Biomass energy is an important member of the global green power/renewable energy family, and its contribution is second only to hydropower and wind power.
What is Biomass Energy?
In ancient times, humans burned wood and cow dung for cooking or heating and used simple waste as fuel, which is the most direct biomass energy. The population was not dense at that time, and although there was no air pollution control equipment, it did not constitute a serious air pollution problem. This way of life is the standard circular economy. Recycling needs no advocacy, and reuse needs no advocacy.
Using animals and plants as fuel, and returning the ashes to nature after burning, is itself recycling. Biomass energy refers to the energy generated by the conversion of biomass, which can refer to any organic matter from animals, plants, algae, etc., which can be used as energy after conversion.
The basic principle of biomass energy or bio-energy is to use sunlight and CO2 to carry out photosynthesis to promote plant growth and then use it as fuel, so it is classified as renewable energy without increasing net CO2 emissions. Therefore, biomass energy is an application that can be used by human energy after biomass transformation, and biomass energy cannot be used directly. Biomass energy is one of the energy sources that can be directly used by humans, such as petroleum and coal. Therefore, conversion technology will affect the amount and efficiency of biomass energy utilization. The economics of using biomass are not particularly clear compared to using cheaper energy sources such as coal, natural gas, or oil. The promotion of global renewable energy, such as energy crops, biomass fuels for transportation, and small distributed power plants, still needs government incentives and subsidies.
Advantages of biomass energy:
- Rich sources.
- Provide low-sulfur fuel to reduce air pollution.
- Provides cheap energy under certain conditions.
- Can reduce environmental hazards, such as garbage and so on.
- Compared with other new energy sources, there are fewer technical problems.
Disadvantages of biomass energy:
- Plants can only convert small amounts of solar energy into biomass.
- The biomass energy density per unit land area is low.
- Susceptible to environmental constraints, lack of land suitable for cropping.
- Land resources are limited.
- Biomass moisture is high (50%-95%).
- Production energy is less than fossil energy.
What are the Types of Biomasses?
Biomass is three states of general matter: Gaseous state, liquid state, and solid state. It has a diverse range of technology options and application types for power generation or as an alternative fuel. Biomass energy is the use of available energy such as electricity and heat obtained through the conversion of biomass crops.
- Gaseous biomass energy, including biogas and synthetic gas, biogas is currently purchased at a guaranteed price by FIT green electricity
Common types of gaseous biomass include biogas and syngas. Biogas is the gas obtained by anaerobic fermentation of organic matter in various biomass such as garbage, kitchen waste, sludge, animal manure, and agricultural and forestry waste in landfills, mainly composed of methane. There are already many pig farmers in Taiwan that turn pig manure into biogas for power generation, and its Green Power Feed-in-Tariffs (FITs) are higher than other renewable energy sources. After good management, there will be no environmental problems. Turning garbage into gold can also be regarded as a model of the circular economy. After electricity is generated, the liquid part becomes biogas slurry, and the solid part becomes biogas residue, which can be irrigated in farmland, as a kind of fertilizer.
At present, the development of the biogas industry in Taiwan is facing the problem of economies of scale, because almost all local pig farmers raise less than 5,000 pigs, but the excreta produced by 5,000 pigs will not be too much, and small-scale biogas power generation equipment is enough. However, pig farmers in some countries raise tens of thousands of pigs at random. The power generation capacity of biogas is large enough to be called economies of scale. That is why the purchase price of local biogas green power is higher than that of solar and wind power. However, the government now hopes that Taiwan sugar will take the lead to expand the scale of pig farmers. In addition, Taiwan’s recycling is good and the agricultural system is complete. In the future, it may be like the European Union. The raw materials for biogas production are no longer limited to pig manure but will expand. As for food waste and agricultural and forestry waste, these are two possible opportunities.
Syngas is a gas that converts biomass into a gas that undergoes chemical reactions in a high-temperature, low-oxygen environment through gasification technology. This gas can be used to generate electricity. However, due to the high technical threshold of gasification, there are very limited cases of long-term operation in Taiwan. To calculate the required purchase price, more information is needed. At present, the lowest wholesale purchase rate of biomass energy can only be purchased. Therefore, it cannot constitute an incentive for industrial production.
- Liquid biomass energy, including bio-alcohol and bio-diesel
The common practice of liquid biomass energy is to make biofuel, which includes bioethanol and biodiesel. Bio-alcohol uses microorganisms as a medium to convert sugar from sugarcane, corn, cassava, sweet potatoes, and other substances into alcohol through fermentation. Biodiesel is the transesterification of oilseed crops, waste cooking oil, and animal fat to become fuel. The energy crops refer to oilseed crops. It is natural for biofuels to use crops as feedstock. However, if the corn that people can eat is used for oil refining, there will be a moral problem in which cars and people compete for food, and even the rich and the poor compete for food. With technological breakthroughs, the trend is to use agricultural waste as raw materials. As gasoline or diesel vehicles are gradually replaced by electric vehicles, the development prospects of biofuels for vehicles will naturally be affected. At present, no electric aircraft has been developed, and IATA still encourages the use of biofuel, which is an important development direction of biofuel in the future.
- Solid-state biomass energy is the incineration of organic waste, and all kinds of waste can be used to generate electricity, with unlimited potential
News often sees waste plastic, waste rubber, waste paper, waste wood, waste fiber, sludge, and agricultural waste such as bagasse, rice husk, and peanut shell. And even general waste burned to generate electricity or go through a screening process to remove substances that are not suitable for combustion are used as fuel for industrial boilers to generate steam for power generation and heat supply. These are probably solid biomass energy. The world-renowned biomass power plant uses wood pellets, sunflower residues, waste olives, peanut shells, rapeseed powder, and other solid biomass as fuel. The power generation of a biomass power plant can be equivalent to 1,000 offshore wind power plants dynamo. With so much waste being produced around the world every day, it is difficult to immediately enter the circular economy. Incineration is probably the most efficient way to recover energy. Although incineration of garbage may not be the best solution, such conversion is a form of biomass energy, and the amount of power generation in Taiwan is considerable. In 2018, Taiwan's incinerators generated 3.36 billion kWh, which can provide about 760,000 households with annual power generation.
How is Biomass Energy Developing in Taiwan?
Municipal waste has many components, 60% to 70% of which have the characteristics of biomass. If the waste classification is implemented, the waste burned in the incinerator can be regarded as basically organic matter-based biomass. However, due to the complex composition of garbage produced in modern society, there are different opinions. Other rules define burning waste to generate energy as renewable energy. Therefore, the power generated by incinerators can be regarded as renewable energy. In Taiwan, the annual power generation exceeds 3 billion kWh.
Does Burning Plastic Count as Biomass Energy?
Plastic is a chemical polymer. Although it is a carbon-containing organic substance, burning plastic is usually not regarded as biomass energy. However, burning plastic can be reused in an energy-based manner, reducing the possibility of being disposed of in the environment, and it is a renewable energy source. Even the European Union, which is the most environmentally conscious, lists plastic recycling as an important transition option in its short-term planning for plastic recycling.
Isn't it Good to Recycle Plastic?
Many people's concept of circular economy is that after a PET bottle is recycled and remanufactured, what comes out is still a PET bottle instead of other things. But the focus of circular economy is flow, including material flow, energy flow, money flow, and information flow. Biomass can challenge our rigid thinking and transform resources into energy. It is more efficient to burn it and reuse it, it can be converted into energy. The conversion and utilization of materials are more efficient, it is resourceful, and it does not necessarily have to be plastic bottles in and plastic bottles out. The internationally accepted evaluation method is not based on feelings, but on scientific life-cycle assessment, and whichever method is more effective is used.
