Glucose lignin production

Production of Lignin Peroxidase. Medium for the inoculum was rich in yeast extract (25 g/1) and glucose (25 g/l) to promote maximal growth of the mycelia. The inoculum of Phanerochaete chrysosporium ATCC 24725 was first cultivated for 3 days at 30°C in five litres of medium divided in five shake flasks. The shake flask batches were transferred to a 100 litre bioreactor and cultivated again for 3 days at 30°C. The batches were stirred and aerated to obtain maximal growth of mycelia. 

Ozone has recently become industrially available at low cost. From the point of view of the development of complete wood utilization, the pretreatment of wood with ozone enhances the yield of glucose by enzymatic saccharification. Ozonized lignin is thereby obtained as a by-product. 

Cellulosic materials are quite variable from source to source, not only in cellulose, hemicellulose, and lignin content but also in the crystallinity of the cellulose. As a consequence, each natural substrate would be expected to have its own unique set of process conditions to optimize glucose yield and minimize secondary product contamination. The next section on kinetics of acid hydrolysis will examine this point. 

Figure 1.2. Differential thermal analysis for the humic acid fraction isolated in NaOH from a sapric histosol (1), from the acid precipitate isolated from products of the reaction of meth-ylglyoxal with glycine (2), and from the acid precipitate formed from the reaction of glucose with glycine (3), alkali lignin (4), casein (5), lignin-casein 3 1 complex (6), and lignin-casein 6 1 complex (7).

Cellulose is found in wood, along with hemicellulose and lignin, and in cotton, linen, hemp, and other similar products. It is a polymer of glucose. It can also be made from sucrose by bacterial means [8]. This bacterial cellulose has high mechanical strength and may become an important material if the cost can be brought down. 

The composition of poplar wood was usedasamodel for the feedstock composition however, as used in this simulation, the poplar is modeled as consisting of only cellulose, xylan, and lignin, with compositions of 49.47, 27.26, and 23.27%, respectively. Laboratory results for carbonic acid pretreatment are relatively scarce, so for the purpose of this comparative study, stoichiometry of pretreatment reactions was assumed to be equal to those used in the comparison model (3) cellulose conversion to glucose 6.5% xylan conversion to xylose 75 and lignins solubilized 5%. Thus, economic comparisons made with this model assess different equipment and operating costs but not product yields. For the successful convergence of the carbonic acid model, the simulation required initial specification of several variables. These variables included initial estimates for stream variables and inputs for the unit operation blocks. 

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