Composition, biomass procedures

In spite of all of this variety of approaches, covering a wide array of metabolism pathways, limitations also exist. Differences in the vulnerability of biofilms have been found to depend on the age, community composition and succession status of the community. In dense biofilms the transfer of contaminants may be limited, resulting in decreased bioavailable concentrations of nutrients or toxicants for the algae. Biofilms show an inverse relationship between metal toxicity and biomass accrual [26], and a similar relationship has been established with nutrients. Therefore, the colonisation time or biofilm thickness are relevant factors to be included in the procedure uses. 

Materials (ASTM).94 In addition, the National Renewable Energy Laboratory95 (NREL) has developed and validated a collection of standard laboratory analytical procedures specifically for the compositional analysis of biomass including, but going beyond those of the ASTM. These wet chemical methods of analysis are based on the fractionation of the biomass sample and the isolation of purified fractions that can be quantified using conventional analytical instruments.96 These methods are primarily used in feedstock-specific portfolios containing analysis methods for each of the relevant constituents. In most cases, these portfolios enable the identification and quantification of greater than 95 percent of the dry mass of biomass feedstock and biomass-derived materials. 

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 ... 

Solka Floe (Fiber Sale and Development, Urbana, OH), a delignified spmee pulp, was the biomass used as the raw material in this work. The composition of this material was analyzed according to National Renewable Energy Laboratory (NREL) standard procedures 001, 002, and 006. The glucan content was 88%. 

Com stover used for this study was harvested in 2003 at the Kramer Farm in Wray, Colorado. The stover was pretreated either in-house at the National Renewable Energy Laboratory or received via subcontract fiom the CAFI [12] pretreatment group members. The samples selected for this study were pietreated by alkaline peroxide (NREL), sulfite steam explosion (UBC), ammonia fiber explosion (MSU), and dilute sulfuric acid (NREL) methods. The composition of the pretreated stover was determined by a two-stage sulfuric acid hydrolysis treatment according to the NREL Laboratory Analytical Procedure titled Determination of Stmctural Carbohydrates and Lignin in Biomass [13]. The pretreatment conditions and compositional information for each substrate are listed in Table 2. 

The carbohydrate composition and lignin were determined using the NREL laboratory analytical procedures (http //wwwl.energy.gov/biomass/analytical procedures.html). The moisture content of the bagasse samples was determined using a moisture analyzer (Computrac MAX 1000, Arizona Instrument Corporation, Tempe, AZ, USA). 

Moisture and ash content of the biomass were determined by the methods of LAP-001 and LAP-005, respectively, which are laboratory analytical procedures developed by the National Renewable Energy Laboratory. Structural analyses of the samples were carried out according to the American Society for Testing and Materials El758-01 standard test methods. The composition of raw materials is listed in Table 1. The solubility of Kraft pine lignin A at room temperature is listed in Table 2. 

Composition analysis of the treated/untreated biomass was done according to the NREL Laboratory Anal)dieal Procedures Preparation of samples for compositional analysis and determination of structural carbohydrates and lignin in biomass (draft version) [32]. The moisture content in biomass was measured by an inftared moisture balance (Denver Instrument, IR-30). Sugar content in compositional analysis and enzymatic digestibility was determined by HPLC using a Bio-Rad Aminex HPX-87P. 

Gibbs free energy minimization provides a practical basis for investigating the fate and removal of alkali species and sour gas components from biomass gasification product gas as a function of temperature and composition of inlet streams. The methane content of the product gas - a result of non-equilibrium conversion - is accounted for in the procedure by setting as inert compounds the corresponding fractions of carbon and hydrogen in the biomass feedstock [42],... 

This chapter is an overview of architectures adopted for the catalytic/biocatalytic composites used in wide applications like the biomass valorization or fine chemical industry. On this perspective, the chapter updates the reader with the most fresh examples of construction designs and concepts considered for the synthesis of such composites. Their catalytic properties result from the introduction of catalytic functionalities and vary from inorganic metal species e.g., Ru, Ir, Pd, or Rh) to well-organized biochemical structures like enzymes e.g., lipase, peroxidase, (3-galactosidase) or whole cells. Catalytic/biocatalytic procedures for the biomass conversion into platform molecules e.g., glucose, GVL, Me-THF, sorbitol, succinic acid, and glycerol) and their further transformation into value-added products are detailed in order to make understandable the utility of these complex architectures and to associate the composite properties to their performances, versatility, and robustness. 

In order to further investigate this hypothesis, solid proton fractions were calculated according to the composition of the sample taking into account the proton densities of the different domains. As the samples were identified to be composed of two distinct fractions of different proton mobility and the fractions were mainly related to the biomass and the water, the sorbitol protons must be either part of the liquid or of the solid proton fraction. Therefore proton densities were calculated for both cases and compared to the experimental results. The proton density of the biomass could not be derived theoretically and was therefore estimated by comparing the calculated and measured results for the samples without sorbitol. The exact procedure is published elsewhere. In case that the sugar protons are not part of the solid protons, the solid fraction fsj is calculated as follows ... 

Another possibility, which is widely used for the production of bio-nanocomposites, also with resin directty obtained from biomass, is extracting cellulose nanociystals (CNC) from other biomass source or from aspecilic cellulose. This led also to original solutions, such as the fabrication of materials including a kind of hierarchical structure, hence introducing both a macrosized reinforcement and a nanosized one. In particular, in a jute and soy flour composite, with glutaraldehyde providing suitable interface adhesion, cellulose nanowhiskers have been introduced in addition or not to nanoclay (Fig. 13.5), a procedure which provided improved thermal, mechanical and dimensional stability (Iman et al., 2013). 

In order to obtain the true coordination of the gold nanoparticles, a correction factor must be used which is based on the composition of the sample, and can be obtained from the XANES fittings of the samples. This procedure provides the true nanoparticle size. The most commonly used equation to determine the size of the Au(0) nanoparticles on biomasses, when using XAS, was developed by Borowski [50]. The equation was first developed for the size determination of small copper nanoparticles in an fee metal, compared to the average grain size as determined by XRD [50]. The Borowski equation has been shown to be valid for all metals with a fee paeking strueture, and is based on a spherieal model for metal... 

Von Stockar and coworkers [28,39] describe a very exact and gentle procedure to prepare biomass for the determination of combustion enthalpy as well as elemental composition. They are convinced that the large scatter in the literature data is due to an inadequate preparation of the cells for combustion. Although developed for microbial cells, their procedure can be applied just as well to other biological samples such as pure substances or tissues. The authors recommend to first freeze-dry (lyophilize) the matter and then to oven-dry it for 24 h at 100 °C. Moreover, methods for the evaluation of residual moisture and ash content are presented. 

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