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Vegetable Oil Fuel Experiments
This article is about vegetable oil used as fuel. For other uses of vegetable oil, see vegetable oil.
Waste vegetable oil which has been filtered.
Many vegetable oils have similar fuel properties to diesel fuel, except for higher viscosity and lower oxidative stability. If these differences can be overcome, vegetable oil may substitute for #2 Diesel fuel, most significantly as engine fuel or home heating oil. For engines designed to burn #2 diesel fuel, the viscosity of vegetable oil must be lowered to allow for proper atomization of fuel, otherwise incomplete combustion and carbon build up will ultimately damage the engine. Many enthusiasts refer to vegetable oil used as fuel as waste vegetable oil (WVO) if it is oil that was discarded from a restaurant or straight vegetable oil (SVO) or pure plant oil (PPO) to distinguish it from biodiesel. HistoryThe first known use of vegetable oil as fuel in a diesel engine was a demonstration of an engine built by the Otto company and designed to burn mineral oil, which was run on pure peanut oil at the 1900 World's Fair. Late in his career, Rudolf Diesel investigated using vegetable oil to fuel engines of his design, and in a 1912 presentation to the British Institute of Mechanical Engineers, he cited a number of efforts in this area and remarked, "The fact that fat oils from vegetable sources can be used may seem insignificant today, but such oils may perhaps become in course of time of the same importance as some natural mineral oils and the tar products are now."[1] Periodic petroleum shortages spurred research into vegetable oil as a diesel substitute during the 30s and 40s, and again in the 70s and early 80s when straight vegetable oil enjoyed its highest level of scientific interest. The 1970s also saw the formation of the first commercial enterprise to allow consumers to run straight vegetable oil in their automobiles, Elsbett of Germany. In the 1990s Bougainville conflict, islanders cut off from oil supplies due to a blockade used coconut oil to fuel their vehicles.[2] Academic research into straight vegetable oil fell off sharply in the 80s with falling petroleum prices and greater interest in biodiesel as an option that did not require extensive vehicle modifications. Application and usability
While engineers and enthusiasts have been experimenting with using vegetable oils as fuel for a diesel engine since at least 1900, it is only recently that the necessary fuel properties and engine parameters for reliable operation have become apparent. A number of peer reviewed studies exists that show reliable long term use of vegetable oil; the German Deutz F3l912W.[3] and a high speed common rail engine fitted to a Mercedes-Benz 220 C Class[4] Most diesel car engines are suitable for the use of SVO, also commonly called Pure Plant Oil (PPO), with suitable modifications. Principally, the viscosity and surface tension of the SVO/PPO must be reduced by preheating it, typically by using waste heat from the engine or electricity, otherwise poor atomization, incomplete combustion and carbonization may result. One common solution is to add a heat exchanger, and an additional fuel tank for "normal" diesel fuel (petrodiesel or biodiesel) and a three way valve to switch between this additional tank and the main tank of SVO/PPO. (This aftermarket modification typically costs about $1200 USD.)[5] The engine is started on diesel, switched over to vegetable oil as soon as it is warmed up and switched back to diesel shortly before being switched off to ensure that no vegetable oil remains in the engine or fuel lines when it is started from cold again. In colder climates it is often necessary to heat the vegetable oil fuel lines and tank as it can become very viscous and even solidify. Single tank conversions have been developed, largely in Germany, which have been used throughout Europe. These conversions are designed to provide reliable operation with rapeseed oil that meets the German rapeseed oil fuel standard DIN 51605. Modifications to the engines cold start regime assist combustion on start up and during the engine warm up phase. Suitably modified indirect injection (IDI) engines have proven to be operable with 100% PPO down to temperatures of -10°C. Direct injection (DI) engines generally have to be preheated with a block heater or diesel fired heater. The exception is the VW Tdi (Turbocharged Direct Injection) engine for which a number of German companies offer single tank conversions. For long term durability it has been found necessary to reduce the oil change frequency and to pay increased attention to engine maintenance. With unmodified engines the unfavorable effects may be reduced by blending, or "cutting", the SVO/PPO with diesel fuel; however, opinions vary as to the efficacy of this. Some WVO mechanics have found higher rates of wear and failure in fuel pumps and piston rings. This can generally be attributed to the use of oils with properties or contaminants that make them unsuitable for use in this type of application, poorly maintained engines, unsuitable engine modifications or operating regimes. Many cars powered by indirect injection engines supplied by in-line injection pumps, or mechanical Bosch injection pumps are capable of running on pure SVO/PPO in all but winter temperatures. Indirect injection Mercedes-Benz vehicles with in-line injection pumps and cars featuring the PSA XUD engine tend to perform reasonably, especially as the latter is normally equipped with a coolant heated fuel filter. Engine reliability would depend on the condition of the engine. Attention to maintenance of the engine, particularly of the fuel injectors, cooling system and glow plugs will help to provide longevity. Ideally the engine would be converted. PropertiesThe main form of SVO/PPO used in the UK is rapeseed oil (also known as canola oil, primarily in the United States and Canada) which has a freezing point of -10°C. However the use of sunflower oil, which freezes at -17°C, is currently being investigated as a means of improving cold weather starting. Unfortunately oils with lower gelling points tend to be less saturated (leading to a higher iodine number) and polymerize more easily in the presence of atmospheric oxygen. ExamplesSome Pacific island nations are using coconut oil as fuel to reduce their expenses and their dependence on imported fuels while helping stabilize the coconut oil market. Coconut oil is only usable where temperatures do not drop below 17 degrees Celsius (62 degrees Fahrenheit), unless two-tank SVO/PPO kits or other tank-heating accessories, etc. are used. Fortunately, the same techniques developed to use, for example, canola and other oils in cold climates can be implemented to make coconut oil usable in temperatures lower than 17 degrees Celsius. Home heatingWith often minimal modification, most residential furnaces and boilers which are designed to burn No. 2 heating oil can be made to burn either biodiesel or filtered, preheated waste vegetable oil. These are generally not as clean-burning as petroleum fuel oil, but if processed at home, by the consumer, can result in considerable savings. Many restaurants will give away their used cooking oil either free or at minimal cost, and processing to biodiesel is fairly simple and inexpensive. Burning filtered WVO directly is somewhat more problematic, since it is much more viscous, but it can be accomplished with suitable preheating. WVO can thus be a very economical heating option for those with the necessary mechanical and experimental aptitude. Combined Heat and PowerA number of companies offer compressed ignition engine generators optimized to run on plant oils where the waste engine heat is recovered for heating. AvailabilityWaste vegetable oilAs of 2000, the United States was producing in excess of 11 billion liters of waste vegetable oil annually, mainly from industrial deep fryers in potato processing plants, snack food factories and fast food restaurants. If all those 11 billion liters could be collected and used to replace the energetically equivalent amount of petroleum (an ideal case), almost 1% of US oil consumption could be offset.[6] However, use of waste vegetable oil as a fuel competes with some already established uses. Pure vegetable oil (pure plant oil)Pure plant oil (PPO) (or Straight Vegetable Oil (SVO)), in contrast to waste vegetable oil, is not a byproduct of other industries, and thus its prospects for use as fuel are not limited by the capacities of other industries. Production of vegetable oils for use as fuels is theoretically limited only by the agricultural capacity of a given economy. Legal implicationsThe conversion of an automobile engine to burn vegetable oil is not legal under US Environmental Protection Agency guidelines.[7] The EPA has not fined anyone for doing so, but certain laws may have to change — or a certification process may need to be established — before VO conversions become more popular in the US. Taxation of fuelTaxation on SVO/PPO as a road fuel varies from country to country, and it is possible the revenue departments in many countries are even unaware of its use, or feel it insufficiently significant to legislate. Germany offers 0% taxation, resulting in their leading on most developments of the fuel use. However SVO/PPO as a road fuel will be taxed with 0,09 €/liter on January, the 1st of 2008 in Germany. From thereon it will rise up to 0,45 €/liter until 2012. There seems to be no clear taxation system in the USA, however given the low rate of fuel taxation, it is unlikely to face anything unfavorable, although charges could vary from state to state. Production of biodiesel in some US regions may require motor fuel taxes to be paid, which are typically used to fund road construction costs.[8] The Government of Canada exempted biodiesel from the federal excise tax on diesel in the March 2003 budget. In Ireland a pilot scheme is currently running (as of April 2006) whereby eight suppliers have been approved to sell SVO/PPO for use as a fuel without the payment of excise duty (Value Added Tax at 21% still applies, SVO from any other source still attracts excise duty at 36.8058 Euro cents per litre plus 21% VAT). Despite its use being common in France, it would appear there has been no legislation to cover this. In the UK, it is legal once duty on the fuel is paid.[9] In the UK, drivers using SVO/PPO have been prosecuted for failure to pay duty to Her Majesty's Revenue and Customs. The rate of taxation on SVO was originally set at a reduced rate of 27.1p per litre, but in late 2005, HMRC started to enforce the full diesel excise rate of 47.1p per litre. Following a review late 2006,[10] HM Revenue & Customs has announced changes regarding the administration and collection of excise duty of biofuels and other fuel substitutes (Veg Oil). The changes came into effect on June 30, 2007. There is no longer a requirement to register (enter premises) or pay duty on vegetable oil used as road fuel if you 'produce' (use) less than 2500 litres per year.[11] For those producing over this threshold the biodiesel rate now applies. HMRC argued that SVOs/PPOs on the market from small producers did not meet the official definition of "biodiesel" in Section 2AA of The Hydrocarbon Oil Duties Act 1979 (HODA), and consequently was merely a "fuel substitute" chargeable at the normal diesel rate. Such a policy seemed to contradict the UK Government's commitments to the Kyoto Protocol and to many EU directives and had many consequences, including an attempt to make the increase retroactive, with one organization being presented with a £16,000 back tax bill. This change in the rate of excise duty has effectively removed any commercial incentive to use SVO/PPO, regardless of its desirability on environmental grounds; unless waste vegetable oil can be obtained free of charge, the combined price of SVO/PPO and taxation for its use usually exceeds the price of mineral diesel. HMRC's interpretation is being widely challenged by the SVO/PPO industry and the UK pure Plant Oil Association (UKPPOA) has been formed to represent the interests of people using vegetable oil as fuel and to lobby parliament.[12] See alsoReferences
External links
Vegetable oil economy is the potential of vegetable oil to replace fossil fuels in the economy and how it compares to other potential replacements. Vegetable oils are the basis of biodiesel, which can be used like conventional diesel. Some vegetable oil blends are used in unmodified vehicles, but straight vegetable oil needs specially prepared vehicles which have a method of heating the oil to reduce its viscosity and surface tension. Vegetable oil can also be used as feedstock for an oil refinery. The list of vegetable oils is long, the vegetable oil market is growing. The availability of biodiesel around the world is increasing. There is significant research in algaculture methods with the intent to make biofuel from algae. 
Future of energy for world economyThere is a limited amount of fossil fuel inside the Earth. Since the current world energy resources and consumption is mainly fossil fuels, we are very dependent on them for both transportation and electric power generation. The Hubbert peak theory predicts that oil depletion will result in oil production dropping off in the not too distant future. As time goes on our economy will have to transition to some alternative fuels. Fossil fuels have solved two problems which could be separately solved in the future: the problem of a source of primary energy and of energy storage. Along with straight vegetable oil and biodiesel, some energy technologies that could play an important part in the future include : Environmentally friendly fuelPlants use sunlight and photosynthesis to take CO2 out of the Earth's atmosphere to make vegetable oil. The same CO2 is then put back after it is burned in an engine. Thus vegetable oil does not increase the CO2 in the atmosphere, and does not contribute to the problem of greenhouse gas. It is really a way of catching and storing solar energy. It is a true renewable energy. Burning fossil fuels releases sulfur dioxide and other harmful air pollution.[2] Because vegetable oil has not been inside the earth for millions of years, it is not contaminated with things like sulfur and burns much cleaner, even than ultra low sulphur diesel. Burning fossil fuels also contributes to the greenhouse gas problem. Note that if fossil fuels are used in any aspect of production and distribution (making fertilizer, tractors, fuel trucks, etc.), then there would be some contribution to pollution. For it to be 100% non-polluting all aspects of vegetable oil production would have to be non-polluting as well. Safety
Vegetable oil is essentially non-toxic relative to other fuels such as gasoline, petroleum-based diesel, ethanol, or methanol, and has a much higher flash point (approximately 275-290 °C)[3]. The higher flash point reduces the risk of accidental ignition. Some types of vegetable oil are edible. Generation and storageTechnologies of hydrogen economy, batteries, compressed air energy storage, and flywheel energy storage address the energy storage problem but not the source of primary energy. Other technologies like fission power, fusion power, and solar power address the problem of a source of primary energy but not energy storage. Vegetable oil addresses both the source of primary energy and of energy storage. The cost and weight to store a given amount of energy as vegetable oil is relatively low compared to many of the potential replacements for fossil fuels. Type of vegetable oilThe list of vegetable oils article discusses which types of vegetable oil are used for fuel and where different types are grown. TransportationFor transportation the energy density and cost to store the energy are important. If the density is low or the cost is too high it is not practical to make vehicles with reasonable range. Vegetable oil and biodiesel are close to regular diesel. Another potential issue for new fuels is the Catch-22 conundrum: if there needs to be expensive new infrastructure before people will make cars running on a new fuel, and there need to be new cars before people will build the infrastructure, how can the transition ever be made? With vegetable oil this is not nearly the problem that it is with some other fuels. The transition from petroleum oil based transportation to vegetable oil based transportation could be gradual and relatively easy compared to hydrogen, ethanol, and most other alternatives. Vegetable oil is used for transportation in four different ways:
Electricity generationVegetable oil is a convenient safe way to store energy for transportation and is similar to the way things have been done. For electricity generation these things are not so important. The most important thing is cost for the electricity produced. The world coal reserves are far larger than the world oil reserves. So replacing the coal used in power plants is not as urgent as replacing the oil used for transportation. The motivation to use vegetable oil for power generation is much less than for transportation. Other methods, like nuclear power, fusion power, wind power and solar power, may provide cheaper electricity, so vegetable oil may only be used in peaking power plants and small power plants, as diesel is limited to today. There is at least one 5 MW power plant that runs on biodiesel. [10]. MAN B&W Diesel, Wartsila and other companies produce engines suitable for power generation that can be fueled with pure plant oils. Market / cost / price / taxes
Availability of biodiesel around the World is improving. It is estimated that by 2010 the market for biodiesel will be 7.5 billion litres (2 billion USgallons) in the U.S and 9.5 billion litres (2.5 billion USgallons) in Europe. [11] Biodiesel currently has 3% of the diesel market in Germany and is the number 1 alternative fuel.[12] The German government has a Biofuels Roadmap in which they expect to reach 10% biofuels by 2010 with the diesel 10% coming from fuel made from vegetable oil. [13] From 2005 to 2007 a number of types of vegetable oil have doubled in price. The rise in vegetable oil prices is largely attributed to biofuel demand. [14] Much of the fuel price at the pump is due to fuel tax. If you buy vegetable oil at the grocery store it does not have such high taxes. So at times people have bought vegetable oil at the store for their cars because it was cheaper. They did this in spite of the fact that packaging by the gallon adds to the cost and it was illegal to use in a car since no fuel tax had been paid on it. [15] Since vegetable oil (even as biodiesel) does not contribute to greenhouse gas, governments may tax it much less than gasoline as they have done with ethanol. [16] This would help them reach Kyoto protocol targets. Production in sufficient quantity
The World production of vegetable oil in 2004/5 was 387.7 million tonnes. Much of this is from Oil Palm, and palm oil production is growing at 5% per year. [17] At about 7.5 lb/USgal (900 g/L) this is about 110 billion USgallons (430 billion L). Currently vegetable oil is mostly used in food and some industrial uses with a small percentage used as fuel. In 2004 the US consumed 530 billion litres (140 billion USgal) of gasoline and 150 billion litres (40 billion USgal) of diesel. [18] In biodiesel it says oil palm produces 5940 litres per hectare (635 USgal/acre) of palm oil each year. To make 180 billion US gallons of vegetable oil each year would require 1,150,000 square kilometres (443,000 sq mi) or a square of land 1070 kilometres (666 miles) on a side.
Algaculture could potentially produce far more oil per unit area. [20] Results from pilot algaculture projects using sterile CO2 from powerplant smokestacks look promising. Genetic modifications to soybeans are already being used. Genetic modifications and breeding can increase vegetable oil yields. From 1979 to 2005 the soybean yield in bushels per acre more than doubled. [21] A company has developed a variety of camelina sativa that yields 20% more oil than the standard variety. [22] Environmental effects
There is concern that the current growing demand for vegetable oil is causing deforestation, with old forests being replaced with Oil Palms. [23] When land is cleared it is often burned, which releases lots of CO2. Vegetable oil production would have to increase substantially to replace gasoline and diesel. With current technology such an increase in production would have a substantial environmental impact. [24] While not immediately toxic to wildlife, spills are still potentially dangerous due to the physical damage caused to ecosystems. These effects may include contamination of tissues impeding their vital functions (e.g. plant stomata, fish gills, bird feathers, and mammal hair), increased biological oxygen demand and chemical oxygen demand leading to deoxygenation of water, and infiltration into soil sediments and aquifer contamination. Food vs fuel debateIn some poor countries the rising price of vegetable oil is causing problems. [25] [26] There are those that say using a food crop for fuel sets up competition between food in poor countries and fuel in rich countries. Some propose that fuel only be made from non-edible vegetable oils like jatropha oil. Others argue that the problem is more fundamental. Farmers can switch from producing food crops to producing biofuel crops to make more money, even if the new crops are not edible. [27] [28] The law of supply and demand predicts that if less farmers are producing food the price of food will rise. It may take some time, as farmers can take some time to change which things they are growing, but increasing demand for biofuels is likely to result in price increases for many kinds of food. Some have pointed out that there are poor farmers and poor countries making more money because of the higher price of vegetable oil. [29] Urgency of transition to renewable transportation
Algae for vegetable oil productionThe silver bullet for the vegetable oil economy is harvesting vegetable oil from algae. Some species of algae contain as much as 50% vegetable oil. Algae have very high growth rates compared to plants normally used to produce vegetable oil. Potentially algae could produce much more oil per area of land than current farming methods. [34] So producing vegetable oil this way should result in less deforestation and less competition for food production land. One expert wrote: "As demonstrated here, microalgal biodiesel is technically feasible. It is the only renewable biodiesel that can potentially completely displace liquid fuels derived from petroleum. Economics of producing microalgal biodiesel need to improve substantially to make it competitive with petrodiesel, but the level of improvement necessary appears to be attainable. " [35]
There is substantial research and development work in this area but as of 2007 there is no commercial vegetable oil produced from algae and used as biofuel. If and when the commercialization challenges are overcome, vegetable oil production could expand very rapidly. Net energy gainTo evaluate potential sources of primary energy it is useful to look at the net energy gain or EROEI. This is the ratio of energy out to energy input. These numbers can change as the technology changes. For example, early photovoltaics technology had EROEI numbers of less than 1 but current cells achieve net energy gain numbers of 10 to 30.
See also
References
WeblinksThis article is licensed under the GNU Free Documentation License. It uses material from Wikipedia Encyclopedia article "Straight Vegetable Oil" |
