Biomass hydrogen production refers to the process of converting hydrocarbons and other components in biomass into hydrogen through various technical means using biomass as raw materials. Biomass refers to various organisms produced by photosynthesis using the atmosphere, water, land, etc., including plants, animals and microorganisms. In biomass hydrogen production, commonly used raw materials include agricultural waste (such as straw, rice husks, etc.), forestry waste (such as wood chips, branches, etc.), energy crops (such as switchgrass, jatropha, etc.), urban organic waste, industrial organic wastewater, etc.
The production principle of biomass hydrogen production The principle of biomass hydrogen production is mainly based on the fact that biomass contains a large amount of organic matter, which is composed of carbon, hydrogen, oxygen and other elements. Through specific technical methods, the chemical bonds of complex organic compounds in biomass are broken, the hydrogen element in it is separated from other elements, and then after a series of reactions and treatments, hydrogen is finally formed.
At present, biomass hydrogen production technology mainly includes two technical paths: thermochemical method and biological method, among which biomass thermochemical hydrogen production technology is relatively mature.
Thermochemical hydrogen production refers to the process of converting biomass into hydrogen-rich combustible gas by thermochemical treatment after high-temperature decomposition, and then decomposing the gas into hydrogen through separation and purification and the action of catalysts. The advantages of this method are that it has a wide range of raw materials, high efficiency in producing hydrogen, and can produce a variety of useful by-products, such as methanol, ethanol, acetic acid, etc. However, since coking and carbon deposition are prone to occur under high temperature conditions, a high-temperature rapid reaction method is needed to solve it. According to the specific hydrogen production process, this path can be further divided into steam gasification hydrogen production technology, supercritical water gasification hydrogen production technology, and biomass pyrolysis reforming hydrogen production technology.
Biological hydrogen production technology is also called microbial degradation method and biomass fermentation method. It uses two key enzymes, hydrogenase and nitrogenase, to catalyze the degradation of water molecules and organic substrates in biomass into hydrogen. Common technologies include photolysis, fermentation, light-dark coupled fermentation, cell-free system hydrogen production and other subdivided technologies. The advantage of this method is that it does not require high-temperature reaction, will not produce coking and carbon deposition, and can also obtain useful by-products such as organic fertilizer. However, since the growth of microorganisms is affected by environmental factors, the reaction conditions need to be controlled to ensure the efficiency of hydrogen production.
