Exxon, Baytown, Tex. 280 Koch Industries, Corpus Christi, Tex. 270 Lyondell-Citgo Refining, Houston, Tex.
All producers have captive supplies of mixed xylenes.
Exxon is the only US producer to use OX captively for phthalic anhydride production. Koch Industries intends to add 75 million to 100 million pounds of capacity at Corpus Christi over the next two years. Lyondell-Citgo's OX production is marketed by Equistar Chemicals. Almost all orthoxylene recovered in the US is consumed in the manufacture of phthalic anhydride. A small amount is used in solvent applications and to make bactericides, soybean herbicides and lube oil additives.