Feedstock processing cost

The price of acetaldehyde duriag the period 1950 to 1973 ranged from 0.20 to 0.22/kg. Increased prices for hydrocarbon cracking feedstocks beginning in late 1973 resulted in higher costs for ethylene and concurrent higher costs for acetaldehyde. The posted prices for acetaldehyde were 0.26/kg in 1974, 0.78/kg in 1985, and 0.92/kg in 1988. The future of acetaldehyde growth appears to depend on the development of a lower cost production process based on synthesis gas and an increase in demand for processes based on acetaldehyde activation techniques and peracetic acid. 

Production this way is thus complex and time consuming, therefore generating an extremely expensive material. Even if new and low-cost feedstocks are applied successfully in future, fermentative synthesis will remain high priced due to this work-up process, which cannot compete with a simple poly(olefin) production (Fig. 9). 

Although the direct oxidation of ethane to acetic acid is of increasing interest as an alternative route to acetic acid synthesis because of low-cost feedstock, this process has not been commercialized because state-of-the-art catalyst systems do not have sufficient activity and/or selectivity to acetic acid. A two-week high-throughput scoping effort (primary screening only) was run on this chemistry. The workflow for this effort consisted of a wafer-based automated evaporative synthesis station and parallel microfluidic reactor primary screen. If this were to be continued further, secondary scale hardware, an evaporative synthesis workflow as described above and a 48-channel fixed-bed reactor for screening, would be used. 

Ethanol can also be produced from "non-food" materials, such as garbage or wastewater sludge, which are "negative-cost" feedstocks. If all American wastes (industrial and municipal) were converted to biofuels, not only would some 50 to 100 million gallons of fuel be obtained, but the emission of methane from landfills and other wastes would also be eliminated. Plasma gasification, a commercially available process, can also simultaneously increase the fuel supply and reduce greenhouse gas emissions. 

Separate out the most abundant impurities first using the positivenegative strategy. This rule anticipates that a major, if not the major, contaminant in a feedstock placed into purification stream may in fact be water. The ability to reduce the operational volume quickly has major ramifications on the product recovery, plant investment costs, and process efficiencies. 

There are continuing efforts to develop cost-effective processes for fuel alcohol production, although the economics are often dependent on the availability of subsidized feedstocks to compete with traditional fuels derived from oil. The pretreatment and fermentation of such feedstocks, derived from corn, sugar cane, and even municipal waste, yields a dilute aqueous solution of ethanol which must be separated from a complex mixture of waste materials and then concentrated by distillation to remove water. Both batch and continuous production processes have been developed, with the requirement for effective bioseparations during both the pretreatment and ethanol recovery parts of the process. 

The process can accept a wide range of low-cost feedstocks, such as ethylene, chlorinated C2 hydrocarbons, and by-product streams from VCM chloromethanes, methyl chloroform, and EDC plants. The product ratio of trichloroethylene to perchloroethylene can be adjusted over a wide range. 

Progress in fermentation processes and identification of lower cost feedstock for manufacture of PHA products to provide lower material costs. 

PHB producers expect continued progress in fermentation processes and identification of lower cost feedstock to provide more reasonable material costs for niche markets. Longer term, crop-based production has potential to drive PHB costs to more competitive levels from improved productivity. P G for example, is investigating the manufacture of Nodax by plant-grown methods. The supplier states that this method could reduce Nodax prices to between 1.0-2.0 per kg. 

Another opportunity for advancement in ethylbenzene synthesis is in the development of liquid phase processes that can handle low cost feedstocks, including dilute ethylene such as ethane/ethylene mixtures. The use of dilute ethylene has become increasingly attractive since it has the potential to debottleneck ethylene crackers. Currently higher temperature, vapor phase technologies can tolerate contaminants that enter with the dilute ethylene feed from FCC units. However, these same contaminants can accelerate catalyst aging in lower temperature, liquid phase operations because they are more strongly adsorbed at the lower temperatures. Acid catalysts that tolerate elevated levels of contaminants would facilitate the development of dilute ethylene-based processes. These same catalysts could be useful in applications where lower cost or lower quality benzene feeds are all that are available. 

As a result of the need for acid-resistant alloys and other equipment required for acid esterification, the process is typically more capital intensive than base trans-esterification. The higher capital costs associated with the use of acidic catalysts are usually offset by the ability of the process to accept lower cost feedstocks (1). Acidic catalysts may be used to recover soap byproducts of alkali-catalyst based tra i-esterification processes (3, 71). In these processes, acid is used to convert soap to free fatty acids and then to esters (see below). 

Because the conventional EB dehydrogenation technologies are relatively mature, there is little room for significant additional reduction in production costs. This situation has motivated a lot of research toward using alternative, lower cost feedstocks for styrene production. One area that has been examined involves a two-step process to convert butadiene to styrene. 

This selection of menthol processes shows how the major producers are those with the most cost-effective processes, but that local economic conditions or feedstock availability can provide niche opportunities for less efficient processes. 

Control of reactivity by catalysis provides the capability to shift to lower cost feedstocks. In the twentieth century, advances in catalysis have allowed the substitution of acetylene with olefins and subsequently with synthesis gas as primary feedstocks. For example, production of acrylic acid, traditionally produced by the Reppe process from acetylene and CO, has now been replaced by catalytic oxidation of propylene. The emergence of paraffins, the hydrocarbon feedstock of the future, will depend on development of catalysts for selective alkane C-H activation (2). 

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