Experimental Research On Biomass Compound Preparation Of Briquette Fuel

With the increased of municipal solid wastes(MSW) output and the significantly reduced of remaining capacity of landfill, how to handle the MSW reasonably is becoming incresaingly important. Currently not only unitary conventional waste disposal techniques such as sanitary landfill, incineration, composting have been unable to meet requirements regarding with the wastes reducing, resource utilizating and innocent processing, but also caused high moisture content organic components and recyclable components of MSW to be wasted. The technology with regard to biodrying pretreatment for preparing briquette utilizes the perishable organic wastes of MSW effectively,and it will reduce secondary pollution caused by the corrupting organics. But the process parameters of MSW biodrying technology are not already perfect, odor pollution problem has not yet been effectively improved, meanwhile coupled of MSW biodrying and briquette fuel molding technology rarely reported.MSW bio-drying were studied using self-made equipment in order to investigate optimized experiment conditions about MSW dewatering and try to improve the source of odor pollution through adjusting biodrying operating conditions of MSW.Briqutte fuels molding process parameters were found out through molding experiments of dried products which was taked from biodrying trials. The combustion characteristics parameters and combustion kinetics of briqutte fuels which was molded with sawdust(sludge) and dried product mixied with different ratio were investigated through thermal gravimetric analysis.The purpose of this study was providing valuable basic data for the production and combustion of briqutte fuels,thereby, finding a new method to the disposal of MSW.(1)MSW bio-drying dehydration Optimizing ExperimentMunicipal solid waste bio-drying dehydration experiments were made with different C/N ratio, inoculating bacteria,adjusting ventilation rate and adding fews green wastes.The result show that the moisture content of MSW dropped substantially and the calorific value increased sharply after 12 days biodrying. The low heat value of MSW reached the economic incinerationcalorific value(7000kJ/kg) after 8 days biodrying in basically.The optimum biodrying dehydration C/N riatio is 20.7. On this condition,1.95 gram water could be removed with consuming 1 gram biodegradable organic matter and the emission concentration of NH3 reduced significantly compared the trial with the lower C/N ratio. Inoculating microbes into the biodrying reactor accelerated organic matter decomposition and dehydration rate of fermented materials. compared with the blank control group, dehydration rates were higher about 2.0%, 0.8%, 6.6% with inoculating garbage pecialized microflora, sludge originated bacterium and leachate rooted bacterium, respectively. Suitable ventilation is conducive to increase fermented materials stack body temperature. Reactor stack body temperatures with ventilation rate of 0.4 L/(kg?min) are higher than other experimental groups. Too large or too small ventilation volume is not conducive to accumulate the stack body temperature of fermented materials. Accompanied by the increasing ventilation rate, NH3 emission concentration decreased sharply and biodegradable organics dewatering capacity presented a growing trend gradually. Adding green wastes into biodrying materiel was beneficial to increasing the pore inside the pile to achieve a rapid increase in temperature, meanwhile it was in favor of reducing the emission concentration of NH3. The fermented materials stack body temperature increased rapidly and reached highest temperature57 ℃ after bio-drying 2days with the biodegradable organics dewatering capacity was up to1.61kg/kg in the course of whole biodrying trial when the green wastes dosage was 200g/kg.In summary, the optimal MSW biodrying parameters were found out through single factor gradual optimization experiment. The optimum biodrying dehydration C/N riatio is 20.7;the best dehydration efficiency microbial strain was the domesticated bacterium which rooted in leachate; 0.4 L/(kg?min) ventilation rate was determined by taking into account energy consumption;The dewatering rate of 200g/kg green wastes with MSW co-processing was optimal.(2) The study of briquette fuel molding process parametersBriquette molding process parameters experiment with bio-dried products blended with sawdust(sludge) were studied using XQ-5 embedding sample machine.The result show that molding pressure, particle size, additives have a certain influence on the Briquette density. It was little effect on the Briquette density when molding pressure was over 35 Mpa. Smaller particle size of bio-dried products is conducive to compressing into tight briquette. The density of briquette which was added into some sludges increased rapidly and with its calorific value declined slightly.Adding sawdust have little effect on the briquette density, but its calorific value increased sharply.The performance of briquette water impermeability could be improved by heating compression molding or thermoforming process of adding plastic film. The optimum conditions of preparing briquette fuel get obtainted by orthogonal experiment with the sludge as a binder.The resultsindieated the optimal parameters obrained from the study were 30 Mpa of briquette pressure,10%of moisture, 10% of sawdust and sludge.(3) The research on combustion characteristics and combustion kinetics of briquette fuelThe combustion characteristic analysis of typical single-component and mixed briquette which was prepared with bio-dried products and wood(sludge) were worked out by thermal gravimetric analysis technique. The study result show that the ignition temperature of sludge was minimum and sawdust was the higher one. The ignition temperature of blended sawdust briquette increased slightly with the sawdust blending ratio increased, while its performance of flammability and combustion stability increased gradually.On the contrary, mixed briquette which was blended with sawdust preached the opposite trend. Briquette combustion can be divided into three segments weightlessness, the whole process of combustion kinetics could be described by three different reaction mechanism functions. The activation energy of volatile organic compounds and nonvolatile organic compounds combustion period of mixed sawdust briquette presented a slowly growing trend with the sawdust blending ratio increased.