Polyol platform

The slow water removal is obvious within the synthesis of, for example, myristyl myristate determining the total reaction time. In a stirred-tank reactor it takes 24 h to reach a conversion of 99.6% and in a fixed-bed reactor 14 h. Therefore, a new synthesis platform (Figure 4.11) which also enables conversion of highly viscous polyols and fatty acids from renewable resources to ester-based surfactants was designed. It is used by Evonik on a pilot scale, outperforming conventional methods, such as stirred-tank or fixed-bed reactors. In contrast to the setups introduced before, conversion of >99.6% is already obtained after 5.5 h in the bubble column reactor [44-47]. 

Fatty Acid Esters and Fatty Alcohols Fatty acid esters are obtained by transesterification of triglycerides (vegetable oils) or by esterification of fatty acid with alcohol or polyols. Fatty alcohols are obtained by hydrogenation of esters on metal catalysts. Fatty acid esters and fatty alcohols are useful platform molecules to prepare surfactants, emulsifier, lubricants and polymers. 

Xylitol is a specialty chemical with the effects of extreme cooling, caries prevention and safety for diabetes, which are beneficial for manufacturing foods and mouth-care products. As a platform chemical, it also can be converted to various compounds for polymer synthesis and directly polymerized for production of unsaturated polyester resin (Werpy and Petersen, 2004). Danisco (currently part of Dupont Co.) is the largest xylitol producer, and many companies in China and South America (Brazil) manufacture xylitol commercially. The global market of xylitol is estimated to be more than 125,000 tons per year, with 4.5-5.5/kg for bulk purchase and 20/kg in supermarket (da Silva and Chandel, 2012). Xylitol has a 12% share of the total polyols market with growth estimated to increase threefold (da Silva and Chandel, 2012). The xylitol market continues to increase worldwide due to an enhancement in health consciousness and chewing gum market, and new application development as a chemical feedstock. 

Finally, several papers describing the development and use of renewable building blocks are included. Fitzpatrick describes the use of levulinic acid as a chemical feedstock, as well as its continued development. New nanostructural materials based on biopolymers are discussed by van Soest. Robinson presents an overview of a bioreflnery sugar platform leading to the production of polyols. A new approach for the extraction of heteropolysaccharides is given by... 

Polyols An Alternative Sugar Platform for Conversion of Biomass to Fuels and Chemicals... 

Our research has established a clean fractionation of biomass carbohydrate polymers into monomeric polyols which serve as a new alternative sugar platform. Polyols are obtained from biomass by chemical means, rather than by enzymatic degradation, and are further transformed by chemical means into quality fuels and other chemicals. 

In fact, this preparation of inexpensive polyols is the first step in the proposed new platform for a bio-refinery (Figure 4) that is capable of producing several types of products from these intermediate polyols ranging from hydrocarbons to alcohols and hydrogen. 

Anode Catalysts for Direct Polyol Fuel Cells (Ethylene Glycol, Glycerol) Cogenerate Electricity and Valuable Chemicals Based on Anion Exchange Membrane Platform... 

Instead of microbial fermentative processes, chemical conversion of biomonomers yields intermediate chemicals like ethylene, and propylene glycols. Vegetable oils offer a platform to make a portfolio of polyols, lubricants, polyesters, polyamides. In another chapter in this book, we report on ozone mediated transformation of vegetable oils to polyols, urethane foams, polyesters, and polyamides. 

---