Ethanol commodity chemicals from

Commodity Chemicals acetic acid, acetone, butanol, ethanol, many other products from biomass conversion processes. 

Acetic acid (CH3COOH) is a bulk commodity chemical with a world production of about 3.1 x 106 Mg/year, a demand increasing at a rate of +2.6% per year and a market price of US 0.44-0.47 per kg (Anon., 2001a). It is obtained primarily by the Monsanto or methanol carbonylation process, in which carbon monoxide reacts with methanol under the influence of a rhodium complex catalyst at 180°C and pressures of 30-40 bar, and secondarily by the oxidation of ethanol (Backus et al., 2003). The acetic fermentation route is limited to the food market and leads to vinegar production from several raw materials (e.g., apples, malt, grapes, grain, wines, and so on). 

One can envisage the future production of liquid fuels and commodity chemicals in a biorefinery Biomass is first subjected to extraction to remove waxes and essential oils. Various options are possible for conversion of the remaining biofeedstock, which consists primarily of lignocellulose. It can be converted to synthesis gas (CO + H2) by gasification, for example, and subsequently to methanol. Alternatively, it can be subjected to hydrothermal upgrading (HTU), affording liquid biofuels from which known transport fuels and bulk chemicals can be produced. An appealing option is bioconversion to ethanol by fermentation. The ethanol can be used directly as a liquid fuel and/or converted to ethylene as a base chemical. Such a hiorefinery is depicted in Fig. 8.1. 

FIGURE 13.6 Routes to commodity organic chemicals from ethanol. 

TABLE 13.4 Some Commodity Organic Chemicals from Fermentation Ethanol in Brazil ... 

Fermentation has been used in the production of foods and drinks since the days of antiquity. A recent application is the large-scale production of yogurt. Before the advent of cheap petroleum, a variety of other commodity chemicals were produced by fermentation. Acetone and n-butyl alcohol were produced by Clostridium aceto-butylicum.17 Ethanol, which was all made from fermentation, is now made in part by the hydration of ethylene. Acetic acid is now made largely by the carbonylation of methanol (9.2) using a rhodium catalyst in the presence of iodide ion.18... 

The topic of this chapter is the application of reversible chemical complexation for removal and recovery of polar organic solutes from aqueous solution. There are some current examples of such separations, and many more are subjects of active research. One of the most important applications is the recovery of products of biochemical synthesis processes, such as fermentation and enzymatically catalyzed reactions. These separation problems range from recovery of commodity chemicals or fuel substances such as acetic acid and ethanol to isolation of much more complex pharmaceuticals and compounds produced by recombinant DNA and other recently developed biological techniques. Another important application is removal and recovery of polar organics from effluent or recycle water streams. 

Ethanol in the past has been used commercially to synthesize dozens of other high-volume chemical commodities. However, at present, it has been substituted in many applications by less costly petrochemical feedstocks, e.g., ethylene. The availability of low-cost ethanol and the rising cost of ethylene, however, may change this scenario. For example, there is interest in producing ethylene from ethanol [71-73], while the opposite reaction is commercially current. Already, in markets with abundant agricultural products, but a less developed petrochemical infrastructure, such as the People s Republic of China, Pakistan, India, and Brazil, ethanol can be used to produce chemicals, including ethylene and butadiene, that would be produced from petroleum in the West. For example, ethanol may substitute alkenes for the alkylation of aromatics [82]. 

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