Bioethanol is one of the most intriguing biofuels due to its favourable impact on global warming. There are various advantages in terms of sustainability when comparing advanced bioethanol production to standard bioethanol production. For example, the potential for reducing greenhouse gas emissions using non-food crops or residual biomass as raw materials.
The transportation sector’s usage of fossil-derived fuels is a major environmental issue, accounting for 24% of global direct CO2 emissions. Cars, trucks, and buses account for roughly 75% of all CO2 emissions in transportation. Due to the severity of this impact, which has been worse over the past few decades, biomass is essential for producing alternative biofuels, which must be made from sustainable and renewable sources.
Through extensive research and government and industry cooperation, biomass-based liquid fuels, namely bioethanol and biodiesel, have been transformed into a competitive alternative to conventional fuels (gasoline and diesel) in the modern world. These liquid biofuels are regarded as critical components for enhancing energy security. These liquid biofuels are seen as essential components for improving energy security, mitigating climate change, and promoting rural development on a worldwide scale.
Energy Crops
Crops are energy crops if a portion or all of their yield is used as a raw material to generate useful energy. These crops generally produce a large biomass per unit of land and time. The essential features for selecting energy crops are rapid growth. They have the quality of a short period from planting to harvest and the ability to grow in harsh weather and poor soil conditions. In contrast, traditional crops will have low and unreliable yields.
Energy crops are generally divided into two types: herbaceous and woody energy crops. Herbaceous energy crops mainly belong to perennial grasses, including switchgrass, miscanthus, and giant reed, as well as others. On the other hand, with relatively fast growth, short rotation woody crops included poplar and eucalyptus. Both herbaceous and woody energy crops may reduce soil erosion and increase soil carbon and soil fertility in poor soils.
Forest Biomass
Forest biomass has been used as a feedstock for bioethanol synthesis, primarily woody components such as branches, leaves, and lops. Softwood (from gymnosperms) and hardwood are the two types of wood (from angiosperms). Growth rates and densities are significant variances between softwoods and hardwoods. Hardwoods often develop slowly and are so denser than softwoods. This organisation is vital to the lowering of CO2 levels in the atmosphere and the preservation of marginal land. When compared to other raw materials, one of the key advantages of employing forest biomass as feedstock is its flexibility in harvesting time, as these commodities do not depend on seasonality. Eucalyptus nitens bark is a forestry material that is regularly collected during harvesting.
Agricultural Waste
The agricultural residue are defined by the Food and Agriculture Organization (FAO) of the United Nations (UN) as “a crop lost during the year at all stages between the farm and the home level during processing, storage, and transport.” This includes stubble, straw, husks, seeds, and bagasse and covers field and processing residues. The amount of agricultural leftovers available for bioenergy generation in the United States alone is predicted to be 240 million dry t/year by 2030. Rice, wheat, corn, and sugarcane account for many agricultural wastes, with rice straw being the most abundant residue worldwide. It calculated the bioethanol potential of these feedstocks, indicating a possible yield of 205 billion L/year from rice.
Industrial Wastes
Industrial wastes comprise all byproduct streams from existing industrial bio-based sectors such as food, pulp and paper, textiles, and biodiesel and bioethanol-related operations. The use of this form of biomass helps to lessen the environmental impact of various industrial processes by lowering net CO2 emissions, decreasing our reliance on petroleum-based resources, and boosting the economic efficiency of the operations by adding value to what is typically dumped as waste. Brewers’ discarded grains account for approximately 85% of the entire amount of by-products created by the brewing sector among food-derived wastes.
Municipal Solid Wastes
Municipal Solid Waste is waste generated from municipal, community, commercial, institutional, and recreational activities. Garbage, rubbish, ashes, street cleanings, dead animals, medical waste, and all other nonindustrial solid waste are all included. Households, offices, hotels, stores, schools, and other institutions generate MSW. Common waste includes food waste, paper, plastic, rags, metal, and glass; demolition and construction debris; and modest amounts of hazardous garbage such as light bulbs, batteries, automobile parts, and discarded medications and chemicals. MSW is a low-cost, abundant, and mainly renewable feedstock. The average amount of municipal solid waste (MSW) that one person generates per day in the world averages 0.74 kilogrammes but varies greatly, ranging from 0.11 to 4.54 kilos. This figure is always rising because to the exponential growth of the world population, which is directly related to the excessive consumption of energy and natural resources. The organic fraction of MSW (OFMSW) is the most significant fraction of MSW, accounting for 40-50% of total dry matter content. OFMSW is composed primarily of carbs (30-40%), lipids (10-15%), and proteins (5-15%). (dry weight).
Furthermore, OFMSWs typically contain varying percentages of inert materials such as plastic, glass, and textiles, the concentrations of which vary substantially depending on the collection mechanism used. The presence of a large volume of inert materials might cause various technical issues and reduce the effectiveness of the valorisation process. Because OFMW is a complex and varied substrate, its properties and production rates are connected to the sorting system, seasonality, population, dietary habits, and socioeconomic factors. There are two different biowaste sorting systems (source sorted (SSOFMW) and nonsorted (NSOFMW)) that can be used as feedstock for the sequential manufacturing of bioethanol and biogas. Because of its complexity and heterogeneity, OFMW is envisioned as a rigid substrate. The most significant ethanol concentrations obtained after exposing these two substrates to nonisothermal SSF procedures were 51 and 26 g/L for SSOFMW and NSOFMW, emphasising the need for biowaste separation.
A biofuel is a renewable energy source derived from organic materials or byproducts of their processing and conversion. These organic materials, commonly referred to as biomass, can be directly converted into liquid fuels known as “biofuels,” which can be used as a transportation fuel. Transportation fuels are classified as either fossil fuels (primarily crude oil and natural gas) or biofuels (made of renewable resources). The transportation industry is based on liquid fuels. Liquid fuels have the advantage of being simple to store. Gaseous fuels are used less frequently in transportation, and solid fuels have even fewer applications. Currently, the most common biofuels are ethanol and biodiesel.
Biofuels are derived from biomass, and it is generally believed that their combustion is CO2 neutral. The amount of CO2 that was drawn from the atmosphere during photosynthesis and plant growth is roughly equal to what is released after burning. The carbon cycle is completed as a result. Most exhaust streams from combustion engines contain non-toxic substances such as nitrogen, carbon dioxide, and water. The potential of available feedstock sources is critical for biofuels, and the overall biofuel potential is heavily influenced by climate. Climate, Available land for cultivation, and the productivity of dedicated energy crops all significantly impact total biofuel potential. Concerns about global climate change, primarily caused by fossil fuel use, are one of the significant drivers of biofuel development worldwide.
Scientific evidence is that accelerating global warming contributes to greenhouse gas emissions (GHG). Carbon dioxide is a crucial contributor to greenhouse gas emissions (CO2). However, Greenhouse gases include nitrous oxide (N2O), methane (CH4), and several other compounds, which are even more severe than CO2 in terms of global warming. Due to their potential for causing global warming, it has become common practice to weigh their emissions and aggregate them to CO2 equivalents.
On the other hand, greenhouse gases that are directly toxic to human health are also emitted. Particulate matter (PM), volatile organic compounds (VOCs) (including hydrocarbons HC), nitrogen oxides (NOx), carbon monoxide (CO), and a variety of unregulated toxic air pollutants are among the primary transport emissions from the combustion of both fossil and renewable fuels. The type of feedstock is the overall critical point of how biomass production influences climate. It determines the amount of carbon concealed in the soil and the energy yield per unit of land. It is also necessary to consider what crops these crops are replacing. GHG emissions are expected to rise if they replace natural grasslands or forests. But if energy crops are cultivated on barren or dry terrain, traditional crops cannot thrive. In that situation, they can reduce considerably lower related emissions.
First, second, and third-generation biofuels are classified according to the raw materials used to make ethanol or biodiesel. All biofuels have different generations based on their feedstocks. In general, “advanced biofuels” refers to cutting-edge methods of producing biofuels that utilise waste products as feedstock, spent cooking oil, and animal fats.
First-generation Biofuels
Direct fuel extraction from biomass, which is often a food source, is known as 1G biofuel. Biologically categorised as food crop supplies, sugar or starch is fermented to create ethanol fuel. The primary source of sugar is sugarcane, whereas the main source of starch is corn. In addition to cane and corn, first-generation ethanol can also be derived from wheat, barley, and sugar beet. First-generation biodiesel is made from edible oil crops like soybean, rapeseed (canola), sunflower, and palm. These biofuels also support rural communities and agricultural sectors by increasing crop demand. They also have downsides that raise the cost of food and animal feed on a global level. Some areas are experiencing a water shortage, which may also result from the high water use required for the extraction procedures. Another problem is the farming system’s need for hectares of land to produce sufficient crops. The dependence on fossil fuels is further demonstrated by using fossil fuels for power in existing production methods. Biodiesel usually contains recycled restaurant cooking oil; thus, the supply of oil is limited by the use of restaurants.
Second-generation Biofuels
Extracting ethanol and biodiesel from non-edible biomass sources yields 2G biofuel. Grass, agricultural waste, and wood chips are all included in 2G ethanol, which is made of lignocellulosic resources. Most non-edible oils used to make 2G biodiesel come from jatropha (Bhuiya). Jojoba, Karanja, moringa, castor, soapnut, and cottonseed oils. Wood, organic waste, food waste, and particular biomass crops are other biomass sources for the second generation of biofuels. Fast-growing trees like poplar trees require pretreatment, a sequence of chemical reactions that dissolve lignin, the “glue” that keeps plants together, to be used as fuel. Thermochemical or biochemical reactions release the sugars enclosed in the plant fibres during this pretreatment process. The second generation of biofuels solves numerous problems from the first generation. Since they derive from different types of biomass, they do not compete with food crops for fuel. Second-generation biofuels yield significantly more energy than first-generation biofuels. They enable the use of barren land that might not be able to support the growth of food crops. Given that the technology is still in its infancy, future scientific advancements may result in cost savings and higher production efficiency. Nevertheless, given that part of the biomass for second-generation biofuels grows in climates where food crops also thrive, there is still competition for land with some of the biomass. As a result, choosing which crop to cultivate is upon farmers and decision-makers. Biomass is also utilised from cellulosic sources like maise stover (leaves, stalk, and stem of corn) that grow alongside food crops. However, this would deplete the soil’s nutrients, requiring fertiliser to refill them. Furthermore, the biomass must be pretreated to release the trapped sugars.
Third-generation Biofuels
Algae is a single-cell organism that produces the 3G biofuel blend of ethanol and biodiesel. Algae are typically divided according to their habitats, such as non-arable land, freshwater, wastewater, salt, brackish water, or genetically altered algae. Third-generation (algal) biofuels may also avoid the issues of food competition, land use, and water scarcity as they grow at a rapid pace. However, producing biofuels from microalgae is energy-intensive and currently unprofitable.
Third-generation biofuels have a higher energy density per harvest area than first and second-generation biofuels. They are marketed as low-cost, high-energy, and completely renewable energy sources. Algae have a favourable benefit that they can grow in areas where first and second-generation crops cannot, reducing stress on water and arable land. As said before, It can be grown in sewage, wastewater, and saltwater environments like oceans or salt lakes as there is no dependency on water. However, more research is needed to advance the extraction process and make it financially competitive with petrodiesel and other petroleum-based fuels.
Natural gas and crude oil are the primary resources used for producing fuel and industrial chemicals. However, fossil fuel consumption has become a significant worldwide issue. Looking for new sustainable and alternative sources to help ease global environmental concerns is crucial. In recent years the critical source of biofuels has been bioethanol. With biofuels, fossil carbon can be replaced with bio-based carbon from biomass from agriculture, forestry, and municipal waste, contributing to a circular economy. Bioethanol development is a complementary strategy based on better resources with higher eco-efficiency and a lower GHG effect. It is more sustainable than the production of fossil fuels.
Ethanol derived from various bio-based sources (bioethanol) has recently received much interest due to its potential to reduce net carbon dioxide emissions while lowering the world’s growing reliance on fossil fuels. Global ethanol output has more than six-fold expanded since the turn of the century, from 18 billion litres to 110 billion litres in 2019, only to decline to 98.6 billion litres in 2020 owing to the pandemic. The primary feedstocks for ethanol production have been sugar cane and corn. Because of its non-food status and widespread availability, lignocellulosic biomass has recently been another potential feedstock.
Overview
For ethanol manufacturing, three types of feedstock are available. First-generation ethanol is generally from sugar and starch feedstocks. In contrast, ethanol produced from biomass feedstocks is second-generation ethanol. These include lignocellulosic feedstocks, starch-based feedstocks, and sugar-based feedstocks, such as sugar cane and sugar beet (agricultural residues, forest residues, dedicated energy crops, and municipal solid wastes). The ethanol production technologies utilised for each feedstock type, both commercially available, are yet in development, and current production patterns in various areas and nations worldwide.
Due to the pandemic, the global quantity of ethanol has decreased from 110 billion litres in 2019 to 98.6 billion litres in 2020. Using ethanol with 95% gasoline can lower CO2 emissions by 90% and SO2 emissions by 60-80%. It assists the world in addressing some of the world’s air pollution issues, lowering levels of greenhouse gases that cause climate change, and ensuring environmental security. Currently, ethanol is commercially generated through fermentation from a variety of feedstocks. Saccharomyces cerevisiae yeast is used to ferment sugars generated from starch in maise and other grains and sugars already present in sugar cane and sugar beets.
Corn accounts for 60% of ethanol production, sugar cane for 25%, wheat for 3%, molasses for 2%, and other grains, cassava, and sugar beets for the remainder. Over the last three years, the yearly global fuel ethanol production and specific nations’ production contributed at least 1% of the overall production output. Before the COVID-19 outbreak, the top five ethanol producers were the United States, Brazil, the European Union (EU), China, and Canada. India generated significantly more ethanol than Canada in 2020, but the top four ethanol producers’ rankings remained unchanged.
The United States of America
In the United States, ethanol generated from corn reached 6.5 billion gallons (24.6 billion L) in 2007. This number more than quadrupled to around 13.2 billion gallons in 2012. (50.0 billion L). In 2018, the United States exported 6.5 billion L of ethanol, increasing its share of global ethanol exports to 61%. By 2020, there were 208 ethanol-producing facilities in the country, with an installed capacity of 17.44 billion gallons annually (66.0 billion L per year). In contrast to the 15.8 billion gallons produced the year before, the record production in 2020 was 13.8 billion gallons (52.2 billion L) (59.8 billion L). The COVID-19 epidemic directly impacted the demand for transportation fuel, which led to a reduction in ethanol production. While some facilities were shut down due to the recession, others modified their production methods to create an ethanol product suitable for use in hand sanitisers.
Canada
Since the amount of ethanol used in the nation typically outweighs the amount produced, Canada is a net importer of the fuel. Canada made 8000 L of ethanol annually in 1980, but by 2010, that number had climbed to 1.9 billion L. Canada produced 2 billion L of ethanol in 2018 but consumed 3.33 billion L in 2019. However, ethanol production in Canada has increased in recent years, owing primarily to feedstock changes and increasing capacity at existing ethanol facilities in Canada. Canada was listed as the world’s sixth largest ethanol producer in 2020. Canada’s ethanol output accounted for 1.6% of total global production. Corn and wheat were the two most essential feedstocks in ethanol production, contributing 1534.3 million L and 360.7 million L, respectively. Winter barley was proposed as a feedstock for ethanol production. However, this grain hasn’t been applied in industrial ethanol manufacturing facilities.
Brazil
Brazil remained the world’s second-largest ethanol producer. Brazil’s ethanol production, comprising anhydrous and hydrous ethanol, increased by approximately 7% in 2019 compared to 2018. Brazil has produced the most gasoline-ethanol in a decade. In Brazil, sugarcane bagasse is commonly utilised as boiler fuel to transfer energy to sugar mills. As a result, it is used to reduce energy costs and as an alternative to utilising leftover biomass.
In 2020, total ethanol production was 31.35 billion L, with 32 million L produced from lignocellulosic feedstock (bagasse). 2020 ethanol output was around 16% lower than the previous year (37.38 billion L). Sugar-ethanol plants diverted to extract juice from sugar cane toward sugar production in 2020, which reduced ethanol production. The co-products were 120.1 million MT bagasse, 1.88 million MT DDGS, and 108,000 MT corn oil. Corn ethanol output is expected to reach 8 billion L by 2028, according to the Corn Ethanol National Union (UNEM). There are now 11 corn ethanol facilities under development, including nine full-plant varieties (corn exclusively) and one flex plant.
Europe
In 2020, Europe’s total ethanol production was 4.8% of global production. Sugar beets (7.45 million MT), corn (6.35 million MT), and wheat were the principal feedstocks used in ethanol production (2.64 million MT). Belgium, Germany, France, and the United Kingdom usually use wheat. Corn was the favoured feedstock in Hungary because it was readily accessible. Most grains came from Ukraine to feed ethanol facilities near seaports in the Netherlands, Spain, and the United Kingdom. The feedstock for the inland ethanol facilities in Spain combined corn and barley. Sugar beets and their derivatives generate ethanol in France, Germany, the United Kingdom, the Czech Republic, Belgium, and Austria.
The COVID-19 pandemic has reduced ethanol consumption in the EU by 10.1%. This figure, however, was slightly lower than the 13.0% decline in fuel use. The co-products comprised 3.33 million MT per distiller of dried grains with solubles (DDGS) and 188,000 MT of corn oil, according to the 2021 European Union Biofuels Annual Report.
Five additional lignocellulosic ethanol facilities were under construction in Finland (sawdust, 10 million L per year), Italy (biomass, 28 million L per year), Austria (wood sugars, 30 million L per year), Romania (wheat straw, 65 million L per year), and Bulgaria (corn stover, 50 million L per year). All of these plants are scheduled to be operational soon. In 2020, the EU’s ethanol production was 5.47 billion L.
China
From 2004 to 2016, China produced ethanol at an average of 16.8 per cent per year. China produced 6.6 million MT of ethanol in 2018, making it the world’s fourth-largest ethanol-producing country/region after the United States, Brazil, and the European Union. China ordered all gasoline sold in the country to be blended with ethanol by 2020. The objective would exceed China’s estimated domestic production capacity, necessitating ethanol imports from nations such as the United States and Brazil. Corn is China’s primary feedstock, accounting for 64% of total ethanol output in the country.
India
India is the sixth-largest ethanol producer in the world. With a 99% market dominance in 2020, India remained one of the top importers of US ethanol. Due to Prime minister Narendra Modi’s “self-resilient” initiatives, India sets an ambitious goal of E-20 by 2025 while keeping its immediate goal of E-10 by 2022. India has a total installed capacity of 5 billion L of ethanol, with molasses-based distilleries accounting for 4.2 billion L or 85 per cent of total production capacity and grain-based distilleries accounting for 750 million L. (equivalent to 15 per cent).
In India, molasses or sugar juice were the only sources of ethanol in the past. Several feedstocks, including grains, manufacture the ethanol produced in India (rice, wheat, barley, maise, and sorghum). Molasses-based ethanol production in 2020 to be 2.98 billion L. Due to increased government attempts to divert more feedstock into ethanol, India’s 2021 average ethanol blending percentage in gasoline was anticipated at 7.5 per cent. The country’s 2021 ethanol production was forecast at 3.17 billion L, 7% more than 2020.
However, research in biomass ethanol is still needed to enhance the science and bring the technology closer to more comprehensive commercial implementation. Creating high-value byproducts that can be made from C5 sugars and the techniques for their synthesis is one area that requires more study. Xylitol and astaxanthin, among other things, are examples of them. Lignin use is a different topic that still has much room for exploration. There is little room for research to dramatically advance the technology because corn ethanol in the United States and sugarcane ethanol in Brazil has been used commercially for many years.
Similarly to the C5 sugars, lignin can be used as a feedstock to make high-value co-products. Establishing techniques for their synthesis still necessitates considerable research. The production industry has been badly devastated by the COVID-19 pandemic, which has affected the entire planet. As a result, global ethanol production fell in 2020. Although other regions are also affected, they rely less on fuel ethanol markets. Hence the pandemic’s effects there have been considerably less severe.
The recovery is expected to occur after the pandemic ends and the production sectors resume their regular operations. However, production might not be as high as before the global lockdown. The demand for ethanol for hand sanitiser remains high even after the limitations are relaxed during the epidemic. Stronger emission laws and policies support the potential for biofuel production to reduce CO2 emissions in developing nations. Global ethanol production is anticipated to rise once again in the future.
Ethanol is a colourless liquid and a biodegradable fuel. The low toxicity has proved ethanol to cause minimal ecological pollution. It is a high-density fuel which replaces “lead” as an octane enhancer in gasoline. Three kinds of microorganisms are responsible for converting lignocellulosic biomass to bioethanol. These microbes are yeasts, bacteria, and fungi. Among them, yeasts proved to be the best for the ageing process. Combining ethylene with steam is an alternate way to produce ethanol. Mixing ethanol with gas can oxygenate the fuel blend, which burns the whole compound—thus reducing emissions of pollutants.
Depleting natural resources adversely affects the planet. So, the governments of each country are bound to take action. Most organisations are taking the initiative and bringing new technology to biofuel production. Among the biofuels, bioethanol has proved to be a promising fuel to address the energy crisis. In the transportation sector, bioethanol serves as an alternative to petroleum derivatives. Conversion of bioethanol with hydrocarbons, oxygen synthetics and other low atom-weight molecules results in a superior blend.
Classifications
Bio Ethanol is classified into two groups;
Classification of bioethanol through the process of manufacturing.
The traditional method of producing ethanol combines ethylene with steam. It has a chemical reaction by using non-biogenic sources of raw materials. In which ethylene is non-renewable.
Anaerobic sugar fermentation from various renewable sources is a sustainable method of producing ethanol with the help of microbes.
Classification of bioethanol by the source of raw materials.
First Generation (1G) Bioethanol
Raw materials extracted from food-based feedstocks to produce ethanol are sugar and starch, a common type of alcohol. Sugar cane, sorghum, and pearl millets contain glucose, sucrose, and fructose. These are the major components of such feedstocks. This bioethanol production process is not cost-effective, raising the criticism of adopting non-food-based feedstocks.
Second Generation (2G) Bioethanol
Second-generation bioethanol consists of lignocellulosic biomass and industrial wastes. It is readily available and also found in all sectors. Hence, the scope of second-generation ethanol is very promising. But unfortunately, the functioning of these industries depends upon the market demand for ethanol.
Third Generation (3G) Bioethanol
Bioethanol from non-food based feedstock includes many benefits. Such as higher energy density, conversion percentage, ease of cultivation, and lower costs. However, there is a lack of stability in the extraction of algae or other microbes compared to other bioethanol sources.
Fourth Generation (4G) Bioethanol
The fourth-generation bioethanol procedure includes capturing and storing CO2 and later converting the stored CO2 to ethanol. Oxide electrolysis, genetic engineering, and petroleum hydro-processing are some technologies. However, it is in the embryonic stage.
The Properties and Process of Bioethanol
Properties
Ethanol is a popular biofuel which is readily available in the market. The fuel has the potential of conversion to secondary energy resources. Using bioethanol as a transport fuel reduces greenhouse gas (GHG) emissions compared to gasoline or octane. The biodegradation of bioethanol is simple. In contrast to petrol and water, bioethanol is entirely miscible with water in all ratios. While gasoline is immiscible when blended with water. It might cause corrosion-related issues with the mechanical parts particularly those made of copper, brass, or aluminum. Ethanol increases octane more effectively and contains 35% oxygen by mass. It requires fewer additives in its process and pollutes water bodies less. Ethanol improves fuel combustion and lowers particle emissions released during combustion.
“Process of Bioethanol Production”
Process
Bioethanol manufacturing uses biomass (starch and lignocellulosic) as a raw material for a more sustainable alternative. Technologies for developing bioethanol through research, primarily focused on the conversion of biomass waste.
Bioethanol manufacturing from starch involves three sequential steps:
Hydrolysis
Fermentation
product purification.
However, bioethanol from lignocellulosic biomass involves four steps:
Pretreatment
Hydrolysis
Fermentation
Purification
Pretreatment procedures
Physically
Physio-chemically
Chemically
Biologically
It is crucial to choose the best pretreatment strategy. Thus, focus on creating and applying suitable pretreatment techniques and the other phases of bioethanol production.
Possibilities of Bioethanol
Bioethanol-gasoline mixed in the proportion of 10% bioethanol and 90% gasoline is most popularly known as gasohol(E10). Most modern automobiles that run on “internal combustion engines”(ICEs) could quickly burn E10. Bioethanol only acts as a traditional motor fuel by combining with other propellants. The vehicle performance is not degraded with use of ethanol with other blends in such quantity by conventional combustion. This mixture does not need alterations while burning. Blended fuels like E85 contain 85 per cent bioethanol and 15 per cent gasoline.
In recent decades, significant advancements have developed in processing renewable biomass, including cellulose synthesis, pentose and hexose sugar fermentation, and the separation and purification of bioethanol.
Despite these advancements, only sugarcane bioethanol produced in Brazil can match the price of fossil fuels. They regularly conduct market studies, polls, and crop selections, giving them a competitive edge in ethanol’s growth and loss-free production.
The use of synthetic biology and yeast metabolic engineering has a considerable positive impact on future industrial bioethanol production systems.
The availability of biomass and the cost of ethanol are the two limiting factors in the production and use of bioethanol. There are many potential applications for ethanol across several industries.
Analysis
For several biomass feedstocks, Oak Ridge National Laboratory introduced supply cost curves. They found that 144 million dry tonnes of agricultural leftovers are accessible and collected yearly. According to the estimates, this equates to 10–14 billion gallons of bioethanol per year. As a result, without having to compete for any new land. The current biomass sources are sufficient to cover about 10% of our needs for light-duty vehicle transportation.
The growth of energy crops will expand the bioethanol market. Economic modelling supports the research of bioethanol’s market penetration. These predictions stated that if ethanol price is $1 per gallon, bioethanol sales will reach 2 billion gallons annually.
Industry can only lower the cost of ethanol to 80 cents per gallon if yearly ethanol demand reaches 6 or 8 billion gallons. This statement is a feasible target based on recent techno-economic studies.
The United States are one of the significant consumers of ethanol. If farmers are encouraged to cultivate corn more than the paddy, the amount of ethanol generated throughout the country will increase. Cooperative distilleries and production facilities provide financial assistance, and ethanol is sold across all nations at a consistent price and on a dependable market.
“Ban on Internal Combustion Engines by Countries”
Major country’s projects and policies
Nations are struggling to reduce their contribution to carbon emissions, reflecting a negative impact on the planet. A significant issue addressed was temperature rise, leading to melting polar caps.
So, it was about time the nations agreed upon the decarbonisation pact, prompting the “net-zero” concept.
It is to enhance air quality and creating a healthier environment for the future. This generally entails reducing greenhouse gas emissions, conserving water, maximising energy resources, and eliminating waste. Hence, this results in society’s development being more sustainable and adaptable.
Phasing out fossil fuel
Britain became the first G7 nation in the previous year to achieve the net-zero emission target by 2050. This goal calls for significant changes in how Britons travel, consume energy, and eat. Starting from 2030, Britain will ban the sale of petrol and diesel five years earlier than anticipated. Prime Minister Boris quoted this as the “Green Revolution” and focused on reducing emissions to zero by 2050.
However, not only Britain, below are the following nations or regions that have proposed prohibiting vehicles powered by fossil fuels:
USA: In September 2035, Governor Gavin Newsom announced that California would prohibit the sale of new gasoline-powered passenger automobiles and trucks.
Canada: Quebec said that starting in 2035, it would prohibit the sale of new gasoline-powered passenger vehicles.
European Union: On October 23, EU environment ministers agreed to make the bloc’s 2050 net-zero emissions target legally enforceable, but left it up to the leaders to decide on a 2030 carbon reduction target in December.
Germany: In late 2018, German localities began enacting bans on older diesel cars that create more pollution.
Norway: With a target date of 2025, Norway, whose economy is strongly dependent on oil and gas revenue, wants to be the first nation in the world to ban the sale of cars that run on fossil fuels.
In Norway, sales of fully electric vehicles already account for around 60% of all monthly sales.
China: China began researching when it would be appropriate to prohibit manufacturing and selling automobiles that use conventional fossil fuels in 2017.
According to an industry official, new energy vehicle (NEV) sales in China, the world’s largest auto market, will account for half of the recent car sales by 2035.
India: Last year, the country’s national think tank urged scooter and motorcycle manufacturers to develop an electric vehicle transition strategy.
In addition, by 2025, electric scooters with 150cc engines will be manufactured and distributed.
India’s Policies and Projects
Focusing more on second and third-generation bio-ethanol is a crucial strategy for increasing the nation’s ethanol production. Food grains and sugarcane juice for ethanol generation have always come under research in a developing country like India. Therefore, combining household and agricultural waste to produce biofuel will help the supply issue. India produces very little second-generation biofuel at the moment. However, in recent years, public sector oil marketing firms like the Indian Oil Corporation and Bharat Petroleum have established production facilities and invested in the manufacture of second-generation biofuels. The industry has yet to see the effects of these advances.
By 2030, India’s net agricultural residue availability for biofuel generation is approximately 166.6 million tons.
By the same year, the demand for ethanol for gasoline blending would be close to 13.7 million tons (based on the desired mixing rate of 20%).
The development of technology to produce ethanol from cellulosic and lignocellulosic biomass would help focus attention away from food-based biofuels and prevent a future shortage of ethanol feedstock.
Discussions
At a recent state-level conference organized at an institute in Pune, the union minister addressed the issue of switching to alternative fuel ethanol in construction, flex-fueled engines and the agriculture industry, where diesel-based agricultural equipment switches towards gasoline. Similarly, the union road transport and highways minister stated that petroleum products worth $10 trillion (US dollars) lead to imports to meet the needs of the energy and power sectors. In the coming years, the demand for imports may increase to 25 trillion (US dollars), resulting in an economic crisis.
The minister also mentioned that a rise in demand for sugar throughout the globe is a temporary phenomenon. However, there is an urgency in shifting sugar production to ethanol due to policies established.
Brazil manufactures ethanol from sugarcane as crude oil prices rise to $140 per barrel, increasing the demand for sugar from India.
Brazil begins to produce sugar when crude oil prices fall from $70 to $80 per barrel, and when crude oil prices fall, it also reflects a decrease in sugar demand.
Future government measures to encourage the manufacture of ethanol from corn will also be a crucial tactic. Compared to rice or sugarcane, corn takes much less water to grow.
Additionally, reducing the amount of water used for paddy production will aid India, which otherwise could soon experience severe water shortages.
All these actions can decrease the amount of foreign currency, mostly spent on importing fuel, while also assisting India in increasing ethanol production and blending rates.
ETHANOL BLENDING PETROL PROGRAMME (EBP)
The Ethanol Blending Program (EBP) aims to meet the ethanol blend targets combined with gasoline.
Goal: By reducing fuel imports and lowering carbon emissions, it wants to combine ethanol with gasoline, classifying it as a biofuel and saving millions of dollars.
Target: Since ethanol is a cleaner fuel, it is added to a different propellent to lessen the nation’s reliance on petroleum imports. The objective is to reach a 20 per cent ethanol blend in Fuel by 2025, referred to as “E20” in the industry.
In 2018, the Central Government expanded the scope of the EBP programme to extract Fuel from surplus amounts of food grains like remains of fruits and vegetables, sorghum, and pearl millet. Only extra sugarcane production could turn into ethanol for programme purchases.
The government will offer interest subsidies (on loans) to encourage funding in this industry. Blending 20 per cent of ethanol into gasoline by the year 2050 is set up under the Ethanol Blended Petrol (EBP) Program.
Additional Ethanol Demand Scenarios Modeling:
One of India’s top think tanks, the Center for Study of Science, Technology and Policy (CSTEP), utilized “Sustainable Alternative Futures for India”(SAFARI), a long-term simulation model to forecast the demand for ethanol. According to the SAFARI model, socioeconomic elements, including population, GDP, and development objectives, would impact India’s energy consumption and emissions by 2050. Development goals refer to access to food, housing, healthcare, education, transportation, power, and infrastructure.
As the electric vehicle revolution is on the horizon, many uncertainties in future projects are to focus on research and development in different scenarios. Three scenarios for electric mobility uptake to estimate the demand for petrol and ethanol are:
1. Conservative (low EVs) – negligible uptake of electric mobility up to 2030.
2. The Status Quo (BAU, medium EVs): medium uptake of electric mobility, around 15% of car passenger kilometres (pkm) and 30% of two-wheeler and three-wheeler pkm are assumed to be electric by 2030.
3. Low Carbon (high EV uptake): 30% of cars and 80%of two-wheelers and three-wheelers are assumed to be electric by 2030.
Additional Initiatives
E20 Fuel
The Indian government established a 20 per cent ethanol blend in gasoline known as E20 Fuel as its target by 2025. The Indian government has encouraged public comments presenting the acceptance of E20 Fuel.
JI-VAN Pradhan Mantri (2019).
The plan aims to create a biological system for launching business strategies and promote creative projects and initiatives in the 2G ethanol sector.
The Public Biofuel Policy (2018)
MNRE approves this policy to achieve the target of 20% ethanol blended with petrol and 5% biodiesel blended with diesel by 2030.
Reduction in GST
The government has reduced GST on ethanol from 18 per cent to 5 per cent, initiated under the Ethanol Blended Petrol Program (EBP).
Conclusion
The pretreatment of renewable biomass, the production of cellulase, the fermentation of sugars (pentose and hexose), and the separation and purification of bioethanol have seen significant developments in recent decades. Despite these advancements, only Brazil’s bioethanol from sugar cane production makes bioethanol cost-competitive with fossil fuels. They carry out market research and surveys each year and select crops each year, which provides them with a cutting edge to cultivate and produce ethanol without much loss.
Yeasts, especially S. cerevisiae, have long been the masters of alcoholic fermentation. They play a pivotal role in one of the world’s most critical biotechnological sectors. The scope of yeast metabolic engineering and synthetic biology will significantly benefit future industrial bioethanol production system projects. Saccharomyces cerevisiae yeast is an important microorganism used in many sectors. It helps to make various commercial products such as baked goods, alcoholic beverages, biofuels, and medications.
Bioethanol has the potential to significantly reduce the adverse effects of greenhouse gas emissions from fossil fuels, thereby limiting global warming. Particularly with the policies, there is still considerable space for improvement. However, analysing the future market demand, ethanol manufacturing seems to have a promising future.
Fossil fuels are the ancient deposits of decomposed animal and plant remains found in the earth’s crust. They are of three major types: coal, oil and natural gas. The extracted deposits are rich in hydrocarbon compounds. Also, fossil fuels have been the primary energy source for producing heat and electricity. Three notable examples are natural gas for heating, crude oil for transportation and coal-fired electricity. However, as you can see, these fuels have been part of our life for a long time. But unfortunately, there is natural resource depletion around the globe. Also, they are a non-renewable source of energy which adds to the disadvantage. So it is essential to save the remaining fossil fuel deposits for the future.
Pollution caused by the combustion of fossil fuels is more lethal than predicted.
Pollution from fine particulates caused by the combustion of fossil fuels caused the premature death of people in 2018. Based on this, Harvard University, the University of Birmingham, and Leicester University conducted research. The researchers discovered that pollution from fossil fuel combustion killed 8 million prematurely worldwide.
According to reports, three hundred fifty thousand people have died in the United States alone. The primary causes were chronic medical conditions such as lung cancer, heart attacks, and dementia. Similarly, pregnant women and low-income people are more prone to the risk of fine particulate pollution. Thus, reducing our dependence on fossil fuels would improve our health and stimulate the economy by creating new job opportunities.
Burning of Fossil Fuels Causes
Warming Planet: Burning these fuels emits a large amount of carbon dioxide (CO2). Oil, coal, and gas combustion meet our energy needs but contribute to global warming. These emissions trap heat in the atmosphere, causing climate change. The transportation and power sector utilises these burned fossil fuels the most. They account for roughly three-quarters of carbon emissions in the United States.
Forms of air pollution: The burning of fossil fuels emits carbon dioxide and other harmful gases. Such as coal-powered plants generate 35 per cent of toxic mercury and sulfur dioxide emissions in the United States. These emissions have contributed to acid rain and soot particles in the atmosphere. Also, poisonous gases like carbon monoxide and nitrogen oxide released by fossil-fuel-powered vehicles cause smog on hot days. They can lead to respiratory illnesses if exposed for an extended period.
Ocean acidification: By burning oil, coal, and gas, we change the ocean’s chemistry, making it more acidic. Our oceans can absorb up to a quarter of all carbon emissions. The oceans have become 30% more acidic since the industrial revolution. There is also a decrease in calcium carbonate from the sea. It is a substance which helps marine creatures to form new shells. In addition, increased acidity causes slower growth rates and weakened shells. As a result, the entire aquatic food chain is in chaos.
Phasing out fossil fuels
It is undeniable that using fossil fuels has disastrous effects. The melting of ice caps, rising sea levels, extreme heat, and cold weather are all consequences of fossil fuel consumption. These impacts on both people and the economy will cause more delays in the transition process of phasing out fossil fuels. Governments, businesses and communities are increasingly imposing the need for a quicker transition. But unfortunately, each group are setting a higher expectation for the other.
There is also an increased urge from companies to use environmental, social and corporate governance targets and metrics based on ESG investments. All of these are reshaping the financial and economic standards. These organisations are decarbonising their operations. Banks, insurers, and institutional investors are steering toward the “net-zero concept“. Financial systems are also rapidly emerging as critical enablers of the phasing-out process. Many changes are happening due to the phasing out of fossil fuels. But there is a risk of delay in the process. The sectors are more or less dependent on each other, and the cost of decarbonisation is high. All these complications also delay the transition phase as people tend to postpone taking action and prefer a more convenient alternative.
Transition to Renewable energy
While renewable energy sources like wind, solar and geothermal are starting to replace fossil fuels in certain sectors. It still seems far-fetched that the world’s rapid use of fossil fuels can end sooner. However, according to experts, the progress can become a reality with providing enough time and initiatives.
All these require massive changes in transportation alternatives. Still, the most challenging issue would be shifting power supply frameworks.
If renewable resources compete significantly with the fossil fuel industry, we need to begin subsidising them more than fossil fuels.
Fossil fuel companies and utility companies deal with politics since they carried out electricity in the early 1900s, making it challenging to unravel their hold over the energy market since so many stakes are at play.
Since the intention behind these effects is to improve the world, there are a lot of green energy laws and policies that promise to deliver accurate results. Therefore, people seem to think the “green transition” status is active.
At this transition rate, it’s no longer practical for the rich and powerful to deny the reality of global warming and other environmental challenges.
The “green initiatives” are picking up pace, pointing to the worldwide interest in investing in renewable energy and other green advancements over the past decade.
When you look at the raw numbers, they seem to provide some backing for the argument. Global investment in renewables led by the International Energy Agency (IEA) to come in at US$367 billion in 2021—up from $359 billion in 2020 and $336 billion in 2019. That’s a lot of new wind turbines, solar panels and hydroelectric power stations.
Bioenergy
Bioenergy, a type of renewable energy, is an essential substitute for modern potential’s ozone-depleting substance (GHG). All resources are sustainable energy, usually utilized for a bioenergy framework. Specific ongoing frameworks and key future advancements, such as perennial cropping systems, waste and livestock manure utilization, and technologically advanced transition systems, can deliver an 80 per cent to 90 per cent discharge reduction in carbon emission compared to fossil fuel standards.
Direct combustion is the most widely recognized strategy to convert biomass into utilizable energy. Steam turbines provide power by burning biomass, which also includes electricity for industrial processes and buildings.
Direct and Indirect land conversion is taking place due to the rising demand for biomass. This conversion is causing an increase in GHG emissions. The practices of land alterations impact the carbon emissions and vegetation of the soil by absorbing carbon from the atmosphere. Strategies to mitigate the effects of land use change are increasing the number of energy crops grown on low-carbon pastureland and utilizing agricultural and forestry waste. Crops that provide nutrients and fibre and are a source of bioenergy can be planted in an integrated production system reducing the land-use effects and enhancing the land’s usefulness.
The goal of increasing biofuel output will be aided by the evaluation of innovative production and management techniques, crops, cropping systems that are responsive to local conditions, and policies that promote environmentally beneficial outcomes.
Processes and Techniques in Treating Biomass
Scientists are working on different techniques to foster alternate ways of converting and utilizing more biomass energy.
Thermochemical conversion of biomass incorporates pyrolysis and gasification. Both are thermal deterioration processes in which biomass feedstock materials are heated in shut, compressed vessels called gasifiers at high temperatures. They vary in the process temperatures and measures of oxygen present during the cycle. Pyrolysis involves heating organic materials to 800-900°F(400-500℃) when almost oxygen-free. Biomass pyrolysis produces fuels like charcoal, bio-oil, diesel, methane and hydrogen.
Hydrotreating is utilized to process bio-oil (created by rapid pyrolysis) with hydrogen under elevated temperatures and pressures with the activator to produce renewable gasoline, diesel, and jet fuel.
Gasification involves processing organic materials to 1400-1700°F (800-900℃)with infusions of a controlled percentage of oxygen and steam into the vessel to produce carbon monoxide and hydrogen-rich gas called synthesis gas or syngas. Syngas can be utilized to fuel diesel motors, heat, and generate electricity in gas turbines. Similarly, it can be processed to extract the hydrogen from the gas; the hydrogen can then be burned or used in fuel cells. The Fischer-Tropsch method can be applied to the syngas to process them further and create liquid fuels.
Transesterification is a chemical process that converts unsaturated fat”methyl esters” (FAME) from vegetable oils, animal fats, and lubricants into biodiesel.
Biological conversion incorporates a fermentation process to convert biomass into ethanol and anaerobic processing to produce renewable natural gas. Renewable natural gas, also called biogas or biomethane, is produced in anaerobic digesters at sewage treatment with plants, dairy and livestock activities. It also forms or could be captured from solid waste landfills. Properly treated renewable natural gas has similar purposes to non-renewable natural gas.
In 2020, biomass provided around 4,532 trillion British thermal units (TBtu), or about 4.5 quadrillions Btu, equivalent to 4.9% of total U.S. primary energy consumption. Of that sum, around 2,101 TBtu were from wood and wood-derived biomass, 2000 TBtu were from biofuels (essentially ethanol), and 430 TBtu were from the biomass in municipal wastes. The sum in TBtu and percentage shares of total U.S. biomass energy use by the consuming sector in 2020 were: Industrial—2,246 TBtu—(50%) Transportation—1,263 TBtu—(28%) Residential—458 TBtu—(10%) Electric power—424 TBtu— (9%) Commercial—141 TBtu—(3%) Industrial and transportation represent the most extensive amounts. In terms of energy content, Wood products and paper ventures use biomass in consolidated intensity and power plants to process heat and produce power. Liquid biofuels (ethanol and biomass-based diesel) represent a large portion of the transportation area’s biomass consumption.
The residential and commercial use firewood and wood pellets for heating. In some cases, the retail sector sells the additional renewable natural gas produced at municipal sewage treatment and waste landfills. The purpose of these impacts is to change the world with green energy laws and activities to draw attention to the effects. Unfortunately, people are still unaware of the green transition and its impact. At this transition rate, it’s no longer practical for the rich and powerful to deny the reality of global warming and other environmental challenges. The “green initiatives” are picking up pace, pointing to the worldwide interest in investing in renewable energy and other green advancements over the past decade. The Bioenergy Technologies Office (BETO) is teaming up with industries to develop next-generation biofuels made from wastes, cellulosic biomass, and algae-based resources. BETO is focused on developing hydrocarbon biofuels-otherwise called drop-in fuels, which can act as petrol substitutes in refineries, tanks, pipelines, pumps, vehicles, and smaller engines.
Bioethanol
Ethanol is renewable hydrolysis or sugar fermentation fuel derived from bioresources (biomass).
It is alcohol based blending agent with gas to build octane and cut down carbon monoxide and other smog-causing emanations.
The most common ethanol blend is E10 (10% ethanol, 90%gasoline), compatible with most conventional fuel-controlled vehicles up to E15 (15 per cent ethanol, 85 per cent gas).
Flex Fuel Vehicles can run on ethanol-blended gasoline. They can run on E85, an elective fuel with a much higher ethanol content than regular gas (a gas ethanol mix containing 51 per cent -83 per cent ethanol, depending on geography and season). In the United States, ethanol accounts for 97 per cent of all fuel.
Plant starches and sugars are the major sources of producing ethanol. Yet, researchers are proceeding to foster innovations that would consider the utilisation of cellulose and hemicellulose, the non-consumable fibrous material that comprises the bulk of plant matter.
The usual method of changing from biomass to ethanol is ageing; during ageing, microbes utilise plant sugars and produce bioethanol.
Biodiesel
Biodiesel is a fluid fuel from vegetable oils and animal fats.
It is a cleaner consumption substitution for oil-based fuel. Hence, It is non-toxic and biodegradable
Usually made by mixing alcohol with vegetable oil, animal fat, or recycled cooking grease.
It is fuel compression-ignition (diesel) engines like petroleum-derived diesel.
Usual blends of biodiesel mixed with petroleum diesel includes B100 (pure biodiesel) and the most common blend, B20 (a blend containing 20% biodiesel and 80% petrol diesel).
Renewable hydrocarbons “Drop-In” fuels
Gas, diesel and Jet fuel contain a combination of hydrocarbon particles burned to produce energy.
Hydrocarbons produced from biomass sources through organic and thermochemical processes are sustainable.
Biomass-based sustainable hydrocarbon fuels are almost identical to the petroleum-based energy source designed to replace them.
They’re viable with today’s engines, pumps, and other infrastructure.
India’s Initiatives
India has over two decades of experience in planning and implementing bioenergy programs. These programs have undergone changes, reflecting the elements of the policy environment.
Due to rapid economic development, India has one of the world’s fastest-growing energy markets. By 2035, India aims to be the second-largest contributor to global energy demand, accounting for 18% of the increase in global energy consumption.
In 2020-21, the per-capita energy consumption was 0.6557 Mtoe, excluding conventional biomass use.
The energy intensity of the Indian economy is 0.2233 Mega Joules per INR (53.4 kcal/INR).
Net energy import dependency was 41.2 in 2020-21.
India’s developing energy demands and limited domestic oil and gas reserves, the nation has ambitious projects to grow its sustainable and nuclear power program.
India has the world’s fourth-biggest wind power market and plans to add around 100,000 MW of solar power by 2022. India also plans to increase its contribution towards nuclear power for overall electricity generation capacity from 4.2% to 9% within 25 years. The nation has five nuclear reactors under development (third highest in the world) and plans to build 18 additional atomic reactors (2nd highest in the world) by 2025. During the year 2018, India’s total investment in the energy sector was 4.1% (US$75 billion) of US$1.85 trillion worldwide investment.
In November 2021, the nation promised to arrive at net-zero emanations in 2070. It declared a target of 45% by 2030 to reduce its CO2 emission intensity of GDP, yet the reference used for this target has not been revealed. In its most memorable NDC, India designated a decrease of its CO2 power by 33-35% by 2030 compared to 2005.
The nation also aims for 40% of the total electricity capacity based on non-fossil fuel sources by 2030 (32% in 2020). In 2019, the public authority declared a 100% railway electrification target in 2030 as part of its strategy to deduct the country’s Co2 emissions.
The experience shows that in spite of several financial incentives and favourable policy measures, the rate of effect of Bioenergy Technologies (BETs) is low because of the industrial, technical, market and credit barriers.
Initiatives and policies barriers to “BET”
Rational and Economic tariffs.
Inducement to promote private sector participation.
Motivating institutions and empowering the community.
Financial support for the large-scale presentation programs and for focused research and development
Land tenure arrangements to produce and promote biomass.
The worldwide mechanism for addressing environmental changes like the Clean Development Mechanism(CDM) and the Global Environment Facility (GEF) is an incentive promoter for BETs.
Strategy to reduce Fossil Fuel Consumption
Elimination of fossil fuel subsidies creates $35 billion from the taxpayer’s reserves fund allotted for future sustainable projects.
Increase the social cost of carbons (SCC). It has been unaccounted for damage to the ecosystem through carbon emission for years. U.S. Federal government uses SCC to evaluate the climate impacts of policies.
A government clean power standard requires a percentage of electricity sold by the utilities to come from clean electricity sources. Such a standard exists in a few states and usually involves a share of clean energy on the electric grid, increasing over time.
Price to be paid on carbon emission by the emitters. Carbon pricing policies can strategise in various ways, which in return help to cut down the emission in the long run. Trading off the emission is also a way which is similar to the Northeast’s Regional Greenhouse Initiative, in which the market decided on a carbon cost. Thus, all these initiatives will decrease the emission of Co2 and create a new income stream for clean energy investments.
In short, all these changes would affect our planet. We habitants are responsible for taking initiatives accordingly so that we and our future generations don’t have to face the worst possible outcomes. Also, If we do not change ourselves to better alternatives, we might run out of resources faster than we all anticipated. So, it’s crucial for a dynamic change that might help us preserve the remaining fossil fuel for best use and switch to a better world of renewable energy sources.
Decide you are not going to give up our planet without a struggle – Act now!!!
