Biomass Subject

Study of the behavior of biomass subjected to concentrated radiation (solar pyrogasification). Determination of the conditions enhancing the production of either oils or gases for electricity generation or chemical preparation. 

It should be emphasized that, though this book is edited and all the papers reviewed by independent referees, I have not attempted to convert an author s views with which I disagree to my own way of thinking. However, these instances are in the minority. Universal agreement on a given biomass subject does not exist necessarily among those who have been in the field, mainly because some of the work has not yet progressed to the point where the ultimate answers are in hand. 

Alternative feedstocks for petrochemicals have been the subject of much research and study over the past several decades, but have not yet become economically attractive. Chemical producers are expected to continue to use fossil fuels for energy and feedstock needs for the next 75 years. The most promising sources which have received the most attention include coal, tar sands, oil shale, and biomass. Near-term advances ia coal-gasification technology offer the greatest potential to replace oil- and gas-based feedstocks ia selected appHcations (10) (see Feedstocks, coal chemicals). 

Projections of market penetrations and contributions to primary consumption of energy from biomass are subject to much criticism and contain significant errors. However, even though these projections may be incorrect, they are necessary to assess the future role and impact of renewable energy resources, and to help in deciding whether a potential renewable energy resource should be developed. 

Biological—Biochemical Processes. Fermentation is a biological process in which a water slurry or solution of raw material interacts with microorganisms and is enzymatically converted to other products. Biomass can be subjected to fermentation conditions to form a variety of products. Two of the most common fermentation processes yield methane and ethanol. Biochemical processes include those that occur naturally within the biomass. 

Another hydrogenation process utilizes internally generated hydrogen for hydroconversion in a single-stage, noncatalytic, fluidized-bed reactor (41). Biomass is converted in the reactor, which is operated at about 2.1 kPa, 800°C, and residence times of a few minutes with steam-oxygen injection. About 95% carbon conversion is anticipated to produce a medium heat value (MHV) gas which is subjected to the shift reaction, scmbbing, and methanation to form SNG. The cold gas thermal efficiencies are estimated to be about 60%. 

A typical penicillin broth contains 20-35 mg/1 of antibiotic. Filtration is used to remove mycelial biomass from fermentation broth. The filtration may be subjected to filter aided polymers. Neutralisation of penicillin at pH 2-3 is required. Amyl acetate or butyl acetate is used as an organic solvent to remove most of the product from the fermentation broth. Finally, penicillin is removed as sodium penicillin and precipitated by a butanol-water mixture. 

Production of hydrogen and its derivatives from bio-based raw materials has also been a subject of much research. Several reports can be found on the photocatalytic reforming of biomass to hydrogen [14]. 

In gasification, biomass is subjected to partial pyrolysis under sub-stoichiometric conditions with the air quantity... 

The microorganisms determined as active biomass constitute a central platform for description of the processes in a sewer. Classification of the microorganisms will, however, not be dealt with as a major subject in this context. But, it is especially important to determine under which redox conditions the microorganisms are active. 

Although experimental studies under sewer conditions are subject to high variability, it can be concluded that the removal of the components shown in Table 5.1 is mainly attributed to the activity of the heterotrophic biomass. Theoretical considerations and a number of studies like the one performed by Almeida (1999) clearly demonstrate that the heterotrophic biomass is central for understanding aerobic transformations. Studies by Stoyer (1970), Stoyer and Scherfig (1972), Koch and Zandi (1973), Pomeroy and Parkhurst (1973) and Green et al. (1985) have also focused on removal of organic matter in sewers, primarily in terms of BOD and COD. 

Various gasification schemes have been conceived for the direct production of H2 (and C02) instead of synthesis gas. Matsumura has reviewed the gasification of biomass with near- and super-critical water [42], The presence of liquid water suppressed the formation of char but not of tars. Full gasification proceeds in the presence of metal catalysts at 350-600 °C but also in absence of any catalysts at 500-750 °C. This subject is discussed elsewhere in this book [26],... 

Whenever possible, measures that vary on a continuous scale (e.g., biomass) should be used with subjective estimates of injury (e.g., indexes of visible injury). 

Oros DR, Simoneit BRT, Identification of molecular tracers in organic aerosols from temperate climate vegetation subjected to biomass burning, Aerosol Sci Tech... 

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