Cellulose elemental composition

Bio-oil from rapid pyrolysis is usually a dark brown, free-flowing liquid having a distinctive smoky odor. It has significantly different physical and chemical properties compared to the liquid from slow pyrolysis processes, which is more like a tar. Bio-oils are multicomponent mixtures comprised of different size molecules derived primarily from depolymerization and fragmentation reactions of the three key biomass building blocks cellulose, hemicellulose, and lignin. Therefore, the elemental composition of biooil resembles that of biomass rather than that of petroleum oils. Basic properties of biooils are shown in Table 33.7. More detail on fuel-related characteristics is provided in the literature.571... 

The elemental composition of the oil and residue was determined by an elemental analyzer (AMCO, NA-1500). The carbon amount in the aqueous phase was measured by a TOC meter (Yanaco, TOC-8L). Cellulose remained after the reaction was measured as glucose unit preserved in the residue. That is, the residue was hydrolyzed to glucose, and the glucose amount was measured by the phenoUsulftiric acid method. The amount of cellulose was calculated by the following equation. 

Traditionally thermal liquefaction studies on biomass have been carried out in the presence of one or both of the reducing gases, hydrogen and carbon monoxide (2, 3 4 J5, 6). Equation 1, in which cellulose has been used to approximate the elemental composition of wood, shows that theoretically a reducing gas is not required for wood liquefaction when internal carbon is used to remove the oxygen. 

The Whatman No. 1 paper (as received) contained 4.1 vol Z moisture and 0.074 wt Z ash. All results reported here are on a moisture- ash-free basis unless other wise specified. Table II summarizes some analytical results of cellulose and condensed-phase cellulose pyrolysis products. A comparison of the results In Table II for cellulose and cellulose tars Indicates that the elemental composition of these two materials Is very similar. (The heating... 

The extent of extraneous deposits on the Marine specimens varies widely. Some areas are almost completely free of deposits, others have moderate amounts of deposits, and some areas are so heavily covered diat die fiber surface itself is not visible. Of die Marine Silks, 29049 and 33707 have die most deposits, and 29054 has fewer deposits. In comparison with the Historic Silks however, all Marine Silks have more deposits. These deposits appear very different from those observed on the Historic Silks. The first is a continuous pastelike deposit with small beaded structures less than 0.5 pm in diameter on its surface (Figure 5). These deposits are similar to those reported by Chen and Jakes 10) and Jakes and Wang (7) on cellulosic fibers from the SS Central America. Second, discrete cube shaped particles of varying size up to 1.5 pm in diameter that appear crystalline (Figure 6). Similar particles were found on cotton fibers from the same site 10). Third, irregular shaped discrete particles approximately 2 to 2.5 pm in diameter were observed occasionally. Table II summarizes the elemental composition of the cube shaped discrete deposits, irregular shaped deposits, and continuous pastelike encrustations observed on the marine fibers. 

Details " Payen determined elemental composition of carboxymethyl cellulose In 1838 ... 

Although starch polymers from different natural sources have the same elemental composition, starch polymers are composed of linear amylose and branched amylopectin molecules. The ratios of linear and branched molecules in starch polymers are dependent on the source of starch. Proteins and biopolymers are more complex and variable in composition and structure than cellulose and starch polymers. The properties of proteins and biopolymers are dependent on their natural sources. ... 

Wesley and Wall (19) collected and analyzed airborne dust samples collected from three areas within five Mississippi gins in 1975. The general composition of their samples are summarized in Table IV. These data show the dust to be about 30 percent cellulosic, the remainder being soil and other materials. The quantitative elemental analysis of their samples is detailed in Table V. Although the percentages are different, the constituents in these samples of gin dust are very similar to those listed by Brown (18) in whole plant parts. None of the data presented have identified residues from insecticides or harvest aid chemicals. This may be because they were not specifically sought. 

A more recent analytical tabulation covering individual trace elements, amino acids, and volatile fatty acids, together with proximate analyses, ADF, MADF, NDF, cellulose, lignin, starch, water soluble carbohydrates, etc., has the title UK Tables of Nutritive Value and Chemical Composition of Feedingstuffs (MAFF, 1990). 

This technique has also been employed for the preparation of a catalytic imprinted membrane by coating a cellulose membrane with a polymer incorporating particles imprinted with the transition-state analogue of a dehydrofluorination reaction [264]. The application of such an MIP composite membrane as the recognition element in an optical sensor has been reported for digitoxin analysis in serum samples by embedding digitoxin-MIP particles in polyvinyl chloride film in presence of plasticizer by the dry inversion process [265],... 

---