| According to statistics,the market size of the medical waste disposal industry reached 8.5 billion yuan by the end of 2022.Medical waste contains many infectious viruses and bacteria that undergo a chemical and physical transformation in nature,causing potential damage to soil and water quality and ultimately endangering the ecological environment and human health.Plasma gasification technology is suitable for application in the treatment of medical waste due to its high efficiency,environmental friendliness and high energy conversion rate.This process both solves environmental pollution problems and alleviates energy constraints.However,plasma gasification technology is costly and energy-intensive in its application and requires superior system design solutions to improve energy utilization and to combine with other process designs to produce highvalue-added products or to recycle waste heat.Therefore,it has become a vital means to increase the quality and efficiency of medical waste disposal,and it is crucial to promote the coordinated and compatible development of energy and an ecological environment.This paper focused on the disposal and utilization of medical waste based on plasma gasification and proposed a novel solid waste power generation system coupled with incineration(novel system 1)and a hydrogen/methanol preparation system based on plasma gasification for medical waste(novel system 2)from the perspective of thermal power conversion utilization and thermochemical transformation utilization,respectively.Among them,the novel system 1 used the plasma gasifier to treat the medical waste synergistically and the fly ash discharged from the incineration unit,and then fed the syngas into a gas turbine cycle with high energy conversion efficiency and recovered the waste heat through the incineration unit in order to solve the problem of inefficient and polluting medical waste disposal.The novel system 2 used the syngas exiting the plasma gasifier to produce hydrogen/methanol and used recovery of process waste heat,greatly improving energy utilization efficiency,solving the waste pollution problem yet alleviating energy scarcity and also reducing carbon emissions.The combination of thermodynamic and economic analysis has been used to effectively promote the optimization and development of novel systems and achieve the reduction,harmless and resourceful disposal of medical waste.In response to the need to reduce costs and increase efficiency in the medical waste disposal process,a novel solid waste power generation system coupled with plasma gasification and incineration has been proposed.The net power of medical waste power generation can reach 4.24 MW,and medical waste power generation efficiency reached 37.83%.The economic analysis showed that the net present value of the medical waste power generation process could reach 304.69 million yuan,and the initial cost can be recovered in only 3.75 years,which has significant economic advantages compared to traditional waste incineration units.Three plasma gasification-based systems to produce hydrogen/methanol from medical waste have been proposed to address the need for energy use and low-carbon production in the medical waste disposal proc ess.Among them,the hydrogen production system(Scheme A)converted medical waste into hydrogen;the methanol production system(Scheme B)converted medical waste into methanol;and the dual fuel system for hydrogen and methanol production(Scheme C)converted medical waste into hydrogen and methanol.The process efficiencies of Scheme A and B can reach 69.45%and 54.08%,respectively,but the system process efficiency of Scheme C is 2.71 percentage points higher than that of Scheme A due to waste gas recycling.Scheme A takes only 3.83 years to recover the initial capital investment with a net present value of 92.83 million yuan showing good economics,while Scheme B has less fluctuation in returns in the face of changing market conditions and good economic sensitivity. |
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