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Akwasi A Boateng - One of the best experts on this subject based on the ideXlab platform.
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Exergy based assessment of the production and conversion of switchgrass, equine waste, and Forest Residue to bio-oil using fast pyrolysis
Industrial and Engineering Chemistry Research, 2015Co-Authors: Joseph Keedy, Eugene Prymak, Nelson Macken, Ghasideh Pourhashem, Sabrina Spatari, Charles A Mullen, Akwasi A BoatengAbstract:The resource efficiency of biofuel production via biomass pyrolysis is evaluated using exergy as an assessment metric. Three feedstocks, important to various sectors of U.S. agriculture, switchgrass, Forest Residue, and equine waste, are considered for conversion to bio-oil (pyrolysis oil) via fast pyrolysis, a process that has been identified as adaptable to on- or near-farm application. Biomass and biofuel production pathways are defined, material flows are determined, and exergy in- and outflows associated with biomass production and conversion are computed, including the depletion of exergy from its natural state (cumulative exergy demand, CExD). Sources of exergy depletion are quantified and categorized by energy carriers, e.g., electricity and diesel fuel, and materials, e.g., fertilizer, as well as renewable and nonrenewable resources. Yields for biomass to bio-oil conversion by fast pyrolysis are determined experimentally. Breeding factors, a measure of exergy production (the ratio of the chemical exergy of the output product to process exergy inputs), are determined for the production of biomass and bio-oil. The quantification of exergy depletion for process pathways enables the possible identification of more sustainable (resource efficient) pathways for biomass and bio-oil production. It is shown, for example, that feedstocks grown primarily for biomass such as switchgrass may be less sustainable using the exergy measure compared to use of Residue (e.g., Forest thinnings) or waste biomass (e.g., equine waste). With regard to the pyrolysis process, there is substantial reduction in exergy depletion when the coproducts noncondensable gases and biochar are recycled and utilized as a source of heat. The sustainability of biomass production and conversion, as measured by exergy depletion, is strongly influenced by energy carriers. The study reveals that the method of electricity production, i.e., on-site generation or grid electricity, as well as the choice of grid electricity can have a significant impact on sustainability. The exergy content of the bio-oil produced varies from 24 to 27 MJ/kg bio-oil, which is much lower than traditional fuels. However, the cumulative exergy depletion for the production and conversion to bio-oil varies from approximately 4 to 11 MJ/kg bio-oil, which is also much lower than traditional fuels. Breeding factors for biomass production and conversion to bio-oil based on cumulative exergy depletion vary from approximately 2 to 5, demonstrating the potential exergy benefit of bio-oil production using fast pyrolysis.
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Exergy Based Assessment of the Production and Conversion of Switchgrass, Equine Waste, and Forest Residue to Bio-Oil Using Fast Pyrolysis
2015Co-Authors: Joseph Keedy, Eugene Prymak, Nelson Macken, Ghasideh Pourhashem, Sabrina Spatari, Charles A. Mullen, Akwasi A BoatengAbstract:The resource efficiency of biofuel production via biomass pyrolysis is evaluated using exergy as an assessment metric. Three feedstocks, important to various sectors of U.S. agriculture, switchgrass, Forest Residue, and equine waste, are considered for conversion to bio-oil (pyrolysis oil) via fast pyrolysis, a process that has been identified as adaptable to on- or near-farm application. Biomass and biofuel production pathways are defined, material flows are determined, and exergy in- and outflows associated with biomass production and conversion are computed, including the depletion of exergy from its natural state (cumulative exergy demand, CExD). Sources of exergy depletion are quantified and categorized by energy carriers, e.g., electricity and diesel fuel, and materials, e.g., fertilizer, as well as renewable and nonrenewable resources. Yields for biomass to bio-oil conversion by fast pyrolysis are determined experimentally. Breeding factors, a measure of exergy production (the ratio of the chemical exergy of the output product to process exergy inputs), are determined for the production of biomass and bio-oil. The quantification of exergy depletion for process pathways enables the possible identification of more sustainable (resource efficient) pathways for biomass and bio-oil production. It is shown, for example, that feedstocks grown primarily for biomass such as switchgrass may be less sustainable using the exergy measure compared to use of Residue (e.g., Forest thinnings) or waste biomass (e.g., equine waste). With regard to the pyrolysis process, there is substantial reduction in exergy depletion when the coproducts noncondensable gases and biochar are recycled and utilized as a source of heat. The sustainability of biomass production and conversion, as measured by exergy depletion, is strongly influenced by energy carriers. The study reveals that the method of electricity production, i.e., on-site generation or grid electricity, as well as the choice of grid electricity can have a significant impact on sustainability. The exergy content of the bio-oil produced varies from 24 to 27 MJ/kg bio-oil, which is much lower than traditional fuels. However, the cumulative exergy depletion for the production and conversion to bio-oil varies from approximately 4 to 11 MJ/kg bio-oil, which is also much lower than traditional fuels. Breeding factors for biomass production and conversion to bio-oil based on cumulative exergy depletion vary from approximately 2 to 5, demonstrating the potential exergy benefit of bio-oil production using fast pyrolysis
Dwight Anderson - One of the best experts on this subject based on the ideXlab platform.
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using sulfite chemistry for robust bioconversion of douglas fir Forest Residue to bioethanol at high titer and lignosulfonate a pilot scale evaluation
Bioresource Technology, 2015Co-Authors: Subhosh M Chandra, John Sessions, Roland Gleisner, Gevan Marrs, Feng Gu, Rick Reiner, Dwight AndersonAbstract:This study demonstrated at the pilot-scale (50 kg) use of Douglas-fir Forest harvest Residue, an underutilized Forest biomass, for the production of high titer and high yield bioethanol using sulfite chemistry without solid–liquor separation and detoxification. Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) was directly applied to the ground Forest harvest Residue with no further mechanical size reduction, at a low temperature of 145 C and calcium bisulfite or total SO2 loadings of only 6.5 or 6.6 wt% on oven dry Forest Residue, respectively. The low temperature pretreatment facilitated high solids fermentation of the un-detoxified pretreated whole slurry. An ethanol yield of 282 L/ tonne, equivalent to 70% theoretical, with a titer of 42 g/L was achieved. SPORL solubilized approximately 45% of the wood lignin as directly marketable lignosulfonate with properties equivalent to or better than
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using sulfite chemistry for robust bioconversion of douglas fir Forest Residue to bioethanol at high titer and lignosulfonate a pilot scale evaluation
Bioresource Technology, 2015Co-Authors: J Y Zhu, John Sessions, Roland Gleisner, Gevan Marrs, Subhosh M Chandra, Rick Reiner, Johnway Gao, Dwight AndersonAbstract:This study demonstrated at the pilot-scale (50 kg) use of Douglas-fir Forest harvest Residue, an underutilized Forest biomass, for the production of high titer and high yield bioethanol using sulfite chemistry without solid-liquor separation and detoxification. Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) was directly applied to the ground Forest harvest Residue with no further mechanical size reduction, at a low temperature of 145°C and calcium bisulfite or total SO2 loadings of only 6.5 or 6.6 wt% on oven dry Forest Residue, respectively. The low temperature pretreatment facilitated high solids fermentation of the un-detoxified pretreated whole slurry. An ethanol yield of 282 L/tonne, equivalent to 70% theoretical, with a titer of 42 g/L was achieved. SPORL solubilized approximately 45% of the wood lignin as directly marketable lignosulfonate with properties equivalent to or better than a commercial lignosulfonate, important to improve the economics of biofuel production.
Gevan Marrs - One of the best experts on this subject based on the ideXlab platform.
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using sulfite chemistry for robust bioconversion of douglas fir Forest Residue to bioethanol at high titer and lignosulfonate a pilot scale evaluation
Bioresource Technology, 2015Co-Authors: Subhosh M Chandra, John Sessions, Roland Gleisner, Gevan Marrs, Feng Gu, Rick Reiner, Dwight AndersonAbstract:This study demonstrated at the pilot-scale (50 kg) use of Douglas-fir Forest harvest Residue, an underutilized Forest biomass, for the production of high titer and high yield bioethanol using sulfite chemistry without solid–liquor separation and detoxification. Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) was directly applied to the ground Forest harvest Residue with no further mechanical size reduction, at a low temperature of 145 C and calcium bisulfite or total SO2 loadings of only 6.5 or 6.6 wt% on oven dry Forest Residue, respectively. The low temperature pretreatment facilitated high solids fermentation of the un-detoxified pretreated whole slurry. An ethanol yield of 282 L/ tonne, equivalent to 70% theoretical, with a titer of 42 g/L was achieved. SPORL solubilized approximately 45% of the wood lignin as directly marketable lignosulfonate with properties equivalent to or better than
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using sulfite chemistry for robust bioconversion of douglas fir Forest Residue to bioethanol at high titer and lignosulfonate a pilot scale evaluation
Bioresource Technology, 2015Co-Authors: J Y Zhu, John Sessions, Roland Gleisner, Gevan Marrs, Subhosh M Chandra, Rick Reiner, Johnway Gao, Dwight AndersonAbstract:This study demonstrated at the pilot-scale (50 kg) use of Douglas-fir Forest harvest Residue, an underutilized Forest biomass, for the production of high titer and high yield bioethanol using sulfite chemistry without solid-liquor separation and detoxification. Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) was directly applied to the ground Forest harvest Residue with no further mechanical size reduction, at a low temperature of 145°C and calcium bisulfite or total SO2 loadings of only 6.5 or 6.6 wt% on oven dry Forest Residue, respectively. The low temperature pretreatment facilitated high solids fermentation of the un-detoxified pretreated whole slurry. An ethanol yield of 282 L/tonne, equivalent to 70% theoretical, with a titer of 42 g/L was achieved. SPORL solubilized approximately 45% of the wood lignin as directly marketable lignosulfonate with properties equivalent to or better than a commercial lignosulfonate, important to improve the economics of biofuel production.
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Robust enzymatic saccharification of a Douglas-fir Forest harvest Residue by SPORL
Biomass and Bioenergy, 2013Co-Authors: Shao-yuan Leu, John Sessions, Junyong Zhu, Roland Gleisner, Gevan MarrsAbstract:Forest harvest Residues can be a cost-effective feedstock for a biorefinery, but the high lignin content of Forest Residues is a major barrier for enzymatic sugar production. Sulfite pretreatment to overcome strong recalcitrance of lignocelluloses (SPORL) was applied to a Douglas-fir (Pseudotsuga menziesii (Mirb) Franco var. menziesii) Forest Residue in a range of sulfite and acid loadings at 165
Rainer Backman - One of the best experts on this subject based on the ideXlab platform.
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mechanisms behind the positive effects on bed agglomeration and deposit formation combusting Forest Residue with peat additives in fluidized beds
Energy & Fuels, 2009Co-Authors: Linda Pommer, Rainer Backman, Marcus Ohman, Dan Bostrom, Jan Burvall, Ingemar Olofsson, Anders NordinAbstract:A compilation was made of the composition of peat from different areas in Sweden, or which a selected But was characterized anal co-combusted with Forest Residue ill controlled fludized-bed agglome ...
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the role of alkali sulfates and chlorides in post cyclone deposits from circulating fluidized bed boilers firing biomass and coal
iomi, 2002Co-Authors: Bengtjohan Skrifvars, Rainer Backman, Tor Lauren, Mikko HupaAbstract:High amounts chlorine and sulphur in a fuel is generally connected with ash related operational problems in the boiler in which the fuel is fired. The problems occur as fireside deposits in different locations of the fluegas channel or as corrosion problems. Sulphur and chlorine together with alkali and earth alkali metals are known to strongly affect the thermal behaviour of the ash. First melting temperatures as low as 515 °C may be found if unsuitable amounts of alkali, sulphur and chlorine is present in the ash. A vast experience on the matter exists from coal firing [Sarofim and Helble 1994; Bryers 1992; Harb and Smith, 1990] as well as from firing different types of waste sludges [Backman et al., 1987] Backman et al., 1996; Salmenoja et al., 1996]. Forrest derived fuels such as wood, bark or Forest Residue (branches and tops) contain usually low amounts of sulphur and chlorine. The low potential for sulphur dioxide emissions from combustion of these kind of fuels as well as the indication of a fairly well behaving ash in most kind of combustion systems, are generally considered as two important advantages for the fuels. Sometimes these general indications are applied also on any type of biomass. This may, however, lead to serious errors since other biomasses such as straw or annually grown energy crops may contain significant amounts of both chlorine and sulphur [Nordin 1993]. In Fig. 1 the amount of chlorine and sulphur is shown for a number of different fuels, including coal, peat, wheat straw and Forest derived fuel. Fluidized bed combustion is regarded as a very flexible combustion system with a capacity to burn a wide range of fuels. From the ash behaviour point of view the low combustion temperature of some 800–900 °C is favourable compared to conventional pulverised systems since operational problems due to a low melting ash are assumed to be avoided. The FBC technique has, however, limits. Common knowledge from conventional
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the ash chemistry in fluidised bed gasification of biomass fuels part i predicting the chemistry of melting ashes and ash bed material interaction
Fuel, 2001Co-Authors: Maria Zevenhovenonderwater, Rainer Backman, Bengtjohan SkrifvarsAbstract:Abstract This paper is part I in a series of two describing the modelling of the ash-chemistry of seven biomass fuels under reducing, pressurised conditions in fluidised bed gasification by means of thermodynamic multi-phase multi-component equilibrium (TPCE) calculations. The fuels considered were Salix, a Scandinavian Forest Residue, Miscanthus, Reed Canary Grass, Eucalyptus, Arundo Donax and Lucerne. The composition and amount of phases have been calculated for the gasification of the fuel as such and in presence of an excess amount of calcite, dolomite, magnesium olivine sand and sand by using TPCE calculations in a temperature interval of 600–900°C and a pressure of 10 bar. It was found that interaction of inorganic compounds released from the fuels with bed material is a prerequisite for the formation of bed agglomerates. The presence of an excess of dolomite decreased the amount of alkali components in the bed, thereby increasing the amount of alkali components volatilised. A silica bed, however, binds most alkali released from the fuel, retaining it in the bed as low melting alkali silicates. The chances of experiencing operating problems due to bed agglomeration may increase hereby significantly. Calculations at atmospheric pressure show that the amounts of melt present will be smaller when compared to pressurised conditions, thereby decreasing the chances of bed agglomeration. In a pressurised gasifier using calcite or dolomite as bed material a small amount of an alkali carbonate rich melt can be expected at temperatures above 620°C with each of the seven biomass fuels fired. In silica-rich cases such as when firing Miscanthus, Reed Canary Grass, Arundo Donax or using a Si-rich bed material a melt can be expected at temperatures above 770°C. The amount of melt is rather high, i.e. 12–100% of the original ash formed. In the case of a magnesium olivine sand bed an alkali melt can be expected at 620°C. At temperatures above 800°C, a silicate melt can form as well. The amount of melt was high, i.e. 60–300% of the original ash formed, showing a significant contribution of the bed material.
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the prediction of behaviour of ashes from five different solid fuels in fluidised bed combustion
Fuel, 2000Co-Authors: Maria Zevenhovenonderwater, Rainer Backman, Bengtjohan Skrifvars, J P Blomquist, Mikko HupaAbstract:Abstract The behaviour of different ashes was predicted by the combination of extended fuel analysis with advanced global thermodynamic equilibrium calculations. The extended fuel analysis is a fractionation method that consists of sequential leaching of a solid fuel with water, ammonium acetate and hydrochloric acid. In order to cover a broad spectrum of fuels a coal, a peat, a Forest Residue and Salix (i.e. willow) were studied. The last was taken with and without soil contamination, i.e. with a high and low content of silica, respectively. Results from the fractionation showed clear differences in mineral distribution in the fuels. More ash-forming elements were present as included minerals in the older fuels. In relatively young fuels, almost half of the inorganic material was found in the soluble fractions after leaching with water and ammonium acetate. Fouling and slagging predictions based on the combined use of the extended fuel analysis and the advanced global equilibrium analysis indicated that no ash-related problems should be expected in FBC boilers firing the studied coal. The peat that was studied could cause minor ash depositions in the flue gas channel at temperatures above 700°C. The studied Forest Residue could form fly ash deposits in the flue gas channel at temperatures between 600 and 860°C. The Salix could cause fly ash depositions at temperatures between 840 and approximately 1000°C. If soil contamination was present as well, Salix could cause bed sintering at temperatures above 1030°C.
Bengtjohan Skrifvars - One of the best experts on this subject based on the ideXlab platform.
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the role of alkali sulfates and chlorides in post cyclone deposits from circulating fluidized bed boilers firing biomass and coal
iomi, 2002Co-Authors: Bengtjohan Skrifvars, Rainer Backman, Tor Lauren, Mikko HupaAbstract:High amounts chlorine and sulphur in a fuel is generally connected with ash related operational problems in the boiler in which the fuel is fired. The problems occur as fireside deposits in different locations of the fluegas channel or as corrosion problems. Sulphur and chlorine together with alkali and earth alkali metals are known to strongly affect the thermal behaviour of the ash. First melting temperatures as low as 515 °C may be found if unsuitable amounts of alkali, sulphur and chlorine is present in the ash. A vast experience on the matter exists from coal firing [Sarofim and Helble 1994; Bryers 1992; Harb and Smith, 1990] as well as from firing different types of waste sludges [Backman et al., 1987] Backman et al., 1996; Salmenoja et al., 1996]. Forrest derived fuels such as wood, bark or Forest Residue (branches and tops) contain usually low amounts of sulphur and chlorine. The low potential for sulphur dioxide emissions from combustion of these kind of fuels as well as the indication of a fairly well behaving ash in most kind of combustion systems, are generally considered as two important advantages for the fuels. Sometimes these general indications are applied also on any type of biomass. This may, however, lead to serious errors since other biomasses such as straw or annually grown energy crops may contain significant amounts of both chlorine and sulphur [Nordin 1993]. In Fig. 1 the amount of chlorine and sulphur is shown for a number of different fuels, including coal, peat, wheat straw and Forest derived fuel. Fluidized bed combustion is regarded as a very flexible combustion system with a capacity to burn a wide range of fuels. From the ash behaviour point of view the low combustion temperature of some 800–900 °C is favourable compared to conventional pulverised systems since operational problems due to a low melting ash are assumed to be avoided. The FBC technique has, however, limits. Common knowledge from conventional
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the ash chemistry in fluidised bed gasification of biomass fuels part i predicting the chemistry of melting ashes and ash bed material interaction
Fuel, 2001Co-Authors: Maria Zevenhovenonderwater, Rainer Backman, Bengtjohan SkrifvarsAbstract:Abstract This paper is part I in a series of two describing the modelling of the ash-chemistry of seven biomass fuels under reducing, pressurised conditions in fluidised bed gasification by means of thermodynamic multi-phase multi-component equilibrium (TPCE) calculations. The fuels considered were Salix, a Scandinavian Forest Residue, Miscanthus, Reed Canary Grass, Eucalyptus, Arundo Donax and Lucerne. The composition and amount of phases have been calculated for the gasification of the fuel as such and in presence of an excess amount of calcite, dolomite, magnesium olivine sand and sand by using TPCE calculations in a temperature interval of 600–900°C and a pressure of 10 bar. It was found that interaction of inorganic compounds released from the fuels with bed material is a prerequisite for the formation of bed agglomerates. The presence of an excess of dolomite decreased the amount of alkali components in the bed, thereby increasing the amount of alkali components volatilised. A silica bed, however, binds most alkali released from the fuel, retaining it in the bed as low melting alkali silicates. The chances of experiencing operating problems due to bed agglomeration may increase hereby significantly. Calculations at atmospheric pressure show that the amounts of melt present will be smaller when compared to pressurised conditions, thereby decreasing the chances of bed agglomeration. In a pressurised gasifier using calcite or dolomite as bed material a small amount of an alkali carbonate rich melt can be expected at temperatures above 620°C with each of the seven biomass fuels fired. In silica-rich cases such as when firing Miscanthus, Reed Canary Grass, Arundo Donax or using a Si-rich bed material a melt can be expected at temperatures above 770°C. The amount of melt is rather high, i.e. 12–100% of the original ash formed. In the case of a magnesium olivine sand bed an alkali melt can be expected at 620°C. At temperatures above 800°C, a silicate melt can form as well. The amount of melt was high, i.e. 60–300% of the original ash formed, showing a significant contribution of the bed material.
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the prediction of behaviour of ashes from five different solid fuels in fluidised bed combustion
Fuel, 2000Co-Authors: Maria Zevenhovenonderwater, Rainer Backman, Bengtjohan Skrifvars, J P Blomquist, Mikko HupaAbstract:Abstract The behaviour of different ashes was predicted by the combination of extended fuel analysis with advanced global thermodynamic equilibrium calculations. The extended fuel analysis is a fractionation method that consists of sequential leaching of a solid fuel with water, ammonium acetate and hydrochloric acid. In order to cover a broad spectrum of fuels a coal, a peat, a Forest Residue and Salix (i.e. willow) were studied. The last was taken with and without soil contamination, i.e. with a high and low content of silica, respectively. Results from the fractionation showed clear differences in mineral distribution in the fuels. More ash-forming elements were present as included minerals in the older fuels. In relatively young fuels, almost half of the inorganic material was found in the soluble fractions after leaching with water and ammonium acetate. Fouling and slagging predictions based on the combined use of the extended fuel analysis and the advanced global equilibrium analysis indicated that no ash-related problems should be expected in FBC boilers firing the studied coal. The peat that was studied could cause minor ash depositions in the flue gas channel at temperatures above 700°C. The studied Forest Residue could form fly ash deposits in the flue gas channel at temperatures between 600 and 860°C. The Salix could cause fly ash depositions at temperatures between 840 and approximately 1000°C. If soil contamination was present as well, Salix could cause bed sintering at temperatures above 1030°C.