Hydrogen energy is regarded as the most promising clean energy in the 21st century, with the advantages of diverse sources, clean and low-carbon, flexible and efficient, and rich application scenarios. The current hydrogen metallurgy process mainly includes blast furnace hydrogen-rich smelting and direct hydrogen reduction. The main purpose of blast furnace hydrogen-rich smelting is to blow hydrogen-rich gas into the blast furnace, such as coke oven gas and natural gas, etc. Every blowing 1m3 of coke oven gas can save 0.6~0.7kg of coke, and the coke ratio can be reduced and the carbon emission can be reduced significantly.
The key technologies of the new coal-to-gas-gas-based shaft furnace direct reduction process mainly include the preparation and optimization of special oxidation pellets for gas-based shaft furnace, the rational selection of coal gasification technology, the optimal control of hydrogen-rich gas-based reduction and the optimization of energy utilization. Considering the equipment characteristics, technical and economic indexes and investment costs of various coal-to-gas processes, the fluidized bed coal-to-gas process, with low investment cost, low oxygen consumption and high production efficiency.
High temperature resistant alloy stove pipe is selected, and the gas heating furnace can heat the purified gas to 930℃ to reach the temperature requirement of reducing gas for gas-based shaft furnace; after dust removal, heat exchange, dehydration and pressurization of gas-based shaft furnace roof gas, it is mixed with the desulfurized crude gas, decarbonized and heated, and sent to the shaft furnace to realize gas circulation.
Hydrogen storage methods mainly include: high-pressure gaseous hydrogen storage, deep-cooled liquefied hydrogen storage, organic liquid hydrogen storage, porous materials and metal alloys and other physical types of solid hydrogen storage. The hydrogen storage technologies that are widely used in industry are high-pressure gaseous hydrogen storage and deep-cooled liquefied hydrogen storage.
At present, industrial hydrogen production technology is still mainly based on petrochemical energy to produce hydrogen, which accounts for more than 95% of the world's total hydrogen production, but this route will produce a large amount of carbon dioxide. At this stage, we should make full use of industrial hydrogen by-products and develop coal-derived hydrogen-rich synthesis gas appropriately; from the consideration of long-term development of hydrogen energy, the large-scale application of low-carbon green hydrogen production technology of biomass resources, wind energy, ocean energy and water energy should be in-depth studied.
