Environment Magazine

Advantages and Disadvantages of Biodiesel Fuel

Posted on the 22 May 2013 by Rinkesh @ThinkDevGrow

What is Biodiesel?

Biodiesel is renewable and clean burning fuel that is made from waste vegetable oils, animal fats, or recycled restaurant grease for use in diesel vehicles. Biodiesel produces less toxic pollutants and greenhouse gases than petroleum diesel. It can be used in pure form (B100) or can be blended with petro-diesel in the form of B2 (20% biodiesel, 80% petrodiesel), B5 (5% biodiesel, 95% petrodiesel) or B20 (20% biodiesel, 80% petrodiesel). Biodiesel has helped several countries in reducing their dependance on foreign oil reserves as it is domestically produced and can be used in any diesel engine with little or no modification to the engine or the fuel system.

Advantages of Biodiesel

  • Produced from Renewable Resources: Biodiesel is a renewable energy source unlike other petroleum products that will vanish in years to come. Since it is made from animal and vegetable fat, it can be produced on demand and also causes less pollution than petroleum diesel.
  • Can be Used in existing Diesel Engines: One of the main advantage of using biodiesel is that can be used in existing diesel engines with little or no modifications at all and can replace fossil fuels to become the most preferred primary transport energy source. Biodiesel can be used in 100% (B100) or in blends with petroleum diesel. For e.g.: B20 is called as 20% blend of biodiesel with 80% diesel fuel. It improves engine lubrication and increases engine life since it is virtually sulfur free.
  • Less Greenhouse Gas Emissions (e.g., B20 reduces CO2 by 15%): Fossil fuels when burnt release greenhouse gases like carbon dioxide in the atmosphere that raises the temperature and causes global warming. To protect the environment from further heating up, many people have adopted the use of biofuels. Experts believe that using biodiesel instead of petroleum diesel can reduce greenhouse gases up to 78%.
  • Grown, Produced and Distributed Locally: Fossil fuels are limited and may not be able to fulfill our demand for coal, oil and natural gas after a certain period. Biodiesel can work as an alternative form of fuel and can reduce our dependence on foreign suppliers of oil as it is produced from domestic energy crops. It is produced in local refineries which reduce the need to import expensive finished product from other countries.
  • Cleaner Biofuel Refineries: When oil is extracted from underground, it has to be refined to run diesel engines. You can’t use it straight away in the crude form. When it is refined, it releases many chemical compounds including benzene and butadiene in the environment which are harmful for animals, plants and human life. Biofuel refineries, which mainly uses vegetable and animal fat into biofuel releases less toxic chemicals, if spilled or released to the environment.

Biodiesel fuel pump

  • Biodegradable and Non-Toxic: When Biofuels are burnt, they produce significantly less carbon output and few pollutants. As compared to petroleum diesel, biodiesel produces less soot (particulate matter), carbon monoxide, unburned hydrocarbons, and sulfur dioxide. Flashpoint for biodiesel is higher than 150°C whereas the same is about 52°C for petroleum diesel, which makes it less combustible. It is therefore safe to handle, store and transport.
  • Better Fuel Economy: Vehicles that run on biodiesel achieve 30% fuel economy than petroleum based diesel engines which means it makes fewer trips to gas stations and run more miles per gallon.
  • Positive Economic Impact : Biofuels are produced locally and thousands of people are employed in biofuel production plant. Since biodiesel is produced from crops , an increase in demand for biodiesel leads to increase in demand for suitable biofuel crops. Moreover, it creates less emission by reducing the amount of suspended particles in the air. This reduces the cost of healthcare products.
  • Reduced Foreign Oil Dependance: With locally produced biofuels, many countries have reduced their dependance on fossil fuels. It may not solve all problems in one blow but a nation can save billions by reducing their usage on foreign oil.
  • More Health Benefits: Air pollution cause more deaths and diseases than any other form of pollution. Pollutants from gasoline engines when released in the air, form smog and make thousands of people sick every year. Biodiesel produce less toxic pollutants than other petroleum products.

Disadvantages of Biodiesel

  • Variation in Quality of Biodiesel:  Biodiesel is made from variety of biofuel crops. When the oil is extracted and converted to fuel using chemical process, the result can vary in ability to produce power. In short, not all biofuel crops are same as amount of vegetable oil may vary.
  • Not Suitable for use in Low Temperatures: Biodiesel gels in cold weather but the temperature that it will gel depends on the oil or fat that was used to make it. The best way to use biodiesel during the colder months is to blend it with winterized diesel fuel.
  • Food Shortage: Since biofuels are made from animal and vegetable fat, more demand for these products may raise prices for these products and create food crisis in some countries. For e.g.: the production of biodiesel from corn may raise its demand and it might become more expensive which may deprive poor people from having it.
  • Increased use of Fertilizers: As more crops are grown to produce biofuels, more fertilizer is used which can have devastating effect on environment. The excess use of fertilizers can result in soil erosion and can lead to land pollution.
  • Clogging in Engine: Biodiesel cleans dirt from the engine. This proves to be an advantage of biofuels but the problem is that this dirt gets collected in fuel filter and clogs it.

B100 biodiesel fuel

  • Regional Suitability: Some regions are not suitable for oil producing crops. The most productive crops can’t be produced anywhere and they need to be transported to the plants which increases the cost and amount of emission  associated with the production and transportation.
  • Water Shortage: The use of water to produce more crops can put pressure on local water resources. The areas where there is water scarcity, production of crops to be used in making of biofuels is not a wise idea.
  • Monoculture: Monoculture refers to the practice of producing same crop over and over again rather than producing different crops. While this results in fetching best price for the farmer but it has some serious environmental drawbacks. When the same crop is grown over large acres, the pest population may grow and it may go beyond control. Without crop rotation, the nutrients of soil are not put back which may result in soil erosion.
  • Fuel Distribution: Biodiesel is not distributed as widely as petro-diesel. The infrastructure still requires more boost so that it is adopted as most preferred way to run engines.
  • Use of petro-diesel to produce biodiesel: It requires much amount of energy to produce biodiesel fuel from soy crops as energy is needed for sowing, fertilizing and harvesting crops. Apart from that, raw material needs to be transported through trucks which may consume some additional fuel. Some scientists believe that producing one gallon of biofuel needs energy equivalent to several gallons of petroleum fuel.
  • Slight Increase in Nitrogen Oxide Emissions: Biodiesel has about 10% higher Nitrogen Oxide(NoX) than other petroleum products. Nitrogen Oxide is one the gas that is used in the formation of smog and Ozone. Once it gets dissolved in atmospheric moisture, can cause acid rain.
Image credit: etcleanfuels , greenenergyfutures

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