Renewable feedstocks advantages

The pyrolysis-based technology, in particular, because of the co-products opportunity, has the most favorable economics. An added advantage of biomass as a renewable feedstock is that it is not intermittent, but can be used to produce hydrogen as and when required. With scientific and engineering advancements, biomass can be viewed as a key and economically viable component to a renewable-based hydrogen economy. Economic viability of different types of energy generation processes is summarized in Table 8.1 (Bockris, 1981 Tanisho, 1996 Benemann, 1997). 

Bioethanol can be regarded as a potential renewable feedstock and is produced as 3-15 vol.% aqueous solution by fermentation. Therefore, the dired transformation of dilute bioethanol to valuable compounds with air can be an environmentally friendly process. Gold catalysts appear to be advantageous in this process over Pd and Pt catalysts. The latter showed inferior seledivity to acetic acid of 60% and 16% for Pd and Pt, respedively, under the same conditions [167]. Furthermore, C02, which can be easily removed from the produd solution, was formed as the major by-produd over Au catalysts, whereas acetaldehyde was also co-produced over Pd and Pt catalysts. 

Related to ionic liquids are substances known as deep eutectic solvents or mixtures. A series of these materials based on choline chloride (HOCH2CH2NMe3Cl) and either zinc chloride or urea have been reported (Abbott et al., 2002 2003). The urea/choline chloride material has many of the advantages of more well-known ionic liquids (e.g. low volatility), but can be sourced from renewable feedstocks, is non-toxic and is readily biodegradable. However, it is not an inert solvent and this has been exploited in the functionalisation of the surface of cellulose fibres in cotton wool (Abbott et al, 2006). Undoubtedly, this could be extended to other cellulose-based materials, biopolymers, synthetic polymers and possibly even small molecules. 

Use renewable feedstocks Use raw materials and feedstocks that are renewable rather than depleting. Renewable feedstocks are often made from agricultural and forest products or are the wastes of other processes depleting feedstocks are made from fossil fuels (petroleum, natural gas, or coal) or are mined. Another advantage of renewable feedstocks is that often the oxidation state of the feedstock is often close to that of the desired product. This simplifies and reduces the number and extent of chemical transformations necessary in a synthetic pathway. 

Basic and applied research efforts show that the oxidative transformation of renewable feedstocks represents a promising approach for the production of high-value chemicals under environmentally acceptable conditions. Many laboratory-scale processes are carried out under mild conditions, and the employment of molecular oxygen ensures ecological and economic advantages. In these processes, a crucial role is played by the catalytic step that requires a specific selectivity toward the desired product. In principle, either enzymatic catalysis or chemical catalysis can be effectively employed in a given process and, in some cases, the performance of the different processes is quite similar as presented in the following sections. 

Besides the advantage of using cellulose as a renewable feedstock, the easy of recoverability of the catalysts from the solid residues and its reuse without any loss of activity or selectivity for several rims were other benefits generated by this composite architecture [20]. 

Biodiesel is a fuel derived from renewable natural resources such as soybean and rapeseed and consists of alkyl esters derived from transesterification of triglycerides with methanol. In spite of all the advantages of biodiesel, such as low emissiotts, biodegradability, non-toxicity, and lubricity, the major hurdle in penetration of biodiesel is its high cost because of the expensive food grade refined vegetable oil feedstock. 

In concepts for new products the performance, product safety, and product economy criteria are equally important. They are taken into account already when the raw material base for a new industrial product development is defined. Here, renewable resources have often been shown to have advantages compared with fossil feedstock. Over the years it has been demonstrated that the use of vegetable fats and oils in oleochemistry allows the development of competitive, powerful products that are both consumer- and environmentally-friendly. Products from recent developments fit with this requirement profile. 

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