Co-combustion of locally available biomass in existing coal-fired power plants is an attractive o... more Co-combustion of locally available biomass in existing coal-fired power plants is an attractive option to increase the share of renewable fuels in the energy market with minimal capital investment. Utilizing existing coal-fired combustion equipment for blends requires knowledge of pyrolysis and combustion characteristics. This study presents thermal evolution profiles (decomposition rates, apparent activation energies and devolatilized compounds) of coal-biomass blends to probe the effect of blend ratios on pyrolysis and combustion behavior. The global rate of pyrolysis of Illinois No. 6 coal and brewer's spent grains (BSG) is a function of fuel composition, though analysis of evolved gases suggests the presence of both potential additive and synergistic interactions on a molecular level. For oxidation, a rapid decrease in peak conversion rate is seen as the percentage of BSG increases from 0% to 20%, becoming less pronounced as the percentage of BSG increases above 20%.
Bringing our society to a carbon-neutral, clean-energy future is an evolutionary process that mus... more Bringing our society to a carbon-neutral, clean-energy future is an evolutionary process that must combine technological advances with available infrastructure. By co-firing biomass in existing coal-fired power plants, we can utilize standing equipment to increase the share of renewables in energy generation portfolios. This study investigates the pyrolysis behavior of blends of sweet cherry pit stones and a West Virginia coal using thermogravimetric analysis at a heating rate of 100 K/min under nitrogen to determine mass loss rates and global activation energies as a function of blend composition. Derivative thermogravimetric curves show two distinct peaks for the fuel blends at temperatures corresponding to peaks for the pure cherry pits and coal. The peak mass loss rates for blends are higher than predicted using an additive scheme at the lower temperature peak and lower than predicted at the higher temperature peak. Global activation energies determined using a first order Arrhenius equation were higher than predicted by a linear addition scheme at lower temperatures, and lower than predicted at higher temperatures, suggesting that the incorporation of the cherry pit biomass may promote devolatilization of the coal at lower temperatures.
No todos los problemas de ingeniería pueden resolverse mediante ecuaciones basadas en leyes o bal... more No todos los problemas de ingeniería pueden resolverse mediante ecuaciones basadas en leyes o balances (de materia, energía, cantidad de movimiento..), debido a que por un lado pueden resultar muy complejos y por otro lado los problemas involucran un gran número de variables. Por ejemplo, para el flujo de un fluido newtoniano en régimen laminar se pueden deducir ecuaciones de flujo y pérdidas de fricción al aplicar un balance microscópico de cantidad de movimiento, tal y como se ha demostrado previamente; sin embargo, para el flujo de un fluido newtoniano en un régimen turbulento no se pueden obtener ecuaciones tan simples. Como consecuencia de esta situación se emplean ecuaciones empíricas basadas en experimentos. Una forma de facilitar la resolución de este tipo de problemas y de otros similares consiste en agrupar las variables en una nueva pseudo-variable adimensional para simplificar el análisis.
Co-combustion of locally available biomass in existing coal-fired power plants is an attractive o... more Co-combustion of locally available biomass in existing coal-fired power plants is an attractive option to increase the share of renewable fuels in the energy market with minimal capital investment. Utilizing existing coal-fired combustion equipment for blends requires knowledge of pyrolysis and combustion characteristics. This study presents thermal evolution profiles (decomposition rates, apparent activation energies and devolatilized compounds) of coal-biomass blends to probe the effect of blend ratios on pyrolysis and combustion behavior. The global rate of pyrolysis of Illinois No. 6 coal and brewer's spent grains (BSG) is a function of fuel composition, though analysis of evolved gases suggests the presence of both potential additive and synergistic interactions on a molecular level. For oxidation, a rapid decrease in peak conversion rate is seen as the percentage of BSG increases from 0% to 20%, becoming less pronounced as the percentage of BSG increases above 20%.
Bringing our society to a carbon-neutral, clean-energy future is an evolutionary process that mus... more Bringing our society to a carbon-neutral, clean-energy future is an evolutionary process that must combine technological advances with available infrastructure. By co-firing biomass in existing coal-fired power plants, we can utilize standing equipment to increase the share of renewables in energy generation portfolios. This study investigates the pyrolysis behavior of blends of sweet cherry pit stones and a West Virginia coal using thermogravimetric analysis at a heating rate of 100 K/min under nitrogen to determine mass loss rates and global activation energies as a function of blend composition. Derivative thermogravimetric curves show two distinct peaks for the fuel blends at temperatures corresponding to peaks for the pure cherry pits and coal. The peak mass loss rates for blends are higher than predicted using an additive scheme at the lower temperature peak and lower than predicted at the higher temperature peak. Global activation energies determined using a first order Arrhenius equation were higher than predicted by a linear addition scheme at lower temperatures, and lower than predicted at higher temperatures, suggesting that the incorporation of the cherry pit biomass may promote devolatilization of the coal at lower temperatures.
No todos los problemas de ingeniería pueden resolverse mediante ecuaciones basadas en leyes o bal... more No todos los problemas de ingeniería pueden resolverse mediante ecuaciones basadas en leyes o balances (de materia, energía, cantidad de movimiento..), debido a que por un lado pueden resultar muy complejos y por otro lado los problemas involucran un gran número de variables. Por ejemplo, para el flujo de un fluido newtoniano en régimen laminar se pueden deducir ecuaciones de flujo y pérdidas de fricción al aplicar un balance microscópico de cantidad de movimiento, tal y como se ha demostrado previamente; sin embargo, para el flujo de un fluido newtoniano en un régimen turbulento no se pueden obtener ecuaciones tan simples. Como consecuencia de esta situación se emplean ecuaciones empíricas basadas en experimentos. Una forma de facilitar la resolución de este tipo de problemas y de otros similares consiste en agrupar las variables en una nueva pseudo-variable adimensional para simplificar el análisis.
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