Producing ethylene and propylene from natural gas via the intermediate synthesis of methyl chloride and its subsequent catalytic pyrolysis

• Published in: Catalysis in industry Vol. 4; no. 4; pp. 231 - 235
• Main Authors: Treger, Yu. A., Rozanov, V. N., Sokolova, S. V., Murashova, O. P.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.10.2012
• Subjects: Catalysis; Catalysis in Chemical and Petrochemical Industry; Chemistry; Chemistry and Materials Science; propylene; catalytic pyrolysis; methyl chloride; methane; silicoaluminophosphate catalyst SAPO-34; oxidative chlorination; ethylene; low molecular weight olefins
• ISSN: 2070-0504; 2070-0555
• DOI: 10.1134/S2070050412040186

An original two-stage process for producing ethylene and propylene from natural gas via the catalytic pyrolysis of methyl chloride produced by methane catalytic chlorination is investigated. The kinetics of the methyl chloride catalytic pyrolysis on a silicoaluminophosphate catalyst SAPO-34 is studied and the process parameters are determined, yielding selectivities of 45% and 35% for ethylene and propylene, respectively, at 70% conversion of methyl chloride. The kinetics of methane oxidative chlorination is investigated on a catalyst that is a mixture of copper, potassium, and lanthanum chlorides deposited on a carrier. Based on the results from kinetic investigations, the process of methane oxidative chlorination is tested on an experimental setup in reactors of different types, two with fluidized catalyst beds (diameters 400 and 45 mm) and one tubular (diameter 27 mm), and on a pilot setup in a two-stage adiabatic reactor (diameter 800 mm). The process is tested with oxygen supply distributed for each stage at temperatures of 300–320°C at the inlet and 400–420°C at the outlet of the catalyst bed. The selectivity for methyl chloride formation among chloromethanes is 90%. A basic scheme is developed for a chlorine-balanced process of ethylene and propylene production from natural gas, and conditions for conducting methane oxychlorination and methyl chloride pyrolysis reactions in industrial reactors are determined. The process can be implemented at plants that need ethylene to increase deliveries of vinyl chloride and are experienced in working with hydrochloric acid and chlorinated derivatives of hydrocarbons.