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The use of fossil fuel as a source of energy has aided the development of the human race for many years. This technology has allowed for many benefits such as electricity, transportation, manufacturing machinery etc. The world is faced with the complex economic and environmental issues associated with energy use that must be addressed if we are to maintain and improve our lifestyle. Our economy depends on low cost energy. The idea of renewable energy has been around for quite some time but did not receive much attention mainly due to lower oil prices over half a century ago.
However the time has now come when it can no longer be ignored as we enter a new level of consciousness about our fuel consumption and the lack of fossil fuels we have including awareness about the impact on the environment[i]. The pressure to have cheaper alternative energy has become more important especially at a time where we are facing a global recession.
As pressing as these economic issues become, we are also faced with even greater environmental consequences if we do not change our energy use patterns. Looming in the background of everything is the mounting concern of carbon dioxide (CO2) build up and other so called greenhouse gases in the atmosphere, which trap the heat that usually radiates from the earth, and cause global climate change[ii].
Therefore clearly, developing alternatives to fuel should be one of the highest priorities of many nations.
With record oil prices, the future of biofuels made from biomass is of keen interest to the world. Global biofuel production has tripled from 4.8 billion gallons in 2000 to about 16.0 billion in 2007, but still accounts for less than 3 percent of the global transportation fuel supply[iii].
This literature reviews the technology of biofuels, their production, usage and impact on a global scale.
What are Biofuels?
A Biofuel is any fuel that is derived from biomass which can be found in many living biological material. More recently living organisms or their metabolic byproducts such as manure from cows have proved to function as biomasses.
These fuels can be burnt to produce heat and power, used to run vehicles (Brazil has the highest proportion of road vehicles designed to run on biofuels which peaked at 90% in the 1980s) or powering fuel cells.
A biofuel is known to have a minimum 80% content by volume of biomass products.
Like coal and petroleum, biomass is a form of stored energy. One of the main advantages of biofuels is compared to most other fuel types is it is biodegradable, and thus relatively harmless to the environment.
A high percentage of biofuels is derived from agricultural products which are required to be specifically grown e.g. sugarcane and corn. Alos biodegradable by-products from industry, agriculture, households and forestry can also be used to produce bioenergy e.g. timber and rice.
There is a growing interest in biofuel technology and it has lead to research currently being carried out into the large scale utilization of micro algae as an energy source. There are processes being developed for biodiesel, ethanol, methanol, methane, and even hydrogen.
Brief History of Biofuels
The initial use of biofuels was in the early days of the automobile industry. A German inventor known as Nikolaus August Otto came through with his invention of running the combustion engine using ethanol. Another historic invention was the powering of diesel engines using peanut oil was by Rudolf Diesel, the German inventor. But unfortunately however in the 19th century when crude oil became cheaper, cars began using fuels from oil which has led to where we are now.
There is an increasingly importance in the use of biofuels as a replacement, now being considered by many countries such as the United Stated, by 2025 aim to replace 75% of the oil coming from the Middle East.
Over the last century, the world has become accustomed to petroleum based transportation fuels, lubricants and other useful products derived from fossil fuels. However the recent oil prices have been escalating ever since the 1970s fuel crisis and the global climate has changing drastically. Perhaps the time has come to learn a lesson from history and adopt the idea of biofuels for the benefit of the living to save the planet instead of taking the easiest and cheapest way out, saving the planet for the next generations to come.
Case Studies and practices of Biofuels
We will now look at a few case studies where Biofuels have been successfully used and utilized.
Case Study 1 - A Lesson from Brazil
Brazil has the world's second largest ethanol program and is capitalizing on plentiful soybean supplies to expand into biodiesel. More than half of the nation's sugarcane crop is processed into ethanol, which now accounts for about 20 percent of the country's fuel supply.
Initiated in the 1970s after the OPEC oil embargo, Brazil's policy program was designed to promote the nation's energy independence and to create an alternative and value-added market for sugar producers. The government has spent billions to support sugarcane producers, develop distilleries, build up a distribution infrastructure, and promote production of pure-ethanol-burning and, later, flex-fuel vehicles (able to run on gasoline, ethanol-gasoline blends, or pure hydrous ethanol). Advocates contend that, while the costs were high, the program saved far more in foreign exchange from reduced petroleum imports.
In the mid- to late 1990s, Brazil eliminated direct subsidies and price setting for ethanol. It pursued a less intrusive approach with two main elements-a blending requirement (now about 25 percent) and tax incentives favoring ethanol use and the purchase of ethanol-using or flex-fuel vehicles. Today, more than 80 percent of Brazil's newly produced automobiles have flexible fuel capability, up from 30 percent in 2004. With ethanol widely available at almost all of Brazil's 32,000 gas stations, Brazilian consumers currently choose primarily between 100-percent hydrous ethanol and a 25-percent ethanol-gasoline blend on the basis of relative prices.
Approximately 20 percent of current fuel use (alcohol, gasoline, and diesel) in Brazil is ethanol, but it may be difficult to raise the share as Brazil's fuel demand grows. Brazil is a middle-income economy with per capita energy consumption only 15 percent that of the United States and Canada. Current ethanol production levels in Brazil are not much higher than they were in the late 1990s. Production of domestic off- and on-shore petroleum resources has grown more rapidly than ethanol and accounts for a larger share of expanding fuel use than ethanol in the last decade.
Case Study 2 - U.S. Ethanol Expansion
A large expansion in ethanol production is underway in the United States, spurred by high oil prices and energy policies
U.S. ethanol production climbed to almost 5 billion gallons in 2006, up nearly 1 billion gallons from 2005. Despite the speed and magnitude of this increase, the industry is stepping up the pace of expansion, with production expected to top 10 billion gallons by 2009[iv].
Market conditions and policy factors are fueling the rising interest in ethanol. A rapid runup of oil prices over the past several years has combined with provisions of the Energy Policy Act of 2005 and already existing Federal and State biofuel programs to provide economic incentives for an expansion of U.S. ethanol production.
This increase in prices reflects rising global demand for crude oil resulting from strong world economic growth, including rapid manufacturing gains in China and India. Further growth in global economic activity will continue to drive up world demand for oil, particularly in highly energy-dependent economies in Asia. Although the increase in demand is likely to be partly offset by future oil discoveries, new technologies for finding and extracting oil, and continued expansion and improvement in renewable energy, oil prices are expected to remain high by historical standards.
Federal tax laws also provide incentives for biofuels. Under current law, blenders can receive tax credits equal to 51 cents per gallon of ethanol blended with gasoline. This makes ethanol more economical to produce, as part of that credit is, in effect, passed back from blenders to ethanol producers. Additionally, ethanol imports are subject to a tariff of 54 cents per gallon, although imports from designated Central American and Caribbean countries are duty-free up to a maximum of 7 percent of the U.S. ethanol marketx.
As a result of these strong incentives, the ethanol production capacity has increased over the last year as more production plants have been build or are under construction. Once the constructions of the new plants are complete the figures are expected to reach 12 billion gallons within a few years.
Ethanol accounts for a small share in the overall gasoline market, but its importance to the corn market is relatively large. In 2006, ethanol (by volume) represented about 3.5 percent of motor vehicle gasoline supplies in the United States. But 14 percent of the U.S. corn crop went to ethanol production, a share projected to grow to more than 30 percent by 2009/10 and to remain at that level in subsequent years. Even so, by the middle of the next decade, ethanol production (by volume) is expected to represent less than 8 percent of annual gasoline use in the United States.
Thus, while the growth in corn-based ethanol can contribute to the Nation's fuel supply, that contribution is relatively small in the gasoline market but can have large effects in the agricultural sector.
The vast expansion in biofuels production and use mandated by EISA will require the development of new methods and equipment to collect, store, and pre-process biomass in a manner acceptable to biorefineries. These activities, which constitute as much as 20% of the current cost of finished cellulosic ethanol, are comprised of four main elements:
- Harvesters & collectors that remove feedstocks from cropland and out of forests.
- Storage facilities that support a steady supply of biomass to the biorefi nery, in a manner that prevents material spoilage.
- Preprocessing/grinding equipment that transform feedstocks to the proper moisture content, bulk density, viscosity, and quality.
- Transportation of feedstocks from the field to the biorefinery.
Case Study 3 - Biofuels in Senegal JATROPHA PROGRAM
It all started in India when Jatropha Carcus-"Honduras" were carried in by Portuguese sailors a few hundred years ago. They were planted around other valuable plantations as a fence because animals and insects were repelled away from it. Meanwhile, Indian farmers found out that the nut contained oil which they used in their oil lamps. Over the years, these farmers bred the plant to have higher oil content as high as 40-50%. India has always been interested to produce biofuels however it had to come from non-food crops. The Biodiesel produced required certain characteristics for example it had to come from non-food crops and grown in non-prime agricultural land. Jatropha fulfilled these requirements as it is resistant to droughts, requiring minimum use of pesticides and fertilizers. Jatropha plants are very hardy and grow very fast producing seeds for extraction within a few months.
The main objective of the program is to ensure Senegal's self-sufficiency in biodiesel by 2012 with the production of 1 190 000 000 litres of crude Jatropha oil. This production will represent 1 134 000 000 litres of refined oil which can be used as biodiesel for vehicles as well as to generate power[v].
It is also the aim of the program to accelerate the modernisation of the agricultural sector, to create 100,000 direct employment opportunities for the local population particularly in the rural areas where the cultivation of jatropha will be mostly undertaken.
The successful implementation of the jatropha program will ensure the diversification of the cultivation of cash crops, reduce the energy bill of households in the country as well as its heavy dependence on imported energy and improve the country's international trade and balance of payment.
Moreover, the program will contribute towards the reduction of environmental pollution caused by vehicle engines; and will also help alleviate poverty and inequality between rural and urban areas.
BIOFUEL PRODUCTION TYPES & SOURCES
Biofuels can be classified in two ways, firstly by the state at which the fuel exists in their natural form which are mainly gas, liquid or solid. And secondly by the sources they have been produced from and the technology used to produce them. In this literature review, biofuels have been classified according the second way.
FIRST GENERATION - (food crops)
First generation biofuels are derived from food crops such as starch, sugar and vegetable oil using conventional techniques discussed later on. Several types of first generation biofuels are discussed briefly below.
Biodiesel is probably the most common and most popular type of biofuel in the world because it also is the easiest to produce from ordinary vegetable oil. Biodiesel is produced very simply by combining any type of oil or biomass with methanol and sodium hydroxide[vi]. It can be used on any diesel engine without any changes to it by mixing with mineral diesel as was described earlier in the "History of Biofuels" section.
These kinds of oil can be either used for cooking purpose or even as fuel. The main fact that determines the usage of this oil is the quality. The oil with good quality is generally used for cooking purpose. Vegetable oil can even be used in most of the old diesel engines, but only in warm atmosphere. In most of the countries, vegetable oil is mainly used for the production of biodiesel.
There has a been great interest shown by European countries and the USA, the graphs below show a rising trend of biodiesel production is USA and many countries of Europe.
Biogas & Syngas
Biogas is produced from organic materials by anaerobic digestion. Waste materials which are biodegradable can also produce biogas if they are fed into anaerobic digesters[vii]. The resulting biomass can be used as fertiliser for agricultural usage. Biogas is rich in methane gas which can be recovered and used as burning fuel. Methane gas is also produced by the natural decay of garbage dumps over time. Another process to produce Syngas or biosyngas is by gasification of biomass into carbon monoxide and hydrogen. Hydrogen can be recovered from syngas or the syngas can be converted to diesel fuel using Fischer-Tropsch process[viii].
Enzymes and micro-organisms are used to produce alcohols through the process of fermentation of starches and sugar[ix]. Ethanol being the most common of those bioalcohol as in bioethanol produced from sugar cane in Brazil. A significant amount of ethanol is also produced from sugar beets and corn by fermentation in other parts of the world.
SECOND GENERATION (non food crops)
Second generation of biofuels had been developed to use biomass left from the non-food parts of current crops such as stems, leaves and husks left behind after the important parts of the crop has been taken. It also includes biomass from non food crops such as Jatropha plant (which are toxic), switch grass and industrial waste such as wood chips, skin and pulp from fruit pressings. This generation of biofuels is not cost competitive with existing fossil fuels, do not threaten food supplies and biodiversity[x].
THIRD GENERATION (agriculture)
Third generation biofuels is obtained from algae and this is also called advanced biofuel. Algae is easy to grow and it is a high-yielding feedstock for the production of biofuel as it produces 30 times more energy per acre of land than traditional crops such as corn or soybean[xi]. They are biodegradable so it is environmentally friendly. Similar to obtaining the oil from vegetation, algae contains almost 40-50% oil which is squeezed out and the remaining biomass can be used as fertilizer or high protein animal feed. The oil from algae can be converted to biodiesel.
FOURTH GENERATION (biodiesel to gasoline)
Last but not least is fourth generation biofuels which is still undergoing research at the highest levels. The main aim is to convert biodiesel into gasoline similar to the one obtained from petroleum but it will be much cleaner with less harmful emissions. This is similar to how natural gas or methane is converted to petrol. However there is much more study required in this part and will probably not be available in 10-20 years time.
- First generation feedstocks include corn for ethanol and soybeans for biodiesel. These feedstocks are currently in use and their yields have been increasing.
- Second generation feedstocks consist of the residues or "left-overs" from crop and forest harvests. They show much promise for near-term adoption with the development of cellulosic conversion technologies.
- Third generation feedstocks are crops whichrequire further R&D to commercialize, such as perennial grasses, fast growing trees, and algae. They are designed exclusively for fuels production and are commonly referred to as "energy crops". They represent a key long-term component to a sustainable biofuels industry[xii].
- Charles E. Wyman (1996) Handbook on Bioethanol - Production and Utilization, Taylor & Francis Publishers, pg 1
- Intergovernmental Panel on Climate Change. 1990. J.T. Houghton, G.J.Jenkins, and J.J. Ephraums, eds. "Climate Change-the IPCC Scientific Assessment," Cambridge, United Kingdom: Cambridge University Press.
- Amber Waves, November 2007, Volume 5, Issue 5, William Coyle - "The Future of Biofuels A Global Perspective.
- Amber Waves, September 2007, Volume 5, Issue 5, Paul. C. Westcot - "U.S. Ethanol Expansion Driving Changes Throughout the agriculture sector."
- Ministry of Agriculture, New orientation for the Agriculture Sector Policy, REVA Plan, Special Biofuels Program, March 2007, "Biofuels in Senegal Jatropha Program 2007-2009."
- Biofuel Organisation: http://biofuel.org.uk/first-generation-biofuels.html
- Biofuel Organisation: http://biofuel.org.uk/first-generation-biofuels.html
- Lee S., Lee L., Encyclopedia of Chemical Processing, CRC Press (2005), "Biofuels and Bioenergy" pp123
- Biofuel Organisation: http://biofuel.org.uk/first-generation-biofuels.html
- RenewableEnergy.com News Article: Next generation of biofuels; http://www.renewableenergyworld.com/rea/news/story?id=49099
- Washington Post News Article; http://www.washingtonpost.com/wp-dyn/content/article/2008/01/03/AR2008010303907.html
- United States Department of Agriculture, "National Biofuels Action Plan", September 2008, Board Action Area 2: Feedstock production pg 5.