Study On Preparation Of Mesoporous Carbon From Solvent Extraction Residue Of Low-Rank Coals

Solvent extraction is an efficient technology to upgrade the low-rank coals. But usually researchers pay more attention to the extracted product so that they ignore the extracted residue which has a high carbon content, it is necessary to study about the utilization of the low-rank coal extracted residue. In this study, 1-methylnaphthalene was used as the solvent to extract two different kinds of low-rank coals to get the extracted residue, then mesoporous carbons were prepared from the extracted residues by CO2 physical activation and KOH chemical activation. The prepared mesoporous carbons were used as catalysts to reduce tar formation during biomass pyrolysis. The capacity of Hg absorption of the prepared mesoporous carbon was also tested in this paper.1-methylnaphthalene was used as the solvent to extract two kinds of low-rank coals(Huo Linhe coal and Shen Fu coal)at the temperature of 350?, the moisture and oxygen content of extracted residue were reduced and the caloric value and gasification reactivity were improved compared with the raw coals. Mesoporous carbons were prepared from the extracted residues by CO2 physical activation, the BET surface area and the pore volume of mesoporous carbons prepared from the extracted residues were greater than raw coals in the same conditions. The BET surface area and the pore volume offered upgrade firstly than descending latter tendency with the increasing of activation time. 15 min was the best when the activation temperatures were the same. KOH chemical activation to prepare mesoporous carbons from coal residue was also studied in this paper. Mesoporous carbons prepared from different raw materials?activation temperature and mass ratio of KOH/coal residue were tested, finding that mesoporous ratio was highest when the activation temperature was 800? and the mass ratio was 2:1. Lower temperature leaded to more micro-pores. It was due to the merging of micro-pores into mesoporous with the improvement of activation temperature.Using the mesoporous carbon prepared by KOH activation as catalysts to reduce the tar formation during biomass pyrolysis was also studied in this paper. The amount of CO2?CO?CH4 raised when catalysts were added. It was because the existence of mesoporous carbon improved the residence time of volatile released during the biomass pyrolysis which leaded the reduction of tar formation, thus the gases increased.In the last chapter of this paper, the mesoporous carbon prepared by KOH activation were used as sorbent to absorb Hg at the room temperature and 150?. The adsorption efficiency are more than 80% of each mesoporous carbon at the room temperature, and the adsorption efficiency decreased because of the enhancement of desorption at the temperature of 150?. The adsorption efficiency of mesoporous carbons who had a higher adsorption efficiency at the room temperature were relative higher at 150?.