Chemicals, biomass acetic acid

Numerous chemical intermediates are oxygen rich. Methanol, acetic acid and ethylene glycol show a O/C atomic ratio of 1, as does biomass. Other major chemicals intermediates show a lower O/C ratio, typically between 1/3 and 2/3. This holds for instance for propene and butene glycols, ethanol, (meth)acrylic acids, adipic acid and many others. The presence of some oxygen atoms is required to confer the desired physical and chemicals properties to the product. Selective and partial deoxygenation of biomass may represent an attractive and competitive route compared with the selective and partial oxidation of hydrocarbon feedstock. 

Animal fats and oilseeds (soybean, cottonseed, coconut, palm) are important feedstocks for plasticizers and cosmetics. Destructive distillation of biomass yields methanol ( wood alcohol ), acetic acid, tar and charcoal, and was the backbone of the chemical industry in former centuries. 

Commodity Chemicals acetic acid, acetone, butanol, ethanol, many other products from biomass conversion processes. 

In almost all organosolv processes, chemical catalysis plays a necessary role, as solvents alone do not function effectively for the separation of biomass.403 The most commonly employed processes, based on the treatment of biomass with aqueous alcohols at elevated temperatures, are autocatalyzed. Acetic acid is generated during the separation process through hydrolysis of acetate groups present on the hemicellulose polymer.397,404 406 Alternatively, acid can be added to the separation medium prior to the process. Adding acid catalyst normally allows lower separation temperatures and milder conditions. Chemical catalysis has proven to be of particular importance for the... 

It is apparent that if one wishes to obtain pure chemicals by biomass pyrolysis, further processing to separate the reaction mixture is necessary. As will be shown later, this did not hinder commercial use of biomass pyrolysis for the manufacture of specific chemicals. The slow, destructive distillation of biomass was commercial technology for the production of several commodity chemicals long before fossil fuels became the preferred feedstocks. Hardwood pyrolysis once served as an important commercial source of methanol, acetic acid, ketones, and other chemicals. 

Other compounds that can be produced directly from biomass in good yields, but which do not retain the basic structural characteristics of biomass, are also classified as commodity chemicals. Examples are acetic acid, methane, and synthesis gas. They are not manufactured in large volumes from biomass because fossil fuels are the preferred feedstocks in commercial production systems. Technically, biomass can serve as a feedstock for production of the entire range of commodity organic chemicals presently manufactured from fossil fuels. The various routes to large-volume chemicals from biomass will be examined later. Consider first some of the existing biomass-based chemicals, most of which are specialty chemicals that are manufactured for commercial markets. 

The period from 1970 to 1985 saw radical changes in the production of acetic acid and acetic anhydride. By 1985, both products would be generated not from ethylene, but from synthesis gas which in turn could be generated fi om abundant resources such as coal, natural gas, and in the future, biomass. At the end of this period, acetaldehyde became a very small contributor to the total acetyl product stream since it was no longer required to make acetic acid or acetic anhydride and ethylene would only be required to produce vinyl acetate and to meet a much diminished acetaldehyde market. These advances were the result of two significant process breakthroughs - the Monsanto Acetic Acid Process and the Eastman Chemical Company Acetic Anhydride Process which will be discussed below. 

The most important process for transforming biomass into chemicals is pyrolysis, used e.g. with wood, to produce acetic acid and charcoal. Other conversion processes which are also used include partial oxidation of waste containing wood... 

Water (electrolysis) Biomass Hydrogen production Chemical products (alkene) Ethanol, acetic acid, formaldehyde Others (H2O2 etc.) storage and transportation... 

Solvent-based pulping (Organosolv) is still in a very early stage of industrial development. In this chemical pulping method the dehgnification of the biomass (usually wood) is done in an organic solvent or solvent plus water system. There are a variety of processes, which use different solvents e. g. ethanol, methanol, acetic acid, formic acid, often in combination with sodium hydroxide, alkaline sulfite, and/or anthraquinone. 

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