Decreasing Emissions and Improving Performance at Dow's LHC7 Ethylene Plant
Bernardo M. Corripio and Susan Belveal. The Dow Chemical Company, Louisiana Hwy 1, PO Box 150, Plaquemine, LA 70765
Starting in 2000, increasingly stringent air quality requirements from the Texas Commission on Environmental Quality (TCEQ) for ozone non-attainment areas forced Dow to consider various options for reducing NOx emissions at its Freeport, TX facilities, located about one hour south of Houston and included in the Houston-Galveston non-attainment region. This site was originally started up in 1941 and has facilities of varying ages, including ethylene plants started up in 1973 and 1995. The older ethylene plant, LHC-7, was a prime candidate for NOx reduction. This paper describes the site-wide study to reduce NOx emissions, the various options for equipment replacement, modification and shutdown considered and the improvements made to the LHC-7 ethylene plant to reduce NOx emissions. These improvements included replacement of a gas turbine driver for the propylene refrigeration compressor with a steam turbine and construction of an all-new furnace section to replace the existing furnaces. Economic, energy efficiency and NOx reduction results of the work will be described.