Terephthalic Acid from Toluene via Dipotassium Terephthalate

Phillips Petroleum and Rhone-Poulenc have developed a toluene-based terephthalic acid (TPA) process in which dipotassium terephthalate is an intermediate and benzene is a by-product. In this review, a process design for a 330 million lb/yr TPA plant and cost estimates on the process are presented. The economics for the toluene-based TPA process are compared with those for the commercial p-xylene-based process (known as the Amoco process) examined in PEP Report No. 9C. With respect to total capital, the two processes are about the same. In the production cost and the sales value, the toluene-based process has a cost advantage over the p-xylene-based process.