Important Technological Breakthrough in Harmless Treatment of Dangerous Waste of Coal Chemical Industry in China
On June 24, the Technical Team of Yanchang Petroleum Hydrocarbon Research Center (hereinafter referred to as Yanchang Hydrocarbon Team) released its major scientific and technological achievements: Multi-effect Heat & amp; Spent-brine Comprehensive Recovery Integration System (MCR). Aiming at the bottleneck problems of low sensible heat utilization rate of syngas and high environmental risk in conventional treatment of hazardous solid waste and impurities in domestic coal chemical industry, the new multi-effect integrated system is a key technology developed successfully by the extension hydrocarbon team and partners through joint scientific and technological research and development for 8 years. The integrated system creatively realizes the perfect coupling of sensible heat recovery of crude syngas, purification of syngas, high concentration waste brine of coal chemical industry, harmless treatment of hazardous waste salt and resource utilization in the same system. It can solidify hazardous waste salt into environmentally harmless and risk-free silica-alumina feldspar vitreous minerals in open environment system.

Li Dapeng, chief expert of petroleum and coal chemical industry, introduced that compared with conventional chilling process and waste boiler process, MCR integrated system has obvious technological innovation advantages: it omits the complex carbon wash tower constructed by conventional process, concentrated black, ash and waste concentrated brine, evaporative crystallization and other treatment systems, and has shorter process, higher integration, lower energy consumption and lower cost-effectiveness ratio. The sensible heat utilization efficiency of syngas and slag has been raised from about 60% to about 90% at the present stage, breaking through the technical bottleneck that the existing waste boiler system is easy to hang slag, plug and scar, but can not run for a long period and has low thermal efficiency. The structure design of inner components is simple, easy to operate and maintain, no wear and tear, and it can realize safe, long period and high efficiency operation. At the same time, by-product high quality superheated steam and conversion reaction can be achieved. Steam breaks through the problem that conventional waste cookers need to build spare furnaces, which leads to high investment. It saves the operation cost of treating dangerous solid waste and concentrated salt water. Dry ash removal is adopted. There is no black water and ash water in the system, and there is no dangerous solid waste discharged from the system. The apparent heat utilization efficiency of syngas and molten slag is greatly improved, and the heat consumption efficiency and power consumption are obviously reduced.
Because of the advanced technology concept, compared with the existing technology, MCR technology integration system has created five first times, that is, the first time to achieve high integration of syngas purification, efficient sensible heat recovery, harmless treatment of highly concentrated waste brine and resource reuse with the concept of short-flow and high-energy circulating fluidized bed technology; the first time through high-rate inert particle circulation, system self-heating and material recycling. Mutual supply and simultaneous solidification of heavy metals and soluble components in miscellaneous salts can solve the high-cost treatment of waste concentrated brine and the potential high environmental risk of miscellaneous salt hazardous waste; break through the technical bottleneck of low thermal efficiency and long-term operation of conventional syngas waste boiler system for the first time; realize sensible heat efficient utilization, harmless hazardous waste and resources by using circulating fluidized bed process for the first time For the first time, we have realized a number of technological integration and collaborative innovations in the development of key core equipment in the aspects of sensible heat efficient utilization of syngas, hazardous waste of solid salt and CO2 emission reduction, and developed a series of patented equipment and patented processes with independent intellectual property rights. Up to now, relevant technologies have been applied for. / More than ten patents have been authorized.
It is understood that the fluidized bed sensible heat recovery system designed with similar mechanism has been applied in the IGCC project of Kemper and the 100t/d double fluidized bed gasification industrial test facility in the United States, and has achieved long-term, continuous and stable operation. The investment of the disposable equipment of MCR technology can be fully recovered within one year, which has good economic and environmental benefits.
Li Dapeng pointed out that according to authoritative official data, by 2020, the total coal consumption in China's coal chemical industry will reach 300 million tons per year, and more than one million tons of impurity salt will be produced annually after the treatment of wastewater. If MCR integrated technology is adopted, it can produce 165 million tons of high quality superheated steam annually, consume about 350 million tons of coal chemical wastewater including high-concentration waste brine per year, reduce the total cost of treatment of high-concentration waste brine and dangerous solid waste of miscellaneous salts by about 126 billion yuan per year, and increase the economic income of the whole industry by 29 billion yuan per year or more. In addition, annual emission reductions of carbon dioxide, highly concentrated waste brine, hazardous waste of impurities, SO2 and NOX can be achieved by 36.445 million tons, 15.48 million tons, 103 million tons, 113,000 tons and 98,800 tons respectively (in terms of annual coal consumption of 300 million tons in the coal chemical industry). In this sense, MCR technology has a very broad market application prospect.