Investigation On Equipment And Process Of Biomass Pyrolysis And Liquefaction

The development and utilization of renewable and clean energy has been drawing more and more attention as a result of the rapid growth in energy consumption, the limited reserves and non-renewable Characteristics of fossil fuels, particularly the environmental pollution brought by the excessive use of fossil energy. Biomass is the only friendly to environment and renewable energy sources with fixed carbon on Earth. Various research institutions have been giving more and more attention to biomass pyrolysis and liquefaction technology because liquid bio-oil can be produced which is easy to transport and store and is expected to replace liquid fuel or chemical raw materials.In this paper, the equipment and energy consumption of biomass pyrolysis and liquefaction in FB is researched, and then the device structure and process has been optimized. The main research results are as follows:1. It is can not feeding uniformly with the screw feeding system because the biomass are easy to form bridge and hang to the wall of storage bin. Therefore, the spring bar component which is drove by the rotation of the second screw is set in the storage bin to shock and mix the biomass material. As the reciprocating shock of the spring bar component in the storage bin, the biomass particles flow into the first screw instead of form bridge or hang to the wall of storage bin. The feeding is very continuous and stable after this development and the transportation capacity is improved greatly without additional energy consumption2. A new exhaust gas circulation system is set to the original equipment. The bio-gas and nitrogen gas which flows to air directly previous flows to a buffer and then to FB as carrier gas. The producing cost and the pollution to the air is lower as a result of the recycle of the exhaust gas.3. A cooling water tank is set at the end of second screw to prevent biomass material from coking here.4. It is high energy consumption and need inert gas for in FB biomass pyrolysis and liquefaction system. On the basis of analysis of the system energy consumption and energy use of by-product char and bio-gas, the process is optimized via separating a part of pyrolysis gas without cooling to be used as carrier gas and burning the bio-gas to heat biomass raw materials. Thus, the inert gas nitrogen gas and its heating and cooling energy consumption is saved, it need not to use other energy to heat biomass raw materials, and atmospheric pollution from exhaust gas is reduced.