LINDE GAS INC. - DECATUR PLANT - Executive Summary |
|
Linde Gas Inc . Executive Summary Accidential Release Prevention and Emergencey Response Policies At the Decatur Linde Gas , Inc. Facility Safety has always been the first consideration in the design and operation of this plant . Nevertheless there is always the possiblity of equipment failure , operator error or force of nature which could cause a serious environmental problem . Linde Gas , Inc . is committed to making protection of human heath , safety and the environment our first priority . We will operate on the premise that all accidents and incidents are preventable and will work toward this goal . Linde Gas , Inc . Decatur will fulfill this policy commitment through the application of a comprehensive Risk Management System which will provide all stakeholders with ongoing assurance that : - safety , heath and environmental laws , regulations , and permit requirements are adhered to - identifiable safety , health and environmental risks associated with Linde Gas , Inc . ope ration are assessed and successfully managed - Systems are in place to manage change - An Environmental contingecy plan is in place - An Emergency Response Procedure is in place An excellent safety performance is everyone's responsibility , and it is this site policey that all employees must adopt and are encourage safe work practices and conduct for all work related activities in an environmentally responsible manner . General Information of the Facility : Linde Gas hydrogen gas generation plant and liquid carbon dioxide recovery unit in Decatur , Alabama provide hydrogen feed stock for pipeline distribution to Bunge Foods in Decatur and serve as a supplemental sourse to Solutia ( Monsanto ) facilities . The manufacturiing process includes taking Natural Gas as the feed stock , mixing it with steam , after which it is preheated then pass through a reformer where the methane and water mix is converted to hyrogen , Carbon Monoxide and Carbon Dioxide . The reformer gas is the n pass through to a high temperature shift reactor , where the carbon monoxide will be reacted with excess steam present in the gas stream to produce additional hydrogen by the following reaction . CO + H20 = CO2 + H2 The gas then is cooled and CO2 is stripped off and sent to a CO2 Liquefaction process before being transfer to storage for distribution . The hydrogen is pass through a high pressure purification step from which it is transfer directly to clients by way of a pipeline . Regulated Substance Handled at the site : Anhydrous Ammonia is used in two areas of the site : 1) Ammonia is used as a refrigerent in the CO2 Liquefaction process to convert CO2 from the gas to the liquid state. The refrigerent package is a close loop system that contains approximately 4500 lbs of Amonnia at any one time . 2) Ammonia is also used on our site as a reducing agent to reduce the amount of nitrogen oxides emmisions from our process flue gas . The site uses a Selective Catalytic Reduction system design specific to reduce oxides of nitrogen from exhaust gases . Auxiliary equipment supporting the Selective Catalytic System includes a 10,000 gallon Ammonia storage tank , Diluge system for the tank , collection system for spills , welded transfer pipe to the Selective Catalytic Reduction system "SCR" , a NOx control system pannel . The system makes use of anhydrous ammonia diluted to approximately five percent concentration with abient air .The ammonia is injected upstream of the catalyst face and mixed with the exhust gas . As this mixture flows through the catalyst bed , a chemical reaction occurs which results in the NOx reduction to nitrogen gas and water vapor . The Worst-case release scenario and The alternative release scenario for Anydrous Ammonia at the Linde Gas , Inc . Decatur site : Introduction - The analysis was performed on the 10,000 gallon Ammonia Storage tank that is located on the southeast corner of the facility . The location itself is on a penin sula of land surrounded by Wheeler lake on the north , east and south side . The models focused on the area to the west where other facilities are located and on the site control building . The models were run on PHAST Professional , Version 5.1 . This product of DVN Technica is widely used for many air modeling applications The scope of the analysis included modeling a worst case release scenario of a vessel rupture and an alternative release scenario of lifting relief valves . Worst - Case Release The worst case release scenario was performed following federal Risk Management Plan ( RPM ) guidelines . The following parameters were used ( per 40 CFR 68 Of RMP ) : - Wind speed of 3.4 mi / hr and an atmospheric stability class of F . - Ambient temperature of 77 F - Relative humididty of 50 % - Ground level release ( 0 feet ) - Surface roughness of 0.17 For toxic exposure , the Emergency Response Planning Guideline ( EPRG ) 2 levels were used . This level is equivalent to 200 ppm ammonia . Three approximated distances were used in the calculations. The first distance of 200 feet is the approximate distance to the west fence line and to the control building . The second distance of 600 ft represents the southeast corner of the Solutia Facility . The third distance of 1600 feet corresponds to the Novacor's eastern property line . The Novacor property lline is the major area of concern . The following assumptions were made : - The vessel is 80% full ( 8,000 gal ) . This corresponds to 39,020 lbs of ammonia - The vessel is within a concrete - diked area approximately 15' x 45' - The vessel inventory empties to the diked area over a 10 minute period ( 3902 gal / min ) . This is typical for ammonia vessel rupture scenarios - The ammonia in the vessel is pressurized to 180 PSIG , with a corresponding temperature of 94.8 F - No mitigation credit is taken while vessel empties ( i .e. deluge not activated ) Summary of R esult The reults of the study showed that thr plume becomes buoyant and detaches from the ground at a distance of roughly 60 feet . At a distance of 1600 feet the plume has a centerline concentration of 2446 ppm , but this concentration is at a height of 90 ft . The erpg 2 level of 200 ppm is reached at a distance of 4023 ft and a plume height of 204 feet . Based on these results , a vessel rupture would have no impact on the Novacor property at ground level . On - site impacts for this scenario are of concern . At the distance of 200 ft ( approximate control room distance ) , the plume ceterline concentration is estimated to be 357 , 147 ppm . At this distance , the plume is less than 1ft from the ground . ALTERNATE RELEASE SCENARIO The alternate release scenario involved relief of the vessel contents from two 2" x 3" relief valves. The alternate release scenario was performed folowing federal Risks Management Plan guidelines . The following parameters were used ( per 40 CFR 6 8 of RMP ) : - WIND SPEED OF 8.6 mi / hr and an atmospheric stability class of F - Ambient temperature of 73 F - Relative humity of 80% - Surface roughnes of 0.17 Once again ERPG 2 Levels were used and the same distances of interest ( 200 , 600 , 1600 ft ) were calculated The following assumtions were made : - To capture the worst case scenario , two relief valves were assumed to be relieving simultaneously . Since PHAST does not allow input of this case directly , one relief valve was modeled and the orifice and tailpipe size were adjusted to simulate two relief valves lifting - The vesel is 80% full ( 80,000 gal) . This corresponds tp approximately 39,020 lbs of Ammonia - The relief valves relieve at 265 psig , with a corresponding temperature of 119 F - The release height was 15 ft , which included a 5 ft standpipe Summary of Result The calculated release rate was 615 lbs / min . The ERPG 2 concentration of 200 ppm was reached at a distance of 5 68 ft . At this distance the cloud is still buoyant and has not touched down .The cloud edge touches down at a distance of 975 feet and is below 200 ppm . At 1600 feet , the centerline concentration is 49 ppm , which is well below the allowed 200 ppm . This relief valve scenario would have no on site impact what so ever . Based on these results , the current vessel and relief valve configuation ( Assuming a 5ft standpipe ) is adequate to protect the Novacor property from ERPG 2 Ammonia concentrations General Accidental Release Prevention Program and Chemical - Specific Prevention Steps : Linde Gas Inc. , Decatur Plant Process is designed and operated under strick parameters to reduce risk of accidents . The safety of Linde Gas Employees and the citizens of the surrounding communities are of paramount importance . As a result of Linde Gas commitment to the safety of its employees , its surrounding community , and to fully comply with OSHA's standard 29 CFR 1910.119 ( Process Safety Management of Highly Hazardous Chemicals ) Linde Gas has a Process Safety Management ( PSM ) Program . This Program is intended to prevent or reduce the risk of any major industrial incident that might expose employees to the hazard of toxicity , fire , or explosion caused by highly hazardous chemicals The elements of the program are : 1. Employee Participation 2. Process Safety Information 3. Process Hazard Analysis 4. Operating Procedures 5 Training 6 Contractor Safety 7 Pre-Startup Safety Review 8 Mechanical Integrity 9 Hot Work Permit 10 Management of Change 11 Incident Investigation 12 Emergency Response Plan 13 Compliance Audit , and 14 Trade Secrets The objective of these provisions is to develop a protective approach to the identification , evaluatioin , and prevention of chemical releases which result from lack of procedures , human error , or equipment failure . Linde Gas , Inc . has also developed and implemented a Best Management Practice plan which prevent , or minimizes the potential for , the release of pollutants from ancillary activites , including material storage areas; plant site runoff; inplant transfer , process and material handling areas;loading and unloading operations to the waters of the State. The Ammonia storage areas are all with in dike areas equiped with sumps that pump to a holding tank for testing . The 10,000 gallon Ammonia tank has an added deluge protective feature that can be operated at a safe distance in the control room . Wind socks are also located within the site to determine wind direction . An emergency response plan is in place and the site is currently working with the Decatur Fire Department to work out a schedule for a drill . The Five Year Accident History The site has not had an accidential release since its start up on September 1998 The Emergency Response Program The intent of the management at this site is to be pro - active , reduce risk , provide a s afe , healthy work site and prevent accidents and emergencies from ocurring as much as feasible . The Emergency Action Plan is developed to minimize threats to life , heath and property when unplanned events happen. The Emergency Response Program was developed base on the following Assumptions 1. There are few locations in the plant at which personnel are highly concentrated 2. Operations in the plant may be isolated on short notice from other sections 3. Personnel are trained operators who understand their section of the plant thoroughly and who have been trained on steps to be taken to assure safe operation in that section 4. Damage to one section of the plant by fire , explosion or other catastrophic failure can be limited to that section Linde Gas , Inc in the event of an incident would need to rely on assistanse from the Decatur Fire Department and Local Law enforcement .The existance of an emergency will be reported immediately by any individual calling 911 . In order that the 911 officer realizes the urgency of the call , the individual reporting will state "emergecy call". Facts to be reported to the 911 officer will enclude the following : - Name of the individual making the report - Where the call is being made from - Nature of occurrence - Weather there has been loss of life or injury to personel If the incident involves a release the proper Emergency Relase Notifications must also be made : - Morgan county EMA - State Emergency Response Commission - National Response Center Note: The local LEPC is currently in the process of purchasing and installing a emergency siren system along the Hiway 20 industrial corridor, that will not only sound the alarm but will also give information and instructions for any incident that may occur. Also in the works is a emergency phone system that will in the event of an emergency allow the EMA to contact only the effected areas with a recorded message stating the nature of the emergency. These systems will greatly aid the EMA in any emergency that may arise. Further information that must be provide would include the following : - Name of chemical release - Estimated quantity release - Time and duration of release - Release ocurred in air , water, or land - Known or anticipated acute or chronic health risks and where appropriate , advice concerning medical attention necessary for exposed personnel - Proper precautions to take as result of release including evacuations In house training of personel includes : 1 ) Scott Air Pack Training by the Fire Department 2) CPR From Medworks in Decatur 3) First Aid From Medworks in Decatur 4) Proper Use of a Fire extinqesher by the Fire Department 5 ) Wriiten Test on Site Emergency Action Plan 6) Written Test on Environmental Plan 7) Monthly safety meetings , where operators are orally quized on corrective actions to take in emergency situations Other elements included in the emergecy ac tion plan includes : 1.) An emergency escape procedure and emegency escape assignment 2.) Procedures to be followed by employees who remain to operate critical plant operations before they evacuate 3. ) Procedure to account for all employees after emergency evacuation has been completed 4.) First aid duty assignment for first man on the scene 5) An alarm sytem schedule to be installed in July Fire Prevention Elements include 1) Hot Work Permits 2) House Keeping Policey 3 ) Nitrogen Blankets on AFT Tank ( Combustible Oil ) |