An Experimental Study On The Gas And Soot Formation In Ethanol Pyrolysis

Nowadays, the conventional fuels such as coal, oil and gas mass burn, which not only consumes lots of non-renewable resources but also brings serious environmental problems, such as acid rain, greenhouse effect, and the fog haze. These phenomenon both affect human health and the development of society. Facing the increasingly serious environmental situation, there is an urgent hope to find a new type of clean energy to replace the traditional ones. Ethanol is one of the most representative resources.In this paper, ethanol is used as the research object during the process of experiment. Through the control of temperature, reactant concentrations and residence time respectively, can we study the gas production and carbon deposition during the pyrolysis of ethanol. The yield of ethanol pyrolytic carbon under these different factors is compared by applying the longitudinal comparison method. SEM scanning technology is used to analysis the surface morphology produced under different space time. On the basis of CHEMKIN software, the process of ethanol fuel pyrolysis under different temperature and concentrations of reactants respectively can be obtained to explore the main gas products and sensitivity analysis of methane, ethylene and ethanol. By adding water vapor, methane and oxygen into the process of ethanol pyrolysis respectively, can we explore the influence of different additives on the yield of pyrolytic carbon. By simulating the gaseous product content, the change of reaction process can be obtained. By using TGA to analysis the carbon formed at different temperature, TG and DGT can be produced. Coats-Redfern integral method is used to calculate the activation energy and pre-exponential factor. Calculating ignition temperature, combustion characteristics and burnout characteristics index by TG and DTG curve and then analyzing its activity is a key point. By comparing with traditional graphite and inferior coal, the reasonable ways to reduce or even eliminate the pyrolysis of solid product can be found.The significant results are listed as following.(1) Temperature, reactant concentrations and residence time all play very significant impacts on the gas and carbon products during ethanol pyrolysis. There is a big difference among gaseous products. Effects from small to large on carbon production is reaction time, reactant concentration and pyrolysis temperature. The reaction time has the largest effect on carbon yield. The longer the reaction time is, the greater the surface of carbon particle size has.(2) Through numerical study it can be found that with the increasing of temperature, ethane and ethylene faced the dehydrogenation to generating acetylene gradually. Large amounts of acetylene transforms into carbon deposition when the temperature is higher than 1200 °C.(3) Water vapor and oxygen reduce the production of carbon by changing the direction of pyrolysis reaction and reacting with the carbon deposition. Methane which is a gas addictive would have the opposite effect.(4) The activity of the pyrolytic products under different temperature are different: the higher the temperature is, the bigger activation energy of the solid sediments is. This rule applies to both combustion characteristics and burnout characteristics index. The solid sediment at higher temperature is more difficult to eliminate.