Process and device for preparing oxygen through thermal decomposition of sulfuric acid phase in iodine-sulfur circulation

Abstract

The invention provides a process and a device for preparing oxygen through thermal decomposition of a sulfuric acid phase in iodine-sulfur circulation, and belongs to the related technical field of hydrogen preparation through thermal chemical circulation. The process comprises a sulfuric acid phase steam stripping purification section, a rectification concentration section, a washing section and a sulfuric acid thermal decomposition and mixed gas blending process and device. According to the invention, a shell pass and a tube pass of a novel shell-and-tube heat integration composite tower are filled with a 1# filler and a 2# filler respectively, N tower sections of a composite section are coaxially connected in a sealed mode, and a sulfuric acid phase steam stripping purification section, a reaction rectification section and a washing section are coupled together, so that gradient utilization of energy is achieved; a process gas containing O2 and SO2 decomposed by sulfuric acid is blended with O2 extracted by a system, and the blended gas is used as a steam stripping purification gas which respectively enters the steam stripping purification section of the shell pass of the composite tower and an HIX steam stripping purification tower; and compared with a traditional process for preparing oxygen through sulfuric acid phase thermal decomposition, the process of the invention has the advantages that the quality and the energy utilization rate of the system are improved, the purification efficiency is improved, and the energy consumption and the production cost are reduced.

Description

technical field [0001] The patent of the invention relates to a process and device for preparing oxygen by phase thermal decomposition of sulfuric acid in iodine-sulfur cycle hydrogen production, which belongs to the related technical field of iodine-sulfur thermochemical cycle hydrogen production. Background technique [0002] The main energy in today's world is fossil fuels. Oil and natural gas are non-renewable energy sources that pollute the environment. Fossil fuels emit a large amount of CO2, which intensifies the greenhouse effect. Therefore, the scientific community is seeking new energy sources that do not contain carbon. Hydrogen energy is considered to be an alternative energy carrier in the future due to its high energy density, cleanness and non-toxicity, many forms of compounds and large reserves. However, there are many disadvantages in the traditional hydrogen production method: fossil fuel dry gas hydrogen production process CO 2 There are many emissions, t...

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Problems solved by technology

However, there are many disadvantages in the traditional hydrogen production method: fossil fuel dry gas hydrogen production process CO 2 There are many emissions, the prepared hydrogen contains sulfur, and high-purity hydrogen needs to be desulfurized and purified; the electrolytic hydrogen production process has low efficiency and high cost; the hydrogen obtained from biomass decomposition hydrogen production is limited, and cannot be used in large-scale industrial applications, etc.

The sulfuric acid phase thermal decomposition oxygen production process in the traditional iodine-sulfur cycle is complicated. The SA stripping purification section generally uses a stripping purification tank or a rectification tower. In addition, the SA rectification concentration section and the stripping gas water washing section require two rectification towers. The stripping purification tower consumes energy, and the high temperature of the SA rectification and concentration tower is difficult to couple with the stripping tower. The structure of the ordinary rectification tower cannot solve the problem, and cascade utilization of energy cannot be realized.

If the sulfuric acid phase thermal decomposition oxygen production process in the traditional iodine-sulfur cycle does not involve the SA stripping section and directly enters the SA rectification and concentration section process, a small amount of HI in the gas phase will be brought into the SA rectification and concentration section, which will affect the decomposition of sulfuric acid to form O 2 Purity, part of HI is decomposed into H 2 , which affects the energy consumption and safety performance of the system. If inert gas is used for stripping, by-products will be generated and the system cost will increase; the HIX stripping section of the traditional process does not involve the HIX stripping section and directly enters the HIX high-pressure reactive distillation process, a small amount of SO in the gas phase 2 Bringing it into the HIX reaction distillation section will affect the energy consumption and safety performance of the HIX reaction system. If pure O 2 Purification will consume the main acid HI, and if inert gas is used for stripping, by-products will be generated, and the system cost will increase

Insufficient recovery of acidic water in sulfuric acid phase thermal decomposition oxygen production process in traditional iodine-sulfur cycle, resulting in system I 2 and SO 2 Consumption

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