Method and device for preparing H2 and separating CO2 based on calcium-based sorbent

Abstract

The invention discloses a method and a device for preparing H2 and separating CO2 based on a calcium-based sorbent. The method comprises that a calcium-based sorbent and pulverized coal are fed into a gasification reactor by a screw charging machine; the pulverized coal is gasified by steam to produce water gas; CH4 in the water gas is reformed into CO and H2 and CO undergoes conversion reactions to produce CO2 and H2; CO2 is absorbed by the calcium-based sorbent; H2 and residual CO2 enter into an absorption reactor; unreacted coke and CaCO3 enter into a calcination reactor; pure oxygen is fed into the calcination reactor; the coke and the pure oxygen burn and produce CO2; CaCO3 is decomposed into CaO and CO2; after separation adopting a separator, CO2 enters into a preheater and gives out heat; CaO is separated into two parts by a returning valve and one of the two parts enters into the gasification reactor and the other one of the two parts enters into the absorption reactor; CaO in the absorption reactor absorbs residual CO2 and produces CaCO3; after separation adopting a separator and condensation, clean H2 is obtained; and the separated CaCO3 enters into the calcination reactor so that sorbent recycle is realized.

Description

technical field [0001] The invention relates to a method for producing hydrogen and separating CO 2 The method and device, especially relate to a kind of utilizing calcium-based absorbent to produce hydrogen and separate CO 2 methods and devices. Background technique [0002] Since the industrial revolution, the scope of human activities has continued to expand, social productivity has continued to increase, and the economy has become more and more vigorous. However, human demand for energy has also increased, especially the consumption of fossil fuels. Traditional Advanced energy utilization technology also emits a large amount of carbon dioxide while obtaining energy. As of 2005, CO in the atmosphere 2 The concentration has increased by 35% compared to pre-industrial revolution. Carbon dioxide is a kind of greenhouse gas. The massive emission of carbon dioxide intensifies the "greenhouse effect". The global climate continues to warm, and the resulting disasters are more...

AI Technical Summary

Problems solved by technology

[0004] (1) The conventional coal gasification hydrogen production technology based on calcium-based absorbents uses a single fluidized bed as the gasification reactor, and the gasification reaction temperature is between 600 and 750°C. In a single gasification reactor, due to The chemical reaction is restricted by thermodynamic equilibrium and chemical reaction kinetics, and neither can be completely reacted. At the same time, the chemical reaction will also be affected by the heat and mass transfer of the reactor. Therefore, the purity of hydrogen produced in a conventional single gasification reactor is limited. 40-60%

[0005] (2) In order to increase the purity of hydrogen in the produced gas, a reforming reactor and a hydrogen enrichment device are usually added at the tail, and the reforming reactor will remove the CO and CH in the produced gas 4 and other impurity gases are converted into CO 2 and H 2 , through the hydrogen enrichment device, the purity of the final hydrogen can reach more than 99%, which meets the needs of terminal equipment such as fuel cells, but increases the complexity and investment cost of the system

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