Renewable base chemicals

An overview of cellulose-based chemicals and fuels systems is presented in Figure 1. In this cyclic system, demand for fuels and chemicals leads to the organization of factors of production (land, labor, capital, etc.) for the generation of biomass for use as a renewable resource. The plant culture activity is called silviculture if trees are the desired biomass or agriculture if herbaceous plants are grown... 

Industrial (white) biotechnology is rapidly gaining momentum as a cost-effective and environmentally-friendly technology for producing bio-based chemicals, materials, and fuels in a safe and sustainable way from renewable resources. 

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. 

Doi, S., J.H. Clark, D.J. Macquarrie and K. Milkowski, New Materials Based on Renewable Resources Chemically Modified Expanded Corn Starches as Catalysts for Liquid Phase Organic Reactions, Chemical Communications, 2632-2633 (2002). 

The overall physical and mechanical properties of the various materials prepared utilizing renewable resource diisocyanates and polyols have been shown to be comparable to those of materials derived from oil-based chemicals. 

Toxicity tests may be static, continuous-flow, or static renewal based on the toxicant dosing technique. Static and continuous-flow procedures are more widely used in toxicity tests conducted with pure chemicals and animal test species. Chronic toxicity tests conducted with effluents are usually static renewal, and those with algae are static. There is no change or renewal of the test substance with dilution water in a static test. This design is the simplest and least expensive however, the toxicant concentrations may decrease due to adsorption and biodegradation. The test solutions and dilution water are renewed periodically, usually daily in a static-renewal test. In a continuous-flow test, the dilution water and test substance are continuously or intermittently renewed. The exposure concentrations remain fairly constant and dose-response relationships can be well defined. 

It also aims at the utilization of renewable resources with the challenge of replacing oil-based chemicals and fuels. Environmental processes play a major role in industrial biotechnology, enabling clean and sustainable production and, furthermore, providing a safe environment most notably in crowded areas, big cities, and industrial areas. These technologies represent big business. 

The symposium on which this book is based is certainly not the first to describe the concept of using renewables as chemical feedstocks. Well into the 20th century, renewable feedstocks supplied a significant portion of the nation s chemical needs. The chemurgy movement of the 1930s, led by such notables as William Hale and Henry Ford, promoted the use of farm products as a source of chemicals, with the belief that anything that can be made from a hydrocarbon could be made from a carbohydrate" (I).li is only in the period of time between 1920 and 1950 that we have witnessed the transition to a nonrenewables based economy (2). 

An answer to this question must begin with an economic comparison. Certainly the primary driver for greater domestic use of renewable feedstocks is cost because it will be the chemical industry that needs to be convinced of the value of renewables. That argument is only won by favorable economics. As shown in several studies, not all renewables-based materials are reasonable targets for biomass based processes, primarily for economic reasons (14). 

With the rapidly increased production cost of fossil-(petroleum)-based chemicals, it has been suggested that the biological production of fumaric acid from renewable resources can replace current petrochemically based maleic anhydride/acid process. This chapter reviews the accumulated knowledge and recent research, as well as a critical analysis of future perspectives to develop economically competitive bio-based fumaric acid processes to replace the petrochemical route. 

The use of soy-based (renewable feedstock) chemicals to prepare toner for laser printers and... 

Doi S, Clark JH, Macquarrie DJ, Milkowski K (2002) New materials based on renewable resources chemically modified expanded com starches as catalysts for liquid phase organic reactions. Chem Com 22 2632-3... 

DuPont, the US-based chemicals major, which revolutionised the fibre industry with the introduction of man-made fibres like nylon, rayon and spandex now offers Sorona, a polymer which is made with agricultural feedstock instead of petrochemicals. Sorona has high renewable ingredients content - 37 per cent by weight. 

Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene. The isomer found in orange peel is (+)-limonene (Figure 20.71). It is thought that its high abundance in this part of the fruit is connected with the fact that it is an insecticide. As well as its smell, limonene also contributes to the flavour of the fruit and as such has been used as a food additive for many years. Limonene is an important precursor in the biosynthesis of (-)-menthol, which is the major component of mint and the molecule responsible for the herb s refreshing taste. It is used in chemical synthesis as a precursor to carvone and as a renewably based solvent in cleaning products. It is readily prepared in the laboratory by steam distillation of the zest of an orange or lemon. 

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