Alfol®

The Alfol process (Figure 7-7) for producing linear primary alcohols is a four-step process. In the first step, triethylaluminum is produced by the reaction of ethylene with hydrogen and aluminum metal ... 

Figure 7-7. The Alfol process for making even-numbered straight-chain aipha aicohois.

Higher molecular primary unbranched or low-branched alcohols are used not only for the synthesis of nonionic but also of anionic surfactants, like fatty alcohol sulfates or ether sulfates. These alcohols are produced by catalytic high-pressure hydrogenation of the methyl esters of fatty acids, obtained by a transesterification reaction of fats or fatty oils with methanol or by different procedures, like hydroformylation or the Alfol process, starting from petroleum chemical raw materials. 

Aluminum Organic Synthesis of Alcohols (Ziegler-Alfol Process)... 

Linear, even-numbered, primary alcohols—like the natural fatty alcohols—are produced by the aluminum organic alcohol synthesis after Ziegler, the so-called Alfol process. This alcohol synthesis proceeds in three steps ... 

For this alcohol synthesis stoichiometric amounts of aluminum alkyls are required. Beside the wanted fatty alcohols high-purity aluminum oxide is formed. This aluminum oxide is of high value, e.g., for the production of catalysts and improves the economy of the Alfol process. 

A further narrowing of the molecular weight distribution in the fatty alcohol mixture of the Alfol process was realized in the so-called Epal process of the Ethyl Corporation [38a,44]. In this process the reaction product of the growth reaction is in a first step transalkylated by a C4-C10 olefin mixture ... 

The olefins and aluminum alkyls are separated by distillation. The aluminum trialkyl obtained in the second transalkylation step contains predominantly C12-C18 alkyl groups and is subsequently treated in the same way as in the Alfol process. Table 10 shows the different alcohol mixtures of the Alfol and Epal process. A disadvantage of the Epal alcohols is their higher degree of branch-... 

TABLE 10 Typical Distribution of the Alcohols in the Alfol and Epal Processes... 

The Ziegler process produces linear alcohols with an even number of carbon atoms and is based on the polymerization of ethylene under catalytic conditions, generally with triethylaluminum as in the Alfol and the Ethyl processes. The distribution of alkyl chains depends on the version of the process employed but the alcohols obtained after fractionation can be equivalent to those obtained from fats and oils or have purpose-made distributions depending on the fractionation conditions. 

A published account of laboratory batch sulfations of Alfol 1214 SP, Alfol 1216 SP, and natural coconut alcohol using chlorosulfonic acid at atmospheric pressure and 16 L/min dry air sparged through the reaction mixture to remove HC1 is available [42], The optimal conditions and the characteristics of the triethanolamine alcohol sulfates obtained are shown in Table 1. 

Alfol 1214SP Alfol 1216SP Coconut alcohol... 

Alfol Also called the Conoco process and the Muhlheim process. The same name is used for the products as well. A process for making linear primary alcohols, from C2 to C28, from ethylene. The ethylene is reacted with triethyl aluminum, yielding higher alkyl aluminums These are oxidized with atmospheric oxygen under mild conditions to aluminum alkoxides, which are then hydrolyzed by water to the corresponding alcohols ... 

Epal A process for making linear aliphatic alcohols by reacting ethylene with triethyl aluminum and oxidizing the products. Similar to Alfol, but incorporating a trans-alkylation stage that permits a wider range of products to be made. Developed by Ethyl Corporation (now Albermarle Corporation) and operated in the United States since 1964. 

The straight-chain alcohol used for this ester is known commercially as Alfol 610 and is produced by the Ziegler polymerization of ethylene. The composition of the alcohol is 20% Ce. 35% Cs. and 44% C10. 

The ALFOL alcohol process is described in Figure 2. Conoco uses a two-step process for the synthesis of triethyl-aluminum—hydrogenation followed by ethylation. Triethyl-... 

Oxidation of the trialkylaluminum mixture is carried out using dry air in agitated batch reactors in the ALFOL alcohol process. Reactor temperature is maintained at approximately 35°C by cooling and the oxidation is operated at about 50 psig. Approximately six hours is required for each batch of growth product to be completely oxidized. The oxidation reactors are operated in staggered fashion to minimize the maximum heat load. 

Stripped alkoxides are then sent to the hydrolysis reactor. In the current ALFOL alcohol process, hydrolysis is accomplished using water instead of dilute sulfuric acid which results in a mixture of alcohols and alumina slurry being formed in the hydrolysis reactor. This mixture is phase separated. 

Alcohols are dried and sent to a distillation train where they are separated by conventional fractional distillation. Crude alcohols are separated into C2-C%, C6-C10, C12-Cu, C16-C18, and C20 + fractions. High purity, individual homologs are prepared by redistillation of the appropriate mixture. The product alcohols are marketed as ALFOL alcohols by Conoco Chemicals. 

Ethyl s version of the Ziegler alcohol process has been modified in order to control the product alcohol distribution. Whereas the Conoco ALFOL alcohol process affords the full range of alcohols, C2-C3o, in a Poisson distribution, Ethyl s product distribution can be modified, for example, as shown in Figure 3 to give carbon number distributions to fit the needs of the market. 

Since the Conoco ALFOL alcohol process has already been described in detail, only those areas where the two processes are different will be covered. Preparation of triethylaluminum appears similar in both processes. Ethyl s scheme is believed to use a ballmilling procedure to obtain an active aluminum... 

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