What are the common biomass fuel used in gasification?
Using biomass resources as fuel, primarily agricultural and forestry wastes, is known as burning biomass (such as straw, sawdust, bagasse, rice bran, etc.). The primary distinction is between fossil fuels. Direct combustion of biomass is a highly polluting fuel that is only permitted for use in big stoves in rural regions and is not permitted in cities, according to Chinese national policy and environmental protection requirements.
What is Biomass Gasification?
In order to create combustible fuel, biomass raw materials (such as firewood, sawdust, wheat straw, rice straw, etc.) are either formed into a specific shape or are simply crushed and treated before being transferred to a gasifier for gasification and cracking. the procedure for cleaning gas before getting product gas.
The idea is that high polymers in biomass will undergo pyrolysis, oxidation, reduction, and reformation reactions under specific thermodynamic circumstances with the assistance of some air (or oxygen) and water vapor, and the tar associated with pyrolysis will be further heated. converting into small molecular hydrocarbons through catalytic or mechanical cracking to produce gases that contain CO, H2, and CH4.
Biomass has a strong activation of coke because it contains cellulose, hemicellulose, lignin, inert ash, etc., which has a high oxygen content and volatile matter. Biomass has a higher activity level than coal, making it a better candidate for gasification.
Biomass gasification mainly includes gasification reaction, catalytic conversion of syngas, and gas separation and purification process. The focus of gasification conversion is the adjustment and control of gas composition and yield. Biomass gasification is different from pyrolysis. The gasification process requires a gasification medium (usually air), and the calorific value of the gas is low, generally 4-6 MJ/m3; the pyrolysis process usually does not require a gasification agent, and its products are Liquid gas, and carbon are three types of products, and the calorific value of gas is relatively high, generally 10-15 MJ/m3. The gasification process is accompanied by the pyrolysis process, and pyrolysis is the first step of gasification.
Catalysts are employed to reduce or completely eliminate the tar formed during the pyrolysis reaction because the goal of biomass gasification is to produce clean product gas.
What is the most common biomass fuel?
Crops specifically cultivated as raw materials for biofuels include corn and soybeans, mainly in the United States; linseed and rapeseed, mainly in Europe; sugar cane in Brazil; and coconut oil in Southeast Asia. Biodegradable products produced by industry, agriculture, forestry, and general households can be used as raw materials, such as straw, wheat stalks, rice bran, wood, manure, wastewater and kitchen waste…etc. These feedstocks are converted into biogases via anaerobic digestion.
Many scientists are now beginning to study the use of algae or cyanobacteria as another biofuel raw material. The application level includes biodiesel, methanol, ethanol, methane, and even hydrogen fuel. Research using marijuana as a raw material is also increasing, but marijuana research has to face legal issues. Juhuang grass is fast harvested, large in size, and has an energy ratio of 5:3 to coal when burned, so 5 tons can replace 3 tons of coal. In addition, the grass does not need to be refined into a liquid state like biodiesel before it can be used. It can be used after simple processing Direct combustion is suitable for economically poor areas or low-cost industries, so the giant king grass has been listed as a cutting-edge anti-globalization measure and is being studied.
In some industrialized countries, such as Germany, energy from food is cheaper per unit of fuel than fuel because fuel is more taxed than food.
Future Development of Biomass Fuel
One of the future development directions will be the generation of biodiesel from algae (such as seaweed). Algae biofuel has a high production efficiency, requires no arable land, and can lessen the potential influence of bioenergy on the cost of agricultural products. However, there still has to be some technological advancements. Although some algae are genetically modified, the cost of algae biomass fuel is still quite expensive. Another issue is preventing such algae from blending into the ecology.
Advantages of gasification of biomass fuel
As a clean, sustainable energy source, gasification of biomass can be used for a variety of purposes in addition to replacing fossil fuels. The low calorific value air gas can be utilized for cooking or as fuel for industrial furnaces after being cooled and filtered. It can be used as engine fuel to power electricity-producing gas turbines or internal combustion engines. Additionally, it can be utilized as a boiler fuel on its own or in combination with coal to create steam for district heating, power production, etc. The higher quality, medium calorific value gas can be utilized as a synthetic raw material gas for dry synthetic liquid fuel or chemicals after modulation.