Lignin hydrolytic

The feedstock materials used in this work included medium density polyethylene (PE), atactic-polypropylene (aPP), isotactic-polypropylenc (iPP), beech wood, pine wood, cellulose and hydrolytic lignin. The size of the wood biomass and the plastic particles was less 0,1 mm. 

Microporous sorbents produced by pyrolysis and gasification of hydrolytic lignin... 

In R sia many researchers focused their efforts on the development of technology for the synthesis of porous materials from hydrolytic lignin, and certain results have been achieved in the field. According to some publications, not only common sorbents production was tried to solve environmental problems [7,S], but also the synthesis of soibents for special purposes, in particular for gas mixtures separation [9]. 

This study focuses on the processes producing a microporous structure of carbon soibents di g a thennal treatment of hydrolytic lignin in inert and oxidizing media, and veriff es adsoibents capability of separating He-hydrocaibon mixtures. 

Hydrolysis lignin, produced at the Krasnoyarsk Biochemical Plant, was used as raw to produce micro-porous soibents. Hydrolytic lignin consists of lignin (61.3%), cellulose (13.3%), substances extracted by alcohol-benzene mixture (15%), ash (3.3%), sulfur (0.4%), The summed pore volume of raw lignin was 1. IcM /g, its specific surface was... 

Therefore, most likely high heating rates prevail de-polymerization of hydrolytic lignin accompanied by removal of low molecular fragments. At low heating rates important become the slow processes of poly-condensation and thickening of low molecular aromatic compounds required to form microstructures with the smallest pores. 

Thus, regarding the effect of thermal treatment of hydrolytic lignin on the size of lignin carbon pores, the optimum regimes of thermal treatment produce sorbents with a pore size of 0.7-1.0 run. A pilot batch of such tnicroporous carbon was produced, its texture... 

Plachenov T.G., Akhmina E.I., Boikova G.I., Vorozhbitova L.N. Sokolovskaya L.I. (1983) C aibon adsorbents from hydrolytic lignin Journal pricladnoi chimii, 56.1296. 

Schipko M.L., Baklanova O.N., Duplyakin V.K. Kuznetsov B.N. (1996) Powdery and molded soibents from lignite and hydrolytic lignin. Chimiya w interesach to/cA/vogo razvitia, 4,467. 

Timofeev A.F., Kolosentsev S.D., Gavrilov D.N. Plachenov T.G. (1986) Molecular-sieve properties of carbon adsorbents on the basis of hydrolytic lignin. Journalpriclacbtoi chimii, 59, 1210. 

Stalugin A.B, Kondratenok B.M., Dudkin B.N., Lyubitova S.G., Mordvanyuk S.A. (1993) Some problems of carbonization of hydrolytic lignin and production of active carbons on its basis, Trudi Komi nauchnogo centra Ur 0 RAN, 129, 113,... 

The approaches adopted in attacking the lignin molecule can be divided into three categories oxidative, reductive and hydrolytic degradations. 

During heating the pH dropped below 4 due to the formation of acetic acid. The acid caused hydrolysis of hemicelluloses and formation of furfural. It is thus possible that the delignification was caused by hydrolytic cleavage of interunit linkages. Figure 3 shows that the dissolved lignins... 

Production and Hydrolytic Depolymerization of Ethylene Glycol Lignin... 

High hydrolytic resistance against aqueous acid and base The modified lignins were found not to consume more alkali than the parent lignin (i.e., 50-80 mg KOH/g of derivative as compared to 85 mg KOH/g of parent lignin) ... 

Some results of the modification of lignin sulfonate Ultra B002 by reaction with terephthaloyl chloride are summarized in Table VI. The total hydroxyl content of the lignosulfonates as well as their derivatives are presented in Table VII. The hydrolytic resistance of selected products is evaluated in Table VIII. The results presented in Tables VI-VIII stress several advantages of the derivatives with terephthaloyl chloride. The modified lignin sulfonates were insoluble, or only very slightly soluble, in organic solvents. They were, however, soluble in dimethyl sulfoxide. Ordered structures were identified by X-ray studies (16,17). 

Table VIII. Hydrolytic Resistance of the Lignins Modified with Terephthaloyl Chloride...

Possibilities include (a) the hydrolysis of the lignin-carbohydrate bond by small amounts of water present in the wood despite all precautions to make the system anhydrous, (b) the dehydration of carbohydrates under these conditions to produce water and hence hydrolytic conditions, (c) transacetalization of the extracting acetal with carbohydrates to liberate alcohol and create conditions of alcoholysis, and (d) transacetalization of the extracting acetal with free or bound keto groups in the wood to liberate acetone and create conditions of acetonolysis. 

Typically, the raw material for cellulose processing is a lignin-hemicellulose-cellulose (LHC) complex that is not very amenable to hydrolysis. Various pretreatments involving size reduction, separation of constituents of the complex, and processes to increase the accessibility of cellulose to hydrolytic agents may be required. These activities convert a relatively intractable raw material into a cellulosic substrate. 

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