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CN-122010047-A - Sulfur-iodine circulating photo-thermal-thermochemical hydrogen production method and system

CN122010047ACN 122010047 ACN122010047 ACN 122010047ACN-122010047-A

Abstract

The invention relates to a sulfur-iodine circulating photo-thermal-thermochemical hydrogen production method and a system, wherein the method comprises the steps of purifying water, Mixing SO 2 gas and I 2 solution, carrying out Bunsen reaction, carrying out liquid-liquid separation on a Bunsen reaction product to obtain H 2 SO 4 phase solution and HI x phase solution, concentrating the H 2 SO 4 phase solution to obtain concentrated sulfuric acid, sending the concentrated sulfuric acid into a sulfuric acid decomposition reactor to carry out sulfuric acid decomposition reaction, recycling the obtained SO 2 gas for Bunsen reaction, carrying out sulfuric acid decomposition reaction under the catalysis of V 2 O 5 /diatomite catalyst, taking diatomite as a carrier, taking V 2 O 5 as an active component, concentrating the HI X phase solution to obtain HI concentrated solution, sending the HI concentrated solution into the HI decomposition reactor to carry out HI decomposition reaction to obtain H 2 gas and I 2 solution, purifying the H 2 gas, and collecting the I 2 solution for recycling the Bunsen reaction. the V 2 O 5 /diatomite catalyst has porous surface, good high temperature resistance and thermal shock resistance, can continuously run in high temperature environment for a long time, can resist sulfuric acid steam corrosion, has no influence on product purity and process stability due to impurity precipitation, reduces catalyst loss, is naturally formed by diatomite, The interconnected micro-nano hierarchical pore structure provides a unique anchoring site and a dispersing environment for the V 2 O 5 active component, can further improve the catalytic effect and efficiency, is beneficial to the rapid diffusion and escape of the macromolecular product SO 2 gas and O 2 , and prevents the problems of blocked active sites and the like.

Inventors

  • LI JIA
  • LUO XIAOWEI
  • SUN DAPENG
  • ZHOU YAJUN

Assignees

  • 中冶南方工程技术有限公司

Dates

Publication Date
20260512
Application Date
20260226

Claims (10)

  1. 1. A method for producing hydrogen by sulfur-iodine circulating photothermal-thermochemical process, the method comprising: Mixing purified water, SO 2 gas and I 2 solution, carrying out a Bunsen reaction, and carrying out liquid-liquid separation on a Bunsen reaction product to obtain H 2 SO 4 phase solution and HI x phase solution; Concentrating the H 2 SO 4 phase solution to obtain concentrated sulfuric acid, sending the concentrated sulfuric acid into a sulfuric acid decomposition reactor to carry out sulfuric acid decomposition reaction to obtain SO 2 gas, H 2 O and O 2 , wherein the sulfuric acid decomposition reaction is carried out under the catalysis of a V 2 O 5 /diatomite catalyst, the V 2 O 5 /diatomite catalyst takes diatomite as a carrier, V 2 O 5 is an active component, the content of the active component V 2 O 5 is 6.5-8.5wt% and the content of the diatomite is 68.5-82.0wt% in the total mass of the catalyst, and the SO 2 gas is recycled for the Bunsen reaction; And concentrating the HI X phase solution to obtain HI concentrated solution, sending the HI concentrated solution into a HI decomposition reactor to perform HI decomposition reaction to obtain H 2 gas and I 2 solution, purifying the H 2 gas, and collecting the purified H 2 gas, wherein the I 2 solution is recycled for the Bunsen reaction.
  2. 2. The method for producing hydrogen by photo-thermal chemistry of sulfur and iodine recycling according to claim 1, wherein 8.0-20.0wt% of ultra-macroporous silica is added into carrier diatomite in the V 2 O 5 /diatomite catalyst, the average pore diameter of the ultra-macroporous silica is 100-500 nm, and the weight ratio of the ultra-macroporous silica to the diatomite is (6-20): (40-55).
  3. 3. The sulfur iodine circulating photothermal-thermochemical hydrogen production process of claim 1, wherein concentrating said HI X phase solution comprises: Purifying the HI X phase solution to obtain HI X purified liquid; And carrying out electrodialysis purification on the HI X purified liquid to obtain the HI concentrated liquid.
  4. 4. A process for the photothermal-thermochemical hydrogen production by the circulation of sulfur and iodine as claimed in claim 3, wherein the ratio of the yin to the yang membranes is 2:1 during the electrodialysis purification.
  5. 5. The method for preparing hydrogen by sulfur-iodine circulating photo-thermal-thermochemical method according to claim 1, wherein the HI decomposition reaction is carried out under the catalysis of a Pt/CeO 2 double-component catalyst, wherein in the Pt/CeO 2 double-component catalyst, ceO 2 is used as a carrier, pt is used as an active component, the loading amount of Pt is 0.5-1.0wt%, and the specific surface area of the CeO 2 carrier is more than or equal to 150m 2 /g.
  6. 6. The method for producing hydrogen by photo-thermal and thermo-chemical reaction using sulfur and iodine recycle according to claim 1, wherein the Bunsen reaction is performed in a Bunsen reaction tower, wherein the purified water, the SO 2 gas and the I 2 solution are mixed in a static mixer outside the tower, and then the mixture is fed into the Bunsen reaction tower to perform the reaction.
  7. 7. A sulfur-iodine cycling photothermal-thermochemical hydrogen production system, the system comprising: The Bunsen reaction device is used for mixing purified water, SO 2 gas and I 2 solution and carrying out Bunsen reaction; The liquid-liquid separation device is connected with the product discharge channel of the autogenous reaction device and is used for carrying out liquid-liquid separation on the autogenous reaction product to obtain an H 2 SO 4 -phase solution and an HI x -phase solution; The sulfuric acid concentration device is connected with the H 2 SO 4 phase solution discharge channel of the liquid-liquid separation device and is used for concentrating the H 2 SO 4 phase solution to obtain concentrated sulfuric acid; A sulfuric acid decomposition reactor connected with a concentrated sulfuric acid discharge channel of the sulfuric acid concentration device and used for carrying out sulfuric acid decomposition reaction on the concentrated sulfuric acid to obtain SO 2 gas, H 2 O and O 2 , wherein an SO 2 gas outlet of the sulfuric acid decomposition reactor is communicated with an SO 2 gas inlet of the self-generated reaction device, and the sulfuric acid decomposition reactor is provided with a V 2 O 5 /diatomite catalyst adding channel; HI concentrating device connected to HI x phase solution discharge channel of the liquid-liquid separating device, to concentrate the HI X phase solution to obtain HI concentrated solution; And HI decomposition device connected to HI concentrate discharge channel of said HI concentration device, for making said HI concentrate undergo HI decomposition reaction to obtain H 2 gas and I 2 solution, in which the I 2 solution outlet of said HI decomposition device is communicated with I 2 solution inlet of said self-contained reaction device.
  8. 8. The sulfur iodine circulating photothermal-thermochemical hydrogen production system of claim 7, wherein said HI concentrating means comprises: HI purification device, it links up with said HI x phase solution discharge channel of liquid-liquid separation device, is used for purifying said HI X phase solution, get HI X purified liquid; And the electrodialysis purification device is connected with the HI X purified liquid discharge channel of the HI purification device, and the HI X purified liquid is subjected to electrodialysis purification to obtain the HI concentrated liquid.
  9. 9. The sulfur-iodine circulating photo-thermal-thermochemical hydrogen production system of claim 8, wherein in the electrodialysis purification device, the ratio of the negative membrane to the positive membrane is (1.5-2): 1.
  10. 10. The sulfur and iodine circulating photothermal-thermochemical hydrogen production system of claim 7, wherein said authigenic reaction device comprises a authigenic reaction tower and a static mixer external to the tower, said static mixer having a purified water inlet, a SO 2 gas inlet, an I 2 solution inlet, and a mixture outlet connected to said authigenic reaction tower.

Description

Sulfur-iodine circulating photo-thermal-thermochemical hydrogen production method and system Technical Field The invention belongs to the technical field of hydrogen energy preparation, and particularly relates to a sulfur-iodine circulating photo-thermal chemical hydrogen production method and a sulfur-iodine circulating photo-thermal chemical hydrogen production system. Background The hydrogen energy is used as a clean and efficient secondary energy carrier and becomes one of the core directions of energy transformation. The current mainstream hydrogen production technology mainly comprises three major types of fossil fuel hydrogen production, electrolytic water hydrogen production and thermochemical hydrogen production, wherein the fossil fuel hydrogen production has the problem of high carbon emission and cannot meet the low-carbon development requirement, the electrolytic water hydrogen production needs to convert electric energy into chemical energy firstly, and the electric energy mainly comes from renewable energy sources such as photovoltaics, wind power and the like or traditional thermal power, so that the multi-conversion loss of electric energy-heat energy-chemical energy exists, the energy utilization efficiency is low (only 20-35%), the energy utilization efficiency is influenced by the fluctuation of electricity price, the manufacturing cost is high, and the method is difficult to be applied to remote solar energy enrichment areas in a large scale by depending on power grid infrastructure. The photo-thermal-thermochemical hydrogen production technology is used as a novel green hydrogen preparation route, and has the core advantages that solar energy can be directly converted into high-temperature heat energy through condensation and heat collection, the intermediate stage of electric energy conversion is skipped, the hydrogen production chemical reaction is directly driven, the energy conversion loss is greatly reduced, and the theoretical energy utilization efficiency can reach 40-55 percent, which is far superior to that of the traditional water electrolysis hydrogen production route. The photo-thermal chemical hydrogen production has the core advantages of higher efficiency and electric energy conversion skipping, namely, the photo-thermal chemical hydrogen production has the advantages of zero carbon emission in the whole process, consumption of water and solar energy, no greenhouse gas and pollutant emission, complete compliance with low-carbon environment-friendly development requirements, realization of thermal energy storage through heat storage media such as molten salt, effective solving of the problems of solar energy intermittence and volatility, realization of 24-hour continuous stable hydrogen production, improvement of the annual utilization rate of a system, natural separation of hydrogen and oxygen in different reaction links, no need of expensive gas separation equipment, low purification cost, high product purity up to 99.99%, no need of depending on electric energy of a power grid, avoidance of cost risks caused by fluctuation of electricity price, realization of large-scale and distributed hydrogen production in particular adaptation to regions with poor solar energy enrichment but power grid infrastructure such as northwest desertification and Qinghy elevation, maximization of solar energy utilization rate, realization of high-efficient coupling of solar power generation power station (CSP) and high-hydrogen production infrastructure, realization of further improvement of economic co-production system. Sulfur-iodine circulation (SI circulation) is used as one of the multi-step thermochemical hydrogen production routes with the most industrialization potential in the field of photo-thermal-thermochemical hydrogen production, and water is split into three mild reactions, namely a bunsen reaction, sulfuric acid decomposition and HI decomposition through cyclic reciprocation of sulfur and iodine elements, so that the extreme high temperature of 2500 ℃ or above is not needed, the 400-850 ℃ heat energy provided by a photo-thermal system can be perfectly adapted, and the high-efficiency conversion of solar energy to hydrogen energy is realized. However, the existing sulfur-iodine circulating photo-thermal hydrogen production process has a plurality of technical defects, such as high reaction energy consumption, low conversion efficiency, serious equipment corrosion under high-concentration acid and high-temperature environment, short service life, high supplement cost and the like caused by unreasonable process parameters, and large loss of circulating medium (SO 2、I2). Disclosure of Invention The invention relates to a sulfur-iodine circulating photo-thermal chemical hydrogen production method and a sulfur-iodine circulating photo-thermal chemical hydrogen production system, which at least can solve part of defects in the prior art. The invention relates to a sulfur-iodine ci