New HPPOa technology for propylene oxide production: from laboratory reactor to commercial pilot installation

Abstract

The development of HPPOa technology on production of propylene oxide from propylene and hydrogen peroxide with the use of acetonitrile as a solvent instead of methanol is shortly described. Laboratory studies included the development of a new catalyst and its testing in a flow fixed bed (4-10 cm3) reactor at 40-550C/3.0 MPa. Proposed TIS-1 catalyst was synthesized using dispersed Newsil 115 silica instead of traditional TEOS for TS-1 zeolite obtaining. Silica Ludox 40 and starch were used in the synthesis of TIS-1 catalyst also. On the basis of determined molar composition of reaction 60% H2O2 - propylene- 85% acetonitrile mixture and a load on catalyst the HPPOa (hydrogen peroxide to propylene oxide in acetonitrile) technology for a pilot installation with capacity of 2000 t/y has been developed. The main equipment – 3 reactors, 6 distillation columns, absorber, heat exchangers were made in Ukraine by Techinservice Manufacturing Group Ltd. At the beginning 2019, the construction of HPPOa installation at the olefin plant of Karpatnaftochim Ltd in Kalush began. The first start of this installation took place in June 2020. That is, in a very short time, 3 years after the start of laboratory tests. Technological HPPOa scheme includes epoxidation of propylene, preliminary separation of the product mixture, purification of propylene oxide, propylene compression, purification of propylene from propane, absorption of propylene with acetonitrile, regeneration of acetonitrile. The installation is a rather complex engineering system, some elements of which operate under both high (30 atm) and low (0.1 atm) pressure at temperatures from -30 to 1500C. Now the installation is brought to design capacity with the production of commercial propylene oxide with a polymer purity of 99.95% without the use of traditional ammonia and hydrazine. Fully automated installation is serviced by 4 operators working in two shifts. Consumption of 100% H2O2 and propylene per 1 ton of propylene oxide consists 0.68 and 0.75 tons, respectively. Ltd ”Karpatnaftochim” intends to build a facility for production of propylene oxide with a capacity of 130,000 tons per year using HPPOa technology.