Composition, biomass

Torsvic V, Goksoyr J, Daae FL, Sorheim R, Michalsen J, Salte K (1994) Use of DNA analysis to determine the diversity of microbial communities. In Ritz K, Dighton J, Giller KE (eds) Beyond the biomass compositional and functional analysis of soil microbial communities. John Wiley, Chichester, pp 39-48... 

This work deals with the selection of strains of N2-fixing blue-green algae on the basis of biomass composition, productivity and tolerance to temperature and pH. Outdoor culture of the most adequate strains has been tested in order to derive optimal conditions for growth. 

Macromolecular biomass composition is of obvious interest when the biomass itself is the product, such as algal biomass in [18], or for production of singlecell protein, for e.g. animal feedstock. Moreover, for a precise metabolic flux analysis, changes in biomass composition should be taken in account. For example, Henriksen et al. [19] observed with E. coli under different growth rates, that the levels of DNA and lipids were relatively constant, whereas the proteins and stable RNA levels increased with the specific growth rate and the total amount of carbohydrates decreased. 

An alternative, at least semi-quantitative method to follow changes in biomass composition is infrared (IR) spectroscopy [22]. From dried samples of microbial cells, IR spectra can be obtained which contain information on all major cell components. The spectra are analysed as a multi-component mixture Characteristic bands in the spectra are identified, the extinction coefficients for each component (protein, carbohydrate, lipid, and nucleic acids) at each band are determined, and the concentrations are calculated by a system of linear equations. The method gives results on all major cell components simultaneously, and is relatively quick and easy to perform, compared to the chemical analysis methods. For details see Sect. 8.4 below. 

Rayner, A. D. M. (1994). Pattern-generating processes in fungal communities. In Beyond the Biomass Compositional and Functional Analysis of Soil Microbial Communities, ed. K. Ritz, I. Dighton K. E. Giller. Chichester, UK John Wiley, pp. 247-58. 

Flash pyrolysis in FFR is a usefnl means to remove snlphnr from coal [19, 21]. As shown by Li et al. [22], it can also be ntilized to remove heteroatom molecules from biomass. Both the yield and the composition of the resnltant gas depend on the biomass composition. The gas ontpnt is richer in hydrogen in the case of cellulose and hemicel-Inlose than in the case of lignin. Smaller biomass particle sizes and higher fast pyrolysis temperatnres also boost hydrogen content. The total of carbon monoxide and hydrogen content is reported to be 65.4% for legnme straw and 55.7% for apricot stone. 

TABLE 12.3 Comparison of Biomass Compositions and Methane Fermentation Under High-Rate Mesophilic Conditions ... 

In the theoretical studies, a stoichiometric model was employed to describe the overall combustion process and to examine the effects of the biomass composition on a fuel s combustion behaviour in term of flue gas composition, heat output and combustion temperature under ideal conditions. Incorporation with the correlations derived from the experimental work allows prediction of heat efficiency likely to be realised in a real combustion situation for stoker combustors. Good agreement between predicted and empirical results gives confidence in applying the technique to evaluate combustion performance of various biomass fuels without have to undertake combustion trials. 

What are unambiguous ways to study biomass composition and its relationship to pyrolysis rate and products Are traditional, operational definitions of composition such as cellulose, Klason or Kraft lignin, and extractives weight fraction useful What other composition metrics are useful especially as under-utilized or transgenic biomass species are examined ... 

Our methods and experiments (UW) previously addressed composition effects in pyrolysis of RDF (Lai, et al 1993) and wood (Krieger-Brockett, et al 1997). In those papers and this one, even minor components are shown to alter pyrolysis slate when appropriate statistical methods are used. This paper briefly summarizes our work on pyrolysis product slates resulting from large- or macro-particle devolatilization (in which heat transfer is a slow process) of native biomass compositions in under-utilized species. The method has general applicability and owing to the limited scope of this article, the reader is referred to Somasundaram (1990), Lai (1991) and Rodriguez (1996) for details and extensive literature reviews with only a few relevant articles mentioned here,... 

Correlations have been developed to obtain each one of the above candidate values, as functions of the biomass compositions and are detailed in previous publications [4-7J. The correlations used for this purpose arc presented here for the sake of completeness. Based on these, the stepwise procedure to calculate the different rating indices can be laid down as follows ... 

Raveendran, K, "Studies on Influence of Biomass Composition on Pyrolysis", Ph. D. Thesis, 1995, Interdisciplinary Program in Energy Systems Engineering, Indian Institute of Technology, Bombay, India. 

Madhupratap, M., Gopalakrishnan, T.C., Haridas, P. and Nair, K.K.C. (2001) Mesozooplankton biomass, composition and distribution in the Arabian Sea during the fall intermonsoon Implications of oxygen gradients. Deep-Sea Research II, 48, 1345—1368. 

Property Tables of Various Liquids, Gases, and Fuels Table 3.18 Typical biomass compositions (wt. %)... 

---