Fatty Acids and Derivatives from Coconut Oil

1 Fatty Acids and Derivatives from Coconut Oil Gregorio C. Gervajio 1. THE WORLD’S FATS AND OILS OUTPUT The oleochemical industry is fairly well developed and its future secure because of a reliable supply of raw materials. The world’s fats and oils output has been growing rapidly over the past few decades, far beyond the need for human nutrition. The world’s production and consumption of natural oils and fats has grown from 79.2 million t in 1990 to 117 million t in 2001. Malaysia, Indonesia, and Argentina are notable excess-supply producers; India, the European Union countries, and China are notable high-demand areas that supplement regional production through imports (1). The principal raw materials from which the natural fatty acids are derived are tallow, crude tall oil, coconut, palm kernel, and soybean oils. Many new fatty acid plants have been built in Southeast Asia, which is a major source of coconut and palm oils used as raw materials for the production of C8–C14 fatty acids. Altogether, those countries (excluding China and India) have producers of fatty acids from oil splitting with a capacity of 1.5 million t. Significant amounts of the increasing production are being exported to other areas, including the United States, Western Europe, and Japan (2). The Philippines, a major producer of coconut oil, established its first oleochemical plant of limited capacity in 1967. The plant produced only 3,000 t/year of coco Bailey’s Industrial Oil and Fat Products, Sixth Edition, Six Volume Set. Edited by Fereidoon Shahidi. Copyright # 2005 John Wiley & Sons, Inc. 1 2 FATTY ACIDS AND DERIVATIVES FROM COCONUT OIL fatty alcohols using KAO’s technology via the methyl ester route. This was followed by a moderate-size plant, a joint venture between KAO Japan and a local partner commissioned in 1980, producing 25,000 t of coco fatty alcohol and a host of oleochemical derivatives. COCOCHEM’s cocochemical plant, established in 1984, was the biggest in the region during that period, with a splitting capacity of 70,000 t crude coconut oil and producing 36,000 t of fatty alcohols, 9,000 t of glycerine, and various cuts of fatty acids and fatty alcohols. The plant uses the Lurgi technology of the hydrogenation of fatty acids to produce fatty alcohols. Recent data for the Phillippines listed a capacity of 25,000 t of alcohol products from coconut oil by the fatty acid hydrogenation process for Cocochem and 4,000 t for Colgate. Phillippinas Kao produced 30,000 t of alcohol products from coconut oil using the methyl ester hydrogenation process (3). Consumption of fatty acids in the United States, Western Europe, and Japan totaled 2.5 million t in 2001. There was a sharp decline in production and consumption of fatty acid in North America after the events of September 2001. However, growth is expected at the rate of 2.3% for the consumption of split acids for the period 2000–2006. Growth in Western Europe is expected at the rate of 1.2%/yr for the period 2001–2006. Japan’s consumption is expected to decline (2). 2. THE ROLE OF COCONUT OIL IN THE OLEOCHEMICAL INDUSTRY WORLDWIDE Coconut oil and palm kernel oil, a coproduct of palm oil, comprise less than 5% of the total natural fats and oils, but they are important feedstocks of the oleochemical industry. Coconut oil is commercially a major source of lauric acid. Together with palm kernel oil and, to a small extent, babassu oil, it belongs to the so-called lauric oils, which are characterized by their high lauric oil content of approximately 50%. The lauric oils are highly desirable materials in the oleochemical industry worldwide because of the importance of the lauric fraction especially in the manufacture of soaps and detergents (4). Coconut oil is well positioned because it has the unique advantage of having its fatty acid composition falling within the carbon chain spectrum highly desired by the oleochemical industry where the C12 and C14 fatty acid fractions are sought after. Table 1 shows the fatty acid composition of coconut oil and palm kernel oil. The caproic to capric (C6–C10) fatty acid fractions comprising approximately 15% are good materials for plasticizer range alcohol and for polyol esters. The latter are used in high-performance oil for jet engines and for the new generation of lubricants. These acid fractions are also the basic material for the manufacture of medium-chain triglycerides, a highly valued dietary fat. The C12–C18 fatty acid fractions, approximately 85% of the coconut oil fatty acid composition, are the primary raw materials for detergent-grade fatty alcohols. Coconut oil is a primary source of basic oleochemicals and a host of other oleochemical derivatives. Figure 1 indicates some of the major processes by which THE ROLE OF COCONUT OIL IN THE OLEOCHEMICAL INDUSTRY WORLDWIDE 3 TABLE 1. Fatty Acid Composition of Coconut and Palm Kernel Oils (5). Fatty Acid Formula Coconut Oil (%) Palm Kernel Oil (%) Caproic C6H12O2 0.2–0.8 0–1 Caprylic C8H16O2 6–9 3–5 Capric C10H20O2 6–10 3–5 Lauric C12H24O2 46–50 44–51 Myristic C14H28O2 17–19 15–17 Palmitic C16H32O2 8–10 7–10 Stearic C18H36O2 2–3 2–3 Oleic C18H34O2 5–7 12–19 Linoleic C18H32O2 1–2.5 1–2 Figure 1. Oleochemical raw materials and their derivatives (6). 4 FATTY ACIDS AND DERIVATIVES FROM COCONUT OIL various oleochemicals and their derivatives can be obtained from fats and oils. These processes are applicable to coconut oil with the exception of epoxidation and direct sulfation because coconut oil lacks the necessary unsaturation to initiate the two reactions. As can be seen from Figure 1, a great number of oleochemicals can be derived from natural fats and oils. These olechemicals find increasing use in various applications. 3. TYPES OF FATTY ACIDS AND DERIVATIVES FROM COCONUT OIL AND THEIR GENERAL APPLICATIONS Coconut oil is one of the most important raw materials for the oleochemical industry. The whole range of its fatty acid composition is used as the starting material for a wide variety of oleochemical products. Fatty acids are the building blocks that, with proper selection and application of oleochemistry, are converted to higher valued products. Coconut oil is considered a saturated oil. From Table 1, it can be seen that coconut oil has approximately 92% saturated fatty acid, from caproic to stearic, and only around 8% unsaturated fatty acid, composed of oleic acid and linoleic acid. 3.1. Types of Fatty Acids from Coconut Oil Fatty acids obtained by the high-pressure splitting of coconut oil, as discussed later in this Chapter, are distilled and can be fractionated into various fractions or individual cuts. Types commercially available are the following (7). 1. Whole distilled coconut fatty acid. Arefined product whose fatty acid composition is identical to that of the original oil. 2. Caprylic, capric acid. The low-molecular-weight fraction comprising around 55% C8 and 40% C10 fatty acid fractions with small amounts of C6 and C12 fractions. 3. Topped coconut fatty acid. The C12–C18 fraction after topping off the C8–C10 fraction. 4. Lauric, myristic acid. The medium-chain fatty acid fraction comprising approximately 72% C12 and 26% C14 fatty acid fractions with traces of C10 and C16 fatty acid fractions. 5. Lauric acid. A pure-cut C12 fatty acid with a purity of 99% minimum with traces of C10 and C14 fatty acid fractions. 6. Myristic acid. A pure-cut C14 fatty acid with a purity of 98% minimum and traces of C12 and C16 fatty acid fractions. There is a market for individual cuts of fatty acids of high purity. These are highly desired by certain industries, such as the cosmetic industry, and command higher prices. Table 2 shows the typical composition and properties of these types of fatty acids as produced by United Coconut Chemicals Philippines, Inc. TABLE 2. Fatty Acid Product Specifications (7). Color Lovibond 5.25 inches Approximate Unsaponifiable Carbon Chain Distribution Fatty Acid Product Iodine Acid Saponification Titer Matter Y R Products Code Value Value Value (C) (% maximum) (maximum) (maximum) C6 C8 C10 C12 C14 C16 C18 C18 : 1 C18 : 2 Whole distilled Philacid 6–10 268–274 269–275 21–25 0.5 15 1.5 0.5 7.5 6.5 48 18 9 2 7 2 coconut fatty acid 0818 (C8–C18) Caprylic–capric Philacid 0.8 maximum 355–365 356–366 1–5 0.5 — — 4 55 39 3 — — — — — acid (C8–C10) 0810 Topped coconut fatty Philacid 8–12 254–260 254–260 25–29 0.5 15 1.5 — — 1.0 55 22 10 2.5 8 2 acid (C12–C18) 1218 Lauric acid (C12) Philacid 0.3 maximum 279–281 279–281 42–43 0.5 8 0.8 — — 0–1 99 min. 0–1 — — — — 1200 Myristic acid (C14) Philacid 0.3 maximum 245–247 245–247 53–54 0.5 8 0.8 — — — 0–2 98 min. 0–2 — — — 1400 Lauric–myristic acid Philacid 0.5 maximum 268–273 268–273 33–35 0.5 10 1.0 — — 1 72 26 1 — — — (C12–C14) 1214 6 FATTY ACIDS AND DERIVATIVES FROM COCONUT OIL 3.2. Oleochemical Derivatives from Coconut Oil and Their General Applications Coconut fatty acids and their various fractions, aside from being used directly, are converted further to other derivatives. Their range of application covers a broad spectrum in the oleochemical industry. As shown in Figure 1, fatty acids can under- go different processes in the manufacture of various oleochemical derivatives.

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