Fat splitting

Enzymatic fat splitting Enzymatic hydrolysis Enzymatic methods Enzymatic oxidation Enzymatic resolutions... 

Figure 1- 1 Flow Diagram for Armour s Soap Plant. Courtesy of Ladyn, H. W., Fat Splitting and Soap Making Go Continuous, Chemical Engineering Aug. 17, 1964, p. 106.

Alcohols are also widely produced from fats and oils, and in some cases one of the oldest techniques utilised in the manufacture of soap, fat splitting, is also used as part of the process. Vegetable oils as well as animal fats are all triglycerides and consequently a key step of the various technologies used in the alcohol manufacture involves the separation of glycerine. Oleochemical alcohols are produced using two... 

When lipases are used for enzymatic conversions, the enzyme is mainly active at a phase boundary, which can effectively be provided by a membrane. Additionally, for conversions requiring two phases (e.g. fat splitting [84—86] and esterifications [87]), the membrane also keeps the two liquid phases (an oil and an aqueous phase, respectively) separated. This is schematically depicted in Fig. 13.11. The equilibrium reactions involved are... 

The manufacture of fatty acid from fat is called fat splitting (B), and the process flow diagram is shown in Fig. 3. Washouts from the storage, transfer, and pretreatment stages are the same as those for process (A). Process condensate and barometric condensate from fat splitting will be contaminated with fatty acids and glycerine streams, which are settled and skimmed to recover... 

Figure 3 Fatty acid manufacture by fat splitting (B) (from Ref. 13).

In the fatty acid distillation process, wastewater is generated as a result of an acidification process, which breaks the emulsion. This wastewater is neutralized and sent to the sewer. It will contain salt from the neutralization, zinc and alkaline earth metal salts from the fat splitting catalyst, and emulsified fatty acids and fatty acid polymers. 

A process flow diagram for the glycerine recovery process uses the glycerine byproducts from kettle boiling (A) and fat splitting (B). The process consists of three steps (Fig. 5) (a) pretreatment to remove impurities, (b) concentration of glycerine by evaporation, and (c) distillation to a finished product of 98% purity. 

Parameter Batch kettle (A) Fat splitting (B) Fatty acid neutralization Glycerine (C) concentration (D) Glycerine Flakes and distillation (E) powders (F) Bar soap (G) Liquid soap (H)... 

Batch Fat splitting neutralization Glycerine Glycerine Flakes and Bar Liquid... 

Nilsson, R. and Will art, S. 1960. Lipolytic activity in milk. II. The heat inactivation of fat splitting in milk. Milk Dairy Res., Alnarp. Sweden, Rep. 64,... 

Fatty acids are obtained by fat splitting using water (hydrolysis), methanol (metha-nolysis), and base (saponification) of amines (aminolysis). Splitting with water or methanol can be considered transesterification because glycerol is liberated. The methanolysis is the reaction taking place in biodiesel production as the resulting product is called fatty acid methyl ester. 

In the past, glycerol was produced mainly from propene via allyl chloride and epi-chlorohydrin, a process developed by I. G. Farben and in operation since 1943. Today, glycerol is obtained almost completely as a coproduct in oleochemistry (fat splitting) and biodiesel production (transesterification) with 110 kg crude glycerol or 100 kg pure glycerol per ton of biodiesel [37]. With the rise in biodiesel production, the availability increased while the price decreased drastically by approximately 66% within 15 years in the United States [38]. 

From Bookish, M., Fats and Oils Handbook, AOCS Press, Champaign, IL, 1998, with permission. bFrom Sonntag, N. V, Fat Splitting, Esterification, and Interesterification, in Bailey s Industrial Oil and Fat Products, 4th ed Vol. 2., D. Swem, Ed., pp. 97-173, John Wiley Sons, New York, 1982. With permission. cn = native r = randomized. 

A number of other batch fat splitting plants is also available. 

Continuous Fat Splitting Process. Currently, continuous fat splitting is the most widely used process in the industry. In the single-stage splitting process, fat and water are fed countercur-rently into a continuous flow column at up to 260°C/60 bar pressure conditions. The glycerin... 

Fig. 36.11. Single-stage countercurrent fat splitting plant. (Courtesy Lurgi GmbH, Frankfurt am Main, Germany.)...

The other method for making soap comprises fat splitting followed by the neutralization process with sodium hydroxide. 

Base catalyzed hydrolysis. Historically, soaps were produced by alkaline hydrolysis of oils and fats, and this process is still referred to as saponification. Soaps are now produced by neutralization of fatty acids produced by fat splitting (see below), but alkaline hydrolysis may still be preferred for heat-sensitive fatty acids. 

Fat splitting. The industrial production of fatty acids uses the direct reaction between water and fats, which proceeds rapidly at 250°C and 2-6 MPa (20-60 bar). Under these conditions, water is moderately soluble in the oil phase, and stepwise hydrolysis of the triacylglycerols proceeds without the aid of a catalyst. The reaction is carried out with a countercurrent of water that removes the glycerol formed, resulting in 99% conversion to fatty acids. Glycerol is recovered from the aqueous phase. Sonntag has reviewed industrial fat sphtting in detail (20). 

Uses of Oieochemicais Based on Palm Oil and Palm Kernel Oil. (a) Fatty Acids. The most common method for the production of fatty acids adopted by the oieochemicais industry is high-temperature and high-pressure fat splitting. The fatty acid mixture produced is separated into broad cuts or pure fatty acids by simple or fractional distillations. Tables 50 and 51 list examples of fatty acids derived from palm products. The exact specifications of the various fatty acids produced vary slightly depending on the exact raw materials and process used. The specifications could also change due to continuous upgrading of processes. 

N. O. V. Sonntag, Fat Splitting, Esterification, and Interesterification, Bailey s Industrial Oils and Fats, 4th ed., Wiley, New York. 

Fat splitting is a reversible reaction. At the point of equilibrium, the rates of hydrolysis and re-esterification are equal. The glycerine byproduct must be withdrawn continuously to force the reaction to completion. 

There are at least four known methods of fat splitting. These are (1) Twitchell process, (2) batch autoclave process, (3) continuous process, and (4) enzymatic process. 

Twitchell Process. The Twitchell Process (9) is one of the earliest processes developed for fat splitting. It is still used in a small way because of its low initial cost and simplicity of installation and operation. However, it is no longer of great commercial importance, due to its high-energy consumption and poor product quality. The process makes use of the Twitchell reagent and sulfuric acid to catalyze the hydrolysis. The reagent is a sulfonated mixmre of oleic or other fatty acid and naphthalene. 

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