Our future on this planet is in danger, but it doesn't have to be. One of the major causes of air pollution, climate change, and our depleting energy reserves is humankind's excessive reliance on fossil fuels. This non-renewable source is being consumed far faster than it is being replenished. Add to that the fact that burning fossil fuels contributes heavily to global warming and poor air quality. In such circumstances, biofuel production - mainly the biodiesel production process - offers a viable alternative, particularly if you're already in the oils and fats processing industry.
What are biodiesels?
Biodiesel is a green fuel source - chemically, mono alkyl esters - with different variants of biodiesels used in automotives, power generation, heating, and other applications by either blending it with traditional diesel or using it in its pure form. Biodiesel can be produced using non-edible vegetable oils, used cooking oils, animal fats, yellow grease, or other byproducts of the oil production process. In fact, research is also in progress to use algae as feedstock in the biodiesel production process.
The importance of biofuel production steps
While naturally derived oils and fats like refined vegetable oil, tallow, or recycled greases are wonderful sources of energy, they cannot be used directly to power your cars or heat your homes. These oils and fats are triglycerides which are a lot more viscous than the fuel your vehicles require. Using blends of these oils directly as vehicle fuel can degrade vehicle performance by causing engine deposits in the long term, lube-oil gelling, ring sticking, and a number of other issues that will impact the longevity of the vehicle, whether it is used in a car or as aviation fuel.
Biofuel production steps: Transesterification
Biofuels production can involve many different techniques, including direct consumption via burning (like with wood or animal waste), bacterial decomposition, or conversion to liquid or gaseous forms of fuel. Central to the biodiesel production process, however, is the process of transesterification.
Feedstock + alcohol (often in the presence of a catalyst) --> biodiesel + glycerine
The feedstock here can be any of those mentioned above: tallow (or animal fat), canola oil, soybean oil, palm oil etc. While methanol is the most commonly used alcohol for its cost-effectiveness, ethanol or propanol may also be used. The catalyst used in the transesterification process of biodiesel production must be an alkali, usually sodium hydroxide, sodium methylate, or potassium hydroxide.
Now coming to the products resulting from the biodiesel production process. The biodiesel derived from transesterification is in the form of an ester, referenced based on the biodiesel raw materials used. For instance, an ester produced using canola oil as feedstock and methanol as the alcohol will be called canola methyl ester. Similarly, esters produced using ethanol and propanol are called ethyl esters and propyl esters, respectively. Finally, glycerine, the byproduct, isn't just discarded. Glycerine, in itself, is a sugar with important applications in the pharmaceutical and cosmetics manufacturing industries. So biofuel production steps like transesterification are fairly important additions to the oils and fats value chain: not only do they minimise the need for waste management, but they also provide additional sources of revenue by producing glycerine or glycerol for other industries.
The conditions for efficient biofuel production via transesterification
Depending on the quality of the feedstock, either esterification or transesterification can be used for the biodiesel production process. At present, most industry players rely on transesterification, or base catalysis. But the success of this method depends on the properties of the feedstock. If the feedstock has a free fatty acid (FFA) content of less than 0.1%, moisture content of less than 0.1%, and phosphorus content of less than 10 ppm, only then is the process efficient.
These conditions can be achieved via a number of pretreatment techniques. Washing with hot water helps to eliminate mineral acidity and water-soluble impurities. The oil is then dried and treated with phosphoric acid and bleaching earth to eliminate phosphates, soap, and metal contaminants. After filtration, the resulting material undergoes deacidification to remove FFAs.
Meanwhile, transesterification is a reversible reaction, which means that specific interventions are required to keep the equilibrium towards reaction products. This is done by using excess alcohol and continuously removing glycerine. Subsequently, high-purity methanol is recovered and recycled for another round of transesterification. The resulting biodiesel is treated with citric acid and centrifugal separation to remove soap, methanol, and glycerol traces. Finally, biodiesel is distilled under vacuum and high temperature to achieve a high-quality distilled biodiesel ready to be distributed by pipeline, truck, or train to wholesalers, fuel terminals, and consumers.
Is biofuels production all about transesterification?
No! While the biodiesel production process to produce fuel for vehicles and heating is pretty important to the oils and fats industry, biodiesel is not the only biofuel. Methane, hydrogen, bio-compressed natural gas (bio-CNG), ethanol, and butanol are also biofuels.
Biofuels may be either primary or secondary. Primary biofuels offer a more direct fuel source, like the wood and dry animal waste we mentioned earlier, which can be burned directly to produce heat energy. Secondary biofuels are ones that involve a certain number of biofuel production steps. While the first generation comprises ethanol derived from food crops rich in starch or from waste animal fats, the second generation (bioethanol and biodiesel) comes from non-food cellulosic biomass from oil-rich plant seeds like jatropha and soybean. The third generation, like the aforementioned algae research, includes biofuels production from microalgae, cyanobacteria, and other microbial life - this last generation, given the vast quantity of microbial life on earth, presents a promising solution to meeting the world's extremely high energy needs.
Towards a greener future…
As the global population rises, global energy demand is set to increase exponentially. Conversely, the availability of fossil fuels will reduce significantly as humankind takes from the earth faster than these resources can be replenished. Additionally, with already heavy pressures on the earth's resources, the problem of greenhouse gas emissions from fossil fuels only exacerbates planetary crises. Renewable energy sources like solar and wind are critical solutions to our climate and energy issues. Where solar and wind may not be useful, biofuels can be. Ultimately, biofuels production is a crucial component of the future of the world.
Kumar's biodiesel plant
Kumar's biodiesel plant promises a long life, minimal maintenance requirements, and wear and tear parts that are specially treated for durability. It is a single plant with multiple feedstock options. Kumar's biodiesel manufacturing plant produces top quality biodiesel which adheres to EN 14214 and BIS 15607:2005 standards. Designed to guarantee a high conversion rate, low methanol consumption, reduced catalyst consumption, low utility consumption, and production of pharma-grade glycerine, Kumar is the process engineering partner you need.
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