Rongrong Miao

Catalytic gasification of phenol in supercritical water with Ru/graphitized carbon black

Phenol is a long-lived intermediate, and it is ubiquitous in the supercritical water gasification (SCWG) processes of various organic materials such as biomass, lignite and sewage sludge. In this work, ruthenium supported on graphitic carbon black (Ru/GCB) was prepared for catalytic gasification of phenol in supercritical water. It exhibited excellent catalytic performance towards phenol gasification, a nearly complete gasification of phenol was achieved at a moderate temperature of 500 °C with an 1 g g−1 catalyst loading. Kinetic study indicated the activation energy and the frequency factor for phenol gasification were 154.0 ± 27.2 kJ mol−1 and 23.2 ± 4.5, respectively. Furthermore, catalyst recycling experiments were conducted to evaluate the stability of Ru/GCB catalyst in the SCWG. X-ray diffraction, Raman spectrum, N2 adsorption, X-ray photoelectron spectroscopy and transmission electron microscopy were performed to characterize the fresh and used catalyst in order to investigate possible changes of catalyst after the recycling, the results indicated that the catalyst was found to be stable for phenol gasification under the experimental conditions.

Catalytic Liquefaction of Lignite by Supercritical Ethanol

Catalytic hydrogenation liquefaction by supercritical ethanol is an effective method for the efficient utilization of lignite. The liquefaction efficiencies of lignite 1(L1) and lignite 2(L2),which were collected from Zhaotong, Yunnan, were compared. It was found that the liquefaction efficiency of L1 was better than L2 but the gas yield of L2 was higher than L1 under the same reaction conditions, indicating that both of them could be effectively conversed. The yields of lipids and phenols in the components of liquefaction products were significantly different, and the liquefaction of L2 could achieve the desired conversion effect by changing the reaction conditions. Increasing the amount of ethanol could promote liquefaction efficiency, however, when the ratio of ethanol to coal(E/C) were 20 and 30, the growth rate of the yield of liquefied oil was quite lower than the previous stages. This phenomenon indicated that with the decrease of lignite concentration, the mass transfer effect of ethanol as a solvent in the reaction was getting better and better, and the liquefaction rate increased rapidly. But the higher system pressure was not conducive to liquefaction in high temperature conditions. In addition, the esterification reaction between ethanol and the intermediates of hydrocracking reaction could facilitate liquefaction reaction.