Chemical feedstocks, future

As will be evident from the above discussion many valuable chemicals can be made from renewable resources. In many cases current production methods fail to compete effectively with routes from fossil sources. With advances in biotechnology and increasing oil prices, renewable feedstocks will become more commercially attractive, especially for fine, speciality and pharmaceutical chemicals. If future bulk chemical production were to... 

Once syngas and methanol can be produced viably from renewable resources then established synthetic pathways can be used to produce a whole variety of bulk chemical feedstocks (Scheme 6.16). (There is insufficient space to discuss the details here and readers are invited to consult a textbook of industrial chemistry.) By analogy, syngas and/or methanol will become the petroleum feedstock of the future. 

Gas-to-liquid technology is at the same time an economically viable option for the recovery of stranded gas and an option to produce clean fuels or chemical feedstocks. Besides the financial incentive to monetise otherwise worthless gas, GTL has received added impetus in recent years, especially with regard to diesel fuel also, the trend in industrialised nations to reduce sulphur and particle contents in fuels is likely to accelerate. However, GTL competes with LNG for reserves of inexpensive, stranded natural gas further declines in LNG supply costs could undermine the attraction of GTL. The future of GTL further hinges on the reduction of... 

Cellulose is the most abundant renewable resource available for con- version to fuel, food, and chemical feedstocks. It has been estimated by Ghose (11) that the annual worldwide production of cellulose through photosynthesis may approach 100 X 109 metric tons. As much as 25% of this could be made readily available for the conversion processes. A significant fraction of the available cellulose, i.e., 4-5 X 109 t/year, occurs as waste, principally as agricultural and municipal wastes. Cellulose must be viewed, therefore, as an important future source of fuel, food and chemicals (see Table I). 

The above is followed by an overview of the assessment of the potential for future exploitation of plants for chemical feedstocks through developments in biotechnology and biorefining. 

Major oil spills attract the attention of the public and the media. In recent years, this attention has created a global awareness of the risks of oil spills and the damage they do to the environment. However, oil is a necessity in our industrial society, and a major sustainer of our lifestyle. Most of the energy used in Canada and the United States is for transportation that runs on oil and petroleum products. According to trends in energy usage, this is not likely to decrease much in the future. Industry uses oil and petroleum derivatives to manufacture such vital products as plastics, fertilizers, and chemical feedstocks, which will still be required in the future. 

The biochemical reaction catalyzed by epoxygenase in plants combines the common oilseed fatty acids, linoleic or linolenic acids, with O2, forming only H2O and epoxy fatty acids as products (CO2 and H2O are utilized to make linoleic or linolenic acids). A considerable market currently exists for epoxy fatty acids, particularly for resins, epoxy coatings, and plasticizers. The U.S. plasticizer market is estimated to be about 2 billion pounds per year (Hammond 1992). Presently, most of this is derived from petroleum. In addition, there is industrial interest in use of epoxy fatty acids in durable paints, resins, adhesives, insecticides and insect repellants, crop oil concentrates, and the formulation of carriers for slow-release pesticides and herbicides (Perdue 1989, Ayorinde et al. 1993). Also, epoxy fatty acids can readily and economically be converted to hydroxy and dihydroxy fatty acids and their derivatives, which are useful starting materials for the production of plastics as well as for detergents, lubricants, and lubricant additives. Such renewable derived lubricant and lubricant additives should facilitate use of plant/biomass-derived fuels. Examples of plastics that can be produced from hydroxy fatty acids are polyurethanes and polyesters (Weber et al. 1994). As commercial oilseeds are developed that accumulate epoxy fatty acids in the seed oil, it is likely that other valuable products would be developed to use this as an industrial chemical feedstock in the future. 

Hydrogen has many and versatile uses It plays a significant role as a chemical feedstock for industrial and petrochemical processes, e.g., in the conversion of coal into clean synthetic fuels or in the generation of process heat. Furthermore it possesses a huge potential as a direct fuel for producing mechanical energy, heat, or electricity for a future large-scale use. 

The trend in chemical feedstocks is towards less expensive, more available ones and away from the expensive, more reactive feeds. For example, the extensive use of acetylene as a feedstock in the 1930-1940 s has been replaced in the 1960-1980 s by olefins and diolefins. The future trend appears to be towards paraffins and synthesis gas (Figure 20). Continued developments in fundamental catalyst science will serve as the basis for the design of the catalytic single-step processes of the future which will efficiently utilize inexpensive, readily available feeds. 

Chitin, a waste material from crab and shrimp processing, is poly(N-acetyl-D-glucosamine). The de-acetylated form, chitosan, is primarily used in water purification but is also used as a chemical feedstock. For example, chitosan can be depolymerized to the monomer, which is used as a hair-setting agent in shampoo and hair conditioner. In the future, graft polymers of chitosan may form biodegradable films. Already, carboxymethylated chitin is approved as a food wrap. 

In conclusion, there is still a long way to go before reaching the goal of ideal synthesis when chemists can selectively functionalize arbitrarily specified C—H bonds of any chemical feedstocks as they want. However, we do have reasons to believe that every firm step towards to this ambitious goal will undoubtedly lead to fruitful outcomes that will be beneficial for the future of organic synthesis. 

Electrochemistry is clearly an important component of the technology of many quite diverse industries. Moreover, the future for electrochemical technology is bright and there is a general expectation that new applications of electrochemistry will become economic as the world responds to the challenge of more expensive energy, of the need to develop new materials and to exploit different chemical feedstocks and of the necessity to protect the environment. 

Research into the bacterial production of 2,3-butanediol (see section 2,3 Butanediol Production in Chapter 2) also has been considerable. The future prospects of large-scale fermentative production of 2,3-butanediol as a fuel or as a major chemical feedstock will depend on the need to substitute for present petroleum-based products such as 1,3-butadiene and methyl ethyl ketone (Maddox 1996). 

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