Biodiesel sample in flask. Image by Shizhao. License: http://www.gnu.org/licenses/fdl.html GNU FDL
One of the major goals of bio energy is to produce a fuel that has a carbon neutral or even negative impact on the atmosphere. Plants and other organisms take carbon from the atmosphere as they grow. When biomass or biofuels are consumed for energy that carbon is then released back into the atmosphere. This is in stark contrast to fossil fuels which release carbon that has been out of the atmosphere for thousands of years.
Environmental Impact of Biological Power
Although one of the major goals of biofuels is producing fuel that has a neutral or negative carbon footprint but this can be offset by certain things. Crops used for biofuel production use carbon from the atmosphere which is released during combustion. This cycle doesn’t take into account nitrogen oxide and other pollutants and green gases released during the production and use of fertilizers, pesticides, and other agricultural aids that may be used.
Ethanol plant in Turner County, SD, USA. Image by Jon Platek.
Biofuels in particular also have an impact on the supply of food crops which can cause changes in the price of food locally and globally. When corn is being used to produce ethanol instead of eaten the supply of corn is diminished and thus the price increases. Some studies have shown that this impact is not negligible and is already contributing to famine and negative food market fluctuations.
Types of Biofuels
All biofuels are derived from organic matter. One exception is cutting edge technology like microbes that convert water and carbon into hydrocarbons (gasoline and more) but these still use organic organisms to produce fuel. Most biofuels are produced from plant crops or waste with sugar cane and corn being popular choices. This biomass is altered by chemical or biological processes to arrive at the final biofuel product.
Probably the most popular biofuel in the average person’s life is direct use of biomass through burning. Wood (biomass) is simply ignited and the heat energy produced can be used for cooking and warmth.
Ethanol is a common biofuel that is most commonly produced by fermenting biomass with specific yeast that consumes sugars and produces ethanol as a waste product. Sugar cane and corn are popular biomass crops used to produce ethanol. Ethanol is a bioalcohol and the most popular bioalcohol but there are other biofuels like methanol which can also be bioalcohols.
Biodiesel gained a lot of popularity in the last few decades due to the rising price of oil and the fact that it can be used in any diesel engine. Transesterification modifies the fatty acid esters in oils and fat to biodiesel through exposure to alcohols. Unlike ethanol which relies on biomass crops high in sugar, biodiesel biomass needs to be high in oils and fats. This makes waste animal fat and crops like palm oil, soy, or flax popular choices for transesterification. It also explains why waste vegetable oil from restaurants and fast food establishments is so popular among biodiesel enthusiasts.
Diagram of a domestic biogas plant. Image by Unknown.
Syngas (synthetic gas) is produced by combustion of biomass in an environment that is low in oxygen. Instead of igniting when the temperature is increased past the combustion point the organic matter being used will begin to produce syngas. Normal combustion produces carbon dioxide and water but syngas is actually carbon monoxide, hydrogen, and hydrocarbons. This mixture is a more efficient energy source when combusted than simply burning the original organic matter and using the heat energy.
There are many emerging biological energy sources that aren’t being utilised outside of laboratory and research settings. Genetically modified crops and microbes is one of the most promising of these technologies so far. Crops can be genetically modified to produce ideal biomass such as increasing sugar, oil, or carbon levels in the plant. Algaes and other micro-organisms are being modified to produce biofuels. One recent example of this is a modified E. Coli that can produce hydrocarbons from nothing more than water (hydro) and air (carbon) using sunlight for energy.
Biofuels in the News
| Biofuels a boon for Brazil’s rural poor, but obstacles remain elsewhere – 2013-05-24 Biofuels have long been hailed as one of the potential answers to climate change. Their environmental credentials are controversial, but a … |
| Biofuel Stock Addresses High Fuel Costs in Caribbean – 2013-05-24 BioFuel Aruba is one firm working towards addressing these concerns by promoting biofuel usage in Aruba. Founded by biodiesel activist … |
| Biofuels: Game-changer in aviation fuel? – 2013-05-24 Government, industry and society at large must now join forces to ensure that we quickly gain access to a continuous supply of biofuel. (Photo … |
| Algae Biofuel Industry Plans Conflict with Several Studies and Issues – 2013-05-24 UC-Davis, one of the institutions most actively pursuing algae biofuel research, concludes that algae has the potential to provide for 100% of … |
| Researchers Design Photobioreactor to Produce Biofuel from Algae – 2013-05-24 This is because biofuels can provide environmental improvements in reducing greenhouse gases, which would not be achieved with the use of … |
| Civil engineers tout biofuel byproducts use in concrete – 2013-05-23 Kansas State University civil engineers are developing a mix that they hope will reduce concrete’s carbon footprint and make it stronger. |
| Biofuels: Game-changer in aviation fuel? – 2013-05-23 Government, industry and society at large must now join forces to ensure that we quickly gain access to a continuous supply of biofuel. (Photo … |
| Lawmakers should not be fooled on biofuel – 2013-05-23 Vierhout claims that the European biofuel industry has invested nearly 8 billion in the past eight years, generating 300 million in revenues for … |
| Study reveals biofuels no substitute – 2013-05-23 AVIATION biofuels produced in Australia using widely touted feedstocks and existing technology would be competitive only if crude oil was … |
| Volume In Focus: BioFuel Energy Corp. (NASDAQ:BIOF), NetApp … – 2013-05-22 BioFuel Energy Corp. (NASDAQ:BIOF) stock climbed 6.22% to $4.88. The company on May 14 announced its first quarter 2013 results. For the … |
