Biomass And Biofuels Flashcards
Biomass
Biomass is fuel developed from natural and organic material or waste, which are renewable and sustainable sources of energy.
The chemical compositions of biomass includes carbon, hydrogen, oxygen, along with nitrogen and alkali atoms, heavy metals, and alkaline earth.
The few types of fuels used to generate biomass are scrap lumber, woody construction and forest debris, certain agricultural crops and wastes, manure, animal waste, ethanol waste, municipal solid waste, landfill gas, other industrial wastes like paper sludge from paper recycling processes.
Conversion to gaseous and liquid biofuels:
Biomass can be converted into alcohol by distillation. Liquid biofuels are ethanol, methanol, gasohol, and biodiesel. Biomass gasifiers convert solid biomass, both woody and powdery materials such as wood agriculture and agroindustrial wastes into gas and liquid. Gaseous biofuels, synthetic natural gas like wood gas, methane 70% and carbon dioxide 30%. Such biomass briquettes can be used as fuels in place of coal and in traditional furnaces or in a gasifier. Gasifiers can convert solid fuels into a more convenient form to use gaseous fuel known as producer gas.
Difference between biomass and other fossil fuels: Time differences, that is time required for it to be generated. It takes carbon out of atmosphere while it is developing and it is returned as it burns. Can be converted into ethanol by a thermal process and into methanol by fermentation and digestion.
Advantages of biomass energy:
Biomass is always and widely available as a renewable source of energy. It is carbon neutral. It reduces overland of fossil fuels. It is less expensive than fossil fuels and makes less garbage and landfills. It reduces waste also.
Limitations of biomass energy:
Biomass is not as efficient as fossil fuels. It’s not entirely clean, can lead to deforestation. Biomass plants require a lot of space. Biofuel alone isn’t as efficient as fossil fuels. In some cases, biomass uses more energy to actually burn the organic matter that it ends up producing. It often has to be blended with petrol and diesel to bring its efficiency up to a speed. This alone means that biomass isn’t available to use on a large scale as it is.
Indian sugar mills are rapidly turning to bagasse. Leftover of cane after it’s crushed and its juice is extracted to generate electricity to clean up the environment, to cut down power costs, to earn additional revenue.
Biogas plant consists of two components, a digester to fermentation of a gas tank, a gas holder to cut off air to the digester and collect gas generated. Any biodegradable substance which can be fermented anaerobically by methane-producing bacteria, cow dung, or feces are collected and put into a biogas digester or fermenter, a large vessel in which fermentation can take place. A series of chemical reactions occur in the presence of methanogenic bacteria, leading to the production of CH4 and CO2.
Recent researches suggest that hydrocarbon producing plants can become alternative energy sources which can be inexhaustible and ideal for liquid fuels. These plants called petro plants, petro crops can be grown on land which are unfit for agriculture and not covered with forests. Jatropha curcas is an important petro plant. Biocrude can be obtained by tapping latex of jatropha curcas. Biocrude is a complex mixture of liquids, terpenoids, triglycerides, phytosterol waxes and other modified isoprenoid compounds. Hydrocracking of biocrude can convert it into several useful products like gas, oil, gasoline, kerosene.
Biofuels
Biofuel is a liquid renewable energy resource which typically takes form of either bioethanol or biodiesel. This liquid is often used to fuel vehicles, especially equipped to burn biofuel.
Biofuels can be liquid, solid, or gaseous in nature. Solid biofuels are wood, dry plant material, and manure. Liquid can be bioethanol or biodiesel. Gaseous is biogas. These can be used to generate heat and electricity.
The main reasons for shifting to biofuels are rising prices of oil, emission of greenhouse gases from fossil fuels, interest for obtaining fuels from agricultural crops for the benefit of farmers, combating climate change, responding to higher energy consumption, securing energy supply, making most of scarce resources, etc.
Categories of biofuels:
First-generation biofuels are made from food sources like sugar, vegetable oil, starch, or animal fats. Common first-generation biofuels are bioalcohol, biodiesel, vegetable oil, biogas. Causes imbalance in food economy.
Second-generation biofuels are produced from non-fruit crops or portions of food crops that are not edible and are considered as wastes like stems, wood chips, fruit skins, peels, husks, etc. The process is used for the production of such fuels are thermochemical reactions or biochemical conversion. Examples, cellulose, ethanol, and biodiesel. Doesn’t affect food economy but it’s complicated. Less greenhouse gases.
Third-generation biofuels are produced from microorganisms like algae. For ex, butanol. Algae can be grown using land and water unsuitable for food production, reducing the strain on already depleting water sources. However, the fertilizers used in the production of such crops can lead to environmental pollution.
Fourth-generation biofuels are crops that are genetically engineered to take in high amounts of carbon, are grown and harvested as biomass. Crops are then converted into fuels using second-generation techniques. Fuel is pre-combusted and carbon is captured, then carbon is geosequestered. It is considered to be carbon negative as its production pulls out carbon from environment.
Advantages of biofuels
They are available. Biofuels can be manufactured from a wide range of materials. Biofuels don’t release as much carbon as fossil fuels do. They can be produced locally, which decreases the nation’s dependence on foreign energy. Biofuel manufacturing plants can employ hundreds and thousands of workers, creating new jobs in rural areas.
Disadvantages of biofuels:
Fossil fuels produce more energy than some biofuels. The production of biofuels require land. This impacts cost of biofuels, as well as that of food crops. It could possibly lead to food shortages. Massive quantities of water is required for proper irrigation of biofuels.
Major types of biofuels:
Bioethanol is derived from corn and sugarcane using fermentation process. When mixed with petrol, it improves combustion performance and it lowers emission of carbon monoxide and sulfur oxide.
Biodiesel is derived from vegetable oils like soy bean or palm oil or vegetable waste oils or animal fats by a biochemical process called the transesterification. It produces very or no amount of harmful gases as compared to diesel and can be used as an alternative for conventional diesel fuels.
Biogas is produced by anaerobic decomposition of organic matter like sewage from animals and humans. Major proportion of biogas is methane plus carbon dioxide. It also has small proportions of hydrogen, sulfide, hydrogen, carbon monoxide, siloxane. It’s commonly used for heating and electricity for automobiles.
Biobutanol is produced in the same way as bioethanol through fermentation of starch. Every content in butanol is highest among the gasoline alternatives, can be added to diesel to reduce emissions, serves as a solvent in textile industry, and also used as a base in perfumes.
Biohydrogen is like biogas. It can be produced using a number of processes such as pyrolysis or gasification or biological fermentation can be perfect alternative for fossil fuels.
Recent initiatives in India and Abroad
International Initiatives on Sustainable Biofuels:
Roundtable on Sustainable Biomaterials. It is an international initiative which brings together farmers, companies, governments, NGOs, scientists who are interested in sustainability of biofuel production and distribution. In 2011, it launched a set of comprehensive and sustainability criteria that is the RSB certification system.
Sustainable Biofuels Consensus is an international initiative to ensure sustainable trade, production, and use of biofuels.
Bonsucro is an international non-profit multitasker organization established in 2008 to promote sustainable sugarcane. Its aim is to reduce environmental and social impact of sugarcane production.
The Midwest Aviation Sustainable Biofuels Initiative was designed to advance aviation biofuel development in a 12-stage region holding different promises for biomass feedstock. The MASBI was to deliver a comprehensive evaluation of the region’s biofuel potential and a plan to support regional and national needs in a responsible manner.
Recent initiatives in India
Accessibility to clean energy
Augmentation of refinery sector: out of 23 refineries operation in the country 18 are public sector, 3 are private sector and two are joint venture. India is a sufficient in refining the capacity for its domestic consumption. It also export sufficient quantity of petroleum products.
The Pradhan Mantri Ujjwala Yojana aims at providing LPG connections to 5 crore women belonging to BPL families
PAHAL is a direct benefit transfer scheme under which customers need to link their Aadhar with their LPG and bank accounts
Kerosene free States aim to bring all households under LPG
Introduction of BS fuel norms there has been a jump from BS-IV to BS-VI’s implementation in the entire country
Ethanol blended petrol program has benefited farmers in addressing stubble burning issues
Biodiesel program by government has paved the way for direct sale of biodiesel for blending with high speed Diesel to all consumers
