Production, isoprene

S. K. Ogorohnikov and G. S. IdUs, Isoprene Production, Izdatelstvo Chimia, Leningrad, Russia, 1973. 

Isoprene (2-methyl 1,3-butadiene) is the second most important conjugated diolefin after butadiene. Most isoprene production is used for the manufacture of cis-polyisoprene, which has a similar structure to natural rubber. It is also used as a copolymer in butyl rubber formulations. 

While most isoprene produced today comes from the dehydrogenation of C5 olefin fractions from cracking processes, several schemes are used for its manufacture via synthetic routes. The following reviews the important approaches for isoprene production. 

Complexes 17-19 can be written in one valence structure as a, /3-unsaturated carbonyl compounds in which the carbonyl oxygen atom is coordinated to a BF2(OR) Lewis acid. The C=C double bonds of such organic systems are activated toward certain reactions, like Diels-Alder additions, and complexes 17-19 show similar chemistry. Complexes 17 and 18 undergo Diels-Alder additions with isoprene, 2,3-dimethyl-1,3-butadiene, tram-2-methyl-l,3-pentadiene, and cyclopentadiene to give Diels-Alder products 20-23 as shown in Scheme 1 for complex 17 (32). Compounds 20-23 are prepared in crude product yields of 75-98% and are isolated as analytically pure solids in yields of 16-66%. The X-ray structure of the isoprene product 20 has been determined and the ORTEP diagram (shown in Fig. 3) reveals the regiochemistry of the Diels-Alder addition. The C-14=C-15 double bond distance is 1.327(4) A, and the... 

Pantothenic acid participates as part of coenzvme A in carbohydrate metabolism (2-carbon transfer-acetate, or pyruvate), lipid metabolism (biosynthesis and catabolism of fatty acids, sterols, +phospholipids), protein metabolism (acetylations of amines and amino acids), porphyrin metabolism, acetylcholine production, isoprene production. 

That this latter reaction has become the basis of a very large isoprene production is not to be credited to my institute but to the cooperation between the two American companies, Goodyear Tire Rubber Co. and Scientific Design Co. These two firms added to our dimerization of propylene the rearrangement of the 2-methyl-l-pentene into 2-methyl-2-pentene and then cracked this product to give isoprene and methane (10). 

The final isoprene product contains 98.5 per cent weight, with a maTitmifn olefins content of 1.5 per cent Figure 6.6 shows a flow sheet of the SNAM process. 

Methylpentenes, which are obtained in about 80% yield, can be used for isoprene production (J ). 

Saturation kinetics is observed in rats and mice. The half-life in rats and mice are 6.8 and 4.4 min, respectively, following inhalation exposure. The presence of isoprene products in the respiratory epithelium... 

Logan B.A., R.K. Monson and M.J. Potosnak Biochemistry and physiology of foHar isoprene production. Trends Plant Sci. 5 (2000) 477-481. 

Fowler, R-, Barker, D "Isoprene monomer production". The Chem. Engineer, 322-327 (ScpL 1971) Monistm. J. Bayer has promising new route to isoprene. 03 md Gas 1. Internal, 11 (10) 35-37 (1971) Reis. T "Isoprene production". Chem and Process Engng, 53 (3)66-72 (1972)... 

Double-stage dehydration of isopentane is one of the major methods among industrial ways of isoprene production. Dehydration of isopentane and isopentene is carried out at high temperatures and is accompanied by formation of by-products. The most noticeable among them is pentadiene-1,3 (piperylene) [239, 240]. Piperylene yield is 10-15% from diene monomers sum. 

One of the directions of piperylene application is cationic oligomerization for production of liquid rubber - the base of synthetic drying oil of SKOP brand. Use of piperylene hydrocarbon fraction as feed stock for synthetic drying oil production allows solving the problem of isoprene production by-product utilization and reducing consumption of plant oils in paintwork and other industry branches [206,241, 242]. 

Stein, C. A. and S. Stein (1992) A model for the global variation in oceanic depth and heat flow with lithospheric age. Nature 359, 123-129 Steinbrecher, R. (1997) Isoprene production by plants and ecosystem-level estimates. In Biogenic volatile organic compounds in the atmosphere (Eds. G. Helas, J. Slanina and R. Steinbrecher), SPB Academic Publishing, Amsterdam, pp. 101-114 Steinbrecht, W., H. Claude, F. Schonenborn, I. S. McDermid, T. Leblanc, S. Godin, T. Song,... 

High-yield production of ethanol and n-butanoP from glucose has been demonstrated via in vitro reconstituted pathways. Another recent example is high-yield isoprene production via an m vitro mevalonate pathway with balancing of the ATP, NADPH and acetyl-CoA cofactors, resulting in 100% molar yield. ... 

Among commercial methods of isoprene production, one of the main methods is the process of two-stage isopentane dehydrogenation. Isopentane and isopentene dehydrogenation is carried out at elevated temperatures followed by the formation of a number of by-products among which a great part is piperylene (pentadiene-1,3) [9, 10]. Piperylene yield is 10-15% of the sum of the diene monomers during isoprene production. 

Both these pools are apparently supplied from the same sources of COgt and the primary products of photochemical reactions, occuring in the membrane of thylakoids. But judging by the isoprene production /14, 16/ the pool AcCoA, presumably is supplied by them in lesser degree than pool BC. Further it. is supposed that the pool AcCoA, beside the main function - the biosynthesis of acetate which than is activated by coenzyme A functions as a supplier of phosphogly ceric acid in chloroplast (Ch) which can be synthesized from... 

Fermentation-based isoprene production uses a continuous gas-phase product recovery. This is possible due to the high vapor pressure of isoprene (400 mm Hg... 

Much of the earlier work on the occurrence and biosynthesis of isoprene was summarized and discussed by Loomis and Croteau (1973). Earlier work indicated that isoprene was produced by a large number of woody species (Rasmussen, 1970,1978), and isoprene production was thought to occur only in woody species. However, R. A. Rasmussen (personal communication, 1979) has recently shown isoprene emission by several species of ferns and by two herbaceous dicot species—velvet bean Stizolobium sp.) and California poppy (Eschscholtzia californica). Bracken fern appears to be an especially active producer of isoprene. 

Pegoraro, E., Rey, A., Abrell, L., Vanharen, J., Lin, G.H. (2006) Drought effect on isoprene production and consumption in Biosphere 2 tropical rainforest. Global Change Biology, 12,456-469. 

Presently, isoprene is being produced via the dehydrogenation of amylenes.the cracking of propylene dimer, (6,7,8) and by the isolation from refinery streams.(9,10,11). Isoprene production... 

Isoprene, 2-methyl-l,3-butadiene, is a common organic compound and a key commodity chemical for the rubber and textile industries. Today, isoprene production at the industrial scale relies on the petroleum-derived feedstock and well-developed chemical processes. However, with increasing industrial demand for isoprene, the current petroleum-based isoprene production capacity is not sufficient for the anticipated future markets. Nevertheless, an alternative process that does not rely on petroleum resources and refining capacity is under development for isoprene production. Bioisoprene, which is produced from renewable feedstock through biocatalysts, will be a promising alternative to petroleum-derived isoprene [1]. 

The microbial production of isoprene or isoprenoids through the MVA or MEP pathway has been reported in a variety of microorganisms. The details of the engineering strategies, especially for isoprene production, are discussed below. The preferred approach of heterologous or endogenous pathway expression is determine d by the me chanism of metabolic regulatory control, the toxicity of the intermediate metabolites, and the characteristics of the key enzymes. 

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