating Manual is a structured document with a particular narrative style. The following is the sequence of the document:
 
- Coversheet with project title and document name i.e. Operating Manual
- 1st sheet with project title, document name i.e. Operating Manual
- List of Contents which includes:
   . Abbreviations and Definitions
   . Introduction which provides an overview of the project
   . Process & Utility System Description
   . Process Control and Automation
   . Equipment Description
   . Start-Up Procedure
   . Normal Operating Procedure
   . Shutdown Procedure
   . Health, Safety & Environment (HSE)
   . Appendices
 
Abbreviations & Definitiions:
The abbreviations and definitions of terms used in the entire document are summarized here.
 
Introduction:
This section provides the brief overview of the project which includes the purpose of the facility and what it contains.
 
Process & Utility System Description:
This section describes in detail the overall facility. The narrative should be in such a manner that the description is in the correct sequence of the process for easy understanding. Utility systems which supplement the main process should be described as a separate sub-section. Wherever possible, process description should be supplemented by simple sketches showing the major equipment and process control for a particular unit operation. This enhances the understanding of the process.
 
Process Control & Automation:
This section provides the description of the overall controls required for the safe, reliable and uninterrupted operation of the plant / unit. This could include flow, pressure, temperature and level control of the plant / unit for the smooth operation of the plant / unit. Controls required for start-up, planned shutdown and to change plant / unit capacity should be mentioned. High and Low alarms for process operating parameters are also described in this section.
 
Plant section-wise or unit-wise control systems should be addressed in a sequential manner in order to explain the process control in continuity.
 
All process safety and shutdown interlocks, automation provided for emergency shutdown of entire plant or unit of the plant should be described in this section. An example of an emergency shutdown could be the description of the Fire and Gas Monitoring system which initiates the plant or unit shutdown.
 
Tag numbers of instruments used for process control and automation should be mentioned for sake of clarity.
 
Equipment Description:
This section provides the functional description of the individual equipment or group of equipment which form a unit operation in the overall context of the entire facility. Description could include operating and design conditions for the individual equipment.
 
Providing tag nos. for the equipment is recommended.
 
Wherever possible, sketches are recommended for the sake of clarity.
 
Start-up Procedure:
This section provides the description of the start-up procedure for the plant / unit under consideration:
 
The first sub-section of this section should address the readiness of the plant to be started-up. By readiness it is meant that the plant / unit is ready to accept the process or utility fluid, raw materials or reactants. This requires that the commissioning check-lists prepared for the plant / unit are ticked off and signed off by the start-up team.  A list of the check-lists may be provided in this section which have been signed-off to indicate readiness.
 
The second sub-section should address the start-up of the utility systems prior to the start-up of the main process. Utility systems could include charging up headers for instrument air, cooling water, inert gas for blanketing / purging etc.
 
The third sub-section should address the start-up of the main process. This section should describe the valves (manual or automated) and instruments to be lined up for introducing the process fluid (e.g. hydrocarbons, chemicals) into the equipment or equipments (e.g. piping, vessels, tanks, reactors) of the plant / unit being started up.
 
Wherever applicable, reference of vendor documents for any equipment / package unit should be provided in this section.
 
Normal Operating Procedure:
This section provides the description of the normal operation of the plant / unit and indicates the parameters to be monitored for maintaining the product quality and operational reliability of the plant / unit.
 
Operating parameters should be mentioned for a particular equipment or unit or the entire plant in this section. Sketches describing the normal operation are recommended for the sake of clarity. Field logging and maintaining history records of critical process parameters from the DCS or SCADA need to be mentioned in this section. Requirements of manning a particular plant section or unit should be mentioned in this section including field monitoring intervals by operating personnel for a particular equipment or unit.
 
While describing any operation it is recommended that equipment, instrument and line tag nos. be mentioned for the sake of clarity.
 
Shutdown Procedure:
This section provides the description of the shutdown procedures to stop the operation of the plant.
 
The first sub-section of this section deals with normal shutdown due to either scheduled maintenance and / or inspection or modification / de-bottlenecking of the plant. In this sub-section, description should be provided for planned reduction / removal of inventory of the process fluids from the equipment or unit to be shutdown. This would include stoppage of fresh feed, gradual reduction of plant / unit throughput to minimise off-specification product and final draining and purging of the equipment / unit for the purpose of complete emptying prior to handing over for maintenance / inspection or modifications / de-bottlenecking.
 
The second sub-section deals with emergency shutdown procedures due to any emergency such as an external fire, water flooding, earth quake, loss of containment of process fluid (gas or liquid leak) etc. In this section description should be provided for the methods for isolation of equipment or unit due to either manual initiation or automatic initiation of an emergency. Manual initiation is emergency initiated by the operator of the plant / unit whereas automatic initiation is emergency initiated by automatic detection of an emergency such as detection of fire or gas leak by an automated Fire & Gas detection system.
 
Usage of tag nos. for equipment, valves and instruments while providing the shutdown procedure description is recommended.
 
Health, Safety & Environment:
This section describes the HSE aspects of the facility that need to be considered.
 
Health:
This sub-section relates to the health of the people and working in the plant or living in the vicinity of the plant whose health should be a concern for the management of the plant. This should also address the health and well being of animals and other living organisms present in the vicinity of the plant, for e.g. marine life in any water body which would be effected by the operations of the plant.
 
In this sub-section a brief description of toxicity of the chemicals used in the plant / unit, acceptable noise levels for humans and other animals, magnitude of injuries due to fire and explosion, first aid measures for treating injuries etc. should be provided.
 
Safety:
This sub-section relates to the safe start-up, operation and shutdown of the plant during its entire lifetime. This section should address the normal hazards those are encountered in day-to-day operations of the plant. This section should also address the safety measures available to prevent any accident.
 
Some of the normal hazards could be loss of containment of any hazardous fluid due to overflow, leak or rupture, static electricity build-up, accidental fall from heights, burns due to exposure to hot surfaces, exposure to toxic fluids while collecting samples and piling up of flammable solid waste (wood, paper, cloth etc.).
 
Description of safety measures should include:
- Special operating procedures for activities like sample collection and regular maintenance of rotating machinery
- Issuance of work permits for hot work and vessel entry
- Usage of personal protective equipment (hard hats, safety shoes, eye goggles, ear muffs, breathing apparatus etc.)
- Provision of field sign boards indicating the type of hazard
- Regular house-keeping
- Emergency evacuation procedures
 
Environment:
This sub-section describes the limits for discharge of hazardous solid, liquid and gaseous effluents to the environment based on local laws and regulations and procedures for compliance to them.
 
Appendices:
The appendices should preferably include the list of Process & Utility Flow Diagrams (PFDs / UFDs), Piping & Instrument Diagrams (P&IDs), Cause and Effect Diagrams (CEDs) and reference vendor documents, table for Alarm / Trip setpoints and lubrication schedule.
 
The above mentioned guidelines should help a process engineer to get started on a plant operating manual.
 
Readers of my blog are welcome to provide their experiences of writing a plant operating manual and I look forward to their comments and observations.
 
Regards,
Ankur.
 
 
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ChExpress Blog - Chexpress - July 16, 2013

July 16, 2013, 4:33 am
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North America


Top Award


PPG Industries’ CEO Charles Bunch will be honored on Oct. 30 with this ICIS Kavaler Award by The Chemists’ Club. The award recognizes Bunch’s contributions to the chemical industry, including the spinoff of PPG’s commodity chemicals business and the acquisition of the architectural coatings unit of AkzoNobel.

Derailment scrutiny


The deadly derailment and explosion of an oil train in Quebec involved DOT-111 type tanker cars, which have come under scrutiny from transportation safety experts concerned with what they say is their tendency to split open during derailments and other major accidents. DOT-111 tank cars are the workhorse of the rail freight industry, hauling all sorts of chemicals and hazardous materials. A 1991 safety study revealed design weaknesses that accident investigators say almost guarantee the tankers will split open in major derailments. The National Transportation Safety Board (NTSB) has noted several problems with the type of car: its steel shell is too thin to resist puncture in accidents; the ends are especially vulnerable to tears from couplers that can fly up after ripping off between cars; and unloading valves and other exposed fittings on the tops of tankers can break down during rollovers. The rail and chemical industries and tanker manufacturers have voluntarily committed to safety changes for cars built after Oct. 2011 to transport ethanol and crude oil, including thicker tank shells and shields on the ends of the tanks to prevent punctures. But, the industry is appealing to regulators to reject the NTSB recommendations that the existing ethanol tankers built under the older specifications be modified or phased out. 

Lawsuit


Two families are suing Allford Propane for more than $2 million over a deadly blast at a Eufaula, Oklahoma sandblasting company. The explosion in May left one man dead and another badly burned. The wrongful death lawsuit filed by the deceased man’s family seeks more than $1 million; the injured man’s family is also seeking more than $1 million. The suit blames the propane company for the explosion.
 

World


Investment


Eni plans to renovate and recover its Gela, Italy refinery. The aim of the project is to create an economically sound refinery capable of meeting the challenges of a competitive and evolving market. The refinery will also be redesigned to be more environmentally friendly and respectful to the local area. The project is estimated to involve an investment of €700 million and should be fully operational in 2017.

Purchase


The VETEK Group has completed its purchase of the Odesa Oil Refinery from Lukoil. The refinery is another link in the closed business cycle VETEK is building: from delivery of crude oil to production and retail sale of finished product. The Odesa refinery will be restarted soon. It can refine 2.8 million tons of crude oil/year. The plant was shut down in Oct. 2010 due to the economic situation that had developed on the oil-product market in Ukraine as well as due to changes to the oil delivery scheme.

Algae-based fuel


PTT has set its sights on introducing algae-based energy by 2017 and it is keen on setting up production facilities in Australia in the near future. The company is already in partnership with the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia’s national science agency, to develop a project involving algae-oil extraction. Currently, the research and development of fuel extracted from marine algae costs about three to four times as much as palm-oil-based biodiesel. 

Lubricant plant


Sinopec has opened its first lubricant manufacturing plant outside Tuas, Singapore. The company has invested about 650 million yuan in the lubricant production facility, which will also serve as its Asia-Pacific hub for logistics and service. The plant is expected to employ between 140 and 150 people and will have an initial annual production capacity of 100,000 tons of lubricant.
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ChExpress Blog - Chexpress - July 30, 2013

July 26, 2013, 5:43 pm
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North America



FEED contract


Fluor Corporation has secured a front-end engineering and design (FEED) contract for Sasols world-scale ethane cracker and associated derivative chemicals facility at is Lake Charles Chemical Complex in Louisiana. FEED work is underway and is expected to be completed in late 2013. The new ethane cracker and associated facilities will allow Sasol to expand its differentiated derivatives business in the United States. Project start up and completion is forecasted in 2017 with the expected production of 1.5 million tons/year of ethylene with downstream derivative plants.
 

R&D center


Bayer CropScience will move its U.S-based research and development operations for vegetable seed and crop-protection products from Davis, California into an existing 164,000-square-foot facility in West Sacramento, California. The move is scheduled to happen in next years first quarter.
 

Isobutanol-blended gasoline


Gevo, Inc. has begun supplying the U.S. Coast Guard R&D Center with initial quantities of finished 16.1 percent renewable isobutanol-blended gasoline for engine testing. The U.S. Coast Guard R&D Center is using the Gevo-blended fuel as part of a 12-month, long-term operational study on marine engines that begin in June. The testing is being performed under a Cooperative Research and Development Agreement among the U.S. Coast Guard, Honda, and Mercury. The testing is focused on two of the Coast Guards platform boats 38-foot Special Purpose Craft-Training Boat and 25-foot Response Boat Small. Isobutanol is a biofuel that compared to ethanol, has higher energy density, lower RVP, and does not present the phase separation issues seen with ethanol. Testing will take place at the U.S. Coast Guard Training Center in Yorktown, Virginia.
 

Expansion


QualiChem has completed a major expansion of its headquarters, laboratory and manufacturing facilities. The companys Salem, Virginia facility is now 70 percent larger, with 35 percent more space for quality control, R&D laboratories and manufacturing, plus 50 percent more floor space for raw material and finished goods. The shipping and receiving area has increased by 233 percent and the company has added a 45-seat training and conference center.
 

World


 

Safety Milestone


Qatargas Laffan Refinery Companys Diesel Hydrotreater (DHT) project completed two million-man hours without any Lost Time Injuries. The DHT Unit is designed to produce diesel with less than 10 parts per million sulphur content with the Euro 5 environmental specification and will be built and integrated into the existing Laffan Refinery by 2014. The Unit will process 54,000 barrels/stream day of straight run Light Gas Oil feedstock from the existing Laffan Refinery 1 and the second planned refinery.
 

Acquisition


FMC Corporation has moved into the Omega-3 market with the $345 million acquisition of Epax. The senior management team at Epax will remain with the business. As part of the deal, FMC has entered into a long-term supply agreement with Trygg Pharma to provide Trygg with high-concentration Omega-3 fish oil for use as an active pharmaceutical ingredient.
 

Pipeline


The first phase of Oman Oil Refineries and Petroleum Industries Cos 280 kilometer Muscat-Sohar pipeline project is expected to be commissioned by the end of 2014. The project is expected to cost between $200 250 million. The first phase will include the construction of a pipeline between Mina al Fahal refinery and Muscat airport. Phase two of the project is currently in the engineering phase and will involve the construction of a pipeline between Mina al Fahal refinery and Sohar Refinery as well as an intermediate storage facility. The company hopes to commission the second phase by 2016.
 

Shale oil deal


YPF has persuaded Chevron Corp. to sign a long-sought deal to invest $1.24 billion in developing Argentinas shale oil deposits. The joint venture adds up to $1.5 billion overall. The YPF-Chevron venture will start with a $300 million pilot hydraulic fracturing project involving more than 100 wells in an area known as the Enrique Mosconi Cluster.  
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Ankur's_Chemical_Engg_Blog - Guidelines For Fuel Gas Supply To Gas Turbines

July 28, 2013, 8:46 am
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Gas turbines (GT) are expensive and a major investment in any oil & gas, refinery, petrochemical or power generation unit. Any breakdown in gas turbines can lead to plant / unit production deferment or loss of power to the power grid if gas turbines are used for electricity genaeration, and spending large sums of money in repairs and overhauling.
 
The basic requirement for any gas turbine is the quality of fuel gas supplied within the design parameters specified for fuel gas for the given gas turbine. Most gas turbine breakdown problems during normal running are associated with large variations in fuel gas parameters from the design parameters as specifiied by the gas turbine manufacturer.
 
Let us come to specifics on what are the basic fuel gas quality parameters which need to be controlled or maintained and what are the means to exercise such control over fuel gas quality. These are listed pointwise below:
 
1. Gas turbines designed for high btu / joule gas (natural gas or high pressure process gas) provide an optimum performance when the calorific value of the gas is high. The efficiency and performance of such turbines is directly affected by the calorific value of the gas.
 
2. Gas turbine manufacturer's specify a minimum fuel gas pressure at their battery limit. In case, the available gas pressure is not sufficient to meet the requirements specified by the GT manufacturer, pressure of the available gas may require to be boosted up using a booster compressor to meet the requirements.
 
3. Fluctuations in the fuel gas Wobbe Index as an indicator of heating value should be kept at a minimum (typically ±5% is acceptable for streams supplying gas turbine fuel). Gas turbine fuel is controlled on a volumetric basis and performance problems can occur when the Wobbe Index fluctuates widely. The gas turbine manufacturer will provide specific guidelines on acceptable Wobbe Index fluctuations. Wider Wobbe Index fluctuations may require fuel gas blending facilities or separate fuel gas manifolds and associated modification to the combustor nozzles.
For definition and values of Wobbe Index refer the link below:
 
http://en.wikipedia.org/wiki/Wobbe_index
 
http://www.engineeringtoolbox.com/wobbe-index-d_421.html
 
4. In cases where the fuel gas contains, sulfur compounds (H2S, mercaptans etc), metals and particulates, extensive gas pre-treatment may be required to reduce them to low-ppm and / or sub-ppm values before allowing them to be used for GTs. The GT manufacturer will specify the maximum allowable values of these unwanted contaminants in the fuel gas.
 
5. Hydrogen content in the fuel can also impact system design. Typically, if the hydrogen content is less than 5% by volume, no special precautions are necessary. For higher values, the GT manufacturer may require an alternate starting fuel as well as design modifications and additional safety devices specific to hydrogen use. Potential swings in hydrogen content in the fuel gas can also impact the design of the combustion controls.
 
6. Fuel gas streams containing olefins should be avoided if possible, especially when specifying gas turbines with Dry Low NOx combustors. Olefins may polymerize and form deposits in small diameter orifices. If fuel gas with olefins cannot be avoided, the manufacturer can provide a design to accommodate the olefins provided the concentration is stable.
 
7. Any liquid and / or solid carryover with fuel gas to GTs can cause flashback and / or plugging of combustor nozzles This is particularly true with dry low NOx combustors.Modern installations for GTs have a Fuel Gas treatment system which is available as a skid mounted package and has several operations to prevent liquid / solid carryover. A typical fuel gas treatment skid would have the following equipment for gas treatment in the order of sequence described below:
 
a.  Provide a Knockout drum (KOD) to remove bulk liquid in the gas as a first step
 
b. Downstream of the KOD provide high efficiency filter-separator to eliminate fine liquid droplets/mist and fine solid particles. Typically the filter-separator can be designed to remove 100% of all liquid droplets above 3 micron & 99.8% of all solid particles less than 3 microns
 
c. Downstream of the filter-separator a gas superheater (electric / water bath etc.) should be provided to ensure that the fuel gas temperature is at least 20°C (36°F) above its hydrocarbon dewpoint. Often, a temperature between 50 to 55°C is maintained which provides an adequate margin over the hydrocarbon dewpoint of the fuel gas.
 
d. Avoid loops or low points on the fuel gas piping running to the GT skid. If loops or low points are unavoidable provide low point drains with traps to prevent accumulation of any liquids.
 
e. Heat tracing of fuel gas piping downstream of the gas superheater may be required to prevent any condensation especially during winter.
 
f. It is a good engineering practice to change the material of construction of the fuel gas piping from carbon steel to stainless steel downstream of the filter-separator to prevent solids (rust) carryover to the GT.
 
The adherence to above guidelines will ensure a long and trouble-free operation of your gas turbine in terms of the fuel gas parameters as provided by the GT manufacturer.
 
Hope readers of my blog find this informative and I look forward to their comments and observations.
 
Regards,
Ankur
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Ankur's_Chemical_Engg_Blog - An Introduction To The Concept Of Double Jeopardy In Process Safety

August 4, 2013, 10:24 pm
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Most Process and / or Safety engineers have to perform an analysis for the scenario or case related to the application of a safety relief device during their engineering career. In the chemical process industry, majority of the cases or scenarios for safety relief device are well defined based on experience gathered over the years for operating various types of chemical process plants including oil and gas separation plants, petroleum refineries, petrochemicals, fine chemicals, pharmaceuticals etc. Some such cases or scenarios frequently encountered in the chemical process industry are:
 
1. External Fire
2. Blocked Outlet
3. Gas Blowby
4. Control Valve fail Open
5. Hydraulic expansion due to uncontrolled heat input also called thermal expansion
6. Utilities Failure (Single or Multiple)
7. Power Failure (Partial or Complete)
8. Tube Rupture
9. Runaway Reactions
10. Check or Non-Return Valve Failure (reverse flow)
11. Vaccum generation due to Steam-Out
 
The above are some of the more common scenarios identified and studied in the chemical process industry for providing and sizing suitable safety relief devices.
 
However, the identification of a failure scenario for a given chemical process plant / equipment is something that requires experience on the part of the process or safety engineer. The experience that I am mentioning comes in the form of either engineering, constructing and operating or all of these for a similar plant / equipment.  Often lack of experience results in either overlooking a credible failure scenario, or to cook up failure scenarios that are unrealistic and cannot stand logical scrutiny.
 
To avoid the uncertainties in defining and analyzing failure scenarios many top engineering and operating companies have pre-defined the failure scenarios for a plant / unit / equipment in their engineering manuals based on their own experience in engineering, constructing and operating a chemical process plant. While this simplifies the task in terms of the time taken for the safety analysis and consequent action for a safety relief device, it is also detrimental to the engineer because he or she is not allowed to use his or her analytical skills to determine a probable failure case. 
 
Coming to the main subject of what is a double jeopardy with reference to the failure analysis of a plant / unit / equipment for providing a safety relief device. I would define it as follows:
 
The simultaneous application of two unrelated failure events for sizing or adequacy check of a safety relief device for a plant / unit / equipment is called double jeopardy. 
 
In the above definition the key word is "unrelated". What do we mean by "unrelated"? It is not easy to identify what is related and what is unrelated. This is where the experience of the engineer counts and also the practices followed by the chemical process industry based on years of operating experience for a similar process plant / unit / equipment. 
 
However, some basic unrelated scenarios can easily be identified. I  will provide some very basic examples of double jeopardy which most new process engineers can easily understand.
 
A. Consider the example of a condenser supplied with cooling water for condensing the process vapors from a distillation column. Let us say that due to partial power failure, the cooling water pump(s) supplying cooling water to the condenser fail and there is a loss of cooling water to the condenser. Let us also take note that the column has a reboiler with steam fed at a controlled rate by a steam control valve for heating the column bottom contents. Can we imagine a combination scenario that when cooling water to the condenser fails at the very same time the steam control valve to the rebolier fails in the open position causing more process vapors to be generated in the column? What would be the relief rate that should be considered for the relief valve provided on the condenser? Should it be the normal vapor from the column top going to the condenser or should you consider the excess process vapors formed due to uncontrolled reboiler heating by steam control valve failing open at the very same time? The answer is quite simple. The flow rate for the relief device will be the vapor flow rate based on the normal vapor flow rate to the condenser when the cooling water failure occurred.
 
The partial power failure causing stoppage of cooling water supply to the condenser and the failure of the reboiler steam control valve in open position at the same time is highly improbable and as such can be considered as two "unrelated" events. It is highly unlikely that when the condenser cooling water supply fails, at the very same time the reboiler steam control valve will fail open, leading to abnormally high vapor flow from the column top.
 
B. A remotely located sales gas pipeline requires planned pigging intermittently. Permanent pig launcher and pig receiver are provided for this purpose. Administrative procedures and mechanical interlocks are in place to ensure that the pig launcher and receiver drain valves remain locked closed before pigging is started. The mechanical interlock ensures that the launcher or receiver cannot be pressurized by opening the gas supply line valve to them unless the drain valves are closed. The drain valves from the launcher and receiver are connected to a covered local pit respectively. There is a degassing local vent from the pit raised to a safe location height of 3 m. Due to administrative procedure failure error as well as mechanical interlock failure, the drain valve on the pig launcher is inadvertently opened during pigging and excess vapors are released from the degassing vent. At the same time accidental ignition occurs at the vent tip due to an ignition source. To prevent thermal radiation hazards to personnel in the surrounding area near the jet fire from the vent, a radiation contour study is mandated which suggests that to mitigate thermal radiation hazard from the jet fire the vent height must be raised to 18 m.
 
How credible is this scenario? Some might argue that this is perfectly credible and the degassing vent height needs to be raised based on the radiation contour study recommendations. I would say that this is not credible and a clear case of double jeopardy and I present the following reason for this:
 
The pigging operation is intermittent. It is a planned exercise with administrative measures as well as mechanical interlocks in place to ensure that drain valves are closed prior to start of pigging operation. Simultaneous failure of administrative measures and mechanical interlocks is unrelated and hence not credible. Presence of an ignition source at the vent tip and leakage of gas from the drain valves during pigging at the same time is unrelated and hence not credible.
 
The logic for relief scenarios needs to be developed based on the aforementioned methodology. Newcomers to process safety engineering should remember that one of the most challenging tasks in process safety engineering is to analyze the credible relief scenarios and identify what is double jeopardy and reject such scenarios which involve double jeopardy.
 
Hope this gives some idea to new entrants in process safety engineering of what "double jeopardy" is all about.
 
Anticipating a lot of comments from the readers of my blog.
 
Regards,
Ankur.
 
 
 
 
 
 
 
 
 
 
 
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ChExpress Blog - Chexpress - August 13, 2013

August 13, 2013, 5:29 am
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North America



Contract


 
A subsidiary of Foster Wheeler AG’s Global Engineering and Construction Group has been awarded an engineering, procurement and construction (EPC) contract by Enterprise Products Operating LLC for a propane dehydrogenation unit (PDH) and associated power, utilities and infrastructure at a plant in Mont Belvieu, Texas. The contract value was not disclosed. The construction will be executed through Foster Wheeler’s combined use of direct-hire labor and subcontractors.
 

Contract


 
A subsidiary of Foster Wheeler AG’s Global Engineering and Construction Group has been awarded a contract by The Dow Chemical Company to provide detailed engineering, procurement and construction management (EPCm) services for the LA-3 Crack More Ethane (CME) project at Dow’s Plaquemine petrochemical facility in Louisiana. The project is aimed at improving the plant ethane flexibility to take advantage of low-cost feedstock. The scope includes brownfield additions and retrofit modifications to the plant. The contract value was not disclosed.
 

Sale


 
ConocoPhillips is selling its stake in a Canadian oil sands project to Exxon Mobil Corp and Imperial Oil Ltd for about $720 million. The all-cash deal involves the sale of 226,000 acres of undeveloped land known as the Clyden oil sands leasehold. After the deal closes, Exxon Canada will own a 72.5 percent interest in the land, with Imperial controlling the rest.      
 
 

World


 

Gas Chemical Project


 
The Irkutsk region will provide assistance to LLC Irkutsk Oil Company (INK) on a 120 billion ruble project to build a gas chemical complex near Ust-Kut, Russia. INK is currently researching the possibility of implementing such a project and is starting to draft a feasibility study for a potential investment project aimed at developing gas reserves at the Yaraktinskoye, Markovskoye and West Ayanskoye hydrocarbon deposits. The project entails the construction of a comprehensive gas treatment unit. INK expects to start supplying pipeline gas to Ust-Kut in the first half of 2016.
 

Contract


 
The National Methanol Company, a manufacturing affiliate of the Saudi Basic Industries Corporation, has awarded the engineering, procurement and construction contract for its polyoxymethylene (POM) project to an unnamed company. This brings National Methanol Company closer to producing high-strength, low-friction engineering plastic. The project is an expansion of the company’s existing operations as a joint venture between Sabic, CTE and Duke Energy. The POM plant is expected to have an annual capacity of 50,000 tons.
 

Project Delay


 
Petronas will start up its $19 billion petrochemicals complex in Malaysia in 2018 – a further delay in the country’s largest-ever infrastructure project. Petronas had already put back the project from late 2016 to early 2017. The project has apparently been complicated by the need to secure water supplies as well as cater for proposed international partners.
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ChExpress Blog - Chexpress - August 27, 2013

August 27, 2013, 7:20 pm
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North America



USGC petrochemical project


 
Chevron Phillips Chemical Company LP has received air permits from the Texas Commission on Environmental Quality (TCEQ) for its planned ethane cracker and polyethylene units. This is in addition to the greenhouse gas permit the Environmental Protection Agency granted for the cracker earlier this year. Pending final board approval, the 1.5 million metric tons/year ethane cracker would be built at the Chevron Phillips Chemical’s Cedar Bayou facility in Baytown, Texas. The new polyethylene facilities, each with an annual capacity of 500,000 metrics tons, would be built on a site near the Chevron Phillips Chemical Sweeny facility in Old Ocean, Texas. The estimated date for the project’s completion is 2017.
 

Acquisition


 
Panda Power Funds will begin construction immediately on an 829-megawatt natural gas-fired power plant in Bradford County, Pennsylvania after acquiring the project from Moxie Energy and completing financing. The Panda Liberty generating station is expected to begin commercial operations by early 2016. This is in addition to the recently announced 859-megawatt gas-fired plant in Maryland, subject to financing and other conditions.
 

Explosion


 
A 10,000-gallon fuel oil tank exploded at Brownies Oil Co. The tank went flying across a road, killing a worker who was welding nearby. The man died from blunt-force trauma to his head. No one else was injured or killed. The tank spilled 7,500 gallons of fuel and flooded a dike encircling the area, but the spill was contained.     
 

World


 

Coal-to-chemicals projects


 
China Coal Energy is stepping up investments in downstream coal-to-chemicals projects amid an oversupply and declining coal prices. The budget this year for projects to expand chemicals production has for the first time exceeded that for coal mines – 17.4 billion yuan for coal-to-chemicals projects versus 3.2 billion yuan for coal mine development. The chemicals include methanol, polypropylene and polyethylene.  
 

Carbon capture-and-use plant


 
Saudi Basic Industries Corp. (SABIC) has hired Linde Group to build the world’s largest plant for capturing and using climate-warming carbon dioxide. An affiliate of SABIC, the United Jubail Petrochemical Company, plans to capture around 1,500 tons/day of carbon dioxide from ethylene plants and purify it for use in SABIC-owned petrochemical plants in Jubail. The carbon capture and utilization plant will prevent about 500,000 tons/year of the gas from being released into the atmosphere. 
 

Gas pipeline


 
Construction of a gas pipeline from Sheberghan gas field in Afghanistan to Tajikistan was recently discussed at a meeting between Ministers in each country. The parties discussed various issues of cooperation in the energy sector. According to preliminary estimates, the overall cost of the project could be up to $300 million.
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Ankur's_Chemical_Engg_Blog - Power Consumption Of Vacuum Pumps

September 1, 2013, 9:09 am
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I am back on my blog after a wonderful holiday to Canada. I had a lot of fun staying in Vancouver and found BC to be a beautiful place.
 
Today's blog entry deals with quick but reliable estimate of the power consumption of vacuum pumps used in the chemical process industry. Some equations are presented below for the benefit of the readers:
 
Liquid Ring (NASH) pump:
 
BkW = 21.4*(SF)0.924
 
Rotary Piston Pump:
 
BkW = 13.5*(SF)1.088
 
where:
 
SF = 0.02-16 for "Liquid Ring (NASH) pump" and SF = 0.01-4 for "Rotary Piston Pump"
 
SF is defined as the "Size Factor" and can be calculated as follows:
 
SF = m / P; kg/ h/torr
 
where:
 
P = Operating pressure of system evacuated, torr (mmHga)
m = Air equivalent flow rate, kg/h
 
"m" can be calculated as follows:
 
m = G*sqroot((273.15+T)*28.96 / (293.15*MW))
 
where:
 
G = flow rate of the process gas being evacuated, kg/h
T = temperature of the process gas being evacuated, ⁰C
MW = molecular weight of the process gas being evacuated
 
The value of 293.15 in the equation indicates a reference temperature of 20 ⁰C for air equivalent flow which is recommended by the "Heat Exchange Institute" (HEI) for vacuum systems.
 
This concludes today's blog entry and I look forward to comments from the readers.
 
Regards,
Ankur.
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ChExpress Blog - Chexpress - September 10, 2013

September 10, 2013, 3:10 pm
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North America



Fertilizer plant


 
Northern Plains Nitrogen is buying land next to Grand Forks’ municipal sewage lagoons. The group is planning a $1.5 billion nitrogen fertilizer plant. The plant will receive gas through an existing pipeline near the project site or directly from the western oil patch through a proposed pipeline.
 

Cracker plant


 
Shell Oil Co. is seeking ethane suppliers for its proposed petrochemical complex at an industrial site about 40 miles north of Pittsburgh, Pennsylvania. Shell is still a year or more away from making a final decision on whether to build the multi-billion dollar plant. Shell says securing enough ethane for the potential cracker plant is a key step. The plant would convert ethane from Marcellus Shale natural gas into more profitable chemicals such as ethylene.
 

Phosphates plant


 
Hubei Xingfa Chemicals Group plans to open a facility in Effingham County in Georgia. The company expects to develop its plant on 83 acres and will establish a production line to produce phosphates, which will be exported through the port of Savannah.
 

World


 

Maintenance


 
Saudi Basic Industries Corp. (SABIC) will close one of its two crackers at its Netherlands plant for maintenance later this month. The Olefins 3 cracker at its Geleen site will close for six weeks beginning September 15 for routine maintenance work. This is part of a $178 million upgrade to increase energy efficiency. The upgrade will reduce the cracker’s energy consumption by 8 percent and increase production by 2 percent.
 

Closure


 
Total has confirmed that it plans to close down its last ethylene-making unit at is Carline site in eastern France, effective the second half of 2015. Cheap U.S. ethylene is forcing European and Asian plants to rethink their output mix.
 

Oil refinery


 
Aliko Dangote, president of Dangote Group, signed a loan worth $3.3 billion from 12 Nigerian and international banks toward a $9 billion project that will give Nigeria its largest oil refinery and petrochemical and fertilizer complex. At the completion of the projects, Nigeria is expected to become self-sufficient in fertilizer and refined petroleum products as well as an exporter. The 400,000 barrels/day oil refinery and complex will become operational in 2016. The plant will also produce 2.8 million tons of urea for fertilizing crops and to produce polypropylene.
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Ankur's_Chemical_Engg_Blog - Design Guide For Sizing Vertical Oil Treaters

September 23, 2013, 3:08 am
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Today's blog entry provides some guidelines for sizing of vertical oil treaters.The procedures described in this blog entry do not give the overall dimensions of the treater, which may include inlet gas separation and free-water knockout sections, dependent on the upstream separation vessels.  However, they do provide a method for specifying heat input required and a minimum size for the coalescing section (where the treating actually takes place), and provide the design engineer with tools to evaluate specific vendor proposals.
 
Before going on to the sizing of the vertical treater let us understand the specific application of a vertical oil treater.The most common type of single-well onshore treater is the vertical treater, shown in the attached sketch.  Vertical treaters are recommended where sand or other solid sediments are considered a potential problem.
 
Let us move on to the sizing equations for a vertical oil treater
 
Heat Input Requirements
 
Metric Units
 
q = 1100*Qo*ΔT* ----------1(a)
 
USC Units
 
q = 15*Qo*ΔT* -------1('b)
 
where:
 
q = Heat input, W (Btu/hr)
Qo = Oil flowrate, m3/hr (BOPD)
ΔT = Temperature increase, ⁰C(⁰F)
(SG)o = Oil specific gravity relative to water
(SG)w = Water specific gravity
Win = Inlet percent water cut, percent
 
Water Droplet Size
 
Metric Units
If µo< 7.0 x 10 –2 Pa s, then dm = 1361*Wc0.33*µo0.25 -----------2(a)
If µo≥ 7.0 x 10 –2 Pa s, then dm = 700*Wc0.33 ------------2('b)
 
USC Units
If µo< 70cP, then dm = 242*Wc0.33*µo0.25 -------------2('c)
If µo≥ 70cP, then dm = 700*Wc0.33 -------------------2(d)
 
µo = Oil viscosity, Pa s (cP)
dm = water droplet diameter, microns
Wc = Outlet Water Cut, percent
 
Vertical-Settling Time Equation
 
Metric Units
d = 806,000*(F*Qo*µo / (ΔSG*dm2))0.5 -------------------3(a)
 
USC Units
d = 81.8*(F*Qo*µo / (ΔSG*dm2))0.5 ---------------------3('b)
 
where:
d = vessel minimum diameter, mm (inch)
Qo = Oil flow rate, m3/h (BOPD)
µo = Oil viscosity, Pa s (cP)
ΔSG = Difference in specific gravity of oil & water
dm = water droplet diameter, microns
F = short-circuiting factor
=1, with very good flow distribution and smaller than 1220 mm (48 inch) diameter
or
= d/1220 (d/48) for treaters over 1220 mm (48 inch) diameter
Note:
First solve Eqn 3 using F=1. If the value of d is less than or equal to 1220 mm (48 inch), this is the final answer. If the value of d is greater than 1220 mm (48 inch), then substitutingF = d/1220 (F = d/48) into above Eqn 3 gives the following modified equation:
 
Metric Units
d = 5.33*108*Qo*µo / (ΔSG*dm2) ----------------4(a)
 
USC Units
d = 139*Qo*µo / (ΔSG*dm2)  --------------------4('b)
 
where:
d > 1220 mm (48 inch)
 
Note:
The height of the coalescing section for a vertical treater plays no part in the settling equation. The cross-sectional area of flow for upward velocity of the oil is a function of the diameter of the vessel alone.
 
Vertical-Retention Time Equation
The oil should be held at a temperature for a specific period of time to enable demulsifying the water-in-oil emulsion. This time can be best obtained by a laboratory bottle test. However, in absence of such data, 20-30 minutes is a good starting point.
 
Metric Units
d2*h = 2.12*107*F*(tr)o*Qo -----------------5(a)
 
USC Units
d2*h = 8.6*F*(tr)o*Qo ------------------------5('b)
where:
h = height of coalescing section, mm (inch)
(tr)o = Oil retention time, minutes (minutes)
 
Re-arranging Eqn 5 by substituting F, we get
 
Metric Units
If d ≤ 1220 mm (F = 1) then
h = 2.12*107*(tr)o*Qo / (d2)  ---------------------6(a)
 
If d > 1220 mm (F = d/1220) then
h = 1.75*104*(tr)o*Qo / (d) ---------------------6('b)
 
USC Units
If d ≤ 48 inch (F = 1) then
h = 8.6*(tr)o*Qo / (d2)  --------------------------6('c)
 
If d >48 inch (F = d/48) then
h = (tr)o*Qo / (5.58*d)  -------------------------6(d)
 
Note:
Part of the overall vessel height is required to provide for water retention. The removal of oil from the water is not of primary concern.
 
Water-Retention Time Equation
 
Metric Units
hw = 2.12*107*(tr)w*Qw / (d2) ----------------7(a)
 
USC Units
 
hw = 8.6*(tr)w*Qw / (d2) -----------------------7('b)
 
where:
hw = height of water, mm (inch)
(tr)w = water retention time, minutes (minutes)
Qw = Water flow rate, m3/h (BOPD)
 
This concludes today's blog entry on sizing or adequacy check of vertical oil treaters, Readers are free to put up questions and I will try my best to answer them.
 
Regards,
Ankur
 

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ChExpress Blog - Chexpress - September 24, 2013

September 24, 2013, 4:53 am
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North America



Packaging Center of Excellence


 
H.B. Fuller Company has decided to invest in a Packaging Center of Excellence in North America to address customers’ packaging adhesives needs across a broad range of applications, substrates and environmental conditions. The center is expected to open in early 2014 and will be the company’s fourth center focused specifically on customer collaboration.
 

Fire


 
A recent fire at Danlin Industries’ facility in Thomas, Oklahoma destroyed a chemical plant and caused small explosions, forcing the evacuation of about a dozen people from nearby homes, but resulting in no injuries. The fire started about three hours after the last employees left the facility. The entire facility burned down. The facility had nontoxic but highly flammable chemicals that are used in the oil and gas production industry. Authorities are still trying to determine the cause of the fire.
 

Gas-to-methanol project


 
Fluor Corporation has been awarded an engineering and design services contract by South Louisiana Methanol L.P. for a potential 5,000 metric tons/day methanol project in St. James Parish, Louisiana. Fluor is working to finalize the process design and complete preliminary design for the facility.
 

World


 

Isobutylene production unit


 
UOP LLC’s technology has been selected to produce key ingredients for fuels and synthetic rubber in China. Panjin Heyun New Material Co. will use UOP’s C4 Oleflex process to produce isobutylene. The company will also use UOP’s Butamer process, which converts normal butane to isobutene, thereby maximizing the feedstock utilization of the UOP Oleflex process. The new unit is expected to start up in 2014 and will process approximately 400,000 metric tons/year of isobutene feedstock at its facility in Liaoning Province, China. UOP will provide the engineering design, technology licensing, catalysts, adsorbents, equipment, staff training and technical service for the project.
 

Refinery substations


 
Siemens has been awarded a turnkey contract by the Kuwait National Petroleum Co. (KNPC) to supply high-voltage substations at refineries south of the city of Kuwait. The $240 million project will provide reliable power supply to two of KNPC’s biggest refineries. The project is scheduled for completion in December 2015.
 

Cost cuts


 
Bayer is stepping up cost cuts at its MaterialScience unit to counter production overcapacity in the industry and high raw material prices. Bayer’s MaterialScience unit makes polycarbonate plastics for panoramic roofs in Daimler’s Smart and Mercedes SLK convertibles and for blu-ray disks. It is also the world’s largest maker of chemicals for insulation and padding foams.
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Ankur's_Chemical_Engg_Blog - The Flip Side Of Engineering Standards And Practices

October 7, 2013, 9:50 am
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Dear All,
 
I like to keep myself abreast of the latest engineering standards and practices from international organizations (API / ISO) and from engineering / operating companies. The best thing about them is I don't have to overload my memory trying to remember established engineering and design practices which are generally well documented in these standards. These standards also help me save time when I am involved in engineering design, and often I quote these standards in the engineering design documentation that I prepare. So reading, knowing and remembering (depending on how good your memory is) these standards apparently seems to be the key for success in any engineering work.
 
So far, so good. Now here comes the flip side. These standards and practices have been developed by fallible humans and are not commandments from god. These standards and practices have evolved over the years and are still getting refined which is evident from the revisions that periodically appear for them. These standards are also written, reviewed and approved by a group of people and organizations who claim that they are the best and most authentic source of information on the particular subject. I am not saying that the credentials of these people and organizations are questionable. My point here is, that there can always be a difference of opinion amongst indviduals or groups on how things should be done (read engineering design). 
 
What "A" expresses as his opinion about the methodology to be adopted may not be agreed by "B" based on different experiences by "A" and "B". However, both "A" and "B" need to provide logical explanation of their ideas and be able to state benefits and disadvantages of their way of doing things. This is what we call as logical progression of any idea and the process of adoption / elimination of the idea based on the end goal to be achieved.
 
What I see today in the younger lot of engineers is the blind adherence to standards and practices without application of logic, functionality and end goal to be achieved. I do believe, that a lot of it has to do with lack of experience but to a certain extent it can also be attributed to finding a easy way out. It is there in the standard so who wants to take the pains to uncover the logic behind it.
 
When I mention all of this, I am not decrying the standards and practices. A lot of the engineering practices prevalent today and documented in these standards and practices have stood the test of time and have evolved and matured to the extent that trying to research them further is simply a waste of precious time, especially if you are an engineer. 
 
My advice to the young entry level engineers is that when you read a standard or practice, try to analyze the logic behind it. Ask questions about it to the more experienced engineers. There will be occasions where even the more experienced engineer may say "Hey, I reckon this is the way it always has been and I can't help you anymore". It would be easy to give up if you get such an answer, but then think that everything has a logic and somebody out there knows that logic and you need to have the resilience to find out that logic.
 
Good luck to all of you young engineers in making the effort to find out the logic on what is written as a standard or practice. I will be more than happy to receive comments on this blog entry.
 
Regards,
Ankur.
 
 
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ChExpress Blog - Chexpress - October 8, 2013

October 8, 2013, 5:40 am
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North America



Regional sales office


 
Dow Chemical Co. has opened a new Southeast regional sales office at is Polyurethane Systems North American Headquarters in Marietta, Georgia. The Southeast Regional Sales Center is home to approximately 50 sales associates who will use the facility to host customer meetings, conduct team events and participate in sales training.

Acquisition


 
Emerson has announced its intent to purchase Virgo Valves and Controls, LTD. Virgo, a manufacturer of ball valves and automation systems, will operate within Emerson Process Management’s final controls business. Terms of the transaction were not disclosed.
 

Natural gas to liquids plant


 
Shell Oil Co. has chosen a site near Sorrento, Louisiana as the potential location for a $12.5 billion natural gas to liquids plant that would create 740 jobs. The company says it will decide after engineering studies and environmental permitting are done. The plant would create natural gas-based diesel and jet fuels along with specialty waxes and products used in plastics and detergents that are normally made from oil.
 

Ethylene cracker project


 
Fluor Corporation and JGC Corporation’s 50/50 joint venture was awarded an engineering, procurement and construction (EPC) contract by Chevron Phillips Chemical Company LP for its U.S. Gulf Coast Petrochemicals Project. The project consists of the ethylene unit (cracker) and associated offsite components to be built at Chevron Phillips Chemical’s existing Cedar Bayou complex in Baytown, Texas. The scope includes engineering and procurement for the outside batter limit as well as direct hire construction for the entire cracker project.
 

World


 

Polyethylene unit


 
Unipetrol has acquired technology and production rights for a new polyethylene unit and wants to pick a contractor for the project in the first half of 2014. Even after posting net losses in 2011 and 2012, the company laid out plans in June to invest almost $1 billion over the next five years in its petrochemical segment. Unipetrol signed a license agreement with Ineos for the right to use a production process and technology for the new polyethylene unit that will help increase utilization of its petrochemical steam cracker.   
 

Investment


 
Odebrecht plans to spend $8.1 billion in Mexico in the next five years in what appears to mark the biggest investment pledge yet from a Brazilian firm there. The company will invest in petrochemicals, renewable energy, ethanol and sugar production and highway concessions.
 

Petrochemical plant


 
Alpek has agreed to form a joint venture through its subsidiary, Petrotemex, with United Petrochemical Company. The joint venture will build a purified terephthalic acid (PTA) and polyethylene terephthalate (PET) plant in Russia’s independent republic of Bashkortostan. Each company will invest $10 million to carry out a feasibility study for the plant, with construction subject to approval by the directors of both companies. The plant would have a maximum installed capacity of 600,000 tons each of PTA and PET and would use Alpek’s IntegRex technology. The plant would use locally sourced paraxylene (PX), with negotiations currently underway with JSOC Bashneft for the feedstock supply.
 

EVA and LDPE plant


 
Saudi International Petrochemical (Sipchem) has begun operations at its new 200,000 ton/year ethylene vinyl acetate (EVA) and low density polyethylene (LDPE) plant at Jubail Industrial City. The company completed the first phase, which includes installation and testing of major equipment and pre-manufactured modules, prior to completion of basic preparations for initial start up during the fourth quarter of this year.
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ChExpress Blog - Chexpress - October 22, 2013

October 22, 2013, 4:47 pm
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North America



Ammonia plant


 
BASF SE and Yara International ASA are considering a big ammonia plant on the U.S. Gulf Coast. While company officials have said everything is still under discussion, a current BASF factory would be the most likely site. BASF has plants in Beaumont, Pasadena and Port Arthur, Texas and in Geismar, Louisiana.  
 

Gas project revamp


 
Imperial Oil Ltd. is looking at a major revamp of its Mackenzie gas project that would see the stalled northern venture reborn as part of an expansive liquefied natural gas (LNG) development. A shift to LNG is under consideration as the Mackenzie pipeline’s economics remain weak due to cheap shale gas across the continent.
 

Ethane cracker


 
Technip was awarded a contract by Sasol to supply its proprietary ethylene technology and front-end engineering design (FEED) for a grassroots ethane cracker. The cracker will be located at Sasol’s Lake Charles, Louisiana site. It is estimated to produce 1.5 million tons/year of ethylene.
 

Sale


 
Dow Chemical Co. will sell its polypropylene licensing and catalysts business to W.R. Grace & Co. for $500 million. This sale is part of Dow Chemical’s strategy to shed its non-core businesses. The polypropylene licensing and catalysts business provides technology and catalysts to make polypropylene, which is used to manufacture plastics and synthetic fabrics. As part of the deal, W.R. Grace will acquire Dow Chemical’s catalysts manufacturing plant in Norco, Louisiana and customer contracts, licenses, intellectual property and inventory. The transaction is expected to close by the end of the year, pending regulatory approvals.
 

World


 

VCM plant


 
Fluor Corporation’s ICA Fluor industrial engineering-construction joint venture with Empresas ICA, S.A.B. de C.V., signed a contract with Petroquimica Mexicana de Vinilo, a joint venture between Mexichem and Pemex, for the revamp of the vinyl chloride monomer (VCM) plant at the Pajaritos petrochemical complex near Veracruz, Mexico. ICA Fluor will be responsible for the engineering, procurement, construction, maintenance and commissioning services to bring the VCM facility to its capacity of 405,000 tons/year from its current nearly 200,000 tons/year. The project is planned to be completed in the fourth quarter of 2015.
 

Butadiene plant


 
MOL’s petrochemicals unit TVK will build a new butadiene plant in Tiszaujvaros, Hungary. The planned investment is $106.4 million. The new plant will have an annual capacity of 130,000 tons and will be opened in the second quarter of 2015.
 

Aromatics plant


 
A subsidiary of Foster Wheeler AG’s Global Engineering and Construction Group has been awarded a contract by Petrochemical Industries Company for a pre-feasibility study and a market report for a proposed aromatics plant in Kuwait. The study is scheduled to be completed in the fourth quarter of 2013.
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Ankur's_Chemical_Engg_Blog - Branded Clothing And Accessories Versus Engineering Books & Journals

November 1, 2013, 12:04 pm
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Dear All,
 
The title of my blog entry may sound quite strange and incomprehensible to many. However strange it may sound, there is a funny and also quite a sad fact about it which I am going to describe in the next few paragraphs.
 
I have a few excel spreadsheets which are available by paying a very nominal amount of money posted on the online store of "Cheresources". Considering the efforts I had to undertake to develop them, sometimes months to fine tune them to bring them to a certain level, the amount spent in buying them is nominal, at least in my opinion. This of course is entirely my opinion and obviously I am entitled to express my opinion on my own blog. Readers of my blog are free to disagree.
 
Now let us come to the real story behind this blog entry.  Not so long back, I had received a couple of emails wherein the writers of these emails wrote that they were young engineers starting out their careers and their pockets were too small to afford buying these spreadsheets and whether I could provide them these spreadsheets free of cost. I had quite a rude shock reading these emails considering the fact that these spreadsheets are quite nominally priced per copy.
 
I had to reply to these mails and this is what I asked them when I replied to them. I asked them whether they were aware of clothing brands like Arrow, Van Heusen and Louis Phillipe. The names I was mentioning are the middle level brands in men's clothing and not the top brands such as Gucci, Armani, Versace etc. I asked them whether any one of them owned a shirt or trouser from these brands and what they had paid for buying them.
 
I had specifically asked this in my reply because I often see amongst the younger bunch of engineers whom I work with, wearing top brands of clothing and carrying top-of-the-line accessories. My own clothing is a ragged mix of unbranded clothing and branded ones. The branded ones are courtesy the lady of my house who happens to be in the field of fashion design and does not see eye-to-eye with me on how men should dress. Well, at least I have no counter for the persuasive charm of my spouse and most of the times I yield to the extravaganza she indulges on my behalf
 
A branded shirt or trouser can easily cost upward of 50 to 60 dollars. The spreadsheets on the online store of "Cheresources" are priced lower.
 
Then how does one explain the email that asks for a free copy of a paid engineering calculation. Well, the answer is quite straightforward. It is not the money but the importance of its utility to the young engineer or engineering student. A branded piece of clothing has far more importance than an engineering calculation or for that matter any engineering literature (books / journals). It is beyond any rational comprehension that something that could enhance one's career can be ignored at the cost of a glitzy piece of clothing. How can anyone forget that any ostentatious lifestyle is just an extension of his or her career? When I say this, I don't mean begetting money by illegal or immoral means.
 
I by no means am implying that young people should shun indulging themselves in good clothes and accessories. What I am trying to convey is that if one can spare money to indulge in these things one can certainly spare something to buy books & literature which can enhance their career. I follow this in my life. If I feel that a particular engineering literature is worth possessing, within my resources and helps me to broaden my engineering knowledge I will not hesitate to buy it.
 
Anyways, to conclude this blog entry, the email I had written to the persons who wanted the engineering calculations for free never replied back to my inquiries. I am still trying to guess whether they felt shamed by my inquiry or thought that what a cranky old geezer I am.
 
I look forward to comments from the readers of my blog.
 
Regards,
Ankur.
 
 
 
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ChExpress Blog - Chexpress - November 12, 2013

November 12, 2013, 12:34 pm
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North America



Proposed fine


 
ExxonMobil faces $2.7 million in proposed fines from The Pipeline and Hazardous Materials Safety Administration for its March 29 pipeline spill in Arkansas. The federal regulator said it found nine probable violations of safety rules in the break in the Pegasus pipeline. The 95,000 barrel/day pipeline has been shut since spilling about 5,000 barrels of oil in Mayflower, Arkansas. Exxon is cooperating with the investigation, but is still reviewing the notice and has not determined its course of action. The company has 30 days to contest the allegations.
 

Layoff


 
Valspar Corp. has laid off about 25 of its Minneapolis, Minnesota corporate and sales workers in the last few weeks. The cuts are part of the company’s effort to restructure and shift resources. Affected workers include those in the corporate, finance and consumer sales units.
 

Plant closure


 
PolyOne Designed Structures and Solutions will close a Warsaw, Indiana plastics factory next year. The closing will put 110 people out of work. The company will cut jobs in stages, beginning in early January and ending about Sept. 30.
 

Proposed fine


 
The U.S. Labor Department’s OSHA has proposed more than $280,000 in fines against contractors working on a power plant in Berlin, New Hampshire. OSHA says workers were exposed to serious and potentially fatal injuries from cave-ins, falls, scaffold collapses, crushing, lead and electrocution hazards. No one was killed or seriously hurt, however. General contractor Babcock & Wilcox Construction Co. Inc. faces more than $116,000 in fines. The other fines were against subcontractors. A Babcock & Wilcox spokesperson says the company disagrees with the findings but will work closely with OSHA to resolve the issues.
 

Ethylene venture


 
Mexichem has entered into a joint venture with Occidental Chemical Corp. known as Oxychem. Oxychem will build a $1.5 billion ethylene plant in the United States. The plant, which will be in Ingleside, Texas should start operations in 2017.
 

World


 

Plant restart


 
Pertamina has restarted a refining and petrochemical complex in East Java, Indonesia owned by TPPI. The move is aimed at reducing imports of oil products and chemicals. The restart could help reduce the current account deficit in Indonesia, where import costs have been rising due to a weak rupiah. Pertamina signed an agreement with TPPI to use the facility for six months. The plant had been idled for nearly two years due to TPPI’s heavy debts. During the six-month timeframe, the plant will process 55,000 to 80,000 barrels of condensate/day and will produce about 1.5 million barrels of gasoil and fuel oil, 36,000 tons of liquefied petroleum gas (LPG) and 2.8 million barrels of light naphtha. A total of 530,000 tons of petrochemicals will also be produced.
 

Purchase


 
Unipetrol has agreed to buy partner Royal Dutch Shell’s 16.3 percent stake in Ceska Rafinerska for $27.2 million. This will boost Unipetrol’s stake in the Czech Republic’s only refinery to 67.6 percent. The deal is expected to be complete in the beginning of 2014.
 

Change in plans


 
Kayan has dropped plans to build an ultra-high molecular-weight polyethylene (UHMWPE) plant in Jubail, Saudi Arabia. In 2012, Kayan and Petrokemya, both affiliates of Saudi Basic Industries Corp. (SABIC), signed a memorandum of understanding to equally own and finance the project. Kayan said that preliminary results of an economic feasibility study were not in line with the company’s growth plans.
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Ankur's_Chemical_Engg_Blog - Pressure Drop Of Pseudo-Plastic Fluids In Pipes

November 14, 2013, 6:48 pm
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Dear All,
 
Pseudo-plastic fluids are a type of non-newtonian fluids and account for a majority of the non-newtonian fluids commonly found in the chemical process industry and specifically in the food processing industry.
 
Today's blog entry provides a methodology to calculate the pressure drop of a pseudo-plastic fluid in a pipe. An example problem is solved at the end of the outlined method. Readers can use the example problem to develop a spreadsheet based calculation
 
For Pseudo-plastic non-newtonian fluids, the power law model is used to define the shear stress versus velocity gradient relationship. The power law equation is as follows: 
 
τ = K*(dV/dy)n
 
where:
τ = shear stress at distance y from pipe wall
K = flow consistency index
dV/dy = velocity gradient or shear rate
n = flow behavior index

For pseudo-plastic fluids n < 1, and for dilatant fluids n > 1. Since the apparent viscosity μ is the slope of the shear stress τ versus velocity gradient plot, we can calculate the apparent viscosity of a non-newtonian fluid that follows the power law from the following equation
 
µ =K*(dV/dy)n-1
 
or 
K = 0.001*µ*(dV/dy)1-n
 
where:
µ = Apparent Viscosity, cP
K = Flow consistency index, Pa.sn
dV/dy = velocity gradient, s-1
n = flow behavior index, dimensionless
 
Power-Law Reynolds Number:
 
RePL = 23-n*(n / (3n+1))n*((V2-n*Dn*ρ) / K)
 
where:
RePL = Power-Law Reynolds Number, dimensionless
V = Velocity of flow in pipe, m/s
D = Inside diameter of pipe, m
ρ = density of the fluid, kg/m3
 
Determining fanning friction factor 'f' for laminar flow of power-law fluids:
 
f = 16 / RePL
 
where:
f = fanning friction factor, dimensionless
 
Note:
The transition from Laminar to Turbulent flow for pseudo-plastic fluids is considered at a Reynolds number of 2100.
 
Determining fanning friction factor 'f' for turbulent flow of power-law fluids:
 
Refer attached chart
 

 
Friction Loss (in head) using Fanning friction factor:
 
hf = 2*f*V2*L / (g*d)
where:
hf = friction loss (in head) in the pipe, m (meters of liquid column)
L = Length of the pipe, m
g = Acceleration due to gravity, 9.81 m/s2
 
Example Problem:
 
A coal slurry is to be transported by horizontal pipeline. It has been determined that the slurry may be described by the power law model with a flow behavior index of 0.4, an apparent viscosity of 50 cP at a shear rate of 100 /s, and a density of 1442 kg/m3. What would be the pressure drop and the horsepower (HP) required to pump the slurry at a rate of 0.06 m3/s through an 8 in. Schedule 40 pipe that is 80 km long ?
 
Inputs:
 
n = 0.4
µ = 50 cP
dV/dy = 100 s-1
ρ = 1442 kg/m3
D = 0.202 m (based on nominal pipe size in inches and Pipe schedule)
L = 80 km
Q = 0.06 m3/s
 
Results:
L = 80,000 m
K = 0.792 Pa.sn
V = 1.87 m/s
RePL = 8025
f = 0.0048 (from chart)
hf = 1358 m
ΔP = 192 bar
HP = 1153038 W = 1153 kW
 
Hope all of you have found this blog entry very informative. I look forward to comments from the readers of my blog.
 
Regards,
Ankur.

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Ankur's_Chemical_Engg_Blog - Frequently Asked Questions (Faq) About Liquefied Natural Gas (Lng)

December 3, 2013, 5:37 am
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Dear All,
 
LNG is a subject of great interest these days considering that it has become a primary source of energy for many countries deficient in fossil fuel based energy resources. It is also of interest because it is among the cleanest of all fossil fuel based energy resources when compared with other fossil fuel energy sources such as coal and crude petroleum and its derivatives. 
 
Today's blog entry tries to put in perspective what LNG is all about. The focus is on introducing what LNG is to new engineers starting their career. The blog entry has been made in the form of 'frequently asked questions' related to LNG. Details are excluded and certain web references are provided as hyper links which can guide the readers where to look for more details. Here goes the FAQ:
 
Q1. What is LNG?
A1. Liquefied Natural Gas (LNG) is natural gas (NG) that is cooled to the point that it condenses to a liquid.
 
Q2. What are the conditions for natural gas to be converted to LNG?
A2. Natural gas condenses to a liquid i.e. becomes LNG at a temperature of approximately -161°C (-256°F) at atmospheric pressure (101.325 kPaa).
 
Q3. Why is it required to convert natural gas to LNG?
A3. Liquefaction of natural gas to LNG reduces the volume of natural gas by approximately 600 times thus making it more economical to store natural gas and to transport gas over long distances for which pipelines are not economically feasible or there are other constraints.
 
Q4. How is LNG stored?
A4. LNG is stored in double-walled storage tanks at atmospheric pressure. The storage tank is really a tank within a tank. The annular space between the two tank walls is filled with insulation. Refer the link below for more information on LNG storage tanks:
http://en.wikipedia.org/wiki/LNG_storage_tank
 
Q5. What materials are used to construct LNG storage tanks?
A5. The inner tank in contact with the LNG is made of materials suitable for cryogenic service and structural loading of LNG. These materials include 9 percent Nickel Steel, aluminum and pre-stressed concrete. The outer tank is generally made of carbon steel or pre-stressed concrete.
 
Q6. How is LNG transported by ships?
A6. LNG tankers are double-hulled ships specially designed to prevent leakage or rupture in an accident. The LNG is stored in a special containment system within the inner hull where it is kept at atmospheric pressure and cryogenic temperature (-161°C). For more details refer the following link:
http://en.wikipedia.org/wiki/LNG_carrier
 
Q7. What is re-gasification of LNG?
A7. LNG has to be converted back to natural gas by warming in a controlled environment at the receiving and re-gasification terminal. The LNG can be warmed by passage through pipes heated by direct-fired heaters, or pipes warmed by seawater, or through pipes that are in heated water.
 
Q8. How is LNG quantified for trading (selling / buying) in the world market?
A8. LNG is generally quantified for trading on a mass basis in terms of millions of tons 
 
Q9. Is there an approximate conversion for LNG mass to NG volume at standard conditions of 1 atmosphere pressure and 60°F?
A9. The approximate conversion for LNG mass to NG volume at standard conditions of 1 atmosphere pressure (14.7 psia /101.3 kPaa) and 60°F is as follows:
 
1 Metric ton of LNG or 1000 kg of LNG = 48,700 Scf of NG = 1379 Sm3 of NG
 
Note: Exact conversion depends on natural gas molecular weight
 
Q10. Is LNG flammable?
A10. LNG when suddenly released from its containment to atmosphere at ambient temperature conditions flashes and forms a vapor-air mixture. This vapor-air mixture forms a visible vapor-air cloud. As the vapor cloud gets warmer in contact with the ambient air it gets lighter than air and rises. A flammable vapor-air mixture can only form if the natural gas vapor concentration in the vapor-air mixture is between 5% and 15% by volume of the vapor-air mixture. A vapor-air mixture with less than 5% by volume of NG cannot cause a flame or fire since the concentration of the vapor (NG) in the vapor-air mixture is not enough to start or sustain a flame or fire or in other words the vapor-air mixture is too lean. The value 5% by volume is thus called the Lower Flammability Limit (LFL) for natural gas. Similarly a vapor-air mixture with more than 15% by volume of NG cannot cause a flame or fire since the concentration of the air (oxygen) in the vapor-air mixture is not enough to start or sustain a flame or fire or in other words the vapor-air mixture is too rich. The value 15% by volume is thus called the Upper Flammability Limit (UFL) for natural gas.
 
Q11. Is LNG explosive?
A11. LNG in its liquid form is not explosive. When LNG forms a vapor-air mixture and is in a confined space with no means to disperse it can cause a vapor cloud explosion if exposed to a source of ignition. Again for the vapor-air mixture to explode, the vapor concentration of natural gas in the vapor-air mixture has to be between 5% and 15% by volume. Thus the term LFL / UFL is interchangeably used with the term Lower Explosive Limit (LEL) and Upper Explosive Limit (UEL).
 
Q12. What are the main uses of LNG?
A12. LNG after re-gasification to NG is primarily used for power generation, home heating and as cooking gas. 
 
For more details related to LNG in general refer to the links below:
http://www.beg.utexas.edu/energyecon/lng/
http://en.wikipedia.org/wiki/Liquefied_natural_gas
 
I have no claim whatsoever as an expert in the LNG field. This is a general information that has been provided in this blog. I will take questions from the readers and try to answer them to the best of my ability.
 
Happy reading.
 
Regards,
Ankur.
 
 
 
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ChExpress Blog - Chexpress - December 10, 2013

December 10, 2013, 9:42 pm
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North America



Sale


 Carlyle Group LP is preparing an initial public offering or sale of PQ Corp that could value the specialty chemical company at up to $3 billion, including debt. The private equity firm, which bought PQ for $1.5 billion in 2007, plans to talk to investment banks to choose underwriters for the proposed offering. Carlyle will also explore a sale of PQ to another firm. 
 

Contract won


 CB&I has been awarded a contract valued at approximately $1 billion by Ingleside Ethylene LLC, a joint venture between Occidental Chemical Corporation (OxyChem) and Mexichem S.A.B. de C.V., for the engineering, procurement and construction of an ethane cracker and associated utilities and offsites to be located at OxyChem’s complex in Ingleside, Texas. The cracker will have the capacity to produce approximately 1.2 billion pounds/year of ethylene from a feedstock that is anticipated to be ethane derived from domestic shale gas. CB&I had previously provided the technology license and basic engineering for the ethylene technology, five short residence time (SRT) cracking heaters and the front end engineering and design (FEED) services.
 

Sale


Dow Chemical Co. will sell a bulk of its chlorine operations – its oldest business – as part of its plan to sell or spin off commodity chemicals assets worth up to $4 billion. Company representatives say this will allow the company to prioritize its capital on higher margin, more consistent earnings growth businesses. Other assets identified for sale by Dow Chemical include the company’s epoxy business and some brine and energy assets, representing a total of $5 billion in revenue.
 

Methanol plant


OCI N.V.’s wholly owned subsidiary Natgasoline LLC plans to build a new greenfield world scale methanol plant in Beaumont, Texas. The plant is expected to have a capacity of up to 5,000 metric tons/day, or 1.75 million metric tons/year. Production is expected to start in late 2016.
 

World


 

Petrochemical plant


Grupa Lotos and Grupa Azoty have announced plans to build a $3.87 billion petrochemical plant by 2020 to reduce Poland’s reliance on imports. The plant will be built in Gdansk with help from state investment vehicle PIR, though most of the cost will have to be funded by debt and possibly a foreign partner. Financing is to be put together in 2015 after the groups complete a detailed feasibility study.
 

Expansion


Ineos is building a new furnace at its petrochemical plant in Rafnes, Norway as it expands capacity to use ethane made from U.S. shale gas it will store in a gas tank under construction at the site. The company is building an ethane storage tank that will enable the plant to produce 570,000 tons/year of ethylene. The extra furnace will enable it to produce 620,000 tons/year. The Norwegian plant currently houses 11 furnaces that process ethane gas and some oil-based liquids into ethylene. By the end of 2015, the company will have built a twelfth at the site. The total investment Ineos will make is around $160 million.
 

Liquid cracker


General Electric Co. and Carbon Holdings have signed a $500 million agreement to provide support in the building of the world’s largest liquid cracker at a petrochemicals complex on the Gulf of Suez. The naptha cracker project is part of the Tahrir Petrochemicals Complex worth $4.8 billion. The construction of the cracker is said to begin sometime in 2014 and construction is expected to take approximately 50 months. The new plant will have an annual capacity of 1,360,000 tons of ethylene and polyethylene as well as significant quantities of propylene, benzene, butadiene and linear alpha olefins.  
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Ankur's_Chemical_Engg_Blog - Time Dependent Gas Release Through A Hole From A Pressurized Container

December 23, 2013, 10:47 am
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Dear All,
 
One of the very important books related to process safety is popularly known as the "Yellow Book" published from the Netherlands and having the full title as:
 
"Methods for the calculation of physical effects - due to releases of hazardous materials (liquids and gases)" - 'Yellow Book' - CPR14E
 
The best part of this book is that it is absolutely free to download from the internet. The units used in the book are purely SI units which might prove somewhat of a dampener fro those quite used to engineering units and English units. In its treatment of the physical phenomena of gaseous and liquid releases it is an absolute delight to read. The coverage is extensive and wherever possible numerical methods to enunciate the physics involved in releases is provided.
 
It also encompasses other safety related topics such as vapor cloud dispersion, vapor cloud explosion, heat flux from fires etc. 
 
Below a link is provided for a free download of the book:
 
http://content.publicatiereeksgevaarlijkestoffen.nl/documents/PGS2/PGS2-1997-v0.1-physical-effects.pdf
 
The title of my blog entry does not suggest anything about the book but I wanted to make it clear that the topic I have chosen  i.e. 'Time Dependent Gas Release through a hole from a pressurized container' is basically picked up from the 'Yellow Book'.
 
I have prepared a spreadsheet based on the theory and equations provided in the 'Yellow Book' for the subject with an example. A few relevant pages of the 'Yellow Book' with certain sections highlighted have also been provided in the spreadsheet. 
 
Those process engineers who have access to HYSYS or any other similar process simulation software where vessel depressurization dynamic utility is available, may find that  the results are not closely matching with the spreadsheet that has been presented along with this blog entry. The reason is that a few simplified assumptions have been done which the book also follows to arrive at the results. Some of these are as follows:
1. The process of the vessel depressurization is considered to be an adiabatic process only.
2. The specific heat or heat capacity at constant volume (Cv) is considered to be constant along the depressurization path although the dynamic change in pressure and temperature during the depressurization will have some effect on the specific heat value. In other words, there will be minor changes in the specific heat value at different dynamic values of pressure and temperature.
3. The specific heat ratio (Cp/Cv) is also considered to be constant along the depressurization path based on the same premise presented above in point number 2.
 
Again the idea of presenting a spreadsheet is to ensure that those process engineers who do not have access to expensive simulation software are not left out.
 
Hope all of you enjoy this blog post and the accompanying spreadsheet. I look forward to your comments and definitely look forward to comparisons of the example given in the spreadsheet with the results obtained form a "Dynamic Depressuring Utility" from a simulation software such as HYSYS or similar.
 
Regards,
Ankur.
 
 
Quick note from the admin:
Download the MS Excel sheet here:
http://www.cheresources.com/invision/files/file/308-time-dependent-gas-leak-outflow-through-a-hole/

 
 
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