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Christodoulos A Floudas - One of the best experts on this subject based on the ideXlab platform.
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Natural Gas to Liquid Transportation Fuels under Uncertainty Using Robust Optimization
2018Co-Authors: Logan R Matthews, Alexander M. Niziolek, Onur Onel, Yannis A Guzman, Christodoulos A FloudasAbstract:The current pricing climate for natural gas and liquid transportation fuels adds a significant amount of uncertainty when designing new natural gas to liquid transportation fuel (GTL) refineries. Robust optimization is a useful tool for optimization under uncertainty and can be specifically applied to the problem of GTL Process Synthesis under feedstock price, product price, and investment cost uncertainty. Using historical data to define uncertain price parameters according to an assumed uniform distribution, a Process Synthesis superstructure with an uncertain objective function was created to maximize the profit of a GTL refinery. Recently developed, tight probabilistic bounds were used a priori and a posteriori in an iterative method to provide solutions with known probabilities of constraint violation for three different uncertainty sets. The relative impact of price and investment cost uncertainties are discussed, as is the impact of uncertainty on the overall guaranteed profit of a refinery, the refinery topology, and product distributions. The profitability results with probabilistic guarantees provide useful information for potential GTL refinery investors in the current uncertain energy markets
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Reprint of: Enhancing natural gas-to-liquids (GTL) Processes through chemical looping for syngas production: Process Synthesis and global optimization
Computers and Chemical Engineering, 2018Co-Authors: William W. Tso, Alexander M. Niziolek, Onur Onel, C. Doga Demirhan, Christodoulos A Floudas, Efstratios N. PistikopoulosAbstract:A Process Synthesis and global optimization framework is presented to determine the most profitable routes of producing liquid fuels from natural gas through competing technologies. Chemical looping is introduced into the framework for the first time as a natural gas conversion alternative. The underlying phenomena in chemical looping are complex and models from methods such as computational fluid dynamics are unsuitable for global optimization. Therefore, appropriate approximate models are required. Parameter estimation and disjunctive programming are described here for modeling two chemical looping Processes. The first is a nickel oxide based Process developed at CSIC in Spain; the second is a iron oxide based Process developed at Ohio State University. These mathematical models are then incorporated into a comprehensive Process superstructure to evaluate the performance of chemical looping against technologies such as autothermal reforming and steam reforming for syngas production. The rest of the superstructure consists of Process alternatives for liquid fuels production from syngas and simultaneous heat, power, and water integration. Among the various case studies considered, it is shown that chemical looping can reduce the break-even oil prices for natural gas-to-liquids Processes by as much as 40%, while satisfying production demands and obeying environmental constraints. For a natural gas price of $5/TSCF, the break-even price is as low as $32.10/bbl. Sensitivity analysis shows that these prices for chemical looping remain competitive even as natural gas cost rises. The findings suggest that chemical looping is a very promising option to enhance natural gas-to-liquids Processes and their capabilities.
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biomass based production of benzene toluene and xylenes via methanol Process Synthesis and deterministic global optimization
Energy & Fuels, 2016Co-Authors: Alexander M. Niziolek, Onur Onel, Yannis A Guzman, Christodoulos A FloudasAbstract:The pursuit toward an environmentally sustainable energy landscape requires the development of economically competitive renewable Processes. Efficient utilization of renewable resources is an important first step toward meeting this goal. To this extent, we introduce a systematic deterministic global optimization-based Process Synthesis framework that determines the most profitable Processes to produce benzene, toluene, and/or xylenes from biomass via methanol. Our framework incorporates several novel, competing, and/or commercial technologies. We quantify the effect that biomass type has on the overall profit of a refinery by investigating forest residues, agricultural residues, and perennial crops as potential feedstocks. A thorough economic analysis, together with material, energy, carbon, and greenhouse gas balances, are provided for every proposed Process design. The capability of our proposed approach is illustrated through several case studies that produce varying ratios of p-, o-, and m-xylene acr...
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production of benzene toluene and xylenes from natural gas via methanol Process Synthesis and global optimization
Aiche Journal, 2016Co-Authors: Alexander M. Niziolek, Onur Onel, Christodoulos A FloudasAbstract:A systematic global optimization-based Process Synthesis framework is presented to determine the most profitable Processes to produce aromatics from natural gas. Several novel, commercial, and/or competing technologies are modeled within the framework, including methanol-to-aromatics, toluene alkylation with methanol, selective toluene disproportionation, and toluene disproportionation and transalkylation with heavy aromatics, among others. We propose a stand-alone chemicals facility: the main products are aromatics with allowable by-products of gasoline, liquefied petroleum gas, and electricity. Several case studies are discussed that produce varying ratios of para-, ortho-, and meta-xylene across multiple refinery capacities. The results indicate that utilizing natural gas for the production of aromatics is profitable with net present values as high as $3800 MM dollars and payback periods as low as 6 years. The required investment for these refineries represents as much as a 65% decrease compared to published estimates of similar coal-based capacity plants. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1531–1556, 2016
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biomass to liquid transportation fuels via biological and thermochemical conversion Process Synthesis and global optimization strategies
Industrial & Engineering Chemistry Research, 2016Co-Authors: Alexander M. Niziolek, Onur Onel, Logan R Matthews, Neesha Pinnaduwage, Christodoulos A FloudasAbstract:Biological conversion of biomass into gasoline, diesel, and kerosene provides an alternative means to meet liquid transportation fuel demand, going beyond the traditional thermochemical methods involving gasification, Fischer–Tropsch conversion, and methanol Synthesis. Process Synthesis is an ideal methodology for comparing the developing biological technologies with established thermochemical methods through input–output modeling of biorefinery units and inclusion in a superstructure. The resulting model takes the form of a mixed-integer nonlinear optimization problem with full heat, power, and water integration. In the novel superstructure, the MixAlco Process for biological conversion is modeled, in which biomass is fermented into carboxylic acid salts which are further upgraded into liquid transportation fuels. The model is solved to global optimality based on the minimization of the cost of liquid transportation fuels production using a branch-and-bound global optimization algorithm to provide upper ...
Christos T Maravelias - One of the best experts on this subject based on the ideXlab platform.
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thermal fractionation and catalytic upgrading of lignocellulosic biomass to biofuels Process Synthesis and analysis
Renewable Energy, 2017Co-Authors: Wangyun Won, Christos T MaraveliasAbstract:Abstract Multi-stage thermal biomass decomposition coupled with catalytic upgrading has a number of advantages over conventional single-stage pyrolysis with hydrotreating. However, significant gaps still exist in our understanding of the design of such Processes. In this paper, we synthesize alternative catalytic upgrading strategies through integration of different chemistries. Using experimental data, we develop a Process model for all strategies and conduct heat integration to minimize utility requirements. Then, using a wide range of technoeconomic analyses, we identify (1) the relationship between Process complexity and the resulting fuel-range carbon yields and economic feasibility, (2) the economic advantage of integrating different thermal decomposition fractions, and (3) the key cost drivers of the integrated Processes.
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simultaneous chemical Process Synthesis and heat integration with unclassified hot cold Process streams
Computers & Chemical Engineering, 2017Co-Authors: Lingxun Kong, Venkatachalam Avadiappan, Kefeng Huang, Christos T MaraveliasAbstract:Abstract We propose a mixed-integer nonlinear programming (MINLP) model for the simultaneous chemical Process Synthesis and heat integration with unclassified Process streams. The model accounts for (1) streams that cannot be classified as hot or cold, and (2) variable stream temperatures and flow rates, thereby facilitating integration with a Process Synthesis model. The hot/cold stream “identities” are represented by classification binary variables which are (de)activated based on the relative stream inlet and outlet temperatures. Variables including stream temperatures and heat loads are disaggregated into hot and cold variables, and each variable is (de)activated by the corresponding classification binary variable. Stream inlet/outlet temperatures are positioned onto “dynamic” temperature intervals so that heat loads at each interval can be properly calculated. The proposed model is applied to two illustrative examples with variable stream flow rates and temperatures, and is integrated with a superstructure-based Process Synthesis model to illustrate its applicability.
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a co solvent hydrolysis strategy for the production of biofuels Process Synthesis and technoeconomic analysis
Reaction Chemistry and Engineering, 2017Co-Authors: Christos T Maravelias, James A. Dumesic, Wangyun Won, Ali Hussain MotagamwalaAbstract:We develop an integrated strategy for the production of ethanol from lignocellulosic biomass. Cellulose and hemicellulose fractions are first hydrolyzed into sugars using a mixture of γ-valerolactone (GVL), water, and toluene as a solvent containing dilute sulfuric acid as a catalyst, and the sugars are then co-fermented into ethanol over engineered yeast strains. Separation subsystems are designed to effectively recover GVL and toluene for reuse in biomass hydrolysis and to recover lignin and humins for heat and power generation. We also develop an alternative Process, in which we recover sugars and GVL from the residual biomass. To minimize utility requirements, we conduct heat integration, which allows us to meet all heating requirements using biomass residues. Finally, we perform a range of system-level analyses to identify the major cost and technological drivers. The proposed strategy is shown to be cost-competitive with other strategies.
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conversion of furfural to 1 5 pentanediol Process Synthesis and analysis
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Kefeng Huang, James A. Dumesic, Zachary J Brentzel, Kevin J Barnett, George W Huber, Christos T MaraveliasAbstract:A new Process for the production of 1,5-pentanediol (1,5-PDO) from biomass-derived furfural is studied. In this Process, furfural is converted to 1,5-PDO in a high overall yield (80%) over inexpensive catalysts via multiple steps involving hydrogenation, dehydration, hydration, and hydrogenation subsequently. To effectively recycle H2 as well as recover 1,5-PDO, detailed separation subsystems have been designed and integrated with reaction subsystems. Furthermore, a pioneer plant analysis is performed to estimate the risk on the cost growth and plant performance shortfalls. The integrated Process leads to a minimum selling price of $1973 ton–1 for 1,5-PDO, which suggests that it could be a promising approach for converting biomass into oxygenated commodity chemicals, which are difficult to produce from petroleum-derived feedstocks. The sensitivity analysis also identifies that the most important economic parameters for the Process include the furfural feedstock price and plant size.
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Simultaneous Utility and Heat Exchanger Area Targeting for Integrated Process Synthesis and Heat Integration
2017Co-Authors: Lingxun Kong, Christos T MaraveliasAbstract:We propose a mixed-integer nonlinear programming (MINLP) model for simultaneous utility and heat exchanger area targeting with variable stream conditions. The model represents the composite-curve-based area targeting method by constructing the hot and cold composite curves mathematically. We introduce a “dynamic” enthalpy grid onto which the stream inlet/outlet temperatures and enthalpies are mapped. By calculating the temperatures at each grid point and the stream heat duties at each interval, the utility consumption and heat exchanger areas are simultaneously optimized using an economic criterion. We discuss preProcessing methods tailored to aid the solution of the proposed MINLP model. The model is applied to two illustrative examples as well as an example where it is integrated with a Process Synthesis model
Josephine A Elia - One of the best experts on this subject based on the ideXlab platform.
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Thermochemical Conversion of Duckweed Biomass to Gasoline, Diesel, and Jet Fuel: Process Synthesis and Global Optimization
2016Co-Authors: Richard C Baliban, Christodoulos A Floudas, Josephine A Elia, Xin Xiao, Zhijian Zhang, Hongbin Cao, Yong QiaoAbstract:Duckweed biomass is gasified in a thermochemical-based superstructure to produce gasoline, diesel, and kerosene using a Synthesis gas intermediate. The superstructure includes multiple pathways for conversion of the Synthesis gas to liquid hydrocarbons via Fischer–Tropsch Synthesis or intermediate methanol Synthesis. Low-temperature and high-temperature Fischer–Tropsch Processes are examined using both iron and cobalt based catalysts. Methanol may be converted to hydrocarbons via the methanol-to-gasoline or methanol-to-olefins Processes. The hydrocarbons will be refined into the final liquid products using ZSM-5 catalytic conversion, oligomerization, alkylation, isomerization, hydrotreating, reforming, and hydrocracking. A Process Synthesis framework is outlined to select the refining pathway that will produce the liquid fuels as the lowest possible cost. A rigorous deterministic branch-and-bound global optimization strategy will be incorporated to theoretically guarantee that the overall cost of the solution chosen by the Synthesis framework is within a small fraction of the best possible value. A heat, power, and water integration is incorporated within the Process Synthesis framework to ensure that the cost of utility production and wastewater treatment are simultaneously included with the Synthesis of the core refining Processes. The proposed Process Synthesis framework is demonstrated using four case studies which determine the effect of refinery capacity and liquid fuel composition on the overall system cost, the refinery topological design, the Process material/energy balances, and the lifecycle greenhouse gas emissions
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coproduction of liquid transportation fuels and c6_c8 aromatics from biomass and natural gas
Aiche Journal, 2015Co-Authors: Alexander M. Niziolek, Onur Onel, Josephine A Elia, Richard C Baliban, Christodoulos A FloudasAbstract:The coproduction of liquid transportation fuels and C6C8 aromatics from the thermochemical conversion of biomass and natural gas (BGTL+C6_C8) is investigated in this article. An optimization-based Process Synthesis framework incorporating multiple Synthesis gas conversion technologies, such as Fischer–Tropsch Synthesis or methanol conversion, is described. Production of aromatics can proceed through several technologies, such as naphtha reforming and aromatization of hydrocarbons via a metal-promoted H-ZSM-5 catalyst. This is the first article in the literature to incorporate an aromatics complex for the coproduction of liquid fuels and C6C8 petrochemicals within a rigorous Process Synthesis and deterministic global optimization framework. The optimal Process topologies across several case studies are discussed and the results indicate that the coproduction of aromatics with liquid fuels can significantly increase the profitability of these refineries. © 2015 American Institute of Chemical Engineers AIChE J, 2015 2014 American Institute of Chemical Engineers AIChE J, 61: 831–856, 2015
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biomass and natural gas to liquid transportation fuels and olefins bgtl c2_c4 Process Synthesis and global optimization
Industrial & Engineering Chemistry Research, 2015Co-Authors: Onur Onel, Alexander M. Niziolek, Josephine A Elia, Richard C Baliban, Christodoulos A FloudasAbstract:This paper introduces a Process Synthesis and a global optimization framework toward the coproduction of liquid fuels and olefins from biomass and natural gas. A superstructure of alternatives is developed at each stage of the Process with different gasification options, natural gas conversion routes, hydrocarbon production, and upgrading methods. Simultaneous heat, power, and water integration is introduced for the optimal usage of the utilities in the proposed plants. The global optimization framework with a branch-and-bound approach is utilized to determine the optimal Process out of numerous alternatives that would give the maximum plant profit. The optimal topologies obtained suggest that the best possible Process depends on the liquid fuels and olefins to be produced. Parametric analysis on different chemicals production levels suggests that both the profit and net present value (NPV) increases substantially at higher chemicals production levels. Economies of scale are present as the case studies at...
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thermochemical conversion of duckweed biomass to gasoline diesel and jet fuel Process Synthesis and global optimization
Industrial & Engineering Chemistry Research, 2013Co-Authors: Richard C Baliban, Christodoulos A Floudas, Josephine A Elia, Xin Xiao, Zhijian Zhang, Yong Qiao, Jie Li, Xuteng HuAbstract:Duckweed biomass is gasified in a thermochemical-based superstructure to produce gasoline, diesel, and kerosene using a Synthesis gas intermediate. The superstructure includes multiple pathways for conversion of the Synthesis gas to liquid hydrocarbons via Fischer–Tropsch Synthesis or intermediate methanol Synthesis. Low-temperature and high-temperature Fischer–Tropsch Processes are examined using both iron and cobalt based catalysts. Methanol may be converted to hydrocarbons via the methanol-to-gasoline or methanol-to-olefins Processes. The hydrocarbons will be refined into the final liquid products using ZSM-5 catalytic conversion, oligomerization, alkylation, isomerization, hydrotreating, reforming, and hydrocracking. A Process Synthesis framework is outlined to select the refining pathway that will produce the liquid fuels as the lowest possible cost. A rigorous deterministic branch-and-bound global optimization strategy will be incorporated to theoretically guarantee that the overall cost of the solu...
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hardwood biomass to gasoline diesel and jet fuel 1 Process Synthesis and global optimization of a thermochemical refinery
Energy & Fuels, 2013Co-Authors: Richard C Baliban, Christodoulos A Floudas, Josephine A Elia, Barri Gurau, Michael B Weingarten, Stephen D KlotzAbstract:A Process Synthesis framework is introduced for the conversion of hardwood biomass to liquid (BTL) transportation fuels. A Process superstructure is postulated that considers multiple thermochemical pathways for the production of gasoline, diesel, and jet fuel from a Synthesis gas intermediate. The hardwood is dried and gasified to generate the Synthesis gas, which is converted to hydrocarbons via Fischer–Tropsch or methanol Synthesis. Six different types of Fischer–Tropsch units and two methanol conversion pathways are analyzed to determine the topology for liquid fuel production that minimizes the overall system cost. Several upgrading technologies, namely, ZSM-5 catalytic conversion, oligomerization, hydrocracking, isomerization, alkylation, and hydrotreating, are capable of outputting fuels that meet all necessary physical property standards. The costs associated with utility production and wastewater treatment are directly included within the Process Synthesis framework using a simultaneous heat, pow...
Richard C Baliban - One of the best experts on this subject based on the ideXlab platform.
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Thermochemical Conversion of Duckweed Biomass to Gasoline, Diesel, and Jet Fuel: Process Synthesis and Global Optimization
2016Co-Authors: Richard C Baliban, Christodoulos A Floudas, Josephine A Elia, Xin Xiao, Zhijian Zhang, Hongbin Cao, Yong QiaoAbstract:Duckweed biomass is gasified in a thermochemical-based superstructure to produce gasoline, diesel, and kerosene using a Synthesis gas intermediate. The superstructure includes multiple pathways for conversion of the Synthesis gas to liquid hydrocarbons via Fischer–Tropsch Synthesis or intermediate methanol Synthesis. Low-temperature and high-temperature Fischer–Tropsch Processes are examined using both iron and cobalt based catalysts. Methanol may be converted to hydrocarbons via the methanol-to-gasoline or methanol-to-olefins Processes. The hydrocarbons will be refined into the final liquid products using ZSM-5 catalytic conversion, oligomerization, alkylation, isomerization, hydrotreating, reforming, and hydrocracking. A Process Synthesis framework is outlined to select the refining pathway that will produce the liquid fuels as the lowest possible cost. A rigorous deterministic branch-and-bound global optimization strategy will be incorporated to theoretically guarantee that the overall cost of the solution chosen by the Synthesis framework is within a small fraction of the best possible value. A heat, power, and water integration is incorporated within the Process Synthesis framework to ensure that the cost of utility production and wastewater treatment are simultaneously included with the Synthesis of the core refining Processes. The proposed Process Synthesis framework is demonstrated using four case studies which determine the effect of refinery capacity and liquid fuel composition on the overall system cost, the refinery topological design, the Process material/energy balances, and the lifecycle greenhouse gas emissions
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coproduction of liquid transportation fuels and c6_c8 aromatics from biomass and natural gas
Aiche Journal, 2015Co-Authors: Alexander M. Niziolek, Onur Onel, Josephine A Elia, Richard C Baliban, Christodoulos A FloudasAbstract:The coproduction of liquid transportation fuels and C6C8 aromatics from the thermochemical conversion of biomass and natural gas (BGTL+C6_C8) is investigated in this article. An optimization-based Process Synthesis framework incorporating multiple Synthesis gas conversion technologies, such as Fischer–Tropsch Synthesis or methanol conversion, is described. Production of aromatics can proceed through several technologies, such as naphtha reforming and aromatization of hydrocarbons via a metal-promoted H-ZSM-5 catalyst. This is the first article in the literature to incorporate an aromatics complex for the coproduction of liquid fuels and C6C8 petrochemicals within a rigorous Process Synthesis and deterministic global optimization framework. The optimal Process topologies across several case studies are discussed and the results indicate that the coproduction of aromatics with liquid fuels can significantly increase the profitability of these refineries. © 2015 American Institute of Chemical Engineers AIChE J, 2015 2014 American Institute of Chemical Engineers AIChE J, 61: 831–856, 2015
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biomass and natural gas to liquid transportation fuels and olefins bgtl c2_c4 Process Synthesis and global optimization
Industrial & Engineering Chemistry Research, 2015Co-Authors: Onur Onel, Alexander M. Niziolek, Josephine A Elia, Richard C Baliban, Christodoulos A FloudasAbstract:This paper introduces a Process Synthesis and a global optimization framework toward the coproduction of liquid fuels and olefins from biomass and natural gas. A superstructure of alternatives is developed at each stage of the Process with different gasification options, natural gas conversion routes, hydrocarbon production, and upgrading methods. Simultaneous heat, power, and water integration is introduced for the optimal usage of the utilities in the proposed plants. The global optimization framework with a branch-and-bound approach is utilized to determine the optimal Process out of numerous alternatives that would give the maximum plant profit. The optimal topologies obtained suggest that the best possible Process depends on the liquid fuels and olefins to be produced. Parametric analysis on different chemicals production levels suggests that both the profit and net present value (NPV) increases substantially at higher chemicals production levels. Economies of scale are present as the case studies at...
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thermochemical conversion of duckweed biomass to gasoline diesel and jet fuel Process Synthesis and global optimization
Industrial & Engineering Chemistry Research, 2013Co-Authors: Richard C Baliban, Christodoulos A Floudas, Josephine A Elia, Xin Xiao, Zhijian Zhang, Yong Qiao, Jie Li, Xuteng HuAbstract:Duckweed biomass is gasified in a thermochemical-based superstructure to produce gasoline, diesel, and kerosene using a Synthesis gas intermediate. The superstructure includes multiple pathways for conversion of the Synthesis gas to liquid hydrocarbons via Fischer–Tropsch Synthesis or intermediate methanol Synthesis. Low-temperature and high-temperature Fischer–Tropsch Processes are examined using both iron and cobalt based catalysts. Methanol may be converted to hydrocarbons via the methanol-to-gasoline or methanol-to-olefins Processes. The hydrocarbons will be refined into the final liquid products using ZSM-5 catalytic conversion, oligomerization, alkylation, isomerization, hydrotreating, reforming, and hydrocracking. A Process Synthesis framework is outlined to select the refining pathway that will produce the liquid fuels as the lowest possible cost. A rigorous deterministic branch-and-bound global optimization strategy will be incorporated to theoretically guarantee that the overall cost of the solu...
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hardwood biomass to gasoline diesel and jet fuel 1 Process Synthesis and global optimization of a thermochemical refinery
Energy & Fuels, 2013Co-Authors: Richard C Baliban, Christodoulos A Floudas, Josephine A Elia, Barri Gurau, Michael B Weingarten, Stephen D KlotzAbstract:A Process Synthesis framework is introduced for the conversion of hardwood biomass to liquid (BTL) transportation fuels. A Process superstructure is postulated that considers multiple thermochemical pathways for the production of gasoline, diesel, and jet fuel from a Synthesis gas intermediate. The hardwood is dried and gasified to generate the Synthesis gas, which is converted to hydrocarbons via Fischer–Tropsch or methanol Synthesis. Six different types of Fischer–Tropsch units and two methanol conversion pathways are analyzed to determine the topology for liquid fuel production that minimizes the overall system cost. Several upgrading technologies, namely, ZSM-5 catalytic conversion, oligomerization, hydrocracking, isomerization, alkylation, and hydrotreating, are capable of outputting fuels that meet all necessary physical property standards. The costs associated with utility production and wastewater treatment are directly included within the Process Synthesis framework using a simultaneous heat, pow...
Alexander M. Niziolek - One of the best experts on this subject based on the ideXlab platform.
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Natural Gas to Liquid Transportation Fuels under Uncertainty Using Robust Optimization
2018Co-Authors: Logan R Matthews, Alexander M. Niziolek, Onur Onel, Yannis A Guzman, Christodoulos A FloudasAbstract:The current pricing climate for natural gas and liquid transportation fuels adds a significant amount of uncertainty when designing new natural gas to liquid transportation fuel (GTL) refineries. Robust optimization is a useful tool for optimization under uncertainty and can be specifically applied to the problem of GTL Process Synthesis under feedstock price, product price, and investment cost uncertainty. Using historical data to define uncertain price parameters according to an assumed uniform distribution, a Process Synthesis superstructure with an uncertain objective function was created to maximize the profit of a GTL refinery. Recently developed, tight probabilistic bounds were used a priori and a posteriori in an iterative method to provide solutions with known probabilities of constraint violation for three different uncertainty sets. The relative impact of price and investment cost uncertainties are discussed, as is the impact of uncertainty on the overall guaranteed profit of a refinery, the refinery topology, and product distributions. The profitability results with probabilistic guarantees provide useful information for potential GTL refinery investors in the current uncertain energy markets
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Reprint of: Enhancing natural gas-to-liquids (GTL) Processes through chemical looping for syngas production: Process Synthesis and global optimization
Computers and Chemical Engineering, 2018Co-Authors: William W. Tso, Alexander M. Niziolek, Onur Onel, C. Doga Demirhan, Christodoulos A Floudas, Efstratios N. PistikopoulosAbstract:A Process Synthesis and global optimization framework is presented to determine the most profitable routes of producing liquid fuels from natural gas through competing technologies. Chemical looping is introduced into the framework for the first time as a natural gas conversion alternative. The underlying phenomena in chemical looping are complex and models from methods such as computational fluid dynamics are unsuitable for global optimization. Therefore, appropriate approximate models are required. Parameter estimation and disjunctive programming are described here for modeling two chemical looping Processes. The first is a nickel oxide based Process developed at CSIC in Spain; the second is a iron oxide based Process developed at Ohio State University. These mathematical models are then incorporated into a comprehensive Process superstructure to evaluate the performance of chemical looping against technologies such as autothermal reforming and steam reforming for syngas production. The rest of the superstructure consists of Process alternatives for liquid fuels production from syngas and simultaneous heat, power, and water integration. Among the various case studies considered, it is shown that chemical looping can reduce the break-even oil prices for natural gas-to-liquids Processes by as much as 40%, while satisfying production demands and obeying environmental constraints. For a natural gas price of $5/TSCF, the break-even price is as low as $32.10/bbl. Sensitivity analysis shows that these prices for chemical looping remain competitive even as natural gas cost rises. The findings suggest that chemical looping is a very promising option to enhance natural gas-to-liquids Processes and their capabilities.
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biomass based production of benzene toluene and xylenes via methanol Process Synthesis and deterministic global optimization
Energy & Fuels, 2016Co-Authors: Alexander M. Niziolek, Onur Onel, Yannis A Guzman, Christodoulos A FloudasAbstract:The pursuit toward an environmentally sustainable energy landscape requires the development of economically competitive renewable Processes. Efficient utilization of renewable resources is an important first step toward meeting this goal. To this extent, we introduce a systematic deterministic global optimization-based Process Synthesis framework that determines the most profitable Processes to produce benzene, toluene, and/or xylenes from biomass via methanol. Our framework incorporates several novel, competing, and/or commercial technologies. We quantify the effect that biomass type has on the overall profit of a refinery by investigating forest residues, agricultural residues, and perennial crops as potential feedstocks. A thorough economic analysis, together with material, energy, carbon, and greenhouse gas balances, are provided for every proposed Process design. The capability of our proposed approach is illustrated through several case studies that produce varying ratios of p-, o-, and m-xylene acr...
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production of benzene toluene and xylenes from natural gas via methanol Process Synthesis and global optimization
Aiche Journal, 2016Co-Authors: Alexander M. Niziolek, Onur Onel, Christodoulos A FloudasAbstract:A systematic global optimization-based Process Synthesis framework is presented to determine the most profitable Processes to produce aromatics from natural gas. Several novel, commercial, and/or competing technologies are modeled within the framework, including methanol-to-aromatics, toluene alkylation with methanol, selective toluene disproportionation, and toluene disproportionation and transalkylation with heavy aromatics, among others. We propose a stand-alone chemicals facility: the main products are aromatics with allowable by-products of gasoline, liquefied petroleum gas, and electricity. Several case studies are discussed that produce varying ratios of para-, ortho-, and meta-xylene across multiple refinery capacities. The results indicate that utilizing natural gas for the production of aromatics is profitable with net present values as high as $3800 MM dollars and payback periods as low as 6 years. The required investment for these refineries represents as much as a 65% decrease compared to published estimates of similar coal-based capacity plants. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1531–1556, 2016
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biomass to liquid transportation fuels via biological and thermochemical conversion Process Synthesis and global optimization strategies
Industrial & Engineering Chemistry Research, 2016Co-Authors: Alexander M. Niziolek, Onur Onel, Logan R Matthews, Neesha Pinnaduwage, Christodoulos A FloudasAbstract:Biological conversion of biomass into gasoline, diesel, and kerosene provides an alternative means to meet liquid transportation fuel demand, going beyond the traditional thermochemical methods involving gasification, Fischer–Tropsch conversion, and methanol Synthesis. Process Synthesis is an ideal methodology for comparing the developing biological technologies with established thermochemical methods through input–output modeling of biorefinery units and inclusion in a superstructure. The resulting model takes the form of a mixed-integer nonlinear optimization problem with full heat, power, and water integration. In the novel superstructure, the MixAlco Process for biological conversion is modeled, in which biomass is fermented into carboxylic acid salts which are further upgraded into liquid transportation fuels. The model is solved to global optimality based on the minimization of the cost of liquid transportation fuels production using a branch-and-bound global optimization algorithm to provide upper ...