The Experts below are selected from a list of 558 Experts worldwide ranked by ideXlab platform
Detlef Stolte - One of the best experts on this subject based on the ideXlab platform.
-
fuel cell systems with reforming of petroleum based and synthetic based diesel and kerosene fuels for apu applications
International Journal of Hydrogen Energy, 2015Co-Authors: Remzi Ca Samsu, Ralf Peters, Joachim Pasel, Detlef StolteAbstract:Abstract This work deals with the theoretical and experimental analysis of fuel-cell-based auxiliary power units operated with reformate from diesel and kerosene reforming for trucks and aircraft. In the theoretical part, a PEFC and an HT-PEFC system were analyzed using process simulation software. In the experimental part, a fuel processor consisting of an Autothermal Reformer, a water-gas shift reactor and a catalytic burner with 28 kW thermal power was characterized using different diesel and kerosene fuels. These fuels included desulfurized Jet A-1 and Aral Ultimate diesel as petroleum-based fuels and GTL kerosene, GTL diesel (winter and summer grades) and BTL diesel as non-petroleum-based synthetic fuels. The PEFC system showed a calculated electrical net efficiency of 28.5%, whereas 22.3% was calculated for the HT-PEFC system. A high-quality reformate was produced using various diesel and kerosene fuel qualities in the Reformer with a relevant technical power class for the APU application. Although a performance loss of the shift reactor was observed, it was kept at an acceptable level at the end of experiments.
-
long term stability at fuel processing of diesel and kerosene
International Journal of Hydrogen Energy, 2014Co-Authors: Joachim Pasel, Ralf Peters, Remzi Ca Samsu, Detlef Stolte, Jo ThieleAbstract:Abstract The long-term stability at Autothermal reforming of diesel fuel and kerosene was studied using Juelich's Autothermal Reformer ATR 9.2, which is equipped with a commercial proprietary RhPt/Al 2 O 3 –CeO 2 catalyst. The experiment was run for 10,000 h of time on stream at constant reaction conditions with an O 2 /C molar ratio of 0.47, a H 2 O/C molar ratio of 1.9, and a gas hourly space velocity of 30,000 h −1 . Kerosene produced via the gas-to-liquid process and diesel fuel synthesized via the bio-to-liquid route were used. Both fuels were almost free of mass fractions of sulfur and aromatics. The trends for the desired main products of Autothermal reforming H 2 , CO, CO 2 , and CH 4 were almost stable when kerosene was used. When the fuel mass flow was switched to diesel fuel however, different modes of catalyst deactivation occurred (active sites blocked by carbonaceous deposits, sintering processes), leading to a decrease in the concentrations of H 2 and CO 2 with a simultaneous increase in the CO content. This paper defines carbon conversion as the decisive criterion for evaluating the long-term stability during Autothermal reforming of kerosene and diesel fuel. Carbon conversion was diminished via three different pathways during the long-term experiment. Undesired byproducts found in the gas phase leaving the reactor had the strongest impact on carbon conversion. These byproducts included ethene, propene, and benzene. Furthermore, a liquid oily residue was detected floating on the condensed unconverted mass flow of water. This happened once during the whole experiment. Finally, undesired organic byproducts were dissolved in the mass flow of unconverted water. These were found to be straight-chain and branched paraffins, esters, alcohols, acids, aldehydes, ketones, etc. Nevertheless, at the end of the long-term experiment, carbon conversion still amounted to more than 98.2%.
-
design and test of a 5kwe high temperature polymer electrolyte fuel cell system operated with diesel and kerosene
Applied Energy, 2014Co-Authors: Remzi Ca Samsu, Ralf Peters, Joachim Pasel, Detlef Stolte, Holge Janse, Werne LehneAbstract:A high-temperature PEFC system, developed with the aim of delivering 5kW electrical power from the chemical energy stored in diesel and kerosene fuels for application as an auxiliary power unit, was simulated and tested. The key components of the system were an Autothermal Reformer, a water–gas shift reactor, a catalytic burner, and the HT-PEFC stack. The targeted power level of 5kW was achieved using different fuels, namely GTL kerosene, BTL diesel and premium diesel. Using an integrated system approach, operation without external heat input was demonstrated. The overall analysis showed slight but non-continuous performance loss for 250h operation time.
-
fuel processing of diesel and kerosene for auxiliary power unit applications
Energy & Fuels, 2013Co-Authors: Joachim Pasel, Ralf Peters, Remzi Ca Samsu, Detlef StolteAbstract:Apart from necessary balance-of-plant components, such as pumps, blowers, sensors, and heat exchangers, the fuel processing unit of a high-temperature polymer electrolyte fuel cell (HT-PEFC) system based on Autothermal reforming contains three main components: the Autothermal Reformer, the water-gas shift reactor, and the catalytic burner. In Julich, several generations of these catalytic reactors have been designed, constructed, and manufactured, with a wide range of thermal powers between 13 and 140 kW. Characteristic common features of the respective reactor generations are described as well as their specific structural features. The experimental part of this paper concentrates on investigations with different generations of reactors for Autothermal reforming using different diesel and kerosene fuels, which were produced either via the gas-to-liquid or bio-to-liquid process or in a conventional manner from crude oil. They mainly differed from each other with respect to their boiling ranges and mass fra...
Ralf Peters - One of the best experts on this subject based on the ideXlab platform.
-
recent advances in diesel Autothermal Reformer design
International Journal of Hydrogen Energy, 2020Co-Authors: Joachim Pasel, A. Tschauder, Remzi Can Samsun, J Meisner, Ralf PetersAbstract:Abstract The Autothermal reforming of diesel fuel is a catalytic process that runs at temperatures of 700 °C–900 °C. Long-chain hydrocarbon molecules react with steam and O2, yielding a product gas that mainly consists of CO, CO2, CH4 and H2. H2 is essential for the operation of fuel cell systems. The Forschungszentrum Julich has been engaged in the cooperative development of technical apparatus for this reaction to be applied in fuel cell systems over the past 15 years, together with many other research groups worldwide, and this paper deals with reactor ATR 14, which is considered the preliminary end-product of Julich's research and development in this field. This paper briefly summarizes Julich's earlier reactor generations and then describes the most recent improvements embodied in the ATR 14. Additionally, the experimental evaluation of the ATR 14 is presented, which demonstrates that it can be operated over a broad load range and with almost complete carbon conversion.
-
advances in Autothermal Reformer design
Applied Energy, 2017Co-Authors: Joachim Pasel, A. Tschauder, Remzi Can Samsun, Ralf Peters, D. StoltenAbstract:Abstract Together with the high-temperature polymer electrolyte fuel cell, the reactor for the Autothermal reforming (ATR) of liquid hydrocarbons, such as diesel fuel or kerosene, is the key component of the Julich fuel cell system in the 5 kWe power class. This paper presents some of Julich’s most recent development in the field of ATR reactors, specifically the ATR 12. ATR 12 is characterized by a new concept for the internal generation of superheated steam as one of the ATR reactants using concentric shells instead of coiled tubing and particularly by the integration of an electric heating wire to enable fast and autonomous start-up. Three different experimental procedures for heating up the ATR 12 are presented and discussed, the most suitable of which enables the start-up of the ATR 12 within approximately 15 min. As a consequence, from the system perspective, the bulky start-up burner, which is also difficult to control, along with the corresponding heat exchanger unit, can be dispensed with. Additionally, comprehensive steady-state experiments identify suitable reaction conditions for the operation of the ATR 12.
-
Electrical start-up for diesel fuel processing in a fuel-cell-based auxiliary power unit
Journal of Power Sources, 2016Co-Authors: Remzi Can Samsun, A. Tschauder, Carsten Krupp, Ralf PetersAbstract:As auxiliary power units in trucks and aircraft, fuel cell systems with a diesel and kerosene reforming capacity offer the dual benefit of reduced emissions and fuel consumption. In order to be commercially viable, these systems require a quick start-up time with low energy input. In pursuit of this end, this paper reports an electrical start-up strategy for diesel fuel processing. A transient computational fluid dynamics model is developed to optimize the start-up procedure of the fuel processor in the 28 kWthpower class. The temperature trend observed in the experiments is reproducible to a high degree of accuracy using a dual-cell approach in ANSYS Fluent. Starting from a basic strategy, different options are considered for accelerating system start-up. The start-up time is reduced from 22 min in the basic case to 9.5 min, at an energy consumption of 0.4 kW h. Furthermore, an electrical wire is installed in the Reformer to test the steam generation during start-up. The experimental results reveal that the generation of steam at 450 °C is possible within seconds after water addition to the Reformer. As a result, the fuel processor can be started in Autothermal Reformer mode using the electrical concept developed in this work.
-
fuel cell systems with reforming of petroleum based and synthetic based diesel and kerosene fuels for apu applications
International Journal of Hydrogen Energy, 2015Co-Authors: Remzi Ca Samsu, Ralf Peters, Joachim Pasel, Detlef StolteAbstract:Abstract This work deals with the theoretical and experimental analysis of fuel-cell-based auxiliary power units operated with reformate from diesel and kerosene reforming for trucks and aircraft. In the theoretical part, a PEFC and an HT-PEFC system were analyzed using process simulation software. In the experimental part, a fuel processor consisting of an Autothermal Reformer, a water-gas shift reactor and a catalytic burner with 28 kW thermal power was characterized using different diesel and kerosene fuels. These fuels included desulfurized Jet A-1 and Aral Ultimate diesel as petroleum-based fuels and GTL kerosene, GTL diesel (winter and summer grades) and BTL diesel as non-petroleum-based synthetic fuels. The PEFC system showed a calculated electrical net efficiency of 28.5%, whereas 22.3% was calculated for the HT-PEFC system. A high-quality reformate was produced using various diesel and kerosene fuel qualities in the Reformer with a relevant technical power class for the APU application. Although a performance loss of the shift reactor was observed, it was kept at an acceptable level at the end of experiments.
-
long term stability at fuel processing of diesel and kerosene
International Journal of Hydrogen Energy, 2014Co-Authors: Joachim Pasel, Ralf Peters, Remzi Ca Samsu, Detlef Stolte, Jo ThieleAbstract:Abstract The long-term stability at Autothermal reforming of diesel fuel and kerosene was studied using Juelich's Autothermal Reformer ATR 9.2, which is equipped with a commercial proprietary RhPt/Al 2 O 3 –CeO 2 catalyst. The experiment was run for 10,000 h of time on stream at constant reaction conditions with an O 2 /C molar ratio of 0.47, a H 2 O/C molar ratio of 1.9, and a gas hourly space velocity of 30,000 h −1 . Kerosene produced via the gas-to-liquid process and diesel fuel synthesized via the bio-to-liquid route were used. Both fuels were almost free of mass fractions of sulfur and aromatics. The trends for the desired main products of Autothermal reforming H 2 , CO, CO 2 , and CH 4 were almost stable when kerosene was used. When the fuel mass flow was switched to diesel fuel however, different modes of catalyst deactivation occurred (active sites blocked by carbonaceous deposits, sintering processes), leading to a decrease in the concentrations of H 2 and CO 2 with a simultaneous increase in the CO content. This paper defines carbon conversion as the decisive criterion for evaluating the long-term stability during Autothermal reforming of kerosene and diesel fuel. Carbon conversion was diminished via three different pathways during the long-term experiment. Undesired byproducts found in the gas phase leaving the reactor had the strongest impact on carbon conversion. These byproducts included ethene, propene, and benzene. Furthermore, a liquid oily residue was detected floating on the condensed unconverted mass flow of water. This happened once during the whole experiment. Finally, undesired organic byproducts were dissolved in the mass flow of unconverted water. These were found to be straight-chain and branched paraffins, esters, alcohols, acids, aldehydes, ketones, etc. Nevertheless, at the end of the long-term experiment, carbon conversion still amounted to more than 98.2%.
Joachim Pasel - One of the best experts on this subject based on the ideXlab platform.
-
recent advances in diesel Autothermal Reformer design
International Journal of Hydrogen Energy, 2020Co-Authors: Joachim Pasel, A. Tschauder, Remzi Can Samsun, J Meisner, Ralf PetersAbstract:Abstract The Autothermal reforming of diesel fuel is a catalytic process that runs at temperatures of 700 °C–900 °C. Long-chain hydrocarbon molecules react with steam and O2, yielding a product gas that mainly consists of CO, CO2, CH4 and H2. H2 is essential for the operation of fuel cell systems. The Forschungszentrum Julich has been engaged in the cooperative development of technical apparatus for this reaction to be applied in fuel cell systems over the past 15 years, together with many other research groups worldwide, and this paper deals with reactor ATR 14, which is considered the preliminary end-product of Julich's research and development in this field. This paper briefly summarizes Julich's earlier reactor generations and then describes the most recent improvements embodied in the ATR 14. Additionally, the experimental evaluation of the ATR 14 is presented, which demonstrates that it can be operated over a broad load range and with almost complete carbon conversion.
-
advances in Autothermal Reformer design
Applied Energy, 2017Co-Authors: Joachim Pasel, A. Tschauder, Remzi Can Samsun, Ralf Peters, D. StoltenAbstract:Abstract Together with the high-temperature polymer electrolyte fuel cell, the reactor for the Autothermal reforming (ATR) of liquid hydrocarbons, such as diesel fuel or kerosene, is the key component of the Julich fuel cell system in the 5 kWe power class. This paper presents some of Julich’s most recent development in the field of ATR reactors, specifically the ATR 12. ATR 12 is characterized by a new concept for the internal generation of superheated steam as one of the ATR reactants using concentric shells instead of coiled tubing and particularly by the integration of an electric heating wire to enable fast and autonomous start-up. Three different experimental procedures for heating up the ATR 12 are presented and discussed, the most suitable of which enables the start-up of the ATR 12 within approximately 15 min. As a consequence, from the system perspective, the bulky start-up burner, which is also difficult to control, along with the corresponding heat exchanger unit, can be dispensed with. Additionally, comprehensive steady-state experiments identify suitable reaction conditions for the operation of the ATR 12.
-
Operating strategies for fuel processing systems with a focus on water–gas shift reactor stability
Applied Energy, 2016Co-Authors: Daniel Krekel, Joachim Pasel, Matthias Prawitz, D. StoltenAbstract:Abstract This contribution deals with the development of suitable operating strategies for diesel/kerosene-fueled fuel cell APUs. The focus is on the Autothermal Reformer (ATR) and the water–gas shift (WGS) reactor. In the first part shutdown experiments under high-temperature shift (HTS) conditions were used to identify the possible detrimental effect of higher hydrocarbons on the activity and stability of two commercial WGS catalysts. The results indicated that 220 ppmv higher hydrocarbons had no negative effect on the catalyst activity/stability. The second part presents fuel processing system experiments, which revealed much higher concentrations of higher hydrocarbons during transients like startup/shutdown than the concentrations investigated in the first part. Through the development of new startup/shutdown strategies concentrations of higher hydrocarbons were lowered by a factor of up to 10 for startup and of up to 400 for shutdown. The results were reproduced using four different diesel and kerosene fuels. The newly developed strategies improve fuel conversion in the Reformer and may possibly prevent catalyst deactivation in the water–gas shift reactor during transient conditions.
-
fuel cell systems with reforming of petroleum based and synthetic based diesel and kerosene fuels for apu applications
International Journal of Hydrogen Energy, 2015Co-Authors: Remzi Ca Samsu, Ralf Peters, Joachim Pasel, Detlef StolteAbstract:Abstract This work deals with the theoretical and experimental analysis of fuel-cell-based auxiliary power units operated with reformate from diesel and kerosene reforming for trucks and aircraft. In the theoretical part, a PEFC and an HT-PEFC system were analyzed using process simulation software. In the experimental part, a fuel processor consisting of an Autothermal Reformer, a water-gas shift reactor and a catalytic burner with 28 kW thermal power was characterized using different diesel and kerosene fuels. These fuels included desulfurized Jet A-1 and Aral Ultimate diesel as petroleum-based fuels and GTL kerosene, GTL diesel (winter and summer grades) and BTL diesel as non-petroleum-based synthetic fuels. The PEFC system showed a calculated electrical net efficiency of 28.5%, whereas 22.3% was calculated for the HT-PEFC system. A high-quality reformate was produced using various diesel and kerosene fuel qualities in the Reformer with a relevant technical power class for the APU application. Although a performance loss of the shift reactor was observed, it was kept at an acceptable level at the end of experiments.
-
long term stability at fuel processing of diesel and kerosene
International Journal of Hydrogen Energy, 2014Co-Authors: Joachim Pasel, Ralf Peters, Remzi Ca Samsu, Detlef Stolte, Jo ThieleAbstract:Abstract The long-term stability at Autothermal reforming of diesel fuel and kerosene was studied using Juelich's Autothermal Reformer ATR 9.2, which is equipped with a commercial proprietary RhPt/Al 2 O 3 –CeO 2 catalyst. The experiment was run for 10,000 h of time on stream at constant reaction conditions with an O 2 /C molar ratio of 0.47, a H 2 O/C molar ratio of 1.9, and a gas hourly space velocity of 30,000 h −1 . Kerosene produced via the gas-to-liquid process and diesel fuel synthesized via the bio-to-liquid route were used. Both fuels were almost free of mass fractions of sulfur and aromatics. The trends for the desired main products of Autothermal reforming H 2 , CO, CO 2 , and CH 4 were almost stable when kerosene was used. When the fuel mass flow was switched to diesel fuel however, different modes of catalyst deactivation occurred (active sites blocked by carbonaceous deposits, sintering processes), leading to a decrease in the concentrations of H 2 and CO 2 with a simultaneous increase in the CO content. This paper defines carbon conversion as the decisive criterion for evaluating the long-term stability during Autothermal reforming of kerosene and diesel fuel. Carbon conversion was diminished via three different pathways during the long-term experiment. Undesired byproducts found in the gas phase leaving the reactor had the strongest impact on carbon conversion. These byproducts included ethene, propene, and benzene. Furthermore, a liquid oily residue was detected floating on the condensed unconverted mass flow of water. This happened once during the whole experiment. Finally, undesired organic byproducts were dissolved in the mass flow of unconverted water. These were found to be straight-chain and branched paraffins, esters, alcohols, acids, aldehydes, ketones, etc. Nevertheless, at the end of the long-term experiment, carbon conversion still amounted to more than 98.2%.
Remzi Ca Samsu - One of the best experts on this subject based on the ideXlab platform.
-
Water-gas Shift Reactor for Fuel Cell Systems: Stable Operation for 5000 Hours
Elsevier, 2018Co-Authors: Pasel Joachim, Remzi Ca Samsu, Tschaude Andreas, Peters Ralf, Stolte DetlefAbstract:The water-gas shift reactor in the fuel processing unit of a fuel cell system has the vital function of reducing the concentration of CO in the reforming reactor's product gas to values of between 1.0 and 1.5 vol% in order to protect the anodic catalyst from becoming irreversibly poisoned. This paper presents Jülich's recent development in this field, specifically the WGS 6 in the 5 kWe class. The WGS 6 is characterized by a fundamentally new concept for arranging high temperature and low temperature shift stages. Both stages are now coaxially integrated in one joint casing to provide higher values for the power density and specific power, whereas in earlier reactor generations, these stages are arranged in two separate, parallel housings. In addition, this contribution presents results from a long-term experiment for 5000 h on stream with WGS 6 and discusses the temporal trends of the product gas composition and reactor temperatures across this timespan. For this experiment, the inlet gas stream is produced by an Autothermal Reformer, which is installed upstream of the WGS 6
-
Advances in Autothermal Reformer development
Elsevier Science, 2017Co-Authors: Pasel Joachim, Remzi Ca Samsu, Tschaude Andreas, Peters Ralf, Stolte DetlefAbstract:Together with the high-temperature polymer electrolyte fuel cell, the reactor for the Autothermal reforming (ATR) of liquid hydrocarbons, such as diesel fuel or kerosene, is the key component of the Jülich fuel cell system in the 5 kWe power class. This paper presents some of Jülich’s most recent development in the field of ATR reactors, specifically the ATR 12. ATR 12 is characterized by a new concept for the internal generation of superheated steam as one of the ATR reactants using concentric shells instead of coiled tubing and particularly by the integration of an electric heating wire to enable fast and autonomous start-up. Three different experimental procedures for heating up the ATR 12 are presented and discussed, the most suitable of which enables the start-up of the ATR 12 within approximately 15 min. As a consequence, from the system perspective, the bulky start-up burner, which is also difficult to control, along with the corresponding heat exchanger unit, can be dispensed with. Additionally, comprehensive steady-state experiments identify suitable reaction conditions for the operation of the ATR 12
-
fuel cell systems with reforming of petroleum based and synthetic based diesel and kerosene fuels for apu applications
International Journal of Hydrogen Energy, 2015Co-Authors: Remzi Ca Samsu, Ralf Peters, Joachim Pasel, Detlef StolteAbstract:Abstract This work deals with the theoretical and experimental analysis of fuel-cell-based auxiliary power units operated with reformate from diesel and kerosene reforming for trucks and aircraft. In the theoretical part, a PEFC and an HT-PEFC system were analyzed using process simulation software. In the experimental part, a fuel processor consisting of an Autothermal Reformer, a water-gas shift reactor and a catalytic burner with 28 kW thermal power was characterized using different diesel and kerosene fuels. These fuels included desulfurized Jet A-1 and Aral Ultimate diesel as petroleum-based fuels and GTL kerosene, GTL diesel (winter and summer grades) and BTL diesel as non-petroleum-based synthetic fuels. The PEFC system showed a calculated electrical net efficiency of 28.5%, whereas 22.3% was calculated for the HT-PEFC system. A high-quality reformate was produced using various diesel and kerosene fuel qualities in the Reformer with a relevant technical power class for the APU application. Although a performance loss of the shift reactor was observed, it was kept at an acceptable level at the end of experiments.
-
long term stability at fuel processing of diesel and kerosene
International Journal of Hydrogen Energy, 2014Co-Authors: Joachim Pasel, Ralf Peters, Remzi Ca Samsu, Detlef Stolte, Jo ThieleAbstract:Abstract The long-term stability at Autothermal reforming of diesel fuel and kerosene was studied using Juelich's Autothermal Reformer ATR 9.2, which is equipped with a commercial proprietary RhPt/Al 2 O 3 –CeO 2 catalyst. The experiment was run for 10,000 h of time on stream at constant reaction conditions with an O 2 /C molar ratio of 0.47, a H 2 O/C molar ratio of 1.9, and a gas hourly space velocity of 30,000 h −1 . Kerosene produced via the gas-to-liquid process and diesel fuel synthesized via the bio-to-liquid route were used. Both fuels were almost free of mass fractions of sulfur and aromatics. The trends for the desired main products of Autothermal reforming H 2 , CO, CO 2 , and CH 4 were almost stable when kerosene was used. When the fuel mass flow was switched to diesel fuel however, different modes of catalyst deactivation occurred (active sites blocked by carbonaceous deposits, sintering processes), leading to a decrease in the concentrations of H 2 and CO 2 with a simultaneous increase in the CO content. This paper defines carbon conversion as the decisive criterion for evaluating the long-term stability during Autothermal reforming of kerosene and diesel fuel. Carbon conversion was diminished via three different pathways during the long-term experiment. Undesired byproducts found in the gas phase leaving the reactor had the strongest impact on carbon conversion. These byproducts included ethene, propene, and benzene. Furthermore, a liquid oily residue was detected floating on the condensed unconverted mass flow of water. This happened once during the whole experiment. Finally, undesired organic byproducts were dissolved in the mass flow of unconverted water. These were found to be straight-chain and branched paraffins, esters, alcohols, acids, aldehydes, ketones, etc. Nevertheless, at the end of the long-term experiment, carbon conversion still amounted to more than 98.2%.
-
design and test of a 5kwe high temperature polymer electrolyte fuel cell system operated with diesel and kerosene
Applied Energy, 2014Co-Authors: Remzi Ca Samsu, Ralf Peters, Joachim Pasel, Detlef Stolte, Holge Janse, Werne LehneAbstract:A high-temperature PEFC system, developed with the aim of delivering 5kW electrical power from the chemical energy stored in diesel and kerosene fuels for application as an auxiliary power unit, was simulated and tested. The key components of the system were an Autothermal Reformer, a water–gas shift reactor, a catalytic burner, and the HT-PEFC stack. The targeted power level of 5kW was achieved using different fuels, namely GTL kerosene, BTL diesel and premium diesel. Using an integrated system approach, operation without external heat input was demonstrated. The overall analysis showed slight but non-continuous performance loss for 250h operation time.
Remzi Can Samsun - One of the best experts on this subject based on the ideXlab platform.
-
recent advances in diesel Autothermal Reformer design
International Journal of Hydrogen Energy, 2020Co-Authors: Joachim Pasel, A. Tschauder, Remzi Can Samsun, J Meisner, Ralf PetersAbstract:Abstract The Autothermal reforming of diesel fuel is a catalytic process that runs at temperatures of 700 °C–900 °C. Long-chain hydrocarbon molecules react with steam and O2, yielding a product gas that mainly consists of CO, CO2, CH4 and H2. H2 is essential for the operation of fuel cell systems. The Forschungszentrum Julich has been engaged in the cooperative development of technical apparatus for this reaction to be applied in fuel cell systems over the past 15 years, together with many other research groups worldwide, and this paper deals with reactor ATR 14, which is considered the preliminary end-product of Julich's research and development in this field. This paper briefly summarizes Julich's earlier reactor generations and then describes the most recent improvements embodied in the ATR 14. Additionally, the experimental evaluation of the ATR 14 is presented, which demonstrates that it can be operated over a broad load range and with almost complete carbon conversion.
-
advances in Autothermal Reformer design
Applied Energy, 2017Co-Authors: Joachim Pasel, A. Tschauder, Remzi Can Samsun, Ralf Peters, D. StoltenAbstract:Abstract Together with the high-temperature polymer electrolyte fuel cell, the reactor for the Autothermal reforming (ATR) of liquid hydrocarbons, such as diesel fuel or kerosene, is the key component of the Julich fuel cell system in the 5 kWe power class. This paper presents some of Julich’s most recent development in the field of ATR reactors, specifically the ATR 12. ATR 12 is characterized by a new concept for the internal generation of superheated steam as one of the ATR reactants using concentric shells instead of coiled tubing and particularly by the integration of an electric heating wire to enable fast and autonomous start-up. Three different experimental procedures for heating up the ATR 12 are presented and discussed, the most suitable of which enables the start-up of the ATR 12 within approximately 15 min. As a consequence, from the system perspective, the bulky start-up burner, which is also difficult to control, along with the corresponding heat exchanger unit, can be dispensed with. Additionally, comprehensive steady-state experiments identify suitable reaction conditions for the operation of the ATR 12.
-
Electrical start-up for diesel fuel processing in a fuel-cell-based auxiliary power unit
Journal of Power Sources, 2016Co-Authors: Remzi Can Samsun, A. Tschauder, Carsten Krupp, Ralf PetersAbstract:As auxiliary power units in trucks and aircraft, fuel cell systems with a diesel and kerosene reforming capacity offer the dual benefit of reduced emissions and fuel consumption. In order to be commercially viable, these systems require a quick start-up time with low energy input. In pursuit of this end, this paper reports an electrical start-up strategy for diesel fuel processing. A transient computational fluid dynamics model is developed to optimize the start-up procedure of the fuel processor in the 28 kWthpower class. The temperature trend observed in the experiments is reproducible to a high degree of accuracy using a dual-cell approach in ANSYS Fluent. Starting from a basic strategy, different options are considered for accelerating system start-up. The start-up time is reduced from 22 min in the basic case to 9.5 min, at an energy consumption of 0.4 kW h. Furthermore, an electrical wire is installed in the Reformer to test the steam generation during start-up. The experimental results reveal that the generation of steam at 450 °C is possible within seconds after water addition to the Reformer. As a result, the fuel processor can be started in Autothermal Reformer mode using the electrical concept developed in this work.
-
Catalytic burner with internal steam generation for a fuel-cell-based auxiliary power unit for middle distillates
International Journal of Hydrogen Energy, 2014Co-Authors: J. Meißner, Remzi Can Samsun, Joachim Pasel, F. Scharf, C. Wiethege, Roland PetersAbstract:Abstract A catalytic burner (CAB) was developed, which utilizes the anode off-gas of a high temperature polymer electrolyte fuel cell (HT-PEFC). This CAB has two functions within the HT-PEFC-system: It has to convert completely all combustible components including methane and carbon monoxide, even in the low ppm range and it has to provide steam to the Autothermal Reformer (ATR). Thereby it increases the system's overall efficiency. Using computational fluid dynamics and experiments with a simple glass model, two catalytic burners (CAB 2 and CAB 3) were designed and constructed for a high temperature PEFC system with thermal powers of 18 kW and 28 kW, respectively. The burners were characterized experimentally in detail. Close attention was given to the steam generation capacity and the thermal behavior. The constructed burners allowed complete conversion of low calorific fuel gases and a reformate in part load of the ATR was burned reliably as well. Superheated steam was generated free of oscillation. Experimental findings with CAB 2 resulted in an improved reactor generation with a reduced specific weight and geometric changes.