Biomass Energy and the Benefits It Brings

According to fast and strong the development of economy, social. The people increasingly needed big energy resources that serve for life. However, the main sources of energy present base on the fossil. This is energy that cannot regenerative. Therefore, there are many ideas, applications about using energy efficiently. Beside some renewable energy was created, Biomass energy is the type of energy that the people use it a long time in different kinds. In the current world, many types of biomass energy have used but the question “How to use biomass energy efficiently and reasonably” still hard question and this question need to be researched carefully.


I. INTRODUCTION
Biomass is a very broad term meaning used to describe substances of biological origin that can be used as an energy source or due to its chemical components [1].
With such a definition, biomass includes natural plants, industrial crops, algae, and other plant species, or agricultural and forestry residues [2] [3].Biomass also includes materials that are viewed as waste from human societies such as waste from the production process of food for drinking water, mud/sewage, fertilizer, and industrial (organic) additive products.industrial by-product and organic components of domestic waste [4].Biomass can also be subdivided into more specific terms, depending on the intended use: generating heat, producing electricity or making transportation fuel [5].Biomass sources are converted into other forms of energy such as electricity, heat, steam, and fuel through metabolic methods such as direct combustion and steam turbines, anaerobic digestion (digestion), co-firing, gasification (gasification) and pyrolysis [6].
Pure vegetable oil is the oil extracted from the extraction of vegetable oil from oilseeds [7].This process is like the production of vegetable oil in the food industry that has good technology [8].Pure vegetable oil can be used directly in improved engines without the use of additives or structural changes [9].Oil-bearing plants for the production of pure vegetable oils used in diesel engines are rapeseed, sunflower, soybean, palm, coconut, peanut, jatropha [10] [11] The largest potential fuel will be used as renewable fuel in diesel engines as biodiesel [12].Production technology starts with oil plants, which are now widely used in Europe [13].This is done mainly due to the favorable characteristics of biodiesel in terms of its ability to blend with traditional diesel fuel and only need to adjust the engine fuel system small [14].
Studies on how to convert oil prepared from marine organisms into stable triglyceride food oils have yielded positive results [15] [16].Among these, seaweed has great potential because it grows very fast, has a high amount of vegetable oil and is cultivated in sea waters, thus minimizing the use of land and water surface [17].This will open a new direction for the vegetable oil industry, which has traditionally been dependent on the plant material grown on the land [18].
The development of biotechnology in recent years has created high-yielding and effective crop varieties, including oil-bearing plants [19][20].Along with that is the application of new technologies in cultivation and cultivation, building areas specializing in oil crops suitable for soil and climate ... will create more sources of vegetable oils for the market [21] [22].
In addition, biomass can also be considered as a form of solar energy storage [23] [24].Energy from the Sun is "kept" by plants through photosynthesis during their development.Biomass energy is considered renewable because it is added much faster than the additional speed of fossil energy that requires millions of years [25] [26].
The use of biomass to create energy has a positive impact on the environment [27].Certainly, biomass burning cannot immediately solve the imbalance of the current CO2 ratio [28] [29].However, the role of biomass contribution in energy production is still significant in protecting the environmental balance, because it produces less CO2 than fossil energy [30].Essentially, CO2 created by burning biomass will be sequestered in newly planted trees to replace fuel.In other words, it is a closed cycle with a very small impact on the environment [31].
In summary, biomass is an attractive source of energy for the following reasons: + First of all, this is a renewable energy source if people can guarantee the speed of replacement planting.
+ Biomass is more uniformly distributed on the Earth's surface than other energy sources (fossil fuels ...) and can be exploited without requiring complex modern techniques.complex and expensive.
+ It creates opportunities for localities, regions, and countries around the world to ensure that their energy supply is independent.
+ This is an alternative to fossil energy, helping to improve the climate change situation that threatens the Earth.
+ It can help local farmers in difficult times of harvest and job creation in rural areas.
Biomass Energy and the Benefits It Brings Do Thi Nguyet, Phan Thi Thuy Hoa, Pham Minh Chau

II. CLASSIFICATION OF BIOMASS ENERGY
A. Liquid fuel -Bio-ethanol (Gasohol): Includes Bio-methanol, Bioethanol, Bio-butanol ...Among these bio-petrol types, Bioethanol is the most commonly used biofuel in the world because of its the ability to produce on an industrial scale from sugar-containing raw materials such as sugarcane, sugar beet and starch-containing raw materials such as cereals, potatoes, cassava ... Biogas containing ethanol with higher octane value than gasoline is usually dynamic [32].The muscle gets hotter quickly.However, the machine also wears more quickly, especially rubber gaskets.The disadvantage of Ethanol is dehumidification, so gasolineethanol contains a lot of water, making it difficult to "fix", rust metal, wear away plastic (plastic), so it is necessary to change materials for the engine, right Regular vehicle maintenance [18].Ethanol tanks must also be made of special metals, and transportation is more difficult than regular gasoline.
-Biodiesel (BioDiesel): Biodiesel can be used instead of diesel because it is similar in quality to diesel fuel but not produced from petroleum but produced from vegetable oil or fat.animals with ester conversion (transesterification).Oils [also known as methyl (or ethyl) ester (FARME) fatty acids are mixed with sodium hydroxide and methanol (or ethanol) to produce biodiesel and glycerine with ester metabolism [33].
-Ethanol (or ethyl alcohol): Ethanol is a liquid, colorless, transparent, flammable fuel.Ethanol is used as an additive for gasoline, with the aim of increasing octane and greenhouse gas emissions [34].Water soluble and biodegradable ethanol.Ethanol is produced from biomass with a high cellulose content (like corn), through fermentation at a dry kiln or wet oven.In both of these kilns, yeast residue (wort) is produced and supplied to livestock on farms [35].

B. Biogas
Biogas is a mixture of methane gas (CH4) and some other gases arising from the decomposition of organic matter in an anaerobic environment [36].The main components of Biogas are CH4 (50-60%) and CO2 (> 30%), the rest are other substances such as N2, O2, H2S, CO ... hydrolyzed in the anaerobic and catalytic environment by heat from 20-40ºC, the low calorific value of CH4 is 37.71.103KJ / m3, so biogas can be used as fuel for an internal combustion engine.In order to use biogas as fuel, biogas must be treated before using to create an explosive mixture with air [37].H2S gas can corrode parts in the engine, its product SOx is also a very toxic gas.Steam has a small content but significantly affects flame temperature, fire limit, low calorific value and air/fuel ratio of Biogas [38].

C. Solid biomass fuel
Including trees, wood fiber, animal waste, agro-forestry waste, urban wood waste, urban solid waste, gas in landfills.

ENERGY
There are many techniques to convert biomass energy into electricity.However, there are some popular methods such as direct-fired or conventional steam approach, pyrolysis, biomass gasification, anaerobic digestion, electricity production from waste landfill emissions, ...

A. Direct-fired, Conventional Steam Boiler
These are two common methods of generating electricity from biomass energy that applicated in most biomass power plants.Both types of systems directly burn bioenergyfeedstock to create steam for rotating generator turbines.These two methods are distinguished in the internal structure of the combustion chamber or furnace [39].At the direct combustion system, biomass is transferred from the combustion chamber bottom and the air is provided at the bottom of the furnace base.Meanwhile, in the conventional boiler method, the draft is transferred into the furnace from above but the biomass is still downloaded to the bottom of the furnace.Traditional direct burning systems are a pile system (two-chamber combustion chamber) or stoker boiler.The hot air was then transferred to a turbine and turned the turbine blades, operating the generator rotor.
When used for direct burning, biomass must be dried, cut into pieces, and pressed into charcoal.
When the preparation is completed, the biomass is fed into the kiln/boiler to generate heat/steam.The heat generated from the heating process, in addition to providing generator turbines, can also be used to heat plants and other construction works, it is exploited to maximize efficiency.This type of plant is also known as a combined heat-energy plant (Combined Heat Power -CHP), which is used to utilize heat and steam to maximize the energy potential created, avoiding wasting energy [40].

B. Pyrolysis
Pyrolysis is the process of burning biomass at very high temperatures and biomass decays in an oxygen-deficient environment.The problem here is that it is very difficult to create a completely oxygen-free environment.Normally, a small amount of oxidation still occurs and can produce some unwanted by-products.In addition, this technology requires a high heat source and very expensive.The process of burning biomass produces pyrolysis oil (pyrolysis oil), coal or synthetic gas (char & syngas).These products can be used similarly to petroleum to generate electricity.Thus, the pyrolysis process does not produce ash or energy directly, but it transforms k into higher quality fuels.This process begins with drying biomass to maximize combustion efficiency, similar to direct burning.When cooled, pyrolysis oil is liquid, brown, and is used as a gasifier fuel.

C. Biomass gasification
Solid biomass can be converted into gaseous form, called syngas.This gas can be supplied to cycle turbines associated with CCGT (Combined Cycle Gas Turbines) or other conversion techniques like coal-fired thermal plants.Many experts hope that biomass gasification will be more efficient than conventional biomass power plants.However, up to now, the process of gasification has not been widely applied in practice but is still at the technical testing stage.The furnaces convert solid biomass into gas that heated biomass in an environment in which solid biomass decomposes into flammable gas.This process is more advantageous than direct burning.Biogas can be cleaned and filtered to classify and separate harmful chemical compounds.Gas products can be used in high-performance generators (in the form of CCGT) -such as a combination of gas and steam turbines -to produce electricity.The performance of these systems can be up to 60%.

D. Anaerobic digestion
This is a biological process in which methane gas is released from the decomposition of organic matter by microorganisms in an oxygen-free environment.This methane can be recovered and used to generate energy.The anaerobic digestion process uses biological wastes such as organic fertilizers and municipal solid wastes.Feces or waste are packed and decomposed by microorganisms and water.This process releases methane in the package, and this gas is fed into another gas container.Since then, methane has been used to power turbines and generate electricity.
At the molecular level, hydrolysis converts organic substances into sugars and amino acids.Fermentation of these materials produces volatile fatty acids [41].These fatty acids then form hydrogen, CO2, and acetate during Acidogenesis.Finally, the methanogenesis process produces biogas, which consists of 55-70% methane gas, 25-35% CO2 and microelements such as nitrogen and hydrogen sulfide.In an anaerobic environment, methane gas can be recovered and used to power gas turbines or even fuel cells [42].
Microbial growth and biogas production are very slow at normal temperatures.Anaerobic digestion usually occurs naturally when the concentration of moist organic matter in an oxygen-free environment, usually at the bottom of ponds, marshes, peat bogs, animal gut and other Anaerobic areas of landfills.The productivity of this process depends on the composition and ability of decomposition of waste materials.However, the speed of this process depends on the density of the microorganisms, their growth conditions and the temperature of the fermentation process [22].
When used as a waste treatment process, the decomposition rate increases quite high in the temperature range of 20-40 degrees C. For urban solid waste, the decomposition rate can be increased in heat.higher level like 50-60 o C.
Anaerobic biodegradable microorganisms are marketed at relatively competitive prices, which are used on farms even on a small scale.Using methane in this way can help reduce bad odors and prevent them from spreading into the air, increasing greenhouse gases and causing fog.

E. Production of electricity from landfill gas emissions
Landfill gas uses the same technique as anaerobic digestion and has the same advantages.Landfill gas is a byproduct of solid waste decomposition, with components comprising 50% methane, 45% CO2 and 4% Nitrogen.Moreover, this is also a positive measure to reduce the rate of wasteland use, landfill to convert into electricity [38].Two ways to acquire landfill include traditional methods such as conventional drilling and push-in.Normally, before the gas recovery, the three-dimensional structure of the landfill is mapped to determine the location of the capacitor and the optimal location for drilling.Traditional drilling methods use conventional drilling techniques with some technical improvements suitable for drilling areas.The pipes can be installed vertically, making gas recovery convenient.The push method uses 3-dimensional maps to find gas wells and can be used for separate drilling positions if necessary.In the context of the increasing exhaustion of fossil fuels, rising world oil prices and increasing reliance on world energy prices, the ability to meet energy requirements for domestic demand is increasingly difficult.The consideration of exploiting clean renewable energy has a very important meaning in terms of economy, society and sustainable development.
Vietnam is a country with great potential for biomass energy from waste from agriculture, garbage, urban wastewater ... distributed across the country, in which some types of biomass can produce electricity.or apply energy cogeneration technology (producing both electricity and heat).This huge amount of biomass, if untreated, will be a major source of pollution and will continue to cause serious impacts on ecosystems (soil, water, and air) as well as human health.
Every year, there are nearly 60 million tons of biomass from agricultural waste in Vietnam, of which 40% is used to meet household energy demand and electricity production.According to calculations, for every 5 kg of rice husk generated 1kWh of electricity, so with the amount of rice husk millions of tons, each year Vietnam can earn hundreds of MW of electricity.Agricultural residues are plentiful in the Mekong Delta, accounting for about 50% of the country's total agricultural waste and the Red River Delta with 15% of the total national production.Therefore, Vietnam has great potential to develop biomass power both now and in the future.However, the number of renewable energy projects in operation until now is still too small and only a few projects are grid-connected biomass, the investment is heavy and lack of a master plan.can and is not commensurate with the existing potential of the country.

A. Biomass power plants in Vietnam
In the North, the project of building a Biomass power plant in Rung Xanh area, Phong Chau town, Phu Ninh district, Phu Tho province has been completed and put into operation since 2013 with a capacity of 40MW and output electricity is 331.5 million kWh / year In the South, Doosan Group (Korea) has invested in building and completing a biomass thermoelectric plant in Minh Hung -South Korea industrial park with a capacity of 19 MW, providing steam 70m 3 / hour.
In Can Tho, the rice husk biomass power plant in Tra Noc 2 Industrial Park invested by Dinh Hai thermo-electric joint stock company has also been completed and put into operation with a capacity of 20 tons of steam/hour.
In Phu Yen, the biomass power plant of KCP Industry Co., Ltd. with a capacity of 60MW has also been completed and merged into the national grid since 2017.

A. Biomass energy can minimize the dependence on expensive, exhausting fossil fuels
Because biomass energy can replace fossil fuels used in vehicles and energy equipment and this is also a sustainable fuel, it can replace expensive fossil energy sources.depleted.

B. Biomass energy can enhance national energy security
The dependence on imported oil may not only deplete the nation's foreign exchange reserves but also create instability in its energy security.Since biomass energy is produced from indigenous materials from many Asian countries, this fuel has served as an alternative fuel for fossil fuels that may reduce dependence on oil imports and strengthen national energy security.

C. Biomass energy can form the participation of small and medium enterprises
Unlike fuel oil and gas, even coal needs to build large infrastructure to exploit and process, with the participation of large corporations and multinational companies, the production of energy Biomass will not require investment and construction of large integrated treatment plants.Therefore, investment and production process of biomass energy may be within acceptable small and medium scale.Based on the input material and the output capacity, the capacity of the biomass energy production plants can be tailored to specific requirements.Activities to produce biomass energy based on agricultural materials or modular systems can be implemented to produce biomass energy for local consumption of motor equipment at sites.camp.Investing in biomass energy can open opportunities for local companies to participate.

D. Environmental benefits
Using biomass energy is to reduce environmental pollution because the materials used to produce biomass energy are alcohol and animal and vegetable fats and oils, do not contain aromatic compounds, extremely low sulfur content, do not contain toxic.Using biomass energy compared to gasoline reduces about 70% of CO2 and 30% of toxic gas, because biomass energy contains an extremely small amount of sulfur, containing 11% oxygen, so it burns cleaner.rapid biodegradable biomass energy, less polluting water and soil sources.
Agricultural crops and other biomass materials are considered to be materials that contribute to carbon neutralization by its actual life cycle, plants collect carbon dioxide through photosynthesis.The input used in the production of biomass energy is considered renewable material and is likely to reduce greenhouse gas emissions.
However, even if the input fuels themselves are able to neutralize carbon, the process of converting raw materials into biomass energy can cause carbon emissions into the atmosphere.Therefore, biomass energy must contribute to reducing carbon emissions, they must be demonstrated to reduce the true emissions of greenhouse gases in all production and use of biomass energy.
In addition, biomass energy when discharged into biodegradable soil is four times higher than that of petroleum fuels and thus greatly reduces soil and groundwater pollution.
Therefore, the use of biomass energy helps to reduce environmental pollution, reduce greenhouse gas emissions to help prevent global climate change.However, how to apply nature to be able to timely restore the supply capacity requires each country to have specific and serious research.
Currently, due to the pressure of finding a new alternative energy source, people are increasingly abusing the production of biomass energy from food crops, notably using corn for biofuel production.(Brazil, America), this will cause instability in food supply to the world.In addition, some places abandon food crops or cut down some forests to grow energy crops, which both cause ecological imbalance, and create unpredictable consequences for biodiversity, while the amount of energy the amount of that amount is not enough to balance it.
In fact, in every country the use of energy is inevitable, the amount of energy consumed more and more for development is of course, but remember, when all actions just serve for the purpose of not only man but also all actions have to go with sustainable principles for nature.That will help the people not face to face with many challenges from nature.

Fig. 6 .
Fig. 6.The biomass power plant in Phu Yen province