The Experiments And Thermodynamics Research On High Temperature Steam Gasification Of Medical Waste

With the environmental problems becoming more and more serious that human beingsfaced, the issue of garbage disposal is concerned by the whole society especially inmedical waste disposal field. The methods of medical waste disposal in our country aremainly burning together with some other processing methods at present. Among theuniversal processing method, the direct burning method can generate harmful substances,such as nitrogen oxides, dioxins, which make a great harmful impact on human andenvironment; High-temperature steam sterilization, microwave sterilization, chemicaldisinfection and some other methods existed some problems that included the processingscope limited, secondary pollution and unobvious capacity reduction effect of trash.Otherwise, pyrolytic incineration method has been extensively applied and can effectivelysolve capacity reduction requirements in recent decade years. But the process can notobtain the complete disposal of garbage resulting from the problem of harmful gas such asdioxins and mercury vapor. Therefore, it is necessary to explore a new method for medicalgarbage disposal for purpose of fully realizing the reduction and the medical wastedisposal without harmful process. Gasification technology of medical waste is the progressof transforming the organic matter in medical waste into combustible gas including thesmall molecule gas such as CO, H2and hydrocarbons by using the thermal chemicalreaction between the gasification agent and medical waste in high temperature. It hasbecome the focus of the domestic and foreign scholars for its characters of reduction,harmless and recycling that happened in the process of medical waste disposal.The paper is based on the research of medical waste gasification technology and a setof steam gasification experiment platform is built in which the down draft gasifier and hightemperature steam is considered as gasifier and gasification agent respectively. The study iscompleted by using the combining methods of theoretical analysis, experimental study andnumerical simulation.900℃is found as the optimal temperature of high temperaturesteam gasification by experimental analysis of gas composition, gas calorific value, and others indexes in which bio-medical waste is used as the experimental material. Meanwhile,the fixed carbon and high temperature steam gasification process had been carried on, theexperiment research concluded that preparation of hydrogen rich gas or high calorific valuegas for the purpose of optimal gasification temperature of800℃and850℃of reducinggas gasification. Reaction activation energy is calculated. The model of medical wastegasification is built by using the chemical process software of Aspen plus. The latex gloves,infusion, medical and others three kinds of medical waste is simulated respectively. Alsothe steam/medical waste quality ratio (S/W ratio) and the influence of gasificationtemperature is analyzed. The conclusions are obtained that the range of optimumtemperature is800~900℃in the progress of medical waste steam gasification, and theoptimum S/W ratio is2.0.According to this paper, the using of high temperature steam gasification for medicalwaste disposal is an effective way and has a great potential for development.