Cellulose, hydrogenation

Structure of cellulose. Hydrogen bonding between glucose units helps make the structure rigid. 

The Shroud is a linen textile that consists of cellulose derived from flax. Each of the constituent elements of the cellulose (hydrogen, carbon, and oxygen) exists in several stable isotopic forms. The lighter isotopes 1H, 12C, and leO are generally more abundant, but smaller concentrations of the heavier D (2H), 13C, and lsO are also present in measurable amounts. In any sample, the relative quantities D/H, 13C/12C, and 180/160 depend on the physical, chemical, and biological history of the material. 

Effect of interaction of acid and cellulose at the stages of impregnation and thermal pretreatment depends on the cellulose properties. The celluloses under study have different ratios of ordered and amorphous regions. They differ also by their degree of polymerization (Table 1) and hydrophilic properties. The presence of phosphoric acid affects the system of the cellulose hydrogen bonds, the crystallinity index and leads to the formation of esters [11,12, 19],... 

Cellulose, hydrogen 1,2-benzenedicarboxylate, 2-hydroxypro-pyl methyl ether [9050-31-1]... 

Figure 2 Example of planar projection of one of the configurations of an ortho-para PF dimmer on the surface of a schematic cellulose crystallite showing a phenolic dimmer (a dihydroxy diphenyl methane) conformation of minimal energy and main dimer-cellulose hydrogen bonding. (From Ref. 8.)... 

Cellulose, hydrogen sulfate, sodium salt. See Sodium cellulose sulfate Cellulose, hydroxybutyl methyl ether. See Hydroxybutyl methylcellulose Cellulose hydroxyethylate Cellulose hydroxyethyl ether Cellulose, 2-hydroxyethyl ether. See Hydroxyethylcellulose Cellulose, 2-hydroxyethyl 2-hydroxy-3-(trimethylammonio) propyl ether, chloride. See Polyquatemium-10... 

Synonyms Cellulose, hydrogen sulfate, sodium salt Cellulose, sulfate, sodium salt SCS... 

Table 1. Fractionation products from synthetic fuels obtained from cellulose hydrogenation.

As stated earlier, the diverse nature of the products obtained from cellulose hydrogenation coupled with the uncontrollable rise in reactor ptressure during the reaction period suggests that cellulose hydrogenation is by free-radical mechanism. In this section we deduce a mechanism for the reaction, from which a rate expression will be obtained. To determine the mechanism, the following assumptions are made ... 

Equation (40) shows that cellulose hydrogenation is first order with respect to cellulose concentration. The reactor pressure increases as the cellulose reacts, to signify that the pressure in the reactor, P is proportional to the concentration of cellulose decomposed. 

Equation (41) shows that the rate of cellulose hydrogenation is first order with respect to the total reactor pressure. 

The energy equivalents or energy requirements for the components of a 1000 tonne per day plant for cellulose hydrogenation are presented in the table below. 

Table 5 gives the values of GER, NER, Xf, and thermal efficiencies for the 1000 tonne per day cellulose hydrogenation plant. The plant was designed by Anagho (1987) for the treatment... 

Table 5. Energy requirement, energy factor and thermal efficiency for 1000 tonne per day cellulose hydrogenation plant.

Cellulose hydrogenation is a complex process in that it takes place under very drastic conditions of high temperature and high pressure, producing a mixture of chemical products. This study shows that the complex reaction can be modelled as a first order rate process with respect to the total reactor pressure. That is. 

The hydrogenation generates Liquid products at a yield of almost 35% by the mass of the dry pulverised cellulose feed. The products obtained are a mixture of saturated, unsaturated paraffinic and aromatic hydrocarbons, which exhibit instability on storage. An energy economic evaluation of a prototype cellulose hydrogenation process shows that it is an... 

Cellulose sulfate Sodium cellulose sulfate 9005-22-5 Cellulose, hydrogen sulfate. R (H2O4S),... 

Cellulose xanthate Cellulose carbonodilhioate 9032-37-5 Cellulose, hydrogen R (CH20S2)xt Unk... 

Hydroxypropyl methyl Cellulose phthalate hydroxypropyl 9050-31-1 Cellulose, hydrogen 1,2-benzene- R (CgHoOa) ... 

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