Biofuels Beyond Ethanol And Biodiesel


The world today has become an increasingly industrial and energy dependent. This increasing need for energy and iminent decline in future fossil fuels has lead to many developments in finding new rewnewable energy sources. Wood, a very important soili biofuel, has been used for thousands of years. An effort has been made to make more environmentally friendly fuels that reduce the amount of greenhouse gases including ethanol and biodiesel. First generation biofuels such as vegetable oil and biodiesel fuels are made from sugars, starches, and animal fats. Bioalcohol and butanol are other examples of such fuels. Biodiesel is one such fuel that when mixed with mineral diesel, can be used in any diesel engine. In the United States, more than 80% of commercial trucks and city buses run on diesel fuel, and therefore, can be switched over to an all biodiesel "diet". The U.S. market for biodiesel is growing by leaps and bounds; "…from 25 million gallons per year in 2004 to 78 million gallons by the beginning of 2005. By the end of 2006 biodiesel production was estimated to increase fourfold to more than 1 billion gallons" [1].


While everyone seems confident that ethanol and biodiesel will someday rid us of our mid-east dependence while simultaneously helping the environment by using renewable resources. Unfortunately, experts are starting to realize that neither of these options are viable in large scale as well as long term.

The main reason that these two will not work is because they are both produced through the fermentation of feedstock. The reason that this is a problem is because of competition to by it between food market and fuel refineries. This was evident in Mexico when high corn prices cause rioting in the capital.

Currently soybean oil is most commonly used for the production of biodiesel and ethanol, unfortunately it is also in high demand in the feedstock industry and its price has risen significantly over the past few years. Palm oil is another popular biodiesel ingredient, used mostly in europe, but in heavy demand in the food industry. It is prized because it produces the most gallons of oil per acre of any of the usable feedstock (635 gallons/acre compared to soybeans 50). Unfortunately palm oil is made in the rainforests of Malaysia and Indonesia and according to a UN report 98 of these rainforest will be destroyed by 2022[8]. A surprising fact about rapeseed based diesel releases almost as much greenhouse gasses as its petroleum based counterpart over its life. The major difference being that the petroleum based diesel releases almost all of its emission at combustion, whereas rapeseed’s emissions come from its refining as growing (farm equipment) processes.

Cascone says one of the major reasons that people have jumped on the feedstock bandwagon so quick was because of the subsidies the government was giving out, caused by farming industry lobbyists whom he says are very good at what they do. Now industries are starting to realize what will happen so they are looking at other potential fuel, and rather that look to grow something to make fuel, they are looking to use waste to make it[10].


Biomass is biological material that can be used directly for heating or burnt as fuel. A large amount of biomass is grown specifically from different plants including hemp, corn, poplar and willow. Also included in biomass are biodegradable fuels that can be burned as fuels and some animal matter that can be used for heat production. Biomass is one of the renewable sources of energy being taken advantage of by both consumers and companies alike.


Although a small and rather new process, farming algae my become the source of many biofuels in the future. These algae can yield between 5,000 and 20,000 gallons of fuel per acre per year [8]. This process is not only desireablt from the yielding standpoint, but because algae are fast-growing and can grow in places that some plants can not. They can grow in deserts where the groundwater is saline, and can grow from 7 to 30 times faster than the next fastest crop. "Research into algae for the mass-production of oil is mainly focused on microalgae; organisms capable of photosynthesis that are less than 2 mm in diameter, including the diatoms and cyanobacteria. This preference towards microalgae is due largely to its less complex structure, fast growth rate, and high oil content (for some species). Some commercial interests into large scale algal-cultivation systems are looking to tie in to existing infrastructures, such as coal power plants or sewage treatment facilities. This approach not only provides the raw materials for the system, such as CO2 and nutrients; but it changes those wastes into resources" [8].


Some problems that have arisen in thiis undertaking is finding a strain of algae with a high enough lipid count with a fast enough growth rate that isn't too hard to harvest. Other problems that have surfaced are the lack of a decent structure that is suitable to grow the large amoutn of algae need for fuel production. A chep source of carbon dioxide is also need for the closed system that is preferred when growing the algae. Otherwise, if an open system is used, the strains are subject to contamination from airborne particcles or substances.


Energy from Wastes

Energy derived from wastes can lead to a potential decine in the need for fossil fuels. A recent publication by the European Union highlighted the potential for waste-derived bioenergy to contribute to the reduction of global warming. The report concluded that 19 million tons of oil equivalent is available from biomass by 2020, 46% from bio-wastes: municipal solid waste (MSW), agricultural residues, farm waste and other biodegradable waste streams [1].


Another type of fuel that could be used is biobutanol. It is has an octane level comparable to that of ethanol but is more convenient for several reasons. First, it has an energy density closer to that of gasoline; meaning that it would have a mile per gallon rating that is very similar, and this would make it more viable for consumers since they are all in the mode of searching for the best fuel mileage. Secondly, because biobutanol has such low water solubility it can be handled just like gasoline. It can use the same infrastructure, including refineries, fuel transportation, storage and gas stations. Ethanol facilities can switch easily and cheaply to producing biobutanol making it easy for industries producing ethanol to switch over[9].

Biobutanol is produced with biowaste. Through processes that are just starting to become commercially viable garbage such as food waste, cardboard, sewage, etc. can be fermented into biobutanol, and some other process are being researched currently to get the fuel out more efficiently. It currently costs NYC $90/ton to ship its garbage to other locations but for $30-50 to ship it to a processing facility that can easily separate the biomass from the metal, plastic, and glass. Also now the fuel will come from cities, where more fuel is needed, rather than ship it out from rural areas[9].

Landfill gas

A type of renewable energy found in many parts of the country is the landfill gas plant. These plants burn landfill gas as their primary fuel. This gas is produced from municipal waste from the landfill. Landfill gas is composed of about 50 % methane. The gas is taken from wells in the landfill and pumped through a compressor to the generation plant through pipes. [1] Landfill gas is a renewable energy source because this gas is continually produced from the landfill after it is full. To help the production of landfill gas, a waste liquid called leachate is circulated from the bottom and pumped to the top of the landfill. [3]

Currently, there are 400 landfill plants in the U.S. Most of these are producing a few megawatts. The largest landfill gas plant is the 50 MW Puente Hills Energy Recovery Facility in southern California. The second largest plant is the 30 MW Fairless Hills Generation Station in Fairless Hills, PA. [4]

Solid Biofuels


Currently, the state of Florida has little renewable energy sources. The biggest product from the state is oranges. So, it seems natural that they would use this as a form of energy. As of now, orange peels are dried and feed to cattle. The oil from the peels is used for cleaning products. One use of orange peels under research is the conversion to methanol. This biofuel would be the fuel for power cells of automotives. There would be enough for 75 percent of every vehicle. [6] Another biofuel that the peels could be converted to is cellulosic ethanol. This conversion could produce about 60 million gallons per year. [5] Presently, the renewable use of orange peels is as a solid fuel. This concept is taken from the wood products industry where saw dust or wood chip are put in the boiler as fuel. Instead of wood, orange peels are acts as the fuel. There would be enough energy to power the juicing machines at the plant. [7]


See also


  9. United Nations Environmental Program, “The Last Stand of the Orangutan” Feb. 6, 2007
  10. Seraf, S. Thomas, B. Hydrocarbon Processing, “Biodiesel: A Feedstock Quandary” September 2007
  11. Cascone,R. Hydrocarbon Processing, “Biofuels: Beyond Ethanol and Biodiesel” September 2007
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