Document BjvzVZ99V2EMG5X8jNGZ5MGL

Tenneco ChemicaL ATenneco Contpdny PO Bo* 849 Psadena Texts 77S01 (713)479-34)1 January 19, 1979 (JWK-9-79) Hr. Bill Stewart Executive Director Texas Air Control Board 8520 Shoal Creek Blvd. Austin, Texas 78758 Dear Mr. Stewart: The following information is presented concerning a discharge of vinyl chloride monomer to the PVC plant flare system at Tenneco Chemicals' Pasadena, Texas complex resulting from the leakage through a relief valve under circumstances described below. Inasmuch as most of the vinyl chloride monomer released from the process was destroyed by combustion in the flare, the incident may not be a release to the atmosphere within the scope of Section 6.65a of the National Emission Standards for Hazardous Air Pollutants-Vinyl Chloride. The incident occurred about 11:00 p.m. on January 16, 1979. The source of the vinyl chloride monomer was the apparent leaking through of the thermal relief valve on the VCM charge filters (L-302C&D). This relief valve discharges to the PVC flare system. The vinyl chloride collects in the flare knockout drum, where it slowly evaporates and is burned at the flare tip. The majority of the safety relief valves in the PVC plant discharge to the flare system for burning rather than going directly to the atmosphere. It is estimated that 10-20 pounds of vinyl chloride were discharged to the flare system. This estimation is based on the appearance and duration of the flaring. The flare was found to be smoking slightly on the night of January 16. An investigation as to the source of the discharge to the flare system was initiated by Operations supervision. Subsequently, the thermal relief valve on the VCM charge filters (two parallel filters in the set) was found to be leaking through. The filters were taken out of service and depressured, stopping the leakage. The relief valve was subsequently replaced. Additionally, an investigation is continuing in regard to possible modifications to this relief valve system. TEM360 Tenneco ChemicaL Mr. Bill Stewart Texas Air Control Board January 19, 1979 Page Two Please let me know if you have any questions or if further information is required. Sincerely, C. E. Crain Mfg. Mgr. - Polymers Mr. Allison Peirce - HCPC Mr. C. E. Crain Mr. C. S. Stutts Mr. R. L. Churchwell Mr. L. L. Bird Mr. T. T. Moore Mr. VJ. P. Anderson TEN 1361