The dry basis elemental composition of the feedstock, shown in Table 2, is identical to previous NREL and PNNL design reports [20,21]. The composition was originally assumed to come from pulpwood. Recent feedstock logistics work at the Idaho National Laboratory (INL) suggests that the use of blended material may be required to meet a cost target of $80/dry U.S. ton while still meeting these specifications [22]. For the purpose of this report, it is assumed that any blended material provided to meet this feedstock elemental composition will not adversely affect fast pyrolysis conversion efficiencies. Ongoing studies being conducted jointly by INL, NREL, and PNNL will provide experimental evidence of the impact of blended feedstocks on fast pyrolysis and gasification processes. Future TEA will be modified to reflect conversion impacts inferred from such studies.This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. not considered in this design in order to focus on the core technology of in situ and ex situ fast pyrolysis vapor upgrading. Aspen Plus ModelAn Aspen Plus Version 7.2 simulation was used as the basis for this report. Since the products in pyrolysis are numerous and varied, only selected model compounds were used to represent the product slate. Additional hydrocarbon species were added to represent hydroprocessing products. Many of the desired molecular species in the desired boiling ranges for light and heavy fractions did not exist in Aspen Plus databanks and physical property parameters needed to be estimated. The biomass feedstock, ash, char, and coke were modeled as non-conventional components. Appendix F provides information about compounds selected to represent the process. The Peng-Robinson with Boston-Mathias modifications (PR-BM) equation of state was used throughout most of the process simulation. The ASME 1967 steam table correlations (STEAM-TA) were used for the steam cycle calculations. Combustor/Regenerator Temperature, °C (°F) 650 (1,202) 720 (1,328) 650 (1,202) Pressure, psia (bar) 117 (8.1) 117 (8.1) 113 (7.8) Excess air (%) 20 20 20 Solids temperature before transfer to reactor, °C (°F) 650 (1,202) 720 (1,328) 341 (645) No. of cyclones per combustor 2 2 2 Area 200 Equipment Cost EstimationsCapital costs for the equipment in this area were estimated by Harris Group. A previously developed spreadsheet tool for gasifier costs was leveraged for this exercise. Cost estimates from this tool were compared with order of magnitude estimates from technology vendors and documented in Appendix I of Worley et al.
Résumé -Boucle chimique pour la combustion du charbon avec un transporteur d'oxygène à base d'oxyde de cuivre -Une analyse préliminaire a été conduite pour estimer les performances d'un procédé en boucle chimique découplé (CLOU, chemical looping uncoupling) pour la combustion du charbon avec un transporteur d'oxygène à base d'oxyde de cuivre. Les avantages de ce système sont démontrés en établissant le bilan énergétique, l'inventaire et le débit de circulation du matériau transportant l'oxygène, les taux de conversion du carbone et la pression partielle en oxygène dans le réacteur de combustion. Pour faire cette analyse, des données expérimentales de cyclage CuO/Cu 2 O ont été utilisées afin de déterminer les cinétiques de décomposition et d'oxydation du matériau. Elles ont été obtenues avec un oxyde non supporté. La cinétique de décomposition est très rapide à 950°C dans les conditions du réacteur de combustion. Il est montré que la cinétique d'oxydation est maximale au voisinage de 800°C, la vitesse décroissant ensuite pour des températures plus élevées, à cause de résistances diffusionnelles liées à la formation d'une couche de CuO entourant le Cu 2 O. L'analyse montre que le CLOU permet une combustion rapide du carbone, les temps de combustion du carbone étant plus lents que les temps de décomposition du transporteur d'oxygène. Pour confirmer le potentiel du procédé, des données cinétiques additionnelles sont nécessaires sur des oxydes supportés à haute température (>850°C), dans les conditions du réacteur de combustion permettant la libération d'oxygène par l'oxyde de cuivre. Abstract -Chemical Looping with Copper Oxide as Carrier and Coal as Fuel -A preliminary analysis has been conducted of the performance of a Chemical Looping system with Oxygen Uncoupling (CLOU) with copper oxide as the oxygen carrier and coal approximated by carbon as the fuel. The advantages of oxygen uncoupling are demonstrated by providing the energy balances
Ex situ catalytic fast pyrolysis of biomass is a promising route for the production of fungible liquid biofuels. There is significant ongoing research on the design and development of catalysts for this process. However, there are a limited number of studies investigating process configurations and their effects on biorefinery economics. Herein we present a conceptual process design with techno-economic assessment; it includes the production of upgraded bio-oil via fixed bed ex situ catalytic fast pyrolysis followed by final hydroprocessing to hydrocarbon fuel blendstocks. This study builds upon previous work using fluidized bed systems, as detailed in a recent design report led by the National Renewable Energy Laboratory (NREL/ TP-5100-62455); overall yields are assumed to be similar, and are based on enabling future feasibility. Assuming similar yields provides a basis for easy comparison and for studying the impacts of areas of focus in this study, namely, fixed bed reactor configurations and their catalyst development requirements, and the impacts of an inline hot gas filter. A comparison with the fluidized bed system shows that there is potential for higher capital costs and lower catalyst costs in the fixed bed system, leading to comparable overall costs. The key catalyst requirement is to enable the effective transformation of highly oxygenated biomass into hydrocarbons products with properties suitable for blending into current fuels. Potential catalyst materials are discussed, along with their suitability for deoxygenation, hydrogenation and C-C coupling chemistry. This chemistry is necessary during pyrolysis vapor upgrading for improved bio-oil quality, which enables efficient downstream hydroprocessing; C-C coupling helps increase the proportion of diesel/jet fuel range product. One potential benefit of fixed bed upgrading over fluidized bed upgrading is catalyst flexibility, providing greater control over chemistry and product composition. Since this study is based on future projections, the impacts of uncertainties in the underlying assumptions are quantified via sensitivity analysis. This analysis indicates that catalyst researchers should prioritize by: carbon efficiency [ catalyst cost [ catalyst lifetime, after initially testing for basic operational feasibility.
The dry basis elemental composition of the feedstock, shown in Table 2, is identical to previous NREL and PNNL design reports [20,21]. The composition was originally assumed to come from pulpwood. Recent feedstock logistics work at the Idaho National Laboratory (INL) suggests that the use of blended material may be required to meet a cost target of $80/dry U.S. ton while still meeting these specifications [22]. For the purpose of this report, it is assumed that any blended material provided to meet this feedstock elemental composition will not adversely affect fast pyrolysis conversion efficiencies. Ongoing studies being conducted jointly by INL, NREL, and PNNL will provide experimental evidence of the impact of blended feedstocks on fast pyrolysis and gasification processes. Future TEA will be modified to reflect conversion impacts inferred from such studies.This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. not considered in this design in order to focus on the core technology of in situ and ex situ fast pyrolysis vapor upgrading. Aspen Plus ModelAn Aspen Plus Version 7.2 simulation was used as the basis for this report. Since the products in pyrolysis are numerous and varied, only selected model compounds were used to represent the product slate. Additional hydrocarbon species were added to represent hydroprocessing products. Many of the desired molecular species in the desired boiling ranges for light and heavy fractions did not exist in Aspen Plus databanks and physical property parameters needed to be estimated. The biomass feedstock, ash, char, and coke were modeled as non-conventional components. Appendix F provides information about compounds selected to represent the process. The Peng-Robinson with Boston-Mathias modifications (PR-BM) equation of state was used throughout most of the process simulation. The ASME 1967 steam table correlations (STEAM-TA) were used for the steam cycle calculations. Combustor/Regenerator Temperature, °C (°F) 650 (1,202) 720 (1,328) 650 (1,202) Pressure, psia (bar) 117 (8.1) 117 (8.1) 113 (7.8) Excess air (%) 20 20 20 Solids temperature before transfer to reactor, °C (°F) 650 (1,202) 720 (1,328) 341 (645) No. of cyclones per combustor 2 2 2 Area 200 Equipment Cost EstimationsCapital costs for the equipment in this area were estimated by Harris Group. A previously developed spreadsheet tool for gasifier costs was leveraged for this exercise. Cost estimates from this tool were compared with order of magnitude estimates from technology vendors and documented in Appendix I of Worley et al.
Chemical-looping with oxygen uncoupling (CLOU) offers a promise to reduce energy penalty by facilitating the capture of CO2 emitted from power plants. It has a potential to lower the oxygen carrier inventory of the fuel reactor in contrast to chemical-looping combustion (CLC). The primary mechanism in CLOU for the combustion of solid fuels is their reaction with gaseous oxygen released by the decomposition of a metal oxide, which differs from CLC of solid fuels where the solid fuel has to be gasified first. The slower gasification reaction in CLC is subsequently followed by combustion of the fuel with a circulating oxygen carrier. The present study is concerned with the rate analysis from reported batch fluidized bed CLOU experimental data of Mexican petcoke particles by a CuO/ZrO2 oxygen carrier. The methodology to determine the kinetic parameters for CuO decomposition and solid fuel oxidation during the fuel reactor stage and for Cu2O oxidation in the air reactor stage have been discussed. The results of the study are expected to help in the development of a process model for CLOU, furthering the development of a pilot scale process.
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