A process concept for the production of benzene-ethylene-SNG from coal using flash hydropyrolysis technology

Abstract

Flash hydropyrolysis (FHP) of coal is an emerging technology for the direct production of methane, ethane and BTX in a single-stage, high throughput reactor. The FHP technique involves the short residence time (1–2 seconds), rapid heatup of coal in a dilute-phase, transport reactor. When integrated into an overall, grass-roots conversion complex, the FHP technique can be utilized to generate a product slate consisting of SNG, ethylene/propylene, benzene and Fischer-Tropsch-based alcohols. This paper summarizes the process engineering and economics of a conceptualized facility based on an FHP reactor operation with a lignitic coal. The plant is hypothetically sited near the extensive lignite fields located in the Texas region of the United States. Utilizing utility-financing methods for the costing of SNG, and selling the chemicals co-generated at petrochemical market prices, the 20-year average SNG cost has been computed to vary between $3–4/MM Btu, depending upon the coal costs, interest rates, debt/equity ratio, coproduct chemicals prices, etc.