Biomass acetic acid

For example, Okabe et al. (1992) [52] report the following growth stoichiometry for the sulfate reducing bacteria Desulfovibrio desulfur icons growing on lactic acid and sulfate, and producing biomass, acetic acid, CO2 and H2S. 

Bio-ethanol is attracting growing interests in relation to the shift of raw materials from petroleum to biomass. A pioneering work by Christensen is that over MgAl203 support gold is much more selective to acetic acid than palladium and platinum in the aerobic oxidation of ethanol in water in a batch reactor. Figure 32 shows that selectivity to acetic acid exceeds 80% [99]. In contrast, Au/Si02 catalysts prepared by deposition reduction... 

Using this two-stage method and acetic acid as substrate, with culture volumes of 4 1 and 12.8 1, respectively, 857 ml of culture broth was harvested per hour containing a biomass concentration of 39 g l1 with a poly(3HB) content of 62%. The resulting productivity was 1.23 g 1 1 h 1 (Table 5). 

Takanabe, K. Aika, K.-I. Inazu, K. T. B. Seshan, K. Lefferts, L., Steam reforming of acetic acid as a biomass derived oxygenate Bifunctional pathway for hydrogen formation over Pt/ZrOz catalysts. Journal of catalysis 2006,243(2), 263-269. 

The application of near-IR spectroscopy for real-time monitoring of glucose, lactic acid, acetic acid and biomass in liquid cultures of microorganisms of the genera Lactobacillus and Staphylococcus has been recently published [76]. The NIR spectrum acquired by the optical-fibre probe immersed in the culture is exploited using a partial least squares (PLS) calibration step, a classical method for IR techniques. 

Numerous chemical intermediates are oxygen rich. Methanol, acetic acid and ethylene glycol show a O/C atomic ratio of 1, as does biomass. Other major chemicals intermediates show a lower O/C ratio, typically between 1/3 and 2/3. This holds for instance for propene and butene glycols, ethanol, (meth)acrylic acids, adipic acid and many others. The presence of some oxygen atoms is required to confer the desired physical and chemicals properties to the product. Selective and partial deoxygenation of biomass may represent an attractive and competitive route compared with the selective and partial oxidation of hydrocarbon feedstock. 

Pyrolysis has a long history in the upgrading of biomass. The dry distillation of hardwood was applied in the early 1990s to produce organic intermediates (methanol and acetic acid), charcoal and fuel gas [3]. Today s processes can be tuned to form char, oil and/or gas, all depending on the temperature and reaction time, from 300 °C and hours, to 400-500 °C and seconds-minutes, to >700 °C and a fraction of a second [3, 19, 23, 24], The process is typically carried out under inert atmosphere. We illustrate the basic chemistry of pyrolysis by focusing on the conversion of the carbohydrate components (Fig. 2.4). The reaction of the lignin will not be covered here but should obviously be considered in a real process. Interested readers could consult the literature, e.g., [25]. Pyrolysis is discussed in more details elsewhere in this book [26],... 

Biomass pyrolysis in the presence of a catalyst, in situ, is considered as one of the options to overcome the problem characteristics of bio-oil mentioned above. Selective removal, by decarboxylation, of carboxylic acids (formic, acetic acids)... 

Animal fats and oilseeds (soybean, cottonseed, coconut, palm) are important feedstocks for plasticizers and cosmetics. Destructive distillation of biomass yields methanol ( wood alcohol ), acetic acid, tar and charcoal, and was the backbone of the chemical industry in former centuries. 

The mechanism of pyrolysis reactions of biomass was extensively discussed in an earlier study (Demirbas, 2000). Water is formed by dehydration. In the pyrolysis reactions, methanol arises from the breakdown of methyl esters and/or ethers from decomposition of pectin-like plant materials. Methanol also arises from methoxyl groups of uronic acid (Demirbas and Giillii, 1998). Acetic acid is formed in the thermal decomposition of all three main components of wood. When the yield of acetic... 

Other important parameters in the steam reforming process are temperature, which depends on the type of oxygenate, the steam-to-carbon ratio and the catalyst-to-feed ratio. For instance, methanol and acetic acid, which are simple oxygenated organic compounds, can be reformed at temperatures lower than 800 °C. On the other hand, more complex biomass-derived liquids may need higher temperatures and a large amount of steam to gasify efficiently the carbonaceous deposits formed by thermal decomposition. 

The yield of 1,3-PD for this reaction is 67% (mol/mol). If biomass formation is considered the theoretical maximal yield reduces to 64%. In the actual fermentation a number of other by-products are formed, i. e., ethanol, lactic acid, succinic acid, and 2,3-butanediol, by the enterobacteria Klebsiella pneumoniae, Citrobacter freundii and Enterobacter agglomerans, butyric acid by Clostridium butyricum, and butanol by Clostridium pasteurianum (Fig. 1). All these by-products are associated with a loss in 1,3-PD relative to acetic acid, in particular ethanol and butanol, which do not contribute to the NADH2 pool at all. 

Applications of photoelectrochemistry in problems related to environmental issues are manifold. The conversion of acetic acid to methane, the oxidative decomposition of biomass, and the photodegradation of organochlorine contaminants which were discussed earlier represent societally important uses of... 

While this reaction is substantially exothermic (6), it provides an intriguing approach to the production of fuels from renewable resources, as the required acids (including acetic acid, butyric acid, and a variety of other simple aliphatic carboxylic acids) can be produced in abundant yields by the enzymatic fermentation of simple sugars which are, in turn, available from the microbiological hydrolysis of cellulosic biomass materials ( ] ) These considerations have led us to suggest the concept of a "tandem" photoelectrolysis system, in which a solar photoelectrolysis device for the production of fuels via the photo-Kolbe reaction might derive its acid-rich aqueous feedstock from a biomass conversion plant for the hydrolysis and fermentation of crop wastes or other cellulosic materials (4). 

Commodity Chemicals acetic acid, acetone, butanol, ethanol, many other products from biomass conversion processes. 

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