Feedstock industrial production

In concepts for new products the performance, product safety, and product economy criteria are equally important. They are taken into account already when the raw material base for a new industrial product development is defined. Here, renewable resources have often been shown to have advantages compared with fossil feedstock. Over the years it has been demonstrated that the use of vegetable fats and oils in oleochemistry allows the development of competitive, powerful products that are both consumer- and environmentally-friendly. Products from recent developments fit with this requirement profile. 

MARCHAIM, U., and CRIDEN, J. Research and development in the utilization of agricultural wastes in Israel for energy, feedstock fodder, and industrial products. In D.L.Wise (Ed), Fuel Gas Production from Biomass . Vol. 1, CRC Press Inc. Boca Raton, Florida, pp. 95-120, 1981. 

The use of forest resources as a feedstock for industrial uses is long established and is, in a sense, superior to the use of agricultural crops, since the supply can be guaranteed well into the future and can be obtained throughout the year, unlike seasonal crops. Although this book is concerned with one small aspect of timber utilization, it should be noted that forest resources can also be used to provide feedstocks for many industrial products, including chemicals. 

The plasticizer-range alcohols are largely used as feedstock for production of high molecular weight diesters of phthalic, adipic, azelaic, and sulftiric acids. All these are used primarily in plasticizers for polyvinyl chloride (PVC) and other plastics. The plastics industry also uses them as additives for heat stabilization, to control the viscosity of PVC plastisols, ultraviolet absorbers, flame retardants, and antioxidants. They are also found in synthetic, lubricants, agricultural chemicals, and defoamers. 

Many renewable feedstocks are currently summarily destroyed (through leaving them to rot or burning) or utilized in a noneconomical manner. Thus, leaves are ritualistically burned each fall. A number of these seemingly useless natural materials have already been utilized as feedstock sources for industrial products with more becoming available. 

Maleic Anhydride. Gas-phase catalytic oxidation of benzene or n-butane is the principal process for the industrial production of maleic anhydride.973 996-999 Until the 1970s commercial production was based predominantly on benzene. Because of its more favorable economics, a switch to butane as an alternative feedstock has taken place since then.966,999-1002 At present almost all new facilities use n-butane as the starting material. Smaller quantities of maleic anhydride may be recovered as a byproduct of phthalic anhydride manufacture (about 5-6%).1003,1004... 

Phthalic anhydride is the most important product in the oxidation of o-xylene, which has become competitive with naphthalene as a feedstock for the industrial production of this component. This process is carried out at 350— 400°C and the industrial catalysts consist of doped V2Os or V2Os—Ti02 mixtures, pure or supported. Maximum yields of 70—75 mol. % (95—105 wt. %) are reported. Carbon oxides are the main by-products, besides minor amounts of tolualdehyde and maleic anhydride. Tolualde-hyde is the main product at low conversion and an essential intermediate in the phthalic anhydride formation, while maleic anhydride is mainly formed as a side-product directly from o-xlyene. 

Mixtures of gaseous or liquid hydrocarbons which can be vaporized represent the raw materials preferable for the industrial production of carbon black. Since aliphatic hydrocarbons give lower yields than aromatic hydrocarbons, the latter are primarily used. The best yields are given by unsubstituted polynuclear compounds with 3-4 rings. Certain fractions of coal tar oils and petrochemical oils from petroleum refinement or the production of ethylene from naphtha (aromatic concentrates and pyrolysis oils) are materials rich in these compounds. These aromatic oils, which are mixtures of a variety of substances, are the most important feedstocks today. Oil on a petrochemical basis is predominant. A typical petrochemical oil consists of 10-15% monocyclic, 50-60% bicyclic, 25-35% tricyclic, and 5-10% tetracyclic aroma tes. 

Natural gas liquids represent a significant source of feedstocks for the production of important chemical building blocks that form the basis for many commercial and industrial products. Ethylene (qv) is produced by steam-cracking the ethane and propane fractions obtained from natural gas, and the butane fraction can be catalytically dehydrogenated to yield 1,3-butadiene, a compound used in the preparation of many polymers (see Butadiene). The -butane fraction can also be used as a feedstock in the manufacture of MTBE. 

In tile industrial production of higher alcohols (above butyls), aldehydes play the role of an intermediate in a complete process that involves aldol condensation and hydrogenation. In the OXO process, olefins are catalytically converted into aldehydes that contain one more carbon titan the olefin in the feedstock. Aldehydes also serve as starting materials in the synthesis of several amino acids. See also Acetaldehyde Aldol Condensation Benzaldehyde and Furfuraldehyde. 

There are rather few reactions that can be described as fully atom economical , i.e. when there are no co-products and all the atoms in the starting material(s) appear in the product(s). However, all isomerisation reactions necessarily fall into this category. The use of a transition metal to catalyse such a process with an appropriate substrate brings the possibility of effecting asymmetric isomerisation, a very efficient method to generate enantiomerically enriched products. Indeed, the asymmetric Rh-catalysed isomerisation of an allylamine to an enamine, which proceeds in over 96% ee, was scaled up a number of years ago for industrial production. The enamine product forms a multi-tonne feedstock for menthol and perfumery synthesis. In contrast, the cyclo-isomerisation of dienes, an equally atom-economical process that generates synthetically useful cyclic products, has seen relatively little development despite the reaction having been known for some 30 years. 

The industrial production of ammonia by use of natural gas feedstock can be represented by the following simplified set of reactions ... 

Extensive use of flowcharts is made as a means of illustrating the various processes and to show the main reactors and the paths of the feedstocks and products. However, no effort is made to include all of the valves and ancillary equipment that might appear in a true industrial setting. Thus, the flowcharts used here have been reduced to maximum simplicity and are designed to show principles rather than details. 

A major issue for biomass as a raw material for industrial product manufacture is variability. Questions of standardisation and specifications will therefore need to be addressed as new biofuels, biomaterials and bioproducts are introduced onto the market. Another major challenge associated with the use of biomass is yield. One approach to improve/modify the properties and/or yield of biomass is to use selective breeding and genetic engineering to develop plant strains that produce greater amounts of desirable feedstocks, chemicals or even compounds that the plant does not naturally produce (Fernando et al., 2006). This essentially transfers part of the biorefining to the plant (see Chapter 2 for some example of oils with modified fatty acid content). 

As Table 2.2.1 demonstrates, the chemical industry step by step has reached a point where fine chemicals are produced from biomass, especially by means of biotechnology. Beginning with the production of bulk chemicals, not only biotechnology but also chemocatalysis is needed to convert renewable feedstock into products in the high quantities characteristic of bulk chemicals. 

Aromatic nitro compounds represent versatile chemical feedstocks for a wide range of industrial products, such as pharmaceuticals, agrochemicals, dyestuffs and explosives. 

Starch can also be modified by fermentation as used in the Rodenburg process. In this case the raw material is a potato waste slurry originating from the food industry. The slurry mainly consists of starch, the rest being proteins, fats and oils, inorganic components and cellulose. The slurry is held in storage silos for about two weeks to allow for stabilisation and partial fermentation. The most important fermentation process that occurs is the conversion of a small fraction of starch to lactic acid by mans of the lactic acid bacteria that are naturally present in the feedstock. The product is subsequently dried to a final water content of 10% and then extruded. 

The reaction is catalyzed by a variety of both acids and bases but simple bases such as NaOH and KOH are generally used for the industrial production of biodiesel [200, 201]. The vegetable oil feedstock, usually soybean or rapeseed oil, needs to be free of water (<0.05%) and fatty acids (<0.5%) in order to avoid catalyst consumption. This presents a possible opportunity for the application of enzymatic transesterification. For example, lipases such as Candida antarctica B lipase have been shown to be effective catalysts for the methanolysis of triglycerides. When the immobilized form, Novozyme 435, was used it could be recycled 50 times without loss of activity [201, 202]. The presence of free fatty acids in the triglyceride did not affect the enzymes performance. The methanolysis of triglycerides catalyzed by Novozyme 435 has also been successfully performed in scC02 as solvent [203]. 

Fats and oils are the feedstocks for the industrial production of fatty acids (102). In addition to a major use in the production of bar soaps, these are also employed as starting materials for the production of fatty amines, amides, alcohols, polyoxyethylene esters, and other derivatives widely used in the nonfood industrial sector. 

---