Energy consumption is inevitable for human existence. There are various reasons to seek an alternative fuel that is technically feasible, environmentally acceptable, economically competitive and readily available. The first main reason is the growing demand for fossil fuels in all areas of human life, from transportation, power generation, industrial processes and residential consumption. Fuel requirements for electricity generation, vehicle operation and cooking are gradually increasing. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”?Get the original essayToday, every country derives its energy needs from various sources. Sources can be broadly classified as commercial and non-commercial. Commercial sources include fossil fuels (coal, oil and natural gas), hydroelectric power and nuclear energy, while non-commercial sources include wood, animal waste and agricultural waste. In an industrialized country like the United States, most energy needs are met from commercial sources, while in a less industrially developed country like India, the use of commercial and non-commercial sources is about equal . (R. Rajasekaran, G. Vijayaraghavan and Marimuthu, 2014) Following the oil crisis of the 1970s, countries turned to biofuels to replace the use of fossil fuels, including launching national biofuel production programs. bioethanol (Worldwatch 2007), while others (e.g. China, Kenya and Zimbabwe) acted in response to the oil crisis but were unable to sustain biofuel production (Liu 2005; Karekezi et al 2004). When oil prices fell again, the momentum for alternative fuels receded, except in Brazil. Current drivers of alternative energy supply include energy supply security issues, oil price volatility, climate change, production costs, etc. (Govinda R and Zilberman, 2014). The production and use of bioethanol has spread to the four corners of the globe. As concerns over oil supplies and global warming continue to grow, more countries are turning to bioethanol and renewable fuels as a way to counter oil dependence and environmental impacts. Global production reached a record high of nearly 23 billion gallons in 2010 and is expected to exceed 1.20 billion by the end of 2020. As the United States has become the world's largest producer of bioethanol fuel in 2010, Brazil remains close behind, and China, India, Thailand and other countries are rapidly developing their own domestic bioethanol industries. . The increased production and use of bioethanol has also led to growing international trade in this renewable fuel. Although the vast majority of bioethanol is consumed within the country in which it is produced, some countries find it more profitable to export bioethanol to countries such as the United States and Japan. The growing bioethanol trade around the world is helping to open new markets for all sources of bioethanol. Sustainable production of bioethanol requires well-planned and robust development programs to ensure that the many environmental, social and economic concerns associated with its use are addressed. adequately. The key toMaking bioethanol competitive as an alternative fuel lies in the ability to produce it from biomass at low cost. Many countries around the world are actively working on the development of new technologies for producing bioethanol from biomass, of which the conversion of lignocellulosic materials seems to be the most promising. (Brajpai, 2013). The increasing demand for bioethanol for various industrial purposes such as alternative energy source, industrial solvents, cleaning agents and preservatives has necessitated increased production of this alcohol. The production of bioethanol is generally carried out by chemical synthesis of petrochemical substrates and conversion of carbohydrates present in agricultural products. Due to depleting reserves and competing industrial needs for petrochemical feedstocks, global emphasis is placed on the production of bioethanol by acid hydrolysis process. Increasing the yield of bioethanol production by acid hydrolysis depends on the use of an ideal acid and appropriate processing technology. (Ali, 2011). However, concerns about the sustainability of biofuel feedstock production, particularly the impacts on food supply, associated land-use change and greenhouse gas (GHG) emissions that The result has dampened some of the enthusiasm for biofuels. in recent years and could affect future demand. Controversies surrounding the scale-up of biofuel production have gained prominence with rising food prices and the resulting global food crisis in recent years. As significant amounts of food crops are diverted to biofuel production, this is expected to help reduce GHG emissions due to the significant energy consumption of the transport sector in most economies. Still, converting forest lands and pastures to grow biofuel feedstocks could free up oil substitution to reduce more GHGs than biofuels. (Govinda R & Zilberman, 2014) Energy independence has become a major issue for most countries around the world in recent years. Each country has its unique profile in terms of energy production, consumption and environmental impact. (Kumar and Sani, 2018). Rising oil prices and uncertainty about the security of existing fossil fuel reserves, combined with concerns about global climate change, have created the need for new transportation fuels and bioproducts to replace fossil fuel-based resources. carbon. Bioethanol is considered the next generation transportation fuel with the greatest potential, and significant quantities of bioethanol are currently produced from agricultural waste via an acid hydrolysis process. The use of lignocellulosic biomass as a feedstock is seen as the next step towards a significant expansion of bioethanol production. Therefore, pretreatment is necessary to increase the surface accessibility of carbohydrate polymers. The purpose of the pretreatment process is to break down the structure of lignin and disrupt the crystal structure of cellulose, so that acids or enzymes can easily access and hydrolyze the cellulose. Pretreatment can be the most expensive step in the biomass-to-fuel process, but it has great potential to improve efficiency and reduce costs through further research and development. (Bajpai, 2016) The last two decades havewere marked by intensive use of fossil fuels to meet per capita energy demand, which triggered the debate on the challenges related to: the depletion of fossil fuel reservoirs, the energy crisis in the following years, carbon emissions carbon and climate. change. This has led to the use of cellulosic agricultural waste for the production of biofuels. This lignocellulosic biomass not only offers the potential to be an ideal feedstock for liquid biofuels (bioethanol, butanol), but also has enormous potential in the production of gaseous fuels as well as value-added products. Lignocellulose became “renewable gold” after the introduction of the “biorefinery” concept to process renewable energy and production of value-added chemicals. (Kumar and Sani, 2018). Thus, biomass can play an important role in the national bioeconomy by producing a variety of biofuels and biochemicals that are currently derived from petroleum-based feedstocks. (Khanal, 2010) Energy is an indispensable component of humanity. Our modern society relies on energy for almost everything, from appliances, lighting, transportation, heating/cooling, communication, to industrial processes to provide products to meet our daily needs. We currently consume approximately 500 quadrillion Btu (QBtu) of energy, approximately 92% of which comes from non-renewable sources such as oil, coal, natural gas and nuclear. Historically, the price of crude oil has been very low (around $20 per barrel in the 1980s and 1990s). Since the turn of this century, crude oil prices have continued to rise and reached $141 per barrel in early July 2008. Declining reserves, in the face of rapidly increasing energy consumption, combined with a growing lack of energy security due to Regional conflicts and environmental destruction resulting from greenhouse gas (GHG) emissions clearly suggest that we must act urgently and decisively to develop sustainable, clean, affordable and renewable energy sources . Fossil fuels contribute immensely to pollution and environmental degradation and also stimulate greenhouse gas emissions leading to ozone depletion (Rabah et al., 2014). Biofuel is a renewable energy source and can therefore be used as an alternative to conventional fossil fuels. (Annika, Suryawanshi, Nair, & Patel, 2017). No one can dispute that fossil fuel reserves are limited, but what is uncertain is the extent of the remaining reserves and their duration. Over the years, many estimates have been made, based on current consumption, reserves and planned new sources. It is also clear that the supply of fossil fuels is limited, given how they were produced, but the discussion focuses on the duration of stocks and the level of fossil fuel reserves. The world's dependence on a constant supply of energy means that whatever the estimate of fossil fuel reserves, renewable sources must be introduced as quickly as possible. (Scragg, 2009) Excessive use of fossil resources causes global warming and depletes available crude oil. Humans have acquired the technology to consume and convert crude oil and derive many benefits from it, but this has also led to massive emissions of carbon dioxide into the environment. Unless our societymoves away from the consumption of crude oil and fossil fuels. Due to the recycled use of renewable resources such as biomass, it is difficult to ensure the sustainability of human life. Converting biomass into biofuels, chemicals, energy and new materials is now vital to solving these problems. Bioethanol production plays a dominant role in the conversion system due to its high productivity and applicability as a liquid fuel and chemical resource. (Watanabé, 2013). Renewable energy derived from wind, solar (photovoltaic), geothermal, ocean (tidal), hydropower and biomass can all contribute equally to our renewable energy portfolio. Although only 8% of our current energy consumption comes from renewable sources, enormous research and technological development efforts are being made to develop many forms of renewable energy. Biofuels/bioenergy derived from biomass (lignocelluloses) have recently received significant attention and are considered a major candidate for renewable energy production, particularly for transportation and cooking fuels. (Khanal, 2008). The disadvantages of cooking fuels derived from fossil fuels (greenhouse gas emissions, pollution, resource depletion, unbalanced supply-demand relationships) are greatly reduced, or even absent, with bio-cooking fuels. Among all biofuels, biobioethanol gel is already produced on a large scale. It produces fewer greenhouse gas emissions than fossil fuels (carbon dioxide is recycled from the atmosphere to produce biomass); can replace harmful fuel additives (e.g., methyl tert-butyl ether) and create jobs for farmers and refinery workers. (Brajpai, 2013). Depletion of fossil fuel reservoirs, over-dependence of developing countries on fossil fuels to meet the growing daily demand, global climate change due to increasing carbon footprint have forced countries to take significant initiatives in favor of the use of renewable bioresources for their sustainable development. The trilema of E's (energy, environment and economy) is leading the global scientific community to develop policies aimed at moving from an economy based on fossils to an economy based on bio, initiated under the name of biorefinery. Biorefineries integrate environmentally friendly and more efficient technologies to reduce the rate of harmful emissions that contribute to poor environmental conditions. Although renewable lignocellulosic biomass generated by photosynthesis has the inherent potential to meet growing energy demands, there are technological challenges associated with the structural complexity of lignin, cellulose, and hemicelluloses. (Kumar & Sani, 2018). One of the main reasons for using bioethanol is to reduce greenhouse gas (GHG) emissions. GHGs are gases that harm the Earth's ability to radiate thermal energy to space. It has been reported that bioethanol produced from lignocellulosics through saccharification and fermentation processes consumes much less fossil energy and emits GHGs over its life cycle than conventional petroleum-derived fuels (Sheehan et al. 2003; Wang 2005; For cellulosic bioethanol gel, it is estimated that GHG emissions will be reduced by approximately 85% for E10 and E85. (Watanabe, 2013)The development of energy systems, 2007).