Friday, February 16, 2007

Biomass Fuel Explained:

A biomass fuel is an energy source derived from living organisms. Most commonly it is plant residue, harvested, dried and burned, or further processed into solid, liquid, or gaseous fuels. The most familiar and widely used biomass fuel is wood. Agricultural waste, including materials such as the cereal straw, seed hulls, corn stalks and cobs, is also a significant source. Native shrubs and herbaceous plants are potential sources. Animal waste, although much less abundant overall, is a bountiful source in some areas.

Wood accounted for 25 percent of all energy used in the United States at the beginning of this century. With increased use of fossil fuels, its significance rapidly declined. By 1976, only 1 to 2 percent of United States energy was supplied by wood, and burning of tree wastes by the forest products industry accounted for most of it. Although the same trend has been evident in all industrialized countries, the decline has not been as dramatic everywhere. Sweden, for instance, still meets 8 percent of its energy needs with wood, and Finland, 15 percent.
Globally, it is estimated that biomass supplies about 6 or 7 percent of total energy, and it continues to be a very important energy source for many developing countries. In the last 15 to 20 years, interest in biomass has greatly increased even in countries where its use has drastically declined. In the United States rising fuel prices led to a large increase in the use of wood-burning stoves and furnaces for space heating. Impending fossil fuel shortages have greatly increased research on its use in the United States and elsewhere. Because biomass is a potentially renewable resource, it is recognized as a possible replacement of petroleum and natural gas.
Historically, burning has been the primary mode for using biomass, but because of its large water content it must be dried to burn effectively. In the field, the energy of the sun may be all that is needed to sufficiently lower its water level. When this is not sufficient, another energy source may be needed.
Biomass is not as concentrated an energy source as most fossil fuels even when it is thoroughly dry. Its density may be increased by milling and compressing dried residues. The resulting briquettes or pellets are also easier to handle, store, and transport. Compression has been used with a variety of materials including crop residues, herbaceous native plant material, sawdust, and other forest wastes.
Solid fuels are not as convenient or versatile as liquids or gases, and this is a drawback to the direct use of biomass. Fortunately, a number of techniques are known for converting it to liquid or gaseous forms.
Partial combustion is one method. In this procedure, biomass is burned in an environment with restricted oxygen. Carbon monoxide and hydrogen are formed instead of carbon dioxide and water. This mixture is called synthetic gas or "syngas." It can serve as fuel although its energy content is lower than natural gas (methane). Syngas may also be converted to methanol, a one carbon-alcohol that can be used as a transportation fuel. Because methanol is a liquid, it is easy to store and transport.
Anaerobic digestion is another method for forming gases from biomass. It uses microorganisms, in the absence of oxygen, to convert organic materials to methane. This method is particularly suitable for animal and human waste. Animal feedlots faced with disposal problems may install microbial gasifiers to convert waste to gaseous fuel used to heat farm buildings or generate electricity.
For materials rich in starch and sugar, fermentation is an attractive alternative. Through acid hydrolysis or enzymatic digestion, starch can be extracted and converted to sugars. Sugars can be fermented to produce ethanol, a liquid biofuel with many potential uses.
Cellulose is the single most important component of plant biomass. Like starch, it is made of linked sugar components that may be easily fermented when separated from the cellulose polymer. The complex structure of cellulose makes separation difficult, but enzymatic means are being developed to do so. Perfection of this technology will create a large potential for ethanol production using plant materials that are not human foods.
The efficiency with which biomass may be converted to ethanol or other convenient liquid or gaseous fuels is a major concern. Conversion generally requires appreciable energy. If an excessive amount of expensive fuel is used in the process, costs may be prohibitive. Corn (Zea mays) has been a particular focus of efficiency studies. Inputs for the corn system include energy for production and application of fertilizer and pesticide, tractor fuel, on-farm electricity, etc., as well as those more directly related to fermentation. A recent estimate puts the industry average for energy output at 133 percent of that needed for production and processing. This net energy gain of 33 percent includes credit for co-products such as corn oil and protein feed as well as the energy value of ethanol. The most efficient production and conversion systems are estimated to have a net energy gain of 87 percent. Although it is too soon to make an accurate assessment of the net energy gain for cellulose based ethanol production, it has estimated that a net energy gain of 145 percent is possible.
Biomass-derived gaseous and liquid fuels share many of the same characteristics as their fossil fuel counterparts. Once formed, they can be substituted in whole or in part for petroleum-derived products. Gasohol, a mixture of 10 percent ethanol in gasoline, is an example. Ethanol contains about 35 percent oxygen, much more than gasoline, and a gallon contains only 68 percent of the energy found in a gallon of gasoline. For this reason, motorists may notice a slight reduction in gas mileage when burning gasohol. However, automobiles burning mixtures of ethanol and gasoline have a lower exhaust temperature. This results in reduced toxic emission s, one reason that clean air advocates often favor gasohol use in urban areas.
Biomass is called as a renewable resource since green plants are essentially solar collectors that capture and store sunlight in the form of chemical energy. Its renewability assumes that source plants are grown under conditions where yields are sustainable over long periods of time. Obviously, this is not always the case, and care must be taken to insure that growing conditions are not degraded during biomass production.
A number of studies have attempted to estimate the global potential of biomass energy. Although the amount of sunlight reaching the earth's surface is substantial, less than a tenth of a percent of the total is actually captured and stored by plants. About half of it is reflected back to space. The rest serves to maintain global temperatures at life-sustaining levels. Other factors that contribute to the small fraction of the sun's energy that plants store include Antarctic and Arctic zones where little photosynthesis occurs, cold winters in temperate belts when plant growth is impossible, and lack of adequate water in arid regions. The global total net production of biomass energy has been estimated at 100 million megawatts per year per year. Forests and woodlands account for about 40 percent of the total, and oceans about 35 percent. Approximately one percent of all biomass is used as food by humans and other animals.
Soil requires some organic content to preserve structure and fertility. The amount required varies widely depending on climate and soil type. In tropical rain forests, for instance, most of the nutrients are found in living and decaying vegetation. In the interests of preserving photosynthetic potential, it is probably inadvisable to remove much if any organic matter from the soil. Likewise, in sandy soils, organic matter is needed to maintain fertility and increase water retention. Considering all the constraints on biomass harvesting, it has been estimated that about 6 million MWyr/yr of biomass are available for energy use. This represents about 60 percent of human society's total energy use and assumes that the planet is converted into a global garden with a carefully managed "photosphere."
Although biomass fuel potential is limited, it provides a basis for significantly reducing society's dependence on non-renewable reserves. Its potential is seriously diminished by factors that degrade growing conditions either globally or regionally. Thus, the impact of factors like global warming and acid rain must be taken into account to assess how well that potential might eventually be realized. It is in this context that one of the most important aspects of biomass fuel should be noted. Growing plants remove carbon dioxide from the atmosphere that is released back to the atmosphere when biomass fuels are used. Thus the overall concentration of atmospheric carbon dioxide should not change, and global warming should not result. Another environmental advantage arises from the fact that biomass contains much less sulfur than most fossil fuels. As a consequence, biomass fuels should reduce the impact of acid rain.

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Wednesday, February 14, 2007

Brazil has 2 million biofuel cars on the road

While the U.S. may only now be talking about reducing its dependance on foreign oil, Brazil was thinking about it decades ago, and put in place a program designed to do just that. The genius idea was to pioneer a technology for vehicles which run on gasoline or on ethanol (alcohol) made from sugar cane. The BBC reports that Brazil is experiencing a revival in the use of these vehicles:

Ethanol-driven cars have been on sale there for 25 years, but they have been enjoying a revival since flex-fuel models first appeared in March 2003.
Just 48,200 flex-fuel cars were sold in Brazil in 2003, but the total had reached 1.2 million by the end of last year and had since topped two million, the Brazilian motor manufacturers' association Anfavea said.
Brazil incents buyers with a lower purchase tax on flex-fuel cars, which helps reduce pollution. However, some say that by using sugar cane to power cars, we are wasting valuable food supplies. And that it stinks. A lot.

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Tuesday, February 13, 2007

Biofuel concerns
Without casting doubts on the technical viability of biofuels for use in internal combustion engines or their ability to counter global warming, a number of environmentalists have pointed out some possible adverse side-effects. What is pointReturn’s response?

The western approach to biofuel so far has been to derive it from field crops like corn, rapeseed, sugar cane, etc. Also, in the west, there is no demand pressure on edible oils and therefore much of it is diverted for biofuel production. Finally, G8 countries are looking to drive cars and trucks with biofuels, the same way they are doing with petrofuels: centralised production and worldwide distribution.
A recent spate of mandates in European countries to use 5% biofuel in blend with petrofuels by 2010 has spawned both enthusiasm and criticism. Corporate appetite for subsidy windfalls has turned their attention to continents with abundant sunshine: south America, Africa and Asia. Here biofuel crops are to be grown and ferried to Europe to meet the government mandate. Thereby hang much of the mounting criticism.
Newspaper headlines reporting criticism might make a lay reader doubt the viability of biofuel itself as an alternative. Since one of the missions of pointReturn is to demonstrate energy self-sufficiency through biodiesel it is important to clarify how none of critics’ concerns is applicable to pointReturn’s approach.
A good place to understand critic’s concerns is to read this article from this Guardian newspaper. It’s a good summary of the involved issues and let me consider them one by one.
1- “Fermentation using fertilisers” does not take into account the fact “those fertilisers may well have been made in factories that burn fossil fuels.” In one with this, are proposals to haul biofuel stocks across oceans in ships driven by petrofuels. At pointReturn only mechanical pressing will be used -if possible by animal power- to extract oil. A nominal filtration is sufficient to use the oil directly in diesel engines. The oils will be non-edible, -mostly pongamia- derived from long-lived trees raised using no chemical fertilisers. The oil will be strictly for rural energy needs such as to generate electricity and use in tractors and short-haul transportation.
2- The next criticiam is that farmers might be tempted to diversify from food production to growing biofuel crops. There is much evidence that this is happening by collusion between ill-informed third world politicians and greedy entrepreneurs on the one one side and carpet-bagging tycoons from the west, on the other. Papers periodically report new big-ticket international collaborations for biofuel production. The land for pointReturn [see link below] was deliberately chosen as one abandoned as un-viable for growing food. It will be used for growing both food and fuel for local needs.
3- Another criticism is that wooded land converted to grow biofuel will endanger wildlife. At pointReturn, energy self-sufficiency is only one of the goals. The major objective is integrated restoration of land as habitat for both man and wildlife. Consider too that biofuel will be extracted from trees and that such trees will be in a stand of diverse species. Sound balance inheres in that approach. The objective is not to extract the maximum from land but to enjoy its natural abundance.
pointReturn deliberately chose abandoned land and proposes to restore it as a bio-diverse patch. It’s policy for energy self-sufficiency is to “produce sustainably and use locally”


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Wednesday, January 17, 2007

Biofuel Demand Could Send Shockwaves through World Economy

Reporting by Roddy Scheer

Esteemed environmental policy analyst Lester Brown of the Earth Policy Institute told reporters last week that Americans and the rest of the world are likely to see sharp increases in the price of corn, let alone the popular biofuel ethanol, due to errors in projections made by federal agriculture planners. “Because of inadequate data collection on the number of new [fuel ethanol distilleries] under construction, the quantity of grain that will be needed…has been vastly understated,” said Brown.

The potential problem stems from the fact that increased demand for home-grown ethanol as a gasoline fuel additive has led to an unprecedented number of new distilleries coming online, according to Brown. While the U.S. Department of Agriculture estimates that America’s ethanol distilleries will need 60 million tons of corn from the 2008 harvest, Brown pegs the real number closer to 139 million tons. “If [our] estimate is at all close to the mark, the emerging competition between cars and people for grain will likely drive world grain prices to levels never seen before,” he said.
And the results could be unsettling. “The U.S. corn crop, accounting for 40 percent of the global harvest and supplying 70 percent of the world’s corn exports, looms large in the world food economy,” said Brown. “Substantially reducing this export flow would send shock waves throughout the world economy.”
Brown suggested several alternate courses for U.S. agricultural and transportation planners to follow. For starters, the equivalent of the 2 percent of U.S. automotive fuel supplies now coming from ethanol “could be achieved several times over, and at a fraction of the cost, by raising auto fuel efficiency standards by 20 percent.” Also, a greater shift to hybrid gas-electric cars would mean less demand not only for gasoline but for ethanol—and corn—as well. Brown is calling for a moratorium on the licensing of new ethanol distilleries “while we catch our breath and decide how much corn can be used for ethanol without dramatically raising food prices.”

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Tuesday, August 15, 2006


Biofuel is any fuel that is derived from biomass recently living organism or their metabolic by products, such as manure from cows. It is renewable energy source, unlike other natural resources suchas petroleum, coal and nuclear fuels.
One definition of biofuel is any fuel with an 80% minimum content by volume of materials derived from living organism harvested within the ten years preceding its manufacture.
like coal and petroleum, biomass is form of stored solar energy. The energy of the sun is "captured" thriugh the process of photosynthesis in growing plants. One advantage of biofuel in comparison to most other fuel types is that the energy within biomass can be stored for an indefinite time period and without any danger.
The production of biofuels to replace oil and natural gas is in active development, focusing on the use of cheap organic matter ( usually cellulose, agricultural and sewage waste ) in the efficient production of liquid and gas biofuels which yield high net energy gain. The carbon in biofules was recently extracted from atmospheric carbon dioxide by growing plants, so burning it does not result in a net increase of carbon dioxide in the Earth's atmosphere. As a result, biofuels are seen by many as a way to reduce the amount of carbon dioxide released into atmosphere by using them to replace nin renewable sources energy. Noticeable is the fact that the quality of timber or grassy biomass does not have a direct impact on its value as an energy-source.


Biofuel was used since the early days of the car industry. Otto Von Nicklaus, the inventor of the combustion engine, conceived his invention to run on ethanol. While Rudolf Diesel, the inventor of the combustion engine, conceived it to run peanut oil. The Ford Model T, a car produced between 1903 and 1926 used ethanol. However, whwn crude oil began being cheaply extracted from deeper in the soil ( thanks to drilling starting in the middle of the 19th century ), cars began using fuels from oil. Then with the oil shock of 1973 and 1979, there was an increase interest from governments and academic in biofuels. However, interest decreased with the counter-shock of 1986 that made oil prices cheaper again. But since about 2000 with rising oil prices, concerns over the potential oil peak, greenhouse gas emissions ( Global warming ), and stability in the Midle East are pushing renewed interest in biofuels. Government officials have made statements and given aid in favour of biofuels. Foe example, U.S.president Geoorge Bush said in his 2006 State of Union speech, that he wants for the United States, by 2005, to replace 75% of the oil coming from the Middle East.


One widespread use of biofuels is in home cooking and heating. Typical fuels for this arewood, charcoal or dried dung. The biofuel may be burned on an open fireplace or in a special stove. The efficiency of this may very widely, from 10% for a well made fire ( even less if the fire is not made carefully ) up to 40% for a custom designed charcoal stove. Inefficent use of fuel may be a minor cause of deforestation( through this is negligible compared to deliberate destruction to clear land for agricultural use ) but more importantly it means that more work has to be put into gathering fuel, thus the quality of cooking stoves has a direct influence on the viability of biofuels.

"American homeowners are turning to burning corn in special stoves to reduce their energy bills. Sales of corn-burning stoves have tripled this year [...] Corn-generated heat costs less than a fifth of the current rate for propane and about a third of electrical heat".

A. Direct electricity generation

The methane in biogas is often pure enough to pass directly through gas engines to generate green energy. Anaerobic digesters or biogas powerplants convert this renewable energy source into electricity. This can either be used commercially or on a local scale.

B. Use on farms

In Germany small scale use of biofuel is still a domain of agricultural farms. It is an official aim of the German government to use the entire potential of 200,000 farms for the production of biofuel and bioenergy. (Source: VDI-Bericht "Bioenergie - Energieträger der Zukunft".

C. Home use

Different combustion-engines are being produced for very low prices lately . They allow the private house-owner to utilize low amounts of "weak" compression of methane to generate electrical and thermal power (almost) sufficient for a well insulated residential home.

D. Rolling Network

Although decentralised biofuel production is possible the so called island operation bears problems with capacity and load balancing. In case vehicles for commuting and social or procurement trips may be used to transport energy we have a so called rolling network. We expect a higher efficiency with wood based biogas which may be purified in a home filling station and released into the natural gas network at work or special receiving gas stations. This kind of business is not bound to constant delivery amounts but very flexible in both directions. Ie. also gas refilling is possible if the wood gas production is low at the moment or the distance travelled was high. With so called plug in hybrid electric vehicles in theory it would be also possible to carry energy produced underway to work or to home and feed it into the grid. But this is less efficient and also less probable.


A. Biologically produced alcohols

Biologically produced alcohols, most commonly ethanol and methanol, and less commonly propanol and butanol produced by the action of bacteria — see alcohol fuel.

B. Biologically produced gases

Biogas is produced by the process of anaerobic digestion of organic material by anaerobes. Biogas can be produced either from biodegradable waste materials or by the use of energy crops fed into anaerobic digesters to supplement gas yields.

Biogas contains methane and can be recovered in industrial anaerobic digesters and mechanical biological treatment systems. Landfill gas is a less clean form of biogas which is produced in landfills through naturally occurring anaerobic digestion. Paradoxically if this gas is allowed to escape into the atmosphere it is a potent greenhouse gas.

C. Biologically produced gases from wastes

Biologically produced oils and gases can be produced from various wastes:

  • Thermal depolymerization of waste can extract methane and other oils similar to petroleum.
  • Pyrolysis oil may be produced out of biomass, wood waste etc. using heat only in the flash pyrolysis process. The oil has to be treated before using in conventional fuel systems or internal combustion engines (water + pH).
  • One company, GreenFuel Technologies Corporation, has developed a patented bioreactor system that utilizes nontoxic photosynthetic algae to take in smokestacks flue gases and produce biofuels such as biodiesel, biogas and a dry fuel comparable to coal .

D. Biologically produced oils

Biologically produced oils can be used in diesel engines:

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