Research on Iron-Containing Magnetic ionic Liquids in Extraction-Deash of Coal Direct Liquefaction Residues Using Ultrasonic Oscillation

摘要

Coal direct liquefaction residues (CDLR) are derived from coal direct liquefaction process, with the yield about 30% of raw coal. CDLR must be used effectively for the purpose of whole economy, resource utilization and environmental protection. In order to separate the liquid components from ash in CDLR, three kinds of iron-containing magnetic ionic liquids ([bmim]FeCl_4, [bPy]FeCl_4, [bmP]FeCl_4) were synthesized, extraction-deash of CDLR was exprimented, and extracts from CDLR were characterized. According to the quantitative analysis and infrared spectroscopy (IR), results showed that [bmim]FeCl_4 was an effective solvent in extraction-deash of CDLR using ultrasonic oscillation instead of traditional mixing methods, compared with [bPy]FeCl_4 and [bmP]FeCl_4. Extract by [bmim]FeCl_4 had ash ratio of 1.0%, while ash ratio of CDLR was 17.3%, which met the requirement of low ash content. At last, extraction-deash mechanism was discussed to further understand the research.