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Biodiesel Fuel from Palm Oil Too Good to Be Used as Fuel?

PETER FÄSSLER The high prices for oil and gas have SULZER CHEMTECH spotlighted other sources of fuel for internal combustion engines. Biofuel, a fuel derived from ethanol, and biodiesel fuel, a diesel- equivalent derived from biological sources, are 2 possible substitutes for petrochemical fuel. Palm oil is increasingly used as feedstock for the production of biodiesel, but certain palm oil fractions have other uses, e.g., in the cosmetics and food industries. Sulzer Chemtech’s technology supports the separation of crude palm oil (CPO) in its valuable constituents.

Biodiesel is composed of fat- tablished on the market. For large- ty acid methylesters (FAME) scale production, however, differ- from transesterified vegetable or ent sources are currently being animal fats and oils. In organic tested, with straight vegetable oils chemistry, transesterification is the (SVO) becoming more and more process of exchanging the alkoxy important. group of an ester compound by an- Palm oil, which currently has an other alcohol. Biodiesel fuel pro- annual global production of more duced from recovered domestic, than 30 million tons, is increas- gastronomic, and industrial waste ingly used as base feedstock for vegetable oils (WVO) is already es- biodiesel (Fig. 1 and box). Stock

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market prices for refined, which can lead to blockage of the Annual World Production Harvested Area of Vegetable Oil 2004/2005 bleached, and deodorized (RBD) fuel injection system. The main 2004/2005 (Mio. tons) (in %)

palm oil are in the region of USD cause for this behavior is methyl- Soybean Palm 600 per ton, making it an attractive palmitate, which is present in high Palm kernel Sunflower seed option in the view of high petrole- quantities and has a high melting Rape seed um prices. point of 30–33 ºC. Therefore, it is Cotton seed Peanut For biodiesel production, Sulzer necessary to further blend or Coconut Olive Chemtech supplies packages for process such biodiesel. the methanol recovery and in cer- The adaptation of biodiesel fuel 1 Palm oil will soon pass soybean oil as the most produced tain cases glycerol purification. for cold-climate use, also called vegetable oil worldwide. Sulzer Chemtech has technology and winterization, lowers the pour equipment that help to separate the oil into its various valu- able fractions. Palm Oil Suitable for Winter Use point. In the case of palm-oil based For use in nontropical countries, biodiesel, winterization is accom- palmitate is purified to a high de- however, biodiesel fuel based on plished by removing a fraction, if gree (Fig. 2). palm oil has the disadvantage of a not all, of the methylpalmitate. Pure methylpalmitate is a valuable high pour point of around 12 °C, During this process, the methyl- raw product for further processing

Palm Oil: Food and Fuel Oil palm Food (frying oil, pastry, The oil palm (Elaeis guineensis) grows palm fruit. In the harvested fruit, fatty margarine, mayonnaise, in a tropical belt of about 10° latitude acids build up rapidly, making the oil and others) Crude palm Oleochemicals (cosmet- north and south of the equator. Especial- rancid and sour. Therefore, the process- oil (CPO) ics, soap, detergent, biodiesel) ly in Malaysia and Indonesia, the culti- ing mills for the flesh have to be located Fruit Fiber Pulp and paper vated area has grown rapidly in recent close to the plantations. The kernel is Sludge Animal feedstuff, soap, fertilizer years, mostly from conversion of planta- processed in kernel crushing plants, Food (frying oil, pastry, margarine, mayonnaise, tions of other economic crops. The trees where the palm kernel oil (PKO) and ice cream, and others) are productive for up to 25 years. Each palm kernel meal (PKM) are extracted. Kernel Oleochemicals (cosmet- ics, soap, detergent) year, large bunches of palm fruits are CPO and PKO differ in their chemical Nut Palm cake Animal feedstuff harvested from the mature trees. These compositions. CPO contains about 50% fresh-fruit bunches (FFB) contain up to saturated fats while PKO contains about 3000 plum-sized fruits. Each fruit con- 80% saturated fats and a high content of percent of CPO and 70 % of PKO are sists of a hard kernel inside a shell. The lauric acid, which, due to its melting used for non-food (oleochemical) appli- crude palm oil (CPO), a yellow-red liq- properties, makes PKO very well suited cations. Palm oil and palm kernel oil uid, is extracted from the flesh of the for the use in food production. Twenty have 2 major nonfood uses—using the oils directly or processing them to oleo- chemicals. Oleochemicals are chemicals derived from biological oils or fats; they have uses similar to those of petro- chemicals, which are chemicals derived from petroleum. CPO is used directly in

Annual production of palm soaps, plastics, drilling mud, and palm- oil in million tons based biodiesel. The oleochemical appli- Indonesia 14.00 Malaysia 15.19 cations of CPO include soap, detergents, Nigeria 0.79 Thailand 0.76 rubber, skin care products, rubber, and Colombia 0.65 cleaning products. Papua New Guinea 0.38 Ivory Coast 0.34 Ecuador 0.34 Costa Rica 0.24 Congo, Democratic Rep. 0.18 The oil palm has a wide range of uses Others 1.17 as fuel and in the food, cosmetics, and Total World 34.04 chemical industries.

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2 Crude palm oil ic reaction promoted by the FFA High-Value By-Products (CPO) and purified themselves. The fatty-acid strip- Palm-oil based methylesters must biodiesel (front) ping, partial bleaching, and de- be split into several different prod- processed in the odorization are done in a palm oil ucts for further processing before Sulzer Chemtech fractional crystalliza- stripper. the palm oil can be used as tion plant in Buchs Preheated CPO enters the stripper biodiesel fuel. The by-products are (CH). The solid frac- column, which is equipped with high-value raw materials and have tions of CPO are structured packings and operated their main applications in market important raw mate- at very low pressure. There, the segments other than fuels. There- rial for the oleo- FFA are stripped off by introduc- fore, fluctuations in fuel prices can chemical industry. ing stripping steam in the bottom be evened out with earnings from and then condensed in the scrub- other palm oil fractions. bing section on the column top. into higher alcohols, e.g., iso- Long Experience propyl-, 2-ethylhexyl, glycolesters. No Thermal Degradation Sulzer Chemtech—with several These alcohols have a wide range Today, even the industrial-scale decades of experience in oleo- of applications as technical oils in purification of nonsaturated C18 chemical processing—can offer so- cosmetics, food, pharmaceuticals, methylester (methyloleate, methy- lutions that satisfy the require- etc. linolate, etc.) to reasonable purity ments of distillation technology is possible due to a much smoother using the high-capacity and high- Smooth Distillation Process distillation process. Thermal efficiency structured packings As a product from a natural degradation can be avoided, be- MellapakPlus™ and BXPlus™. source, CPO is less stable than pe- cause the boiling point of an equiv- Apilot and demonstration plant troleum. Therefore, the tempera- alent methylester is about 20 °C for these applications is currently ture during the distillation must be lower than that of the free fatty under construction in South East controlled precisely to avoid de- acid, and the use of state-of-the-art Asia. Additionally, Sulzer Chem- stroying any ingredients of the column internals allows much tech has supplied more than palm oil during the process. smoother operating conditions. 300 palm oil strippers and 500 CPO contains up to 5 % free fatty Palm-based biodiesel contains a columns for oleochemical distilla- acids (FFA), which must be re- high concentration of tocotrienol, tion in recent years (Fig. 3). In- moved by a physical refining a potential source of natural vita- stalled refining capacity based on process in order to produce RBD min E. Tocotrienols are potent an- Sulzer supplies alone is estimated palm oil. Without this process, the tioxidants; in some cell culture and to be between 18 and 20 million oil would be practically inedible, animal studies, they have exhibit- tons per year. have a short shelf life, and decom- ed anti-cancer properties. Once pose further due to an autocatalyt- further purified, they can be used, e.g., as supplements to cattle food, but also as sun blockers in 3 A palm oil stripper with Sulzer internals on its way to the refinery. cosmetic products. Other interesting components are carotene and phytosterol. Phy- Contact tosterol, a natural cholesterol-low- Sulzer Chemtech AG ering agent used in functional Peter Fässler food, is purified to a high degree Postfach 65 by fractional crystallization (see 8404 Winterthur STR 1/2006, p. 4). Switzerland All these ingredients accumulate Phone +41 52 262 37 29 in the heavy residue of the distilla- Fax +41 52 262 00 64 tion. [email protected]

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