Low tar biomass gasification power generation system

Abstract

The present invention relates to a low tar biomass gasification power generation system, the system is additionally provided with a combustion section, and brings greater convenience to a gasification system furnace-starting process, a furnace of the gasification system is warmed directly by combustion heat of a small size fluidized bed system, the fuel oil consumption of the furnace-starting can be greatly saved, heat produced by fluidized bed combustion can be recovered by a steam water system, a small steam turbine is sued for power generation to achieve the conversion recovery of chemical energy in carbon residue, high-temperature gasification gas discharged out of the gasification furnace and high-temperature exhaust gas after power generation of an internal combustion engine both can be recovered by a heat exchanger, an organic Rankine cycle system is used for realization of recovery of flue gas and process waste heat, and the energy conversion efficiency of the gasification system is significantly improved.

Description

technical field [0001] The invention relates to a power generation system, in particular to a low-tar biomass gasification power generation system. Background technique [0002] Gasification is a common biomass energy conversion method, which has the characteristics of cleanness, high efficiency, strong fuel adaptability and flexible operation, and has broad application prospects. Among various biomass gasification technologies, the downdraft gasifier has the lowest tar content in the gas produced, about 0.5g / Nm 3 ; while the suction type is the most, up to 50g / Nm 3 ; the fluidized bed gasifier is moderate, about 8g / Nm 3 . Among the three gasification technologies, fluidized bed gasification is suitable for large-scale applications, and updraft gasification has the highest energy conversion efficiency, while the existing downdraft gasification technology has the lowest tar content in gas production, but There are still problems such as poor stability of gas production qu...

AI Technical Summary

Problems solved by technology

Among the three gasification technologies, fluidized bed gasification is suitable for large-scale applications, and updraft gasification has the highest energy conversion efficiency, while the existing downdraft gasification technology has the lowest tar content in gas production, but There are still problems such as poor stability of gas production quality, small gasification scale, and low energy utilization rate

[0003] Although the traditional downdraft biomass gasifier has low tar content, the conversion efficiency of coke is not high, and the scale of the system is difficult to expand. The overall gasification efficiency is only 15%, which is far lower than that of general energy-consuming equipment or energy conversion equipment, such as The overall efficiency of coal-fired power plants can reach 40%, and the combined heat and power (CHP) of natural gas can even reach more than 80%. It can be seen that there is still a lot of room for improvement in the conversion efficiency of gasification conversion technology

According to the test, the carbon content of coke in the two-stage down-suction gasifier accounts for about 50%. This part of energy resources cannot be rationally utilized and has a significant impact on the efficiency of the gasification system.

[0004] On the other hand, in the downdraft gasifier, the reactivity of coke to tar is the key factor to determine the tar content in the gas produced by the downdraft gasifier. A large number of "coke deactivation" processes occur in the process of tar removal. To further and stably reduce the tar content of gasification gas and improve gasification efficiency, other more effective methods are required.

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