Design Theory Research Of Critical Devices On Fluidized Self-Heating Type Biofuels

Our country is a big country of petroleum consumption and importing, the amount of petroleum consumption is only next to the United States in the world. At the same time, domestic oil production is severity shortage, import dependency of petroleum expands unceasingly. Net import amount of petroleum of China is 2.19 billion tons in 2009, apparent consumption is 4.08 tons, import dependency is first up to 50%; Net import amount of petroleum of China is 2.49 billion tons in 2010, apparent consumption is 4.49 tons, import dependency is more than 55%; import dependency is expected to as high as 75% in 2012. Such high levels of oil import dependence, our country's energy security has been threatened, once the international oil supply has problems, such as war, our energy supply will be hit hard, even the national economy have the instant paralyzed danger. On the other hand, our country is a large agricultural nation, annual production of crops straw is about 7 million tons, except for all kinds of use, about 3 million tons can.be used as fuel, also annual production of forestry waste is about 9 million tons. If these two types of biomass resources can be effectively used,6 million tons of biofuels can be achieved, if calculating as the calorific value, which is equal to 3 million tons of heavy fuel oil. Therefore transforming crops straw and forestry waste into oil alternative products which have certain economic value and high technical contents, not only can ease the energy shortage status, and can increase farmer's employment chances and personal income. In addition, biomass can be transformed to the alternative products of oil through pyrolysis technology-biofuels do not contain sulfur, can reduce the pollution for the environment, zero emissions of CO2 and comply with the requirements of clean development mechanism (CDM). In this context, the paper carries out biomass biofuels technology research, its purpose lies in providing an advanced theoretical support and technical guarantee for the design of biomass pyrolysis bio-fuel device.Biomass fluidized pyrolysis technology in aboard and domestic country are summarized and discussed in the paper, according to the characteristics of fluidization type pyrolysis technology, summarizing the predecessor's research experiences, presenting the processing routes, system composition mode and key devices of fluidization type self-heating biomass pyrolysis system-theoretical analysis and experimental research of fluidization type self-heating biomass pyrolysis reactor have be done, the obtained achievements of research process are as follows:According to the pyrolysis reaction kinetics theory, the kinetic equation of biomass pyrolysis reaction has been established for the fluidization type self-heating biomass pyrolysis reactor, the biomass pyrolysis product curves can be achieved by solving the equation; using pyrolysis experiment device to carry out experiments, the comparison analysis of the pyrolysis product curves got by experiments and equations has been done, the reliability of pyrolysis equation has been verified; in the study of the biofuels condensation process, based on the known biofuels components, to calculate the different stages of the condensation temperature corresponding the theory condensation amount, through the comparisons of the condensing experimental results of the same stages temperature to verify the validity of the theoretical results, and to determine the most reasonable condensing temperature ranges.According to the theory of gas-solid two-phase flow, proposing a new design thinking of the inner cone type fluidized bed which adding a cone in the inner of the common cylindrical fluidized bed, the cold experimental results show that the fluidization effect is better than the common cylindrical type fluidized bed. At the same time, as the complexity of fluidized state, to establish flow equations of the gas-solid two-phase flow, using FLUENT simulation software, adopting Euler model, the numerical simulation of particle motion state, concentration and speed has been done respectively for the inner cone type fluidized bed, also the comparison analysis of the simulation results of the ordinary cylinder and the inner cone type fluidized bed has been done.Based on the inner cone type fluidized bed reactor, the system components mode has been build up, the system process analysis and the thermal equilibrium research and analysis on the system have also been done, from the economy view, the assumption that the production energy can be obtained by the by-products charcoal and non-condensable gas except for the electric driving, and through the effect of the conversion ratio on the by-product production rate, the optimal conversion rate under the self-heating conditions has been built, the theoretical guidance has been provided for the advanced design that the biofuels system does not depend on the outside heat but can achieve heating balance themselves.According to the proposed assumptions that the system can realize self-heating and heating can be obtained only by the by-products charcoal and non-condensable gas for the whole system, also according to the principle of burning, the design theory research of the gas-solid mixing burning device has been carried out. In addition, in order to put the heat energy of smoke and fumes after burning into use in the fluidization dry process, the design theory research of the fluidization dry and transporting device according to the fluidization dry theory has been carried out.The theoretical guidance and research reference based on the inner cone type fluidized bed reactor of self-heating pyrolysis biofuels system can be provided according to the above research and results. It is expected to provide the theoretical reference for the scale and industrialization of China's biofuels production.