Dubinin isotherms versus the Brouers–Sotolongo family isotherms: A case study

We show how the Dubinin isotherm and its extensions can be related to the isotherms derived from the general Brouers–Sotolongo isotherm. We compare them using benzene vapor adsorbed on activated carbon data from one of the original Dubinin’s paper. We use the same procedure to analyze data from the thesis of Francois Marquez-Montesino on the adsorption on activated carbons prepared from Pinus caribaea saw dust. We conclude by proposing a simple methodology to determine the macroscopic information given by genuine statistical isotherms

Pyrolytic Degradation Studies Of Acacia Mangium Wood

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Pyrolytic degradation of Acacia mangium wood was studied. The chemical composition of biomass, immediate and elemental analyses and calorific value for biomass and char, were determined. The standard and the derivative curve thermogravimetric analysis (TGA and DTG) were obtained. Devolatilization maximum of values between 250 +/- 20 degrees C and 380 +/- 20 degrees C were observed, with completion after 2 h, which confirms the selection of 2 hours for pyrolysis. Kinetic study was performed at different heating rates for a conversion rate from 20% to 80%. Average values of activation energy for temperature in degrees K of 228.57 kJ/mol for Biomass 1 and 199.36 kJ/mol for Biomass 2 were obtained by the isoconversion method of FWO. The lower value of activation energy for Biomass 2 was related to the possible catalytic activity of ash. The values of correlation coefficient from 0.9418 to 0.9946 for Biomass 1 and from 0.8706 to 0.9918 for Biomass 2, indicate the reliability of the first-order reaction model. The caloric values obtained were: Biomass 1 (16962 kJ/kg), Biomass 2 (16974 kJ/kg), chars from Biomass 1 (between 23731 y 26 942 kJ/kg) and gas from Biomass 1 and Biomass 2 (3858.7 and 4859.4 kJ/m(3), respectively).10118251844Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)University of Campinas (SP-Brazil)University of Pinar del Rio (UPR, Cuba)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CAPES [002/2009

Pyrolytic Degradation Studies of Acacia mangium wood

Pyrolytic degradation of Acacia mangium wood was studied. The chemical composition of biomass, immediate and elemental analyses and calorific value for biomass and char, were determined. The standard and the derivative curve thermogravimetric analysis (TGA and DTG) were obtained. Devolatilization maximum of values between 250±20 °C and 380±20 °C were observed, with completion after 2 h, which confirms the selection of 2 hours for pyrolysis. Kinetic study was performed at different heating rates for a conversion rate from 20% to 80%. Average values of activation energy for temperature in degrees K of 228.57 kJ/mol for Biomass 1 and 199.36 kJ/mol for Biomass 2 were obtained by the isoconversion method of FWO. The lower value of activation energy for Biomass 2 was related to the possible catalytic activity of ash. The values of correlation coefficient from 0.9418 to 0.9946 for Biomass 1 and from 0.8706 to 0.9918 for Biomass 2, indicate the reliability of the first-order reaction model. The caloric values obtained were: Biomass 1 (16962 kJ/kg), Biomass 2 (16974 kJ/kg), chars from Biomass 1 (between 23731 y 26 942 kJ/kg) and gas from Biomass 1 and Biomass 2 (3858.7 and 4859.4 kJ/m3, respectively)