Search

Showing total 2 results
Start Over Topic biomass Topic computer simulation
2 results

1. Synergies from combined pulp&paper and fuel production

Author

Tunå, Per, Hulteberg, Christian, Hansson, Jens, Åsblad, Anders, and Andersson, Eva

Subjects
*BIOMASS gasification, *WOOD-pulp, *PULP mills, *FUEL, *COMPUTER simulation, *FISCHER-Tropsch process, *CHEMICAL synthesis, *METHANOL, *CARBON dioxide
Abstract

Abstract: In this paper, the prospect of integrating a combined paper&pulp mill with fuel production via biomass gasification was investigated. In the study, three different types of gasifiers (circulating fluidised bed, entrained flow and indirect gasification) and three fuel processes (dimethyl ether, methanol and Fischer-Tropsch wax synthesis) were investigated using computer simulations. The paper reports differences from the stand-alone cases and the integrated cases, using the electricity equivalence efficiency as a measure. Only 6 out of the 18 integrated cases studied displayed a positive result from integration and no obvious fuel selection that stand out as the most beneficial one, however the synthesis of dimethyl ether is, in combination with all gasifiers assessed a rather good choice, with an change in efficiency from integration ranging from −1% to 4%. Dimethyl ether is not the best choice if the electrical equivalence is to be maximised however. In this case the combination of circulating fluidised bed gasification and methanol synthesis should be pursued. The production of Fischer-Tropsch wax should according to the chosen measure not be produced; however there is an added value in the production of a non-oxygenated fuel which has not been taken into account in this particular study. All cases leads to a reduction of 0.4–0.9 kg CO2 per kg of dry biomass used in the process for fuel synthesis and the possibility to export bark is a more significant factor in this respect than which type of fuel is synthesised. [Copyright &y& Elsevier]

Published
2012
Full Text
View/download PDF

2. Use of thermogravimetric analysis to monitor the effects of natural laccase mediators on flax pulp

Author

Teresa Vidal, Agustín García Barneto, Amanda Fillat, Carlos Vila, and José Luis Gómez Ariza

Subjects
Paper, Thermogravimetric analysis, Environmental Engineering, Bioengineering, engineering.material, Lignin, Polymerization, chemistry.chemical_compound, Crystallinity, X-Ray Diffraction, Flax, Spectroscopy, Fourier Transform Infrared, Organic chemistry, Computer Simulation, Hemicellulose, Biomass, Cellulose, Glucans, Waste Management and Disposal, Renewable Energy, Sustainability and the Environment, Pulp (paper), Laccase, Temperature, General Medicine, Cellulose microfibril, Oxygen, Kinetics, Models, Chemical, chemistry, Chemical engineering, Thermogravimetry, engineering, Xylans, Microfibril, Crystallization
Abstract

The effects of 1-hydroxybenzotriazole (HBT) and the natural laccase mediators gallic acid, caffeic acid and p-hydroxybenzoic acid, on the enzymatic bleaching of flax pulp were compared. The treatment was performed under atmospheric air and oxygen pressure, and, for the first time, monitored by thermogravimetric analysis (TGA) for comparison with chemical analysis, FTIR and X-ray diffraction (XRD) spectroscopies. Thermogravimetric data were simulated by applying a nucleation kinetic equation to a combustion model based on four pseudo-components (hemicellulose, amorphous and crystalline cellulose, and lignin). The results thus obtained show that the effects of the natural mediators are similar to those of HBT and lead to increased order in cellulose microfibril surfaces. An increase in pulp crystallinity was additionally exposed by the XRD and FTIR techniques, and a reduction in microfibril equatorial size by the XRD patterns. Simulated DTG curves were used to determine the kinetic parameters for thermal degradation.

Published
2011