History

In 1890, Rudolph Diesel invented biodiesel, which allowed pure vegetable oils to be utilized in diesel engines for agriculture in areas where petroleum diesel was unavailable. The French government and Dr. Diesel himself were among the first to experiment with vegetable oil fuels, believing that pure vegetable oils might fuel early diesel engines for agriculture in distant regions of the world where petroleum was unavailable.

Modern biodiesel fuel results from research done in Belgium in the 1930s, and it is manufactured by turning vegetable oils into fatty acid methyl esters. Trans-esterification was utilized to convert vegetable oils into fatty acid alkyl esters for use as a diesel fuel alternative since vegetable oil had a lower viscosity. Fatty acid methyl esters are known as biodiesel. Concerns about the environment, energy security, and the usage of agricultural goods have pushed vegetable oils to the fore.

After the terrorist assault of 9/11/2001, which resulted in high oil prices, the biodiesel business acquired a household brand in the United States. Because of worries about global warming, biodiesel is currently utilized worldwide. Biodiesel’s future depends on the world’s capacity to create renewable feedstocks like vegetable oils and fats at a cost comparable with petroleum.

Biodiesel output globally reached 1.1 billion gallons in 2005, with the majority of the fuel produced in the European Union, while biodiesel projects across the world have been on the increase owing to rising crude oil costs and worries about global warming.

Production Methods of Biodiesel: Fuel Quality

Trans-esterification is a chemical reaction in which different oils (triglycerides) are transformed into methyl esters in the presence of a catalyst, such as sodium or potassium hydroxide, in the presence of methanol (FAME) or ethanol (FAEE). Glycerol, traces of methanol or ethanol, unreacted triglycerides, and the catalyst are all by-products of the trans-esterification process that must be eliminated from the completed product.

Transesterification of Biodiesel is as follows –

Where R1, R2 & R3 are the Fatty acid chains of triglycerides.

Methods Used for Industrial Production of Biodiesel:

Supercritical Process – In supercritical methanol, the continuous generation of biodiesel (fatty acid methyl esters) from the transesterification process of coconut oil and palm kernel oil is processed without the need for any catalyst.

Ultra- and high-shear In-line and Batch Reactors – Biodiesel can be produced continuously, semi-continuously, or in batch mode using ultra- and high-shear in-line or batch reactors. This decreases manufacturing time and boosts output volume dramatically.

Lipase-Catalyzed Method – Recently, a lot of attention has been paid to using enzymes as a transesterification catalyst. Researchers discovered that high yields could be achieved from crude and used oils using lipases.

Ultrasonic Reactor Method – The ultrasonic waves in the ultrasonic reactor technique induce the reaction mixture to continually create and collapse bubbles; this cavitation provides the mixing and heating necessary for the transesterification process.

Volatile Fatty Acids from Anaerobic Digestion of Waste Streams – Because of their sustainability, non-toxicity, and energy efficiency, lipids have gotten a lot of interest as a biodiesel manufacturing substrate. However, because of financial constraints, emphasis must be paid to non-edible lipid sources, particularly oleaginous bacteria.

Standards and Properties

Incorporating physical and chemical qualities in the criteria of a sufficient standard is the primary criterion for biodiesel quality. Because of the evolution of compression ignition engines, ever-stricter emission rules, and revaluation of feedstocks’ eligibility in biodiesel production, quality criteria for biodiesel are constantly revised. The existing regulations for controlling biodiesel quality on the market are based on several variables that differ by location.

Specification:

Biodiesel is often combined with petroleum-based diesel fuel in a pure form (referred to as “B100” or “neat biodiesel”). Such biodiesel mixes are labeled BXX, where XX denotes the proportion of pure biodiesel in the blend (for example, “B5,” “B20”).

For both Bharat Stage IV and VI-grade fuels, the automotive diesel fuel standard (IS 1460: 2017) allows for a maximum FAME content of 7% v/v. Biodiesel blending in HSD was formerly allowed up to 5% v/v. Following that, the specification for mixing biodiesel in the range of 6 percent to 20% v/v (IS 16531:2016) was developed.

Biodiesel blends – AG/UG tanks can also be used to hold various Biodiesel mixtures. However, much care must be taken to ensure that the product is homogeneous. This is significant since Biodiesel has a greater density than HSD. It is possible to offer a suitable vertical churning/blending facility. Moisture infiltration and the presence of free water must be prevented.

Some common properties and standards of biodiesel –

Availability of Raw Materials for Biodiesel

Biodiesel is a non-toxic, biodegradable, renewable fuel made from organic and renewable raw materials such as fresh or waste vegetable oils, oilseed plants, and animal fats.

Edible Vegetable Oils – Biodiesel is primarily (more than 95 percent) made from edible vegetable oils (biodiesel first generation). They are readily available on a wide scale from the agricultural industry worldwide. It is now made mostly from soybean in the United States, sunflower in Europe, rapeseed in Canada, and palm in Southeast Asia. However, since they compete with food ingredients, continuous. The large-scale synthesis of biodiesel from culinary oils has recently become a subject of concern.

Non-Edible Oils – Technologies are being developed to use cellulosic resources such as plant leaves and stems, waste biomass, and oilseeds from non-edible plants to manufacture biodiesel (biodiesel, second-generation). Non-edible biodiesel crops are predicted to be grown on the generally unproductive ground and in impoverished areas and damaged forests. Furthermore, non-edible oil plants are well suited to dry and semi-arid environments, requiring little fertilizer and moisture to thrive. Furthermore, due to the presence of hazardous components in non-edible oils, they are not acceptable for human consumption. Using non-edible oils as a raw material in biodiesel synthesis is a potential option for all of these reasons.

Applications

There are various applications for biofuel, which is well-known as a diesel substitute. Many people believe that the material is only utilized for transportation purposes. On the other hand, Biofuel may produce hydrogen, clean oil, and serve as cooking oil, among other things. Biofuels may be used to replace a variety of energy demands, including automobile fuel and central home heating.

The following are the important applications for biofuel.

Transportation – Transportation accounts for 24% of global energy consumption and more than 60% of absorbed oil. This implies that autos consume more than a third of all oil.

Electricity Generation –  Biofuel can be utilized to produce electricity in backup systems when emissions are the most important factor. In reality, the United Kingdom has the greatest market for biofuel. Biofuel transforms into energy generation for over 350,000 houses from waste gas.

Clean Oil Spills and Grease – Oil spills and grease may also be cleaned up with biofuel. Studies say it can be used to clean up regions where crude oil has contaminated the water.

Remove Paint and Adhesive – Biofuel can also be used to replace harmful chemicals we use to remove paint and adhesives. Biofuel is also seen to be the most effective way to eliminate non-critical uses.

Aircraft Fuel -A Czech jet aircraft that runs entirely on biodiesel completed a test flight. Other recent biofuel-powered aircraft flights, on the other hand, used different forms of renewable fuels.