Abstract
Coal is the main energy source in China, and coal chemistry wastewater treatment has always been a research hotspot. For the large amount of concentrated organic wastewater, high cost caused by complex treatment process is the key issue. In this paper, the fixed bed Lurgi gasifier wastewater coupled with solid oxide cells (SOCs) system is employed for its treatment. Based on Aspen Plus software, the purified methane from marsh gas is sent to solid oxide fuel cell (SOFC) for electricity generation. While carbon dioxide separated from biogas purification and acid gas removal enters solid oxide electrolysis cell (SOEC) to produce syngas by co-electrolysis with steam.The simulation results show that the efficiency of SOFC is 48.5 %. The generated electric energy can be used for auxiliary equipment in wastewater treatment and SOEC to produce syngas, recycling of carbon dioxide. SOEC with wind power of 12.84 MW is enough to treat the waste gas generated by the 1,100 t/h Lurgi gasification wastewater treatment process. Economically, the cost of producing syngas, with high purity and fewer contaminant contents, is about 0.126 $/Nm3. It can be used to produce various chemicals, so as to further improve the economic benefit of wastewater treatment.
