Modified forming gasification: a new approach for waste incineration power generation

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Modified forming gasification: A new approach to waste incineration for power generation. Author/Source: China Chemical Industry News. Date: 2019-03-01. Clicks: 70. “Waste incineration for power generation is a mature waste treatment technology used worldwide, led by the United States; however, it only enables single-use of waste.” The waste modification, shaping, gasification, and comprehensive utilization technology we have developed not only ensures continuous, stable, and environmentally compliant waste treatment but also enables the production of a variety of products. The investment required is between 300,000 and 400,000 yuan per ton, and the construction and installation period is only 6 to 8 months. It represents a new technological approach for the development of ’waste-free cities’. ”On February 26, while investigating the polyenergy environmental protection waste modification, shaping, gasification and comprehensive utilization project in Du’an County, Hechi City, a reporter from China Chemical Industry News heard this from Yin Chengguo, the person in charge of industrialization at that company. 　　Waste disposal faces a dilemma. Data shows that in 2015, China’s waste incineration volume reached 61.76 million tons, and by 2020, the country’s waste incineration capacity was expected to reach 591,000 tons per day. The \"Pilot Work Plan for the Development of ‘Waste-Free Cities’\" recently issued by the State Council also calls for continuous efforts to reduce solid waste at its source and to promote its recycling, in order to minimize landfill use and reduce the environmental impact of solid waste to the lowest possible level. 　　“Waste is a resource in the wrong place. ”Yin Chengguo emphasized that as long as the technology is sound, it is possible to maximize the recycling of waste and achieve a closed-loop cycle of materials, thereby transforming waste treatment into a resource-based and environmentally friendly industry. 　　“The current waste management industry faces two main problems: first, it is difficult to maintain environmental standards over the long term; second, the range of products derived from waste management is limited (mainly electricity generation for grid supply), and the profit margins are insufficient, making it an industry with low profits. Based on thorough research and 9 years of technical development, Jueneng Environmental Protection has developed the ’innovated version for waste incineration power generation’ – a modified gasification and comprehensive utilization technology – which can address these two major challenges faced by the industry. ”Yin Chengguo said. 　　The demonstration line is set to go into operation. At present, based on the completion of pilot tests, Jueneng Environmental Protection has established a demonstration production line in Du’an County, Hechi City, for the \"innovative version of waste incineration for power generation – modified gasification and comprehensive utilization technology.\" This approach effectively addresses the issues of poor stability in meeting environmental standards regarding waste treatment, as well as the limited variety of derived products, thereby opening up a new path for the comprehensive utilization of waste through modified gasification. 　　At present, this demonstration production line is in the preparatory phase for operation, and it will contribute to the exploration of a closed-loop material cycle and a waste-free city for garbage management in Du’an County. 　　At the demonstration production line, the reporter saw that it was different from ordinary waste incineration plants: there were no tall chimneys, no sewage to be seen, and no unpleasant odor from the waste. After entering the plant, the waste does not need to be piled up for fermentation; it is directly fed into the sorting line. After going through four crushing processes to reach the desired particle size, additives developed independently are added to modify the waste, after which RDF is formed. This process takes only about 30 minutes; the treated waste is fed into the gasification furnace, and the resulting fly ash is produced in very small quantities, allowing it to be collected and recycled to form slag. Furthermore, the process of crushing and shaping waste can also be carried out underground, and with an air filtration system in place, almost no unpleasant odors are generated. 　　“Based on calculations using this demonstration production line, 1 ton of municipal waste can generate 1,500 Nm3 of mixed gas. Physical adsorption is then used to separate out approximately 10% of this gas in terms of volume, with the hydrogen obtained being purified to 99.9999% for use as a hydrogen energy reserve. The remaining mixed gas is used in internal combustion engines for power generation; at a rate of 1 kilowatt-hour of electricity produced per 2.5 Nm3, 1 ton of municipal waste can generate 540 kilowatt-hours of electricity, resulting in significant economic benefits. ”Yin Chengguo told the reporters. 　　Diversified product structure According to Yin Chengguo, unlike traditional incineration power generation, the products of this process feature diversity. 　　The pre-treated and modified waste, after being gasified in a specially designed gasification furnace, produces a mixed gas that contains 20% hydrogen, 30% carbon monoxide, 11% carbon dioxide, 5% methane, as well as nitrogen and other gases. Part of the hydrogen is used for combustion to generate electricity, while another portion is purified to 99.9999% (other gases can also be purified according to market demands) to serve as a hydrogen energy reserve. This not only opens up new ways for hydrogen production but also represents a transformative change in the waste management industry. After being passivated by high-temperature melting, the heavy metals in the slag are immobilized, and it can be mixed to produce floor tiles or added to concrete. The exhaust gases from internal combustion generators contain nitrogen oxides and carbon dioxide. By applying the relevant technologies from Tsinghua University or the Guotou Microalgae Biotechnology Center to cultivate microalgae in specialized ponds, these microalgae can be either further processed or mixed with municipal waste for reuse in the recycling process. This approach enables maximum reduction in emissions while gradually achieving a closed-loop cycle for waste treatment. 　　It is understood that the production cost of hydrogen, especially 99.9999% high-purity hydrogen, is between 4 and 6 yuan per Nm3, while the market price is around 10 yuan per Nm3; this represents the cost of producing hydrogen at the expense of resources. PolyEnergy Environmental Protection’s new technology generates hydrogen during waste treatment; as a result, the costs of production and purification are very low, resulting in a high added value. 　　Yin Chengguo told the reporters in conclusion, “The hydrogen generated during waste treatment can leverage its advantages of low cost and wide applicability to become part of the **hydrogen energy strategy.” Wherever there is garbage, that is the front line where we, these ‘garbage people’, are brave enough to take on the responsibility. ”