Renewable carbon source

Most of the renewable carbon sources Hsted in Table 8 have carbon contents near this value. When adjusted for moisture and ash contents, it is seen that with the exception of the sludge sample, the carbon contents are slightly higher than that of cellulose, but span a relatively narrow range. 

The greenhouse gas CO2 is a valuable and renewable carbon source for the production of fine chemicals and fuels because it is readily... 

Polyurethanes prepared via the use of renewable carbon sources are a relatively recent introduction to the commercial market. The opportunity is driven primarily by the high and volatile cost of petroleum, and by societal concerns over the... 

Plant oils or their derived fatty acids are inexpensive renewable carbon sources. In addition, the theoretical yield coefficient of bioproducts (PHA) from plant oil and fatty acid is considerably higher than that from sugars. High cell density fed-batch cultures produced value-added products from soybean oil or oleic acid as the carbon source. PHAs with high yield were produced by fed-batch culture of R. eutropha or its recombinant strain from soybean oil. High cell concentrations obtained by fed-batch cultures from oleic acid improved lipase activity by C. cylindracea and 10-KSA by Flavobacterium, sp. DS5, compared with those of flask cultures. There are still many industrially important value-added products that can be produced from inexpensive substrates such as soybean oil. 

Abstract The possible utilization of room temperature ionic liquids (RTILs), instead of volatile organic compounds (VOCs), in the electrochemical procedures of organic synthesis has been discussed. The synthesis of p-lactams, the activation of carbon dioxide and its utilization as renewable carbon source and the carbon-carbon bond formation reactions via umpolung of aldehydes (benzoin condensation and Stetter reaction) and via Henry reaction have been selected as typical electrochani-cal methodologies. The results, related to procedures performed in RTILs, have been compared with those performed in VOCs. The double role of RTILs, as green solvents and parents of electrogenerated reactive intermediates or catalysts, has been emphasized. 

Chapter 16 outlines the possible utihzation of room-temperature ionic liquids (RTILs), instead of volatile organic compounds (VOCs), in the electrochemical procedures of organic synthesis of alpha- and beta-lactams. The activation of carbon dioxide and its utilization as a renewable carbon source is also highlighted. 

Figure 7.8 Synthesis of polylactic acid using renewable carbon source [16].

A relatively new area of research (which is outside of the scope of this chapter but important to mention) is the development of methods to produce so-called bio-based PTA from renewable carbon sources, which was recently reviewed [69]. 

Castilho et al. 2(X)9 Tokiwa and Ugwu 2(X)7). Thus, various attempts are being made to utilize cheap and renewable carbon source to enable the commercialization and widespread use of these polymers. 

Xylan is one of the main non-cellulosic polysaccharides found in plant cell walls and makes up between 10 and 35% of the dry weight. It is an abimdant and renewable carbon source and its hydrolysis is important to many commercial processes. The hydrolysis of xylan is also central to the carbon cycle in nature, making the sugars locked up in the intact plant cell wall available for growth (7). Xylan consists of a backbone of 1,4-linked p-xylose units substituted with arabinofuranose, 4-0-methyl glucuronic acid and acetyl... 

Starch is a renewable carbon source abundantly available from plant sources. However, it is usually hydrolysed to glucose via a two-step process, liquefaction and saccharification, before adding it into the polymer prodnction medium [26]. Kim [27] reported P(3HB) production from starch using Azotobacter chroococcum via a fed-batch fermentation. A PHA content of 46 and 20 wt% with a CDW of 54 g/1 and 71 g/1 were obtained with and without oxygen limitation, respectively. A halophilic bacterinm, Haloferax mediterrane was also reported to be able to produce P(3HB) from starch, but the strain was not favourable due to the salt required for its growth which contributed significantly to the PHA manufacturing cost. 

Carbon dioxide release. Carbon dioxide that is released as the final mineralization product of biopolymers originates from the renewable carbon source for then-biosynthesis. Photosynthetic fixation of the released carbon dioxide by plants generates renewable carbon sources again. Thns, the carbon flnx in the synthesis and degradation of biopolymers is balanced. PHAs therefore do not contribute to global warming. 

Succinic acid has been identified as an important platform chemical that can be produced from renewable carbon sources. The molecules that can be derived from... 

Systems thinking promotes innovations that bridge societal/market needs and health, safety, and environmental impacts Feedstocks are diversified and renewable to avoid resource depletion Renewable carbon sources (e.g., biomass (e.g., plants, trees, etc.) converted to sugars or other simpler molecules. 

PHAs are accumulated within Gram-positive and Gram-negative bacteria as storage compounds. These polymers are biodegradable, biocompatible exhibit thermoplastic properties, emit less carbon dioxide and can be produced from renewable carbon sources. These properties have attracted interest from many researchers as well as industries (Khanna and Srivastava, 2005 Hazer and Steinbuchel, 2007) (Fig. 8.2). 

Biomass such as lignocellulose (e.g., woods and grasses) and aquatic resources (e.g., seaweeds and microalgae) is the only renewable carbon source for the production of chemicals, materials, and fuels. Decreasing fossil resources, global warming, and environmental... 

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