Method for preparing biomass oil in microwave thermal decomposition way

Abstract

The invention discloses a method for preparing biomass oil in a microwave thermal decomposition way, which comprises the following steps: biomass enters a screw conveyer from a storage hopper, the feeding speed of the screw conveyer is 30-60 kilogram/h; the biomass enters a microwave pyrolysis reactor through the screw conveyor, the temperature of the biomass after absorbing microwave rapidly rises to 450-550 DEG C to reach the best temperature 475-500 DEG C of the biomass producing the oil; the biomass is thermally decomposed in the microwave pyrolysis reactor to produce high-temperature organic steam, the organic steam is sent to a cyclone separating device for gas and solid separation to remove carbon grains and sand; the organic steam is discharged through the cyclone separating device, the biomass is sent to a condenser for quenching, a condensable part of the biomass is changed into the biomass oil, and the biomass oil is dropped into an oil tank, thereby the biomass oil is prepared. The invention accords with the best process requirement of the biomass oil extraction without thermal conduction and has low cost, controllable and precise thermal decomposition temperature and no thermal inertia.

Description

【Technical field】 [0001] The invention belongs to the technical field of new energy, and specifically relates to a method for preparing biomass oil by microwave pyrolysis. 【Background technique】 [0002] Human beings are facing enormous pressure on energy and the environment. Today's energy mainly comes from fossil fuels such as coal, oil, and natural gas. Although the application of fossil energy has greatly promoted the progress of society, its resources are increasingly depleted and cannot be achieved. regeneration. At the same time, the excessive use of fossil energy has caused increasingly serious environmental problems. Therefore, the development and search for new alternative energy has become one of the major issues that human society needs to solve urgently. Replacing fossil fuels with biomass energy can not only reduce CO 2 Greenhouse gas emissions can also reduce SO emissions due to fossil fuel use 2 , NO X Therefore, biomass energy is the most important altern...

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Problems solved by technology

[0005] Combining the above existing technologies, it can be known that biomass pyrolysis liquefaction is a process in which biomass is degraded into liquid products and some gas products and solid products after being heated under the condition of complete anoxic or limited oxygen supply. The key to biomass pyrolysis liquefaction The equipment is a pyrolysis reactor. According to different classifications of reactions, the existing domestic and foreign pyrolysis liquefaction technologies mainly include the following types: (1) fluidized bed type, (2) rotating cone type, (3) ablation type; , (1) The main disadvantage of the fluidized bed type is that the introduction of fluidized gas increases the energy consumption of the system, because this part of the added gas will also undergo a process of heating and cooling. In addition, the fluidizing gas also dilutes the pyrolysis process. The non-condensable gas produced greatly reduces its calorific value, which brings difficulties to its application; (2) The main disadvantage of the rotating cone reactor is that the outer rotating cone must be supported by a cantilevered shaft for rotating motion, and the supporting The bearing of the extension shaft must be able to work reliably for a long time under high temperature and high dust conditions, which is quite difficult. In addition, inert heat carriers such as sand are constantly spiraling between the two cone walls, and its friction on the high temperature wall The wear will also be very serious; (3) The ablative pyrolysis liquefier needs inert gas such as nitrogen for cleaning, and there must be rotating parts in the reactor. The advantages of this liquefaction reaction are not obvious enough

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