Environmental footprint feedstock

The conversion of this enormous natural chemical potential to the actual products we want requires chemical technologies and if we are to keep the overall environmental footprint low and build on the head start afforded by renewable feedstocks, these need to be green chemical technologies. Fran Kerton reviews these in Chapter 3. Apart from the tools of biotechnology, some of the key technologies are likely to be alternative solvents - for extraction of valuable plant chemicals and for chemical processing alternative activation methods including microwaves (so... 

Nonetheless, a (partial) switch to renewables is desirable for other reasons, such as biocompatibility, biodegradability and lower toxicity, i.e. renewable raw materials leave a smaller environmental footprint [3]. That the chemical industry has been slow to make the transition, in the three decades following the Report of the Club of Rome, is a consequence of the fact that oil and natural gas are excellent basic feedstocks and highly atom efficient, low waste, catalytic procedures are available for their conversion into commodity chemicals. The same cannot be said for the fine chemicals industry where processes are, generally speaking, much less efficient in many respects and there is considerable room for improvement. 

The need for novel catalytic processes is clear and, as discussed in Chapter 9, combining catalytic steps into cascade processes, thus obviating the need for isolation of intermediate products, results in a further optimization of both the economics and the environmental footprint of the process. In vivo this amounts to metabolic pathway engineering [20] of the host microorganism (see Chapter 8) and in vitro it constitutes a combination of chemo- and/or biocatalytic steps in series and is referred to as cascade catalysis (see Chapter 9). Metabolic engineering involves, by necessity, renewable raw materials and is a vital component of the future development of renewable feedstocks for fuels and chemicals. 

Replacing petro / fossil carbon with bio-based carbon by using plant biomass feedstock in place of fossil feedstock for the manufacture of plastic materials offers a strong value proposition for a zero material carbon footprint. It may also reduce the process carbon and environmental footprint. A methodology for quantification of bio-based carbon content has been developed and codified into the ASTM Standard D6866. Using bio-based carbon content calculations, one can calculate the intrinsic CO2 reductions achieved by incorporating bio-based carbon content into a plastic product - the material carbon footprint. 

Raw materials The successful introduction of a selective blend of solid byproduct wastes into the feedstock replacing quarried raw materials has an immediate effect The lesser the use of primary raw materials the lesser the environmental footprint of a production process. 

Switching the manufacturing base (the origins of the carbon) from petro / fossil to biobased plant carbon feedstock offers an intrinsic zero material carbon footprint value proposition. This is readily apparent from reviewing nature s carbon cycle. Nature cycles carbon through various environmental compartments with specific rates and time scales, as shown in Figure 14.1. 

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