Bioethanol vs Biodiesel

Bioethanol and biodiesel production

When fossil fuels are used, they produce gaseous emissions that contribute to global warming. As a result, alternative green energies derived from food residues, agricultural leftovers, or industrial food residues should be considered for sustainable development. Because of the continual increase in waste, converting waste to alternative energies or biofuels is a beneficial element. Traditional waste disposal methods, such as landfilling or incineration, produce greenhouse gases. Lignocellulose sources containing carbohydrate polymers and lignin are used to produce biofuels. These components are used as feedstock in manufacturing chemical materials, biofuel, biomethane, and biohydrogen, which are alternatives to fossil fuels. Various pretreatment methods and modern technologies are available to improve the biodegradation of various bio-waste or lignocellulose biomass which helps to convert bio-waste to biofuel (bioethanol, biodiesel, and biogas). Many academics worldwide have been developing alternative energy (biofuel) production technologies to replace fossil fuels by lowering the economic cost of bio-waste pretreatment.

Bioethanol is a type of alcohol derived from grain crops. The alcohol is primarily produced through the fermentation of existing carbohydrates in starch or sugar crops. Furthermore, cellulosic biomass is being researched as a source of ethanol production. Transesterification is used to create biodiesel from vegetable oil and animal fat. Bioethanol is similar to gasoline (Petrol), but biodiesel is identical to fossil diesel. Pure biodiesel and bioethanol can be used as fuel in vehicles with adapted engines. Although biodiesel is typically used as a fossil fuel additive, bioethanol is commonly used as a gasoline additive.


The first generation, second generation, and third generation of biofuels are divided based on the feedstock used to make ethanol or biodiesel. Additionally, the term “Advanced Biofuels” is frequently used to refer to innovative biofuel production techniques that utilise waste materials as feedstock, including garbage, used cooking oil, and animal fats.


First-generation biomass, a food source, is utilised to make ethanol and biodiesel. Food crops that are biochemically classified as carbohydrates are used to ferment sugar or starch to produce ethanol. In contrast to corn, the primary source of starch, sugar comes mostly from sugarcane. Wheat, barley, and sugar beets can also make first-generation ethanol in addition to cane and maise. First-generation biodiesel is made from oils such as soybean, rapeseed (canola), sunflower, and palm.


Non-edible sources of biomass are used to create second-generation ethanol and biodiesel. Specific biofuel crops, agricultural residues, and wood chips are all sources of second-generation ethanol. These resources are biochemically classified as lignocellulosic materials. Most of the non-edible oils used to make second-generation biodiesel originate from jatropha. Other small sources include Jojoba, Karanja, moringa, castor, soapnut, and cottonseed oils.


Algae, a single-celled organism, is frequently used to make third-generation ethanol and biodiesel. Typically, algae are divided into groups according to the environments in which they live, such as freshwater, marine, or wastewater habitats. A particular alga is picked depending on its capabilities to produce ethanol or biodiesel.


The production of ethanol and biodiesel involves various biological and chemical procedures. Fermentation and transesterification are the primary processes for making ethanol and biodiesel. Thus, ethanol is produced by fermenting any biomass rich in carbohydrates (sugar, starch, or cellulose) using a method equivalent to beer brewing.
Enzymatic hydrolysis of starch to fermentable sugar occurs before fermentation in the first-generation ethanol manufacturing process. Cellulose is dissociated from the lignocellulosic structure during the production of second and third-generation ethanol utilising a variety of pretreatments.

In theory, making biodiesel is less complicated than making ethanol. The oil is initially extracted from all three types of biodiesel feedstocks. The oil is then transesterified to create biodiesel. Transesterification is a chemical reaction in which an ester reacts with an alcohol to generate another ester and another alcohol. Triglyceride oils (esters) are then blended with methanol (alcohol) to produce biodiesel (fatty acid alkyl esters) and glycerin (alcohol).



  • Ethanol Blended Petrol (EBP) First Generation Program: From 1st January 2003, the Government of India decided to supply ethanol mixed fuel in nine states. Four union territories for the sale of 5% ethanol blended Petrol. The EBP Program aims to achieve several goals, including reducing import dependency, conserving foreign exchange, lowering carbon emissions, and boosting the agriculture sector.
  • The Department of Food and Public Distribution (DFPD) sent a statement to the Cabinet on 25th September 2007, which was reviewed by the Cabinet Committee on Economic Affairs (CCEA) during its meeting on 9th October 2007. In this meeting, the CCEA opted for 5% mandatory ethanol-to-petrol blending and 10% optional blending by October 2007, and 10% mandatory blending by October 2008.
  • Low availability and state-specific issues had slowed EBP Program success. The Ministry of New and Renewable Energy’s (MNRE) previous National Policy on Biofuels – 2009 permitted ethanol production from non-food feedstock such as molasses, celluloses, and lignocelluloses. On 2nd January 2013, a Gazette Notification was released directing OMCs to sell blended ethanol gasoline with an ethanol content of up to 10% as per BIS Specification to reach 5% ethanol blending across the country.
  • As of 31st March 2019, the EBP Program was being implemented in 21 states and four union territories following the partition of Andhra Pradesh and the formation of the new state of Telangana. Also, Public Sector OMCs were buying ethanol from suppliers and selling up to 10% ethanol mixed gasoline.
  • The Government of India launched the “Pradhan Mantri DIVAN (Jaiv lndhan – Vatavaran Anukool fasal awashesh Nivaran) Yojana” on 28th February 2019 as a tool to create 2G Ethanol capacity in the country to encourage the 2G Ethanol sector and support this emerging industry by creating a suitable ecosystem for setting up commercial projects and increasing R&D. On 8th March 2019, the scheme was published in the Extraordinary Gazette of India.


  • The MoPNG established a Biodiesel Purchase Policy in October 2005 to promote biodiesel production in the country, which went into effect on 1st January 2006. OMCs must purchase Biodiesel (B 100) that meets the BIS fuel quality criterion for 5% blending with HSD from authorised procurement centres across the country under this regulation.
  • The Cabinet approved on 16th January 2015 to allow the direct sale of Biodiesel (B 100) to all consumers by private Biodiesel makers and their authorised dealers. Also, the Joint Ventures of Oil Marketing Companies (OMCs) approved by MoPNG.
  • The Motor Spirit and High-Speed Diesel (Regulation of Supply, Distribution and Prevention of Malpractices) Order, 2005 was amended on 10th August 2015, allowing the direct sale of Biodiesel (B100) to Bulk Consumers such as Railways, State Road Transport Corporations, etc. On 10th August 2015, a few retail outlets (petroleum pumps) across the nation began selling mixed biodiesel, which oil marketing companies also introduced.
  • Later, on 29th June 2017, MoP86NG issued Gazette notification No. GSR 728 (E) amending the Motor Spirit and High-Speed Diesel (Regulation of Supply, Distribution, and Prevention of Malpractices) Order, 2005, stating that the Central Government may permit the direct sale of biodiesel (B100) for blending with high-speed diesel to all consumers, subject to the conditions specified in the notification.
  • In March 2016, the ISO 15607 Biodiesel (B100) — Fatty Acid Methyl Esters (Fame) —Specification was modified with the following Scope: “This standard specifies the sample and testing requirements and techniques for biodiesel (B100) — fatty acid methyl esters (FAME) for use in compression ignition engines intended for use as a stand-alone fuel and as a blend stock for diesel fuel. The B 100 stand-alone can also be utilised for heating and industrial engines.
  • In December 2017, BIS updated ISO 1460 (Automotive Diesel Fuel Specification) as “ISO 15607 biodiesel (Fatty Acid Methyl Ester, FAME) can be blended with automobile diesel fuel for up to 7% (v/v)”.


The average calorie consumption is rising along with the global population growth, increasing the demand for rare arable land while raising the energy needs of developing countries. Most likely, biofuel or other alternative renewable sources will be required to supply the extra gasoline. However, rising feedstock prices have restricted biodiesel and bioethanol production. Feedstock accounts for a sizable amount of the cost of producing bioethanol and biodiesel. Large-scale farming for bioethanol and biodiesel feedstock requires much arable land. In this sense, unlike bioethanol, there is no requirement for all biodiesel feedstock to be deforested to free up land for feedstock supplies.

Government support, global trade, and technological advances can continuously lower the economic cost of eventual biofuel production, making it more competitive with fossil fuels. Rising oil prices have provided financial support for biodiesel and bioethanol in recent years. The majority of bioethanol and biodiesel feedstock production is for food feedstock, which has the potential to deplete food supplies. As a result, the global debate between food and fuel demands may heat up. Biodiesel was chosen over bioethanol due to non-food feedstock outputs such as jatropha and algae. Large amounts are necessary for large-scale bioethanol and biodiesel feedstock cultivation.