Zhang Chengfang

Synthesis of mixed alcohols from CO2 contained syngas on supported molybdenum sulfide catalysts

Abstract The performances of active carbon supported molybdenum sulfide catalysts prepared by different procedures or promoted by different elements in the synthesis of mixed alcohols from CO2 containing syngas were examined. The results showed that high alcohol activity and selectivity could be obtained by employing a rapid drying procedure and employing a H2SH2 stream for (NH4)2MoS4 decomposition. Addition of Co, Cr and Cl to KMo C catalyst led to an increase in the alcohol activity or selectivity. The presence of CO2 in the feed caused a greater amount of water to be produced but reduced the formation of CO2. The product distribution was also strongly influenced by the presence of either CO2 or H2S in the feed. Addition of CO2 reduces the formation of higher alcohols while H2S increases higher alcohol formation.

Influence of alkalinity on particle size distribution and crystalline structure in synthesis of zeolite beta

Abstract Influence of alkalinity (OH-/SiO2) on particle size distribution and crystalline structure in synthesis of zeolite beta at a short crystallization period (60 h) has been studied. The results indicate that the highest crystallinity of synthetic zeolite beta at alkalinity of 0.24, 0.35 occurs when Al2O3·H2O and NaAlO2 are respectively used as aluminium sources. At an alkalinity higher than 0.39, zeolite beta can not be obtained when Al2O3·H2O is used as aluminium source. The difference of particle sizes between zeolite beta synthesized from gels of different alkalinity is 0.7–0.8 μm. The widest particle size distribution of zeolite beta synthesized occurs when the alkalinity is 0.23–0.24. Along with the increase of the alkalinity, zeolite beta synthesized changes as follows: vibration peak of 1071 cm−1 by IR moves to a higher position, the framework Si/Al ratio determined by 29Si MAS NMR first increases gradually and then decreases, but the change of OhAl/TdAl ratio determined by 27Al MAS NMR is contrary to that of the framework of the Si/Al ratio. In addition, the Si(O−) site existing in the TEA-β is confirmed by NMR, and the mechanism of alkalinity influencing crystallization is discussed.

Flash hydropyrolysis of Zalannoer lignite

Responses of Northern Chinese Zalannoer lignite to flash hydropyrolysis (FHP) and flash pyrolysis (FP) in a small entrained reactor were explored in experiments at temperatures between 500 and 900°C at pressure up to 6.0 MPa. Compared to FP, FHP can produce more hydrocarbon liquids (HCL) and CH4. At the conditions of 800°C and 6.0 MPa (hydrogen pressure) the maximum yield of HCL (6.62, wt% C) was obtained.

A study on the intrinsic kinetics of steam gasification of Jincheng coal char

Abstract Jincheng anthracite coal in Shanxi province is being used as a raw material for gasification by many ammonia plants in China. This paper reports on a study of the intrinsic kinetics of steam gasification of Jincheng coal char. Experiments were carried out in a tubular fixed-bed reactor under controlled conditions. Gasification rate dependence on carbon conversion, temperature and steam partial pressure was investigated.