216 April 2007, Vol. 18 (4) beyond biodiesel. Salmiah Ahmad, Parthiban Siwayanan, Zulina Abd Murad, Haliza Abd Aziz, and Hoong Seng Soi

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1 216 April 2007, Vol. 18 (4) beyond biodiesel Salmiah Ahmad, Parthiban Siwayanan, Zulina Abd Murad, Haliza Abd Aziz, and Hoong Seng Soi The anticipated decreasing supply of fossil fuel but increasing demand and concern for the environment have led the developed countries to introduce policies to encourage the use of alternative fuels, especially bio -based fuel. Several types of biofuels are now available as substitutes for gasoline (petrol) or diesel. These include oil/fat (either crude, processed, or used), methyl ester from oil/fat, and ethanol or liquid fuel from biomass. Fatty acid methyl ester (ME) has been identified as a suitable substitute for blending with diesel or to be used in diesel engines without the need to modify the engines. The European Union (EU) encourages the use of ME as diesel substitute (biodiesel) as are many other countries, including Malaysia. Production of biodiesel or methyl ester from oils/fats involves the conversion of the free fatty acids and oils/fats using methanol and a catalyst to produce ME and crude glycerine.the glycerine is separated and the ME is washed and then distilled. Many types of oils/fats have been used for the production of ME (biodiesel), including rapeseed oil, soybean oil, tallow, and palm oil. ME from liquid oils such as rapeseed and soybean may be used during winter; those from palm oil solidify in cold temperatures, and some Malaysian manufacturers have installed an additional process in order to produce winter biodiesel. Another unique feature of palm oil is that in crude form it is red owing to the presence of carotenes

2 HEADER/inform 217 BIOFUELS METHYL ESTERS AS THE ROUTE FOR THE PRODUCTION OF SURFACTANTS FEEDSTOCK as well as vitamin E. These vitamins can be extracted after the crude palm oil (CPO) is converted to ME and the ester distilled. Palm oil biodiesel producers therefore have the option to produce not only summer biodiesel, winter biodiesel, and crude glycerine but also vitamins and saturated methyl esters. SATURATED METHYL ESTERS AS FEEDSTOCK FOR THE PRODUCTION OF SURFACTANTS Surfactants are surface active agents that are active at interfaces, reducing the interfacial tension and thereby allowing several reactions to take place.there are at least four types of surfactants: Anionics surfactants having negative charges at the end of the molecules; usually used as active ingredients for cleaning purposes. Cationics surfactants having positive charges at the end of the molecules; usually used as active ingredients in softening and conditioning products. Nonionics surfactants lacking a distinct charge but containing water-soluble head groups; usually used together with anionics to reduce irritancy. Amphoterics surfactants having both positive and negative charges on the molecule; frequently used to enhance the performance of other surfactants. Besides biodiesel, ME have long been used as the starting material for the production of fatty alcoholbased surfactants such as alcohol sulfates (anionics), alcohol ether sulfates (anionics), and alcohol ethoxylates (nonionics). However, the desired chain lengths are C12 14, and therefore, the ME are usually lauric oils-based. Methyl esters can also be used for the production of soap, methyl ester sulfonates (anionics) and esterquats (cationic).the last two surfactants merit further discussion. TABLE. Uses of Methyl Esters Uses Types of esters Status Biodiesel All types but C18:1 Today s hot topic for winter Fatty alcohol C12 C14, therefore Widely practiced production lauric oil-based Soap Mixture of C16 18 and Practiced in Japan C12 14 Methyl ester C14, C16, C18, or their Practiced in USA sulfonates (MES) mixtures. Need to be and Japan fully saturated Esterquats C16, C18 for softening, Practiced in and C18:1 for developed countries rewetting power METHYL ESTER AS FEEDSTOCK FOR THE PRODUCTION OF METHYL ESTER SULFONATES (MES) One of the most interesting alternative uses of saturated ME is in the production of the anionic surfactants, called methyl ester sulfonates (MES). MES is one the cheapest surfactants that can be derived from oleochemicals. It is definitely cheaper than fatty alcohol derivatives since it does not have to undergo high-temperature and high-pressure hydrogenation. Because of this, MES has the potential to compete with LAS (linear alkyl benzene sulfonates), a very important petrochemical-based surfactant that has been used by the cleaning industry for more than 30 years. However, increase in petroleum prices also has resulted in increasing LAS prices, making substitutes competitive. MES is formed by reacting saturated methyl ester with sulfur trioxide. This reaction is rather complicated, and it took researchers and equipment manufacturers more than 20 years to understand the mechanism and

3 218 April 2007, Vol. 18 (4) to develop appropriate plants. In 2000, the Malaysian Palm Oil Board (MPOB) purchased a 20 kg/h sulfonation pilot plant from Chemithon (Seattle,Washington, USA), a MES technology supplier, to produce palm oil-based MES. The pilot plant was commissioned in late 2001, several metric tons (MT) of MES were produced, and the quality was evaluated. The process to produce palm oil-based MES investigated by MPOB includes conversion of SO 2 to SO 3, which is then used to sulfonate saturated palm oil-based methyl ester. This is then followed with digestion, bleaching, neutralizing, and drying to produce high-active dried MES. are either better than or comparable with the best product available in the Malaysian market. Palm oil contains about 50:50 saturated and unsaturated fatty acids. Fatty acid composition reveals that the saturated fraction comprises mainly C16 and C18, and to a much lesser extent C12 and C14. During the production of winter biofuel, the greater the removal of the unsaturated fraction from the C16 mixture, the better the feedstock will be for the production of MES. Besides, many studies have shown that C16 MES has the best detergency. The solid fraction obtained as coproduct from the palm oil winter biofuel process will therefore make an ideal feedstock for the production of MES. Demand for LAS feedstock has been estimated to be 3.4 million MT (MMT) by An assumption of 30% substitution implies demand for 1 MMT of ME for MES production. With the anticipated development of biodiesel in Malaysia and Indonesia there will be enough feedstock for the production of this surfactant. Dried MES have an active matter content of more than 85% and are of good color. High active matter content is of great importance since this provides opportunity for the surfactant to be exported competitively. Surfactants are used to formulate finished products such as detergents and shower preparations. Initially they were available only in solutions, but the high cost of transportation reduced their competitiveness. The ability to produce high active MES now makes it possible to produce surfactants in countries where there is adequate supply of feedstock, to transport it to various regions in the world where there are markets for the finished products, and to be competitive. Many studies conducted by Lion Corporation, headquartered at Tokyo, Japan; Stepan Chemical Company, based in Northfield, Illinois, USA; and MPOB revealed that MES offers an environmentally friendly and viable alternative to the old workhorse anionics LAS. MES has the ability to biodegrade faster and better than LAS. In addition, it has good calcium tolerance, thus greater detergency and less sensitivity to water hardness than other anionic surfactants. MES can easily be formulated into finished products: a powder product requires MES to be ground into powder, followed by the addition of the rest of the additives. For a liquid product, MES is dissolved and other additives are mixed in. In MPOB, the products have been tested against different types of stains, and in most cases, the products formulated with MES METHYL ESTER AS FEEDSTOCK FOR THE PRODUCTION OF ESTERQUATS Distearyldimethyl ammonium had earlier found application as an important active ingredient for softening purposes. However, its unfavorable biodegradation characteristics limited its commercial usefulness. Today, esterquats are becoming the surfactant of choice due to their excellent environmental profile and fabric-softening effect. Moreover, the vegetablebased esterquats, derived from a renewable source, are gaining acceptance over the animal-based raw material since animalbased materials such as tallow are associated with mad cow disease, as well as being unacceptable to a few religions. Palm oil-based esterquats can be derived from abundantly available feedstock, and the saturated hydrocarbon chain in the raw material provides good softening power especially with the presence of C18 chain length. Palm oil-based esterquats were found to have better softening performance than the commercial tallow-based esterquats owing to the higher satu-

4 inform 219 BIOFUELS ration of the feedstock.the saturated ME from palm biodiesel can therefore be a good feedstock for the production of esterquats. However, to increase the rewetting power, some unsaturated hydrocarbon chains must be added. Esterquats are produced via a two-stage process involving the preparation of esteramines from triethanolamine and palm oil-based fatty acid or ester in the first stage and quaternization with an alkylating agent in the second stage in order to introduce the positive charge on the esterquats molecule. Research at MPOB has revealed that the production of esterquats using ME as feedstock requires milder processing conditions than for surfactant derived from fatty acids. From a technical point of view, glycerine s multifunctional structure makes it an ideal starting material for a very large number of products. Currently, glycerine is used in several fields of applications. When cold, supercooled glycerine can resist freezing and therefore finds use as anti-freeze. Due to its miscibility with water and alcohol, it is a good solvent especially for many industrial applications. It is also widely used as a solvent or drug carrier in pharmaceutical and medicinal products, as a humectant in cosmetics, toiletries and personal care products, as an emulsifier in foods, in the making of explosives, and in many other applications. The major potential market for esterquats is, as mentioned previously, in the textile industry, as it has become the worldwide leading ingredient for fabric softener. Apart from fabric care, other applications of esterquats include uses as hair conditioner, as an antistatic agent in polymers, and as an ingredient in bacterial and sanitizer products. GLYCERINE AS FEEDSTOCK FOR THE PRODUCTION OF SURFACTANTS In the oleochemicals industry, the production of soap, fatty acids, and ME for fatty alcohol manufacture is accompanied by the production of glycerine as a by-product. In 1999 the supply of glycerine due to the manufacture of these products was approximately 41, 13, and 25% respectively, with biodiesel accounting for only 7%. However, in 2004, the supply of glycerine from biodiesel production increased to 18%. In 2004, the capacity for the production of glycerine was about 1.3 MMT while the world consumption was about 0.97 MMT. By 2008, consumption is expected to increase to only 1.1 MMT while the production capacity will increase to 1.6 MMT. Increased supply without a parallel increase in the consumption/demand has led to price decreases. Average glycerine prices have declined from $1003 to $840 per MT during the period. Palm oil biodiesel producers have the option to produce not only summer biodiesel, winter biodiesel, and crude glycerine but also vitamins and saturated methyl esters. The increased production of glycerine as a co-product of biodiesel plants has led the EU to finance programs dedicated to the research and development of new uses for glycerol. One of the promising projects is the production of 1,2- or 1,3- propanediol through fermentation of glycerol. These compounds are becoming important raw materials for the manufacture of polymers. Polyglycerol was derived previously from epichlorohydrin or from dehydration of glycerol. Now glycerol is used to produce epichlorohydrin. Polyglycerol is used to produce polyesters, and these are used as emulsifiers in cosmetics and pharmaceutical products as well as in textiles and lubricants. About five years ago there was only one producer in the world for this material, but today there are three. Due to limited supply the current demand is approximately 20,000 MT a year. However, the demand will increase when there is further supply.

5 220 April 2007, Vol. 18 (4) As mentioned, the commercial production of polyglycerol involves the use of epichlorohydrin or dehydration of glycerol. MPOB decided to use dehydration of glycerol to produce polyglycerol; however, instead of conventional heating, microwave heating is used. The use of microwave heating helps to increase the reaction rate, with the advantage of no possible contamination with chlorine. METHYL ESTER AS THE ROUTE TO EXTRACT PRO-VITAMIN A AND VITAMIN E FROM PALM OIL CPO is rich in minor components that can impart unique nutritional properties. The most important of these are palm vitamin E (tocopherols/tocotrienols) and carotenoids (especially alpha- and beta-carotenes). Many research publications have indicated that palm vitamin E acts as a potent biological antioxidant, protecting against oxidative stress and the atherosclerotic process in humans. Tocotrienols, the major components in palm vitamin E, exhibit blood cholesterol-lowering attributes. Studies have also shown that tocotrienols can inhibit growth of human cancer cell lines in culture. CPO is also the richest source of natural carotenoids with a concentration of about mg kg -1, which is about 15 times that in carrots. The main components are beta-carotene (55%) and alpha-carotene (35%), with a smaller amount of lycopene. Research has shown that these natural carotenoids possess antioxidant and anticancer properties and serve as precursors of vitamin A. These vitamins can be recovered from CPO during the production of biodiesel. The recovery of these valuable vitamins offers new opportunities to enhance profitability of the palm oil-based biodiesel investments. BEYOND BIODIESEL: BIOREFINERY The development of biodiesel and expansion in oleochemicals production capacity are welcome developments in the oil palm industry. However, while there are benefits to be harnessed, the industry stands to lose certain revenue if supply and demand are not properly balanced. Developing new uses for the co-products produced by intervention and diversion will remove the excess supply, therefore maintaining the price. However, greater importance is attached to removal of the excess supply through the production of higher value-added products. Salmiah Ahmad, Parthiban Siwayanan, Zulina Abd Murad, Haliza Abd Aziz, and Hoong Seng Soi are all affiliated with the Advanced Oleochemical Technology Division (AOTD), Malaysian Palm Oil Board (MPOB).