Erweiterungen topologischer R�ume

Wilke, Gerhard

doi:10.1007/bf01299271

Cited by 3 publications

(3 citation statements)

References 9 publications

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“…and Wilke-Chang correlations respectively. 37,38,39 The observable modulus ηϕ 2 , which is the ratio of the reaction rate to the effective diffusion inside the catalyst pores, was found to be much less than 0.3 for both hydrogen and acetic acid (Table 2). Therefore, the rate of diffusion within the catalyst pore is greater than the reaction rate; hence, the influence of intra-particle diffusion can be neglected, as the reaction is found to be surface rate limited.…”

Section: External Mass Transfermentioning

confidence: 99%

Kinetics of Hydrogenation of Acetic Acid over Supported Platinum Catalyst

et al. 2019

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Petroleum is non-renewable and contributes to environmental pollution, thus biooil can be substituted as a potential alternative. However, bio-oil in its crude form cannot be used directly as fuel since it contains high proportion of oxygenated, acidic and reactive compounds such as carboxylic acids. These are known to cause corrosion of vessels and pipework, instability and phase separation. The heating value of bio-oil can be improved through hydrodeoxygenation (HDO). In this study, HDO of acetic acid is presented, being a typical model compound found in bio-oil. Kinetic data were obtained over the range of temperature: 175-210 ºC, hydrogen pressure: 20-50 bar, initial acetic acid concentration: 0.16-0.521 M and catalyst loading: 0.2-0.5 g, in a 100mL batch reactor using 4% Pt/TiO2. It was found that catalyst particle sizes < 65 μm and a stirring speed of 1000 min-1 were sufficient to overcome internal and external mass transfer

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Section: External Mass Transfermentioning

confidence: 99%

Kinetics of Hydrogenation of Acetic Acid over Supported Platinum Catalyst

et al. 2019

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“…To verify the effectiveness of polysaccharide (schizophylian) separation from the enzyme, i.e., the separation of the cellulase-xylanase enzyme complex from the polysaccharide, both fractions were examined for enzyme activity and protein content per mg material. Acid hydrolysis of both fractions was done according to the method of Wilke et al 37 in order to determine the carbohydrate content. The neutralized, clear hydrolysates were analyzed with respect to sugars using high pressure liquid chromatography (HPLC) with a Bio-Rad column HPX 87H.…”

Section: Isolation and Detection Of Schizophyllanmentioning

confidence: 99%

Studies on a wild strain of Schizophyllum commune: Cellulase and xylanase production and formation of the extracellular polysaccharide Schizophyllan

Steiner

Lafferty

Gomes

et al. 1987

Biotech & Bioengineering

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A wild strain of schizophyllum commune (Fr:Fr:) isolated in Bangladesh produced cellulase and xyianase in high yields as well as the exobiopolymer schizophyllan. It was found experimentally that concentrations of 4% Avicel, 3.5% peptone, and 0.5% Ca(NO(3))(2).4H(2)O were optimal for growth and product formation. Bacto-peptone was found to be the most suitable substrate of a number of casein, mycological, and meat peptone preparations for enzyme production. Young plate-culture inocula (4 days) were found to be better than comparatively aged fungal cultures (14 days). With the optimized medium, 5 units filter paper (FP) cellulase, 1244 units xylanase, 108 units beta-glucosidase, and 65 units of carboxymethyl (CM) cellulase per mL culture filtrate were obtained in shake flasks. In a laboratory fermentor the respective enzyme activities were 4.5 units FP-cellulase, 1200 units xylanase, 100 units beta-glucosidase, and 60 units CM-cellulase per mL culture filtrate. A biopolymer, reported to be active against can cerous cells, was an additional product in addition to the enzymes.

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“…The glucose content of the washed wood was determined by the method of Wilke et a1. 6 The glucose content of the hydrolyzates was determined in a glucose analyzer. Xylose and cellobiose concentrations were determined by high-performance liquid chromatography (Perkin Elmer LC, Series 2).…”

Section: Methodsmentioning

confidence: 99%

Production of cellulase enzymes and hydrolysis of steam‐exploded wood

Martín

Blanch

Wilke

et al. 1986

Biotech & Bioengineering

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Steam-exploded aspen has been examined as a candidate feedstock for both cellulose production and enzymatic hydrolysis of wood. Batch and fed-batch cultivation methods were evaluated and compared with previous experiments using ball-milled, crystalline cellulose (Solka Floe). Batch cultivation of Trichoderma reesei Rut C-30 on 9 wt% water-washed aspen yielded enzyme productivities and activities comparable to those obtained on Solka Floe (40 FP IU/L-h; 7. 5 FP IU/mL). Fed-batch cultivation of Rut C-30 resulted in higher enzyme productivities and tilers than batch cultivation (50 FP IU/L-h; 15 FP IU/mL). However, the overall enzyme production performance was lower than on Solka Floe at comparable cellulose feeding rates and concentrations. This may be due to the accumulation of steam explosion by-products and lignin in the fermentor.The hydrolysis of water-washed steam-exploded aspen was performed at different enzyme loadings and wood concentrations. Glucose production, using 10 and 15 wt% suspension, showed that while glucose concentration increased with wood load, the yield of glucose derived from cellulose decreased. With 10 wt% suspensions, it was possible to obtain a cellulose conversion to glucose above 95%. Low cellulose levels in the hydrolyzates indicated that the filter paper activity ratios (approximately 1.5), a significant result since the fungus was grown exclusively on wood. mIt also suggested that the observed yield decrease is more likely to be caused by glucose than cellobiose inhibition of the enzymes.

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Erweiterungen topologischer R�ume

Cited by 3 publications

References 9 publications

Kinetics of Hydrogenation of Acetic Acid over Supported Platinum Catalyst

Kinetics of Hydrogenation of Acetic Acid over Supported Platinum Catalyst

Studies on a wild strain of Schizophyllum commune: Cellulase and xylanase production and formation of the extracellular polysaccharide Schizophyllan

Production of cellulase enzymes and hydrolysis of steam‐exploded wood

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