What is Biodiesel?
Biodiesel is a diesel fuel substitute produced from renewable sources such as vegetable oils, animal fats, and recycled cooking oils. Chemically, it is defined as the mono alkyl esters derived from renewable sources. Biodiesel is typically produced through the reaction of a vegetable oil or animal fat with methanol or ethanol in the presence of a catalyst to yield glycerin and biodiesel (chemically called methyl or ethyl esters). Biodiesel can be used in neat form, or blended with petroleum diesel for use in (the) diesel engines. Biodiesel has similar physical and chemical properties to petroleum diesel with reference to the operation of a diesel motor.. Its physical and chemical properties as it relates to operation of diesel engines are similar to petroleum based diesel fuels.
Advantages of using biodiesel
Biodiesel can be used alone or mixed in any ratio with petroleum diesel fuel, when it is burned, CO2 is released into the atmosphere which is then recycled and absorbed by growing plants which can later be processed into fuel. It produces 80% less carbon dioxide, 100% less sulfur dioxide (major component of acid rain) and up to 75% less exhaust smoke emissions. The flash point of biodiesel is ¹ 150°C as opposed to petroleum diesel at ¹ 70°C. It degrades about 4 times faster after spillage and provides significant lubricity improvement over petroleum diesel fuel.
Biodiesel’s attributes
Across the globe environmental concerns and energy security issues have prompted legislation and regulatory actions spurring demand for alternative fuels such as biodiesel. However, the greatest driving force for the use of biodiesel and biodiesel blends is the need to have a fuel that fulfills all of the environmental and energy needs. One of the largest roadblocks to the use of alternative fuels is the change of performance noticed by users. Biodiesel has many positive attributes associated with its use, but by far the most noted attribute highlighted by consumers is the similar operating performance to conventional diesel fuel and the lack of changes required in facilities and maintenance procedures.
Biodegradability
Biodiesel has desirable degradation attributes which make it the fuel of choice by environmentally conscious users. Studies at the University of Idaho, USA, compared the biodegradation of biodiesel in an acqueous solution to diesel fuel and dextrose (sugar). Biodiesel samples degraded more rapidly than dextrose, and were 95% degraded at the end of 28 days. The diesel fuel was approximately 40% degraded after 28 days.
It should also be noted that blending biodiesel with diesel fuel accelarates its biodegradability. For example, blends of 20% biodiesel and 80% diesel fuel degraded twice as fast as petroleum diesel. Thus, biodiesel use has demonstrated biodegradability benefits at levels lower than 100%. Simply stated, neat biodiesel degrades as fast as sugar and a 20% blend will degrade twice as fast as petroleum based diesel fuel.
Flash Point
The flash point of a fuel is defined as the temperature at which the fuel becomes a mixture that will ignite when exposed to a spark or flame. The flash point of biodiesel has been tested and reported by various sources. Specific testing concludes that the flash point of biodiesel blends increases as the percentage of biodiesel increases. Therefore pure biodiesel and blends of biodiesel with petroleum diesel are safer to store, handle, and use than conventional diesel fuel. Neat biodiesel has a flash point (150°C) well above the flash point of petroleum based diesel fuel (¹ 70°C).
Emissions reductions
The use of biodiesel in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle of the engine and testing methods employed.
Particulate emissions from conventional diesel engines are generally divided into three components. Each component is present in varying degrees depending on fuel properties, engine design and operating parameters. The first component, and the one most closely related to the visible smoke often associated with diesel exhaust, is the carbonaceous material. This material is composed of sub-micron sized carbon particles which are formed during the diesel combustion process. It is especially prevalent under conditions when the fuel-air ratio is overly rich. The second component is hydrocarbon material which is absorbed on the carbon particles, commonly referred to as the soluble fration. A portion of this material results from incomplete combustion of the fuel. The remainder is derived from engine lube oil that passes by the piston oil rings. The third particulate component is comprised of sulfates and bound water. The amount of this material is directly related to the fuel sulfur content.
The use of biodiesel decreases the solid carbon fraction of particulate matter (since the oxygen in biodiesel enables more complete combustion to CO 2 ), eliminates the sulfate fraction (as there is no sulfur in the fuel).
In addition to reducing the overall levels of pollutants and carbon, the compounds that are prevalent in biodiesel and diesel fuel exhaust are different. Research conducted by Southwest Research Institue (USA) on a Cummins N14 engine indicates that the biodiesel exhaust has a less harmful impact on human health than petrodiesel. Biodiesel emissions have decreased the levels of all targest polycyclic aromatic hydrocarbons (PAH) and nitrited PAH compounds were reduced by 75-85%.
Lubricity
In the United States the sulfur level of diesel fuel that is used for on-road purposes is limited to 0.05% by weight. This limit was mandated in October 1993 as a method to decrease particulate matter emitted from diesel powered vehicles. With the introduction of mandated Environmental Protection Agency (EPA) low-sulphur diesel fuel, fleet operators began to encounter premature wear and/or failure of injector pumps in increasing numbers. Pump manufacturers such as Bosch began recommending the use of lubricity additives to alleviate the serious damage that the reduced sulphur content of low sulphur diesel was causing to their injection pumps.
Testing at labs such as Southwest Research Institute, Standyne Automotive and Engineering Testing Services have demonstrated that biodiesel provides significant lubricity improvement over petroleum diesel fuel. Lubricity results of biodiesel and petroleum diesel using the High Frequency Reciprocating Rig test indicate that there is a marked improvement in lubricity when biodiesel is added to conventional diesel fuel, even at blend levels below 1%.
Infrastructure
In general, the standard storage and handling procedures used for petroleum diesel can be used for biodiesel. The fuel should be stored in a clean, dry, dark environment. Temperature extremes should be avoided. Acceptable storage tank materials include stainless steel, fluorinated polyethylene and fluorinated polypropylene. Biodiesel has a solvent effect which may release deposits accumulated on tank walls and pipes from previous fuel storage. The release of deposits may clog filters initially and precautions should be taken.
Materials compatability
Biodiesel over time, will soften and degrade certain types of elastomers and natural rubber compounds. Precautions are needed when using high percent blends to ensure that the existing fueling system, primarily fuel hoses and fuel pump seals, does not contain elastomer compounds incompatible with biodiesel. Manufacturers recommend that natural or butyl rubbers not be allowed to come in contact with neat biodiesel.
November 23, 2009
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Biodiesel: Jatropha Curcas – Physic Nut – Under the Spotlight
The prime ingredient in the manufacture of Biodiesel is vegetable oil i.e. sunflower, soya, peanut etc. However, these oils are edible and generally fetch high prices, which precludes them from being used in Biodiesel.
To date Biodiesel has been distilled from spent oil, but insufficient quantities mean that the demand for Biodiesel remains at a premium.
Research pointed the way to JATROPHA CURCAS, also known as the physic nut, which thrives in Zimbabwe and Zambia. It is ideal for the production of Biodiesel and related products, the plant is drought-resistant and frost hardy.
It also produces a higher yield under sub-tropic conditions and, as such, linkages have been established with the KwaZulu-Natal Department of Agriculture and Environmental Affairs (DAEA).
An excellent working relationship has been established between Biodiesel S.A. and the DAEA, leading to the formation of the Jatropha Task Team that is currently undertaking research on the cultivation of the plant.
Environmental concerns
Concerns about Jatropha escaping and posing danger as an invasive species have been assuaged by a long-abandoned experiment at the DAEA experimental farm on the Makatini Flats in northern KwaZulu-Natal.
A number of homesteads are surrounded by mature trees planted in the mid-1980s as living fences, all of which bear seeds profusely. There is no evidence to suggest that any seed has germinated elsewhere, almost 20 years after the first planting.
Potential uses
Jatropha offers a spectrum of potential uses, apart from the principle imperative of Biodiesel production.
WHOLE PLANT:
Erosion control, hedges and crop protection
FRUIT:
SEED FRUIT SHELL: Burning fuel
SEED OIL: Diesel production
SEED CAKE: Soap production, organic fertilizer, chemical production, glycerine and biodegradable cutter bar lubricant (for chain saws).
The physic nut is a drought-resistant plant species which has been widely cultivated in certain African countries as a living fence.
Many parts of the plant are used in traditional medicine. The seeds, however, are toxic to humans, most animals and birds.
Considerable amounts of physic nut seed were produced on the islands of Cape Verde during the first half of this century, constituting an important contribution to the countryâs economy. Seeds were exported to Lisbon and Marseille for oil extraction and soap production. Currently, global production is negligible.
The physic nut is a small tree or large shrub which lives for up to 50 years and can reach a height of up to five (5) meters if not pruned and kept under control. Growth and yield are determined by rainfall and temperature fluctuations.
Pollination of the physic nut is by insects and mostly by moths because of its sweet, heavy perfume at night.
The seeds are black, about two centimeters long and one centimetre thick. The extracted oil has no mutagenic properties, if handled with care, and poses no danger to workers.
The cultivation of the Jatropha plant lends itself to the economic beneficiation of previously disadvantaged communities and efforts are underway to popularise Jatropha among emerging and small scale farmers through the KZN AgriFoundation (KZNAF), a Section 21 company and an affiliate of the DAEA.
In this respect, Biodiesel S.A. has committed itself to the purchase of all seed from emerging farmers.
It is envisaged that the kernels will be bought and transported to the factory where the oil will be pressed and Biodiesel will be produced.
November 23, 2009
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World’s First Air-Powered Car: Zero Emissions by Next Summer (Winter In SA)
Indiaâs largest automaker is set to start producing the worldâs first commercial air-powered vehicle. The Air Car, developed by ex-Formula One engineer Guy Nègre for Luxembourg-based MDI, uses compressed air, as opposed to the gas-and-oxygen explosions of internal-combustion models, to push its engineâs pistons. Some 6000 zero-emissions Air Cars are scheduled to hit Indian streets in August of 2008.
Barring any last-minute design changes on the way to production, the Air Car should be surprisingly practical. The $12,700 CityCAT, one of a handful of planned Air Car models, can hit 68 mph and has a range of 125 miles. It will take only a few minutes for the CityCAT to refuel at gas stations equipped with custom air compressor units; MDI says it should cost around $2 to fill the carâs carbon-fiber tanks with 340 liters of air at 4350 psi. Drivers also will be able to plug into the electrical grid and use the carâs built-in compressor to refill the tanks in about 4 hours.
Of course, the Air Car will likely never hit American shores, especially considering its all-glue construction. But that doesnât mean the major automakers can write it off as a bizarre Indian experiment â MDI has signed deals to bring its design to 12 more countries, including Germany, Israel and South Africa.
November 23, 2009
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First Joule EVs on SA Roads by 2010
Optimal Energy, the Cape Town based company that unveiled a full electric multi-purpose urban passenger vehicle named Joule to the world at the Paris Autoshow in 2008, has announced industrialisation plans to mass produce the vehicle in South Africa from 2012. This announcement comes on the back of a further share issue to the Industrial Development Corporation (IDC), as well as Innovation Fund, the technology investment division of the Department of Science and Technology, for a fourth round capital investment. Optimal Energy intends raising further private capital towards the end of 2009. South Africans can look forward to pilot fleets of Joule on their roads and around the globe from 2010 onwards.
Comments Kobus Meiring, CEO of Optimal Energy, âOptimal Energy is capitalising on South Africaâs technological prowess, its track record of building premium cars for the export market, the current sea of change in transport technology brought about by climate change, pollution and energy security issues, and the immense progress in battery technology. Optimal Energy aims to place South Africa at the frontline of the renewable energy movement with Joule. This investment helps us to drive the industrialisation process, taking us to the next level.â
Graham Geldenhuys, CEO of Step Strategic Venturing, a professional services firm appointed to assist Optimal Energy with the development of its strategy and with facilitation of the capital raising process, adds, âThere is no question that the electric vehicle is a part of our future. It is a privilege working with a company such as Optimal Energy with a business case that has so much potential to tap into the significant opportunity in the alternative energy vehicle market. Securing investment from the IDC and the Innovation Fund attests to this as well as the ability of a world class management team to get the job done.â
Asked if the global economic crisis impacting so heavily on the large automotive manufacturers will hinder production of the Joule, Meiring is firm that it will not. âInterest in the vehicle has been enormous both at a local and international level. The timing of this investment and the planned 2012 start of volume production is ideal. Current market conditions are slowing down the traditional manufacturersâ efforts while the market, especially for clean vehicles, is predicted to be in a strong upward swing from 2012 onwards,â he notes.
Once production of Joule begins, Meiring estimates that Optimal Energy, which currently employs more than 80 highly-skilled personnel, will directly increase headcount to around 1,000 employees while a further approximately 5,000 people will be employed in various related and support industries. âWe are in the process of selecting a site for our first assembly and manufacturing plant. The location of the plant will be announced later this year,â continues Meiring.
Meiring indicates that the Joule will also shatter the stereotype of electric cars being small, slow and unsightly. The Joule is a passenger vehicle with up to six seats, which combines efficiency and performance with an elegant and stylish design. The vehicle was designed by world renowned Keith Helfet, South African born former Jaguar designer; and has received very positive reviews following its 2008 Paris Motor Show unveiling.
âThe Joule comes with all the modern specifications and meets or surpasses international standards. It combines class and sustainability in a way that should give all South Africans a welcome boost of national pride in 2010 with these pilot vehicles on the roadâ concludes Meiring.
November 23, 2009
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