Поиск готовой работы по сайту
Предлагаем нашим посетителям воспользоваться бесплатным программным обеспечением «StudentHelp», которое позволит вам всего за несколько минут, выполнить повышение уникальности любого файла в формате MS Word. После такого повышения уникальности, ваша работа легко пройдете проверку в системах антиплагиат вуз, antiplagiat.ru, etxt.ru или advego.ru. Программа «StudentHelp» работает по уникальной технологии и при повышении уникальности не вставляет в текст скрытых символов, и даже если препод скопирует текст в блокнот – не увидит ни каких отличий от текста в Word файле.
Реферат Palm oil is a form of edible vegetable oil obtained from the fruit of the oil palm tree. Chemistry and processing. Environmental, social and cultural impact. Biofuels and bioproducts. Regional production. Health. Blood cholesterol controversy.
Тип работы: Реферат.
Предмет: Ин. языки.
Уникальность по antiplagiat.ru: --.
Moscow State University of Instrument Engineering and Computer Science
“Industrial development of the African countries.”
2. Chemistry and processing
3. Environmental, social and cultural impact
4. Biofuels and bioproducts
5. Regional production
6.1. Blood cholesterol controversy
Palm oil is a form of edible vegetable oil obtained from the fruit of the oil palm tree. Previously the second-most widely produced edible oil, after soybean oil, 28 million metric tons were produced worldwide in 2004. It may have now surpassed soybean oil as the most widely produced vegetable oil in the world. It is also an important component of many soaps, washing powders and personal care products, is used to treat wounds, and has controversially found a new use as a feedstock for biofuel.
The palm fruit is the source of both palm oil (extracted from palm fruit) and palm kernel oil (extracted from the fruit seeds). Palm oil itself is reddish because it contains a high amount of beta-carotene. It is used as cooking oil, to make margarine and is a component of many processed foods. Boiling it for a few minutes destroys the carotenoids and the oil becomes colourless. Palm oil is one of the few vegetable oils relatively high in saturated fats (like coconut oil) and thus semi-solid at room temperature.
Palm oil (from the African Oil Palm, Elaeis guineensis) was long recognized in West African countries, and among West African peoples it has long been in widespread use as a cooking oil. European merchants trading with West Africa occasionally purchased palm oil for use in Europe, but as the oil was bulky and cheap, palm oil remained rare outside West Africa. In the Asante Confederacy, state-owned slaves built large plantations of oil palm trees, while in the neighbouring Kingdom of Dahomey, King Ghezo passed a law in 1856 forbidding his subjects from cutting down oil palms.
Palm oil became a highly sought-after commodity by British traders, for use as an industrial lubricant for the machines of Britain's Industrial Revolution, as well as forming the basis of soap products, such as Lever Brothers' "Sunlight Soap", and the American Palmolive brand. By c.1870, palm oil constituted the primary export of some West African countries such as Ghana and Nigeria, although this was overtaken by cocoa in the 1880s.
Palm was introduced to Java by the Dutch in 1848 and Malaysia (then the British colony of Malaya) in 1910 by Scotsman William Sime and English banker Henry Darby. The first plantations were mostly established and operated by British plantation owners, such as Sime Darby. From the 1960s a major oil palm plantation scheme was introduced by the government with the main aim of eradicating poverty. Settlers were each allocated 10 acres of land (about 4 hectares) planted either with oil palm or rubber, and given 20 years to pay off the debt for the land. The large plantation companies remained listed in London until the Malaysian government engineered their "Malaysianisation" throughout the 1960s and 1970s.
2. Chemistry and processing.
Palm oil and palm kernel oil are composed of fatty acids, esterified with glycerol just like any ordinary fat. Both are high in saturated fatty acids, about 50% and 80%, respectively. The oil palm gives its name to the 16 carbon saturated fatty acid palmitic acid found in palm oil; monounsaturated oleic acid is also a constituent of palm oil while palm kernel oil contains mainly lauric acid. Palm oil is the largest natural source of tocotrienol, part of the vitamin E family. Palm oil is also high in vitamin K and dietary magnesium.
Napalm derives its name from naphthenic acid, palmitic acid and pyrotechnics or simply from a recipe using naphtha and palm oil.
The approximate concentration of fatty acids (FAs) in palm oil is as follows:
Fatty acid content of palm oil
Type of fatty acid pct
Palmitic C16 44.3%
Stearic C18 4.6%
Myristic C14 1.0%
Oleic C18 38.7%
Linoleic C18 10.5%
Fatty acid content of palm kernel oil
Type of fatty acid pct
Lauric C12 48.2%
Myristic C14 16.2%
Palmitic C16 8.4%
Capric C10 3.4%
Caprylic C8 3.3%
Stearic C18 2.5%
Oleic C18 15.3%
Linoleic C18 2.3%
Fatty acids are saturated and unsaturated aliphatic carboxylic acids with carbon chain length in the range of C6 up to C24. An example of a fatty acid is palmitic acid
CH3 - (CH2)14 - COOH
Splitting of oils and fats by hydrolysis, or under basic conditions saponification, yields fatty acids; with glycerin(glycerol) as a by-product. The split-off fatty acids are a mixture of fatty acids ranging from C6 to C18 depending on the type of Oil / Fat.
Palm oil products are made using milling and refining processes; first using fractionation, with crystallization and separation processes to obtain a solid stearin, and liquid olein. By melting and degumming, impurities can be removed and then the oil filtered and bleached. Next, physical refining removes odours and colouration, to produce refined bleached deodorized palm oil, or RBDPO, and free pure fatty acids, used as an important raw material in the manufacture of soaps, washing powder and other hygiene and personal care products. RBDPO is the basic oil product which can be sold on the world's commodity markets, although many companies fractionate it out further into palm olein, for cooking oil, or other products.
Palm is also used in biodiesel production, as either a simply-processed palm oil mixed with petrodiesel, or processed through transesterification to create a palm oil methyl ester blend which meets the international EN 14214 specification, with glycerin as a by-product. The actual process used varies between countries and the requirements of any export markets. Second-generation biofuel production processes are also being trialled in relatively small quantities.
3. Environmental, social and cultural impact.
Palm oil production is a basic source of income for many of the world's rural poor in South East Asia, Central and West Africa, and Central America. An estimated 1.5 million small farmers grow the crop in Indonesia, whereas about 0.5 million people are directly employed in the sector in Malaysia, plus those connected with spin offs. Not only does the palm represent a pillar of these nation's economies but it is a catalyst for rural development and political stability. Many social initiatives use profits from palm oil to finance poverty alleviation strategies. Examples include the direct financing of Magbenteh hospital in Makeni, Sierra Leone, through profits made from palm oil grown by small local farmers, the Presbyterian Disaster Assistance's Food Security Program, which draws on a women-run cooperative to grow palm oil, the profits of which are reinvested in food security, or the UN Food and Agriculture Organisation's hybrid oil palm project in Western Kenya, which improves incomes and diets of local populations, to name just a few.
As of 2006, the cumulative land area of palm oil plantations is approximately 11 million hectares. In 2005 the Malaysian Palm Oil Association, responsible for about half of the world's crop, estimated that they manage about half a billion perennial carbon-sequestering palm trees. Demand for palm oil has been rising and is expected to climb further.
This rising demand is resulting in tropical forest being cleared to establish new palm plantations. According to UNEP, at the current rate of intrusion into Indonesian national parks, it is likely that many protected rain forests will be severely degraded by 2012 through illegal hunting and trade, logging, and forest fires, including those associated with the rapid spread of palm oil plantations. There is growing concern that this will be harmful to the environment in several ways:
Significant greenhouse gas emissions. Deforestation, mainly in tropical areas, account for up to one-third of total anthropogenic CO2 emissions.
Habitat destruction of certain endangered species (e.g. the orangutans in Borneo, the Sumatran tiger, and Asian rhinoceros.)
Potential extinction of some such species.
Many places that are of interest for growing palm are biodiversity hotspots, increasing the impact of this development on the environment. In addition to environmental impact, the logging and land-clearing by large timber companies that accompany the establishment of palm plantations threatens the livelihood of minority tribes such as the Penan and Iban in Sarawak, Borneo.
Damage to peatland, partly due to palm oil production, is claimed to contribute to environmental degradation, including four percent of global greenhouse gas emissions and eight percent of all global emissions caused annually by burning fossil fuels, due to the large areas of rainforest that are cleared to make way for palm oil plantations. The pollution is exacerbated because many rainforests in Indonesia and Malaysia lie atop peat bogs that store great quantities of carbon that are released when the forests are cut down and the bogs drained to make way for the palm oil plantations.
NGOs have accused the growth of new palm oil plantations as also being responsible for peat forest destruction in Indonesia and for accelerating global warming. Greenpeace concluded that many food and cosmetics companies, including ADM, Unilever, Cargill, Proctor & Gamble, Nestle, Kraft and Burger King, are driving the demand for new palm oil supplies, partly for products that contain non-hydrogenated solid vegetable fats, as consumers now demand fewer hydrogenated oils in food products that were previously high in trans fat content. Friends of the Earth have concluded that the increase in demand comes from biofuel, with producers now looking to use palm as a source.
Environmental groups such as Greenpeace claim that the deforestation caused by making way for oil palm plantations is far more damaging for the climate than the benefits gained by switching to biofuel. The world's centres for oil palm production are Indonesia and Malaysia where rapid deforestation and the drying out of asssociated peatlands are, Greenpeace claim, releasing huge amounts of carbon dioxide into the atmosphere and thereby speeding climate change.Greenpeace identified Indonesian peatlands, unique tropical forests whose dense soil can be burned to release carbon emissions, that are being destroyed to make way for palm oil plantations. They represent massive carbon sinks, and they claim their destruction already accounts for four percent of annual global emissions. Greenpeace recorded peatland destruction in the Indonesian province of Riau on the island of Sumatra, home to 25 percent of Indonesia's palm oil plantations. There are plans to expand the area under concession by more than 11,000 square miles, which would deforest half of the province. They claim this would have devastating consequences for Riau's peatlands, which have already been degraded by industrial development and store a massive 14.6 billion tons of carbon, roughly one year's greenhouse gas emissions.
Research conducted by Greenpeace through its Forest Defenders Camp in Riau documents how a major Indonesian palm oil producer is engaging in the large-scale, illegal destruction of peatland in flagrant violation of an Indonesian presidential order, as well as national forestry regulations. Palm oil from peatland is fed into the supply chain for global brands. They accuse major multinational companies of turning a blind eye to peatland destruction to supply cheap vegetable oil. FoE and Greenpeace both calculate that forests and peatlands that are replaced as palm oil plantations release more carbon dioxide than is saved by burning biofuels in place of diesel.
In Africa, the situation is very different compared to Indonesia or Malaysia. In its Human Development Report 2007-2008, the United Nations Development Program says production of palm oil in West-Africa is largely sustainable, mainly because it is undertaken on a smallholder level. The United Nations Food and Agriculture program is encouraging small farmers across Africa to grow palm oil, because the crop offers opportunities to improve livelihoods and incomes for the poor.
Environmentalists and conservationists have been called upon to become palm oil farmers themselves, so they can use the profits to invest in their cause. It has been suggested that this a more productive strategy than the current confrontational approach that threatens the livelihoods of millions of smallholders.
Many of the major companies in the vegetable oil economy participate in the Roundtable on Sustainable Palm Oil which is trying to address this problem. Meanwhile, much of the recent investment in new palm plantations for biofuel has been part-funded through carbon credit projects through the Clean Development Mechanism; however the reputational risk associated with unsustainable palm plantations in Indonesia has now made many funds wary of investing there.
4. Biofuels and bioproducts.
Palm oil, like other vegetable oils, can be used to create biodiesel for internal combustion engines. Biodiesel has been promoted as a form of biomass that can be used as a renewable energy source to reduce net emissions of carbon dioxide into the atmosphere. Therefore, biodiesel is seen as a way to decrease the impact of the greenhouse effect and as a way of diversif и т.д.................
* Примечание. Уникальность работы указана на дату публикации, текущее значение может отличаться от указанного.