Biological feedstocks

As discussed in Chapter 13, Section 13.2, there are several major categories of biomass that can be used as raw material to replace petroleum as a feedstock for the organic chemicals industry  

Carbohydrate, which has the general formula of approximately CH2O. Carbohydrate is the biomass that is produced initially as glucose sugar from water and carbon dioxide during photosynthesis. It is contained in the structural parts of plants as cellulose, a biopolymer. 

Lignin, a biological polymer with a complex structure, which occurs with carbohydrate cellulose in woody parts of plants where it binds fibers of cellulose together. Relatively few uses have been found for lignin, and it poses impurity problems in extracting cellulose for feedstock use. 

Lipid oils extracted from seeds, including soybeans, sunflowers, and com. 

Hydrocarbon terpenes produced by rubber trees, pine trees, and some other kinds of plants. 

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Human blood plasma contains over 700 different proteins (qv) (1). Some of these are used in the treatment of illness and injury and form a set of pharmaceutical products that have become essential to modem medicine (Table 1). Preparation of these products is commonly referred to as blood plasma fractionation, an activity often regarded as a branch of medical technology, but which is actually a process industry engaged in the manufacture of speciaUst biopharmaceutical products derived from a natural biological feedstock (see Pharmaceuticals). 

This section discusses the production of methanol and ammonia from wood. Methanol is a clean-burning material that may find widespread future use as an automotive fuel (directly or for conversion to gasoline by the Mobil process) as a fuel for industrial or utility boilers, gas turbines, or fuel cells as a chemical intermediate or as a biological feedstock for protein. 

For more than 50 years, industrial chemistry has been based on coal, oil, and gas. Hence renewable resources have become less important, but shortage of resources, the greenhouse effect, growth of the world population, and the pursuit of sustainable development have awoken great interest in the energetic and substantial use of renewable resources in industry and research. A lower dependence on crude oil imports and raw material costs is currently accelerating the shift towards chemical products derived from renewable biological feedstocks. 

Biological materials used as sources of feedstocks are usually complex mixtures, which makes separation of desired materials difficult. However, in some biological starting materials, nature has done much of the synthesis of products from biological feedstocks. Most biomass materials are partially oxidized as is the case with carbohydrates, which contain approximately one oxygen atom per carbon atom (compared to petroleum hydrocarbons, which have no oxygen). This can avoid expensive, sometimes difficult, oxidation steps, which may involve potentially hazardous reagents and conditions. 

Another very important ch ical that has been made from biological feedstocks by fermentation for many years is lactic acid. Lactic acid is the most important hydrocarboxylic acid and is nsed to make a number of chemicals including pyruvic acid, acrylic acid, 1,2-propauediol, lactate esters, and polylactic add polymer. Fermentation of glucose with the intermediate prodnction of pyruvic acid is the leading process for making lactic acid, as shown in Reaction 16.10 ... 

What is a fundamental chemical difference between petroleum aud biological feedstocks ... 

Biopolymers from plants that have the potential for use as biological feedstocks... 

In some cases, an advantage of biological feedstocks is their high content. 

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