Have you ever used biomass energy? Humans started using biomass energy since they start burning woods. We will cover all the information about biomass energy in this article.
What’s in it for me?
- Biomass energy
- Biomass energy conversion processes
- Biofuels categories
- Types of Biofuels
- Uses of Biomass
- Advantages of biomass energy
- Disadvantages of biomass energy
Biomass is organic material since it comes from plants and animals and uses for generating energy. However, this process of energy production from biomass is known as biomass energy.
Mainly it is purposely grown energy crops, wood, forest residues, waste from crops, food processing, animal farming, or human waste.
Due to such wide range composition of biomass can be inconsistent. But generally, it is consists of carbon, hydrogen, and oxygen.
Biomass energy conversion processes
Since we convert biomass into biomass energy through one or more processes. So out of them, some common processes are as follows.
- Combustion process
- Gasification process
- Pyrolysis Process
- Anaerobic Digestion process
- Fermentation process
In this process, biomass burns in the presence of the oxygen as a result it releases heat. However this is the basic method to get energy from biomass material.
Especially the use of the combustion process is for space heating or heating steam to generate electricity.
Differing from combustion In this process, biomass is converting into the combustible gas mixture to use as an alternative to Naturel gas. This combustible gas is nothing but producer gas or Syngas which is a mixture of (CO+H2+CH4).
Syngas produce by the Gasification process using heat, pressure, and partial combustion.
There are 4 processes in biomass gasification as shown in the below image.
This is the process before gasification and consists of thermal decomposition. This process happens in the absence of oxygen.
The product that comes out of this process is a mixture of gas, liquid, and solid char. However their percentage depends upon a parameter of the process.
Anaerobic Digestion process
This is the process in which bacteria break down the biomass material into a gas containing methane and solid residue. Similarly, this process happens in the absence of oxygen.
This methane gas and solid residues we burn to produce energy.
In this process yeast or bacteria added into biomass material to convert carbohydrates in the plant into alcohol or acid. These bacteria survive on sugar to convert biomass into ethanol (alcohol) and carbon dioxide.
The ethanol goes under purification and dehydration process to obtain a higher concentration of alcohol. So that it will achieve the required purity. So it can use as an automotive fuel. The solid residue from the fermentation process can use as a cattle-feed.
So now you know that there are many processes to choose from. Therefore it completely depends on which biomaterial we are using and what is our desired form of energy we want at the end.
Biofuels broadly classified into four categories based on the source of biomass.
These are come from food sources like sugarcane and corn starch
These come from non-food-based biomass sources such as energy crops, agricultural waste, human and animal waste.
Third-generation biofuels come from the algae. This is a very new entry into the biofuels category.
Algae were previously fallen into the Second-generation category but after seeing its advantages like high yield with lower resource input people suggest making a different category.
These come from non-arable land. They don’t require the destruction of biomass. This includes electro fuels and photobiological solar fuels.
Biofuels can produce by using the above-mentioned biofuel production procedures. Most of these can even be produce using two or three of the different biofuel generation procedures.
Types of Biofuels
Biogas is nothing but a mixture of methane, carbon dioxide, and a small amount of hydrogen sulphide which is produce by the process anaerobic digestion of organic material with the use of anaerobes.
The raw material used to produce this biogas is either biodegradable waste materials or crops. In this process, solid by-product digestate is produced which can be used as biofuel or fertilizer.
Farmers produce biogas from manure from their cattle by using anaerobic digesters. Biogas mainly used for cooking and converting it into electricity using a gas engine.
Biogas is a renewable energy source. In India, it is also known as “Gobar Gas”.
It is a mixture of carbon monoxide, hydrogen, and other hydrocarbons, it is an output of partial combustion method (A method in which the amount of oxygen given is not sufficient).
Because of this partial combustion method biomass not get convert completely into the carbon dioxide and water.
The use of syngas made directly in IC engines, turbines, and high-temperature fuel cells.
Syngas can also be used to make methanol, DME, and hydrogen, or converted via the Fischer-Tropsch process (The Fischer–Tropsch process is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons) to produce a diesel substitute, or can produce gasoline.
Firstly ethanol, propanol, and butanol are biologically produced alcohols, they are used in the process of fermentation of sugars, starches, or cellulose.
It is the most commonly use biofluid in the world. We can use it in petrol engines as a gasoline replacement. Ethanol has one third lower energy compared to gasoline.
Animal fats and oil from vegetables, soy, mustard, flax, sunflower, palm, etc. produce biodiesel. However, if we see its chemical composition it mainly consists of fatty acid methyl (or ethyl) esters.
Biodiesel can be used in any diesel engine when fix with mineral diesel, it can be directly used also without mixing but can cause performance problems to the engine.
Biodiesel have flash point very high at 148 degree Celsius compared to petroleum diesel fuel, which has a flashpoint of 52 degree Celsius plus biodiesel is non-toxic and biodegradable makes it a very safe to handle and transport.
Cost-effective compounds that act as octane rating enhancers are known as Bio ether. However it is produced by the reaction between reactive iso-olefins and bioethanol, where bioethanol is made from wheat or sugar beets.
Bioether is very unlike to become a fuel because of its low energy density.
Methyl tert-butyl ether (MTBE) and Ethyl tert-butyl ether (ETBE) are two additives that are most commonly used.
Uses of Biomass
- Firstly, Biodiesel is a non-toxic alternative to diesel fuel with reduced air emissions.
- Secondly, Corn Stover acts as a fuel in boilers for heating buildings.
- Thirdly, by burning yard waste we can convert it into heat or electricity.
- Similarly, unused seed corn used to make ceramics.
- Crop residue burned for grain-drying.
- Switchgrass used as re-burning fuel in coal-fired cyclone burners to reduce nitrogen oxide emissions.
- Manure converted to methane (natural gas).
- Landfill and wastewater methane converted to electricity.
Advantages of biomass energy
- It is a renewable source of energy.
- It is lesser pollution generating energy compare to other conventional energy sources.
- In addition, it brings cleanliness in villages and cities as all waste can be used as biomass.
- On the other hand, It provides manure for agriculture and gardens.
- Presently potential to generate biogas energy is very huge.
- Biomass energy is a cheaper and reliable source of energy compared to solar and wind energy.
- It can generate from easily available sources like every day human and animal wastes, vegetable and agricultural left-over, etc.
- Recycling of waste to generate bioenergy also helps reduces pollution and the spread of diseases.
- Biogas has is 3.5 times Heat energy compare to burning wood.
- The heat generates while using bioenergy is more hence the time required for cooking is very less.
- forest and scrubs are safe when biogas is used as cooking fuel
- It is a very cost-effective means of acquiring energy as compared to crude oil supplies. As crude oil supplies are going low day by day, it is becoming a costly commodity.
- Finally growing biomass crops help reducing carbon dioxide and producing oxygen in the environment.
Disadvantages of biomass energy
- It is not completely clean the use of biomass created emission in addition to carbon.
- It can pollute the local environment although it is very less as compared to fossil fuels.
- Still, the biomass projects are expensive if we compare them to solar and wind power options.
- Though biomass is a renewable energy source it has to be maintained else it can cause deforestation.
- In addition, the land requirement is very large to grow biomass materials.
- The amount of water needed in biomass production is also a concern.
- Also to produce ethanol we use corn and wheat grains in large quantities it can lead to a shortage of food.
- Above all Crops that are using to produce biomass energy are seasonal crops.
Since food is a necessity for human to sustain their lives, and around 90-95 % of food needs to cook well before having it and we generally have our food 2-3 times a day.
Also in developing countries like India, around 90% of our energy consumption from total household energy combustion is to prepare food.
Around 2.9 billion people use biomass energy to prepare their meals and use firewood, charcoal, dung, and agricultural residues as biomass. However, In some rural areas, biomass energy is the only available energy source they have.
Around 70% of the rural Indian population depends on biomass fuels for their daily cooking.
With efforts like electrification, it decreases the reliability of people on biomass fuels very slightly hence it is estimated that by 2030 2.52 billion people will be using biomass energy only for preparing their food.
However India has a potential of 18 GW of energy from biomass and around 32% of primary energy use in India is collected from biomass energy.
Above all Ministry of New and Renewable Energy (MNRE) has set the target to achieve 10 GW of installed biomass power by 2022.
Although the potential for biomass energy is huge and it is a carbon natural fuel source with low cost and extremely diverse. But there are some issues that cannot be neglect. Issues like the efficiency of biomass fuel, space required, and up-front cost.
In conclusion, we have to solve these issues so that biomass energy becomes easy adoption.
Also Read :
We can always grow trees and crops, and waste will always exist therefore we can say biomass energy is renewable.
In Ethiopia 92.9 % of energy supply is from biomass and combustible waste, therefore Ethiopia is the most biomass consumable country.
If we use biomass energy for combined heat and power (CHP) its efficiency is 75-80% while if we use biomass fore electricity generation its efficiency drops to 20-25%. Whereas efficiency of biomass energy further drop if we use it for conversion to liquid fuels for transportation applications.
My name is Vivek Rawool. I am extremely motivated to constantly develop my skills and grow professionally. I have completed my BE Mechanical Degree from Mumbai University and currently working with Paramount India as a Sales and Marketing Engineer. I also do Share market trading and investment.