Effect of Operational Variables on the Hydrogasification of Inner Mongolian Lignite Semicoke

Abstract

Hydrogasification of Inner Mongolian lignite semicoke was investigated at varying operational conditions: grain size of 0.15–0.7 mm, hydrogen flow rate of 300–1500 mL/min, temperature of 700–900 °C, pressure of 0.1–5.0 MPa, and heating rate of 10–30 °C/min, using a self-developed high-temperature and high-pressure fixed-bed reactor with a design parameter of 1000 °C and 12 MPa. The reaction characteristics and mechanism of semicoke hydrogasification were discussed. The results showed that, at a grain size of semicoke of 1200 mL/min, the effects of internal and external diffusion resistances were basically eliminated; the increase of the pressure or heating rate exerted a positive influence on the hydrogasification of semicoke. The optimum reaction conditions were as follows: grain size of 0.25–0.35 mm, hydrogen flow rate of 1200 mL/min, temperature of 800 °C, and pressure of 3.0–4.0 MPa. During hydrogasification, the fracture of alkyl side chains, hydrogenation/methan...