Merisol Antioxidants LLC, Oil City, PA - Executive Summary |
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Merisol Antioxidant LLC's Isobutylene (2 methylpropene) Risk Management Program Executive Summary Accident Release Prevention and Emergency Programs Merisol Antioxidant LLC's Risk Management Plan Program provides a systematic approach to prevent the accidental release of chemicals to the environment. This is accomplished through both engineering and administrative controls. All applicable elements of the U. S. EPA's Prevention Program and OSHA's Process Safety Management standard are adhered to. The Merisol Antioxidants LLC's Emergency Plan is tailored to meet the needs of any foreseeable release at the Oil City, PA facility, and was developed using in put from the local emergency response agencies (Cornplanter Twp. Vol. FD, Rouseville Vol. FD, Oil City FD, And Venango Emergency Management Agency). The plan was submitted and approved by the Venango County, PA Local Emergency Planning Commission (LEPC). Stationary Source and Regulated Substance Handled The Merisol Antioxidants LLC facility located at Oil City, PA is a manufacturing facility that produces Butylated Hydroxy Toluene (BHT), a crystalline Phenolic antioxidant. Isobutylene (2-methylpropene) is stored in bulk on the plant, and is used to add the butyl groups onto mixed cresols (methylphenol). The isobutylene storage tank and associated transfer equipment have several engineered safety features, such as thick walled tanks; excess flow valves; perimeter monitor & alarm systems; pressure relief valves; a flare protected vent system; and administrative procedures to prevent or detect releases. The plant is manned and the isobutylene system is monitored 24hrs a day. There are automated vapor dispersing, fire extinguishing and associated alarm systems around the isobutylene storage and off-loading areas. All storage and handling equipment as well as all safety and countermeasure equipment are on a rigid test and inspection program as well as a general preventive maintenance program. The offsite consequence analysis includes consideration of two release scenarios for this chemical. 1.) The worst case as defined by the EPA, "the owner or operator shall assume that the ... maximum quantity in the largest vessel ... is released as a gas over 10 minutes," due to an unspecified failure. 2.) The alternate case as defined by the EPA as, "more likely to occur than the worst case release scenario". Worst and Alternate Case Scenarios The worst case involves the total failure of one of the on site storage tanks. There are two tanks within 10 feet of each other. Rail cars, which are smaller than a storage tank, are off-loaded to a storage tank from less than 100 feet away. The failure would result in the release of 186300 lbs. of isobutylene within 10 minutes. If all of this were converted to gas, and a ground level ignition source were introduced, the resulting energy release would cause a greater than 1 psi overpressure shock wave for a 2417 ft or 0.46 mi. radius. There are some residences insid e the endpoint boundary of the worse case. There are no schools, hospitals, nursing homes, recreational parks, etc. There are no environmental receptors inside the end point boundary. The alternate case Scenario involves a breach (20% rupture) in a two-inch (i.d.) liquid isobutylene transfer line between the storage tanks and the reactor. The release is 161 lbs./min., which is slightly below the excess flow valve setting of 191 lbs., for 13 min. This would result in 2093 lbs. released, and would result in a concentration of isobutylene above its LEL (2% in air) for a radius of 120 ft from the leak. This radius would extend beyond the boundary of the plant by thirty feet on the West side of the plant. The only receptor in this endpoint boundary is a rail yard. The railroad does occasionally have employees working inside the boundary area. General Accidental Release Prevention Program and Prevention Steps The general accidental release prevention program includes but is not limited t o the following elements. 1.) Safety training for employees who operate, inspect, or repair the isobutylene handling equipment. 2.) Unit specific procedures for operating trouble shooting, and maintaining the isobutylene handling equipment. 3.) A comprehensive preventive maintenance and mechanical integrity program to insure the safety and reliability of the isobutylene handling equipment. 4.) A leak detection and repair (LDAR) program to detect leaking flanges and pumps seals. 5.) A perimeter gas monitoring system at the storage and off-loading areas that is tied into automatic alarms, shutdown interlocks, and water curtains. 6.) An emergency vent flare system to relieve any excess pressure that could occur. 7.) A management of change program. 8.) Our Process Hazards Management Program (PHMP) developed to be in compliance with OSHA's PSM std. (29CFR1910.119) Five Year Accident History There have been no accidental releases of isobutylene within the last five years that meet the crit eria of reporting in "Air Programs, Part 68, Subpart B, 68.42". Emergency Response Program Merisol Antioxidants LLC has a comprehensive emergency contingency program, which has been reviewed by the Venango county EMA and the local fire departments (Cornplanter Twp., Rouseville, and Oil City), and has been approved by the Venango County Local Emergency Planning Commission (LEPC). Merisol Antioxidants LLC does not have an emergency response team for fire response, but all operations and maintenance employees are trained at the 24 hour technician level for hazardous material spills and clean-up. Merisol Antioxidants LLC personnel have been trained how to activate countermeasures and notify emergency response agencies. They have been trained how to assess the situation and communicate to emergency response personnel the most prudent course of action to take to safeguard the community. Merisol Antioxidants LLC management personnel will report to work on site with emergency responders as a resource for controlling releases of isobutylene, and for operating counter measure systems. Merisol Antioxidants LLC personnel will assist the Incident Commander on the scene as specialist in handling isobutylene. The emergency plan is reviewed and resubmitted to the Venango County LEPC every year for its review and approval. Necessary elements of the plan are incorporated into the Venango County Emergency Response Plan. Planned Changes to Improve Safety Merisol Antioxidants LLC has periodic safety reviews of all chemical processes, including the isobutylene alkylation system. Some of the planned changes to improve the safety of the isobutylene storage and transfer system are listed below. 1.) Install high temperature shutdown switches on the isobutylene charge pumps. 2.) Install high-pressure shutdown switches on the discharge of the isobutylene charge pumps. 3.) Install interlocks between the perimeter flammable gas detectors, and the isobutylene storage tanks' discharge valves and charge pumps. 4.) Install interlocks between the fire alarm and the isobutylene storage tanks' discharge valves and the charge pumps. 5.) Install mass meters to compare amount of isobutylene leaving the storage tank to that entering the alkylation reactor; and interlock a maximum difference with discharge valves and charge pumps. Merisol Antioxidants LLC has a continuous improvement philosophy in all safety and environment issues. |