Platform chemical

An alternative possibility is that of the biorefinery. In this concept a few key chemicals would be isolated from a small number of process steps. Whilst there are many possibilities for this, in one example the raw material, say com, could be cmshed to release oil (the first key product). The resulting mass could then be fermented to give several key platform chemicals such as ethanol, lactic acid and acetic acid. This attractive concept would be more viable if all the cellulose and lignin components could be efficiently used in the fermentation process. 

Many industrial organic acids can be produced by fermentation, such as acetic, citric, and lactic acids. Succinic acid is a dicarboxylic acid of potential industrial interest as a platform chemical (1-3). Separation and purification of succinic acid by adsorption was tested to replace current precipitation methods and their associated waste disposal problems. Succinic acid is a valuable intermediate value chemical with a moderate market. For succinic acid to have an economic and energy impact, it will need to become a commodity chemical intermediate with a much lower price. This target price hasbeen estimated to be between 0.22 and 0.30 / lb ( 0.48- 0.66/kg) and is potentially achievable with advanced technology (1). At this price, succinic acid can be catalytically upgraded into other higher valued chemicals suchastetrahydrofuran, 1,4-butanediol, y-butyrolactone, 2-pyrrolidinone, and N-methylpyrrolidinone. 

Index Entries Bioproducts thermoplastics fermentation solvents platform chemicals. 

Platform chemicals are compounds that serve as building blocks for numerous chemical intermediates and end products. An example is ethylene, which serves as the feedstock for derivatives such as acetaldehyde, ethylene dichloride, ethylene oxide, polyethylene, vinyl acetate, and ethyl acetate. Biobased chemicals such as succinic acid, 3-hydroxypropionic acid (3-HP), and butanol also have the potential to be converted into multiple derivatives, some of which are commodity chemicals and others that are higher-value chemicals. 

Butanol is a platform chemical with several large-volume derivatives and is used as a solvent and in plasticizers, amino resins, and butylamines (48). Butanol can also be used as a biobased transportation fuel and is more fuel efficient than ethanol on a volume basis. 

Fig. 4 Renewable platform chemicals used in olefin metathesis (a) plant oils and fatty acids, (b) terpenes and terpenoids, (c) phenylpropanoids, (d) natural rubber (cw-1,4-poly isoprene), (e) carbohydrates, (f) amino acids and peptides, and (g) furans...

Synthesis of Platform Chemicals 2.1 Plant Oils and Fatty Acids... 

Another interesting castor oil-derived platform chemical is 10-undecenal, which is at the same time a challenging substrate for olefin metathesis. For the SM of 10-undecenal, Dixneuf et al. modified C3 and C5 by insertion of SnCl2 into one Ru-Cl bond [48]. Modification of C3 led to a binuclear complex, which showed a conversion of 70% at a catalyst loading of 0.33 mol%. On the other hand, both the modified and unmodified C5 gave conversions over 70% with catalyst loadings of 1.25 mol%, but also led to formation of a high amount of by-products. 

While the ethenolysis of fatty acids and esters yields a-olefins and oo-unsaturated acids and esters, the use of higher olefins or functionalized olefins as CM partners gives access to a wide spectrum of platform chemicals. The wide availability of ethylene makes ethenolysis particularly attractive however, the associated problems regarding loss of catalyst activity already explained have motivated the search for alternative low molecular weight olefins. In this way, 2-butene (butenolysis) has been used to avoid the mentioned problems. Patel et al. reported the butenolysis of different natural oils in the presence of C5 [63], TONs between... 

Scheme 8 CM of 10-undecenoic acid-derived platform chemicals with acrylonitrile [70]...

Some other natural compounds have been transformed for their use in the synthesis of polymers via olefin metathesis processes. As mentioned in the introduction, furans, which are obtained from carbohydrates, are perfect precursors of monomers for ROMP via simple Diels-Alder cycloadditions (n) (Scheme 25) [26]. In this regard, the first example of the ROMP of 7-oxabicyclo[2.2.1]hept-5-ene derivatives was reported by Novak and Grubbs in 1988 using ruthenium- and osmium-based catalysts [186]. The number of examples of ROMP with monomers with this generic structure is vast, and it is out of the scope of this chapter to cover all of them. However, it is worth mentioning here the great potential of a renewable platform chemical like furan (and derived compounds), which gives access to such a variety of monomers. 

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