Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates.To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit has been constructed in this project. The unit is designed to operate at temperatures up to 1100 o C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. The unit was fully commissioned and is operational. A membrane gasification reactor model was developed to consider the H 2 permeability of the membrane, the kinetics and the equilibriums of the gas phase reactions in the gasifier, the operating conditions and the configurations of the membrane reactor. The results show that the hydrogen production efficiency using the novel membrane gasification reactor concept can be increased by about 50% versus the conventional gasification process. This confirms the previous evaluation results from the thermodynamic equilibrium calculation.A rigorous model for hydrogen permeation through mixed proton-electron conducting ceramic membranes was also developed based on non-equilibrium thermodynamics. The hydrogen flux predicted from the modeling results are in line with the data from the experimental measurement. The simulation also shows that the presence of steam in the permeate side or the feed side of the membrane can have a small negative effect on the hydrogen flux, in the order of 10%.
Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying the potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates.To evaluate the candidate membrane performance under the gasification conditions, a high temperature/high pressure hydrogen permeation unit will be constructed in this project. During this reporting period, the design of this unit was completed. The unit will be capable of operating at temperatures up to 1100 o C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. The membranes to be tested will be in disc form with a diameter of about 3 cm. By operating at higher temperatures and higher hydrogen partial pressures, we expect to demonstrate commercially relevant hydrogen flux, 10~50 cc/min/cm 2 , from the membranes made of the perovskite type of ceramic material. The construction of the unit is planned to be completed by the end of the next reporting period.
Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates.To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit has been constructed in this project. During this reporting period, the unit has been fully commissioned and is operational. The unit is capable of operating at temperatures up to 1100 o C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. A double-seal technique has been developed and tested successfully to achieve leak-tight seal for the membranes. Initial data for a commercial Palladium-Gold membrane were obtained at temperatures to 450C and pressures to 13 atm. Tests for the perovskite membranes are being performed and the results will be reported in the next quarter.A membrane gasification reactor model was developed to consider the H 2 permeability of the membrane, the kinetics and the equilibriums of the gas phase reactions in the gasifier, the operating conditions and the configurations of the membrane reactor. The results show that the hydrogen production efficiency using the novel membrane gasification reactor concept can be increased by about 50% versus the conventional gasification process. This confirms the previous evaluation results from the thermodynamic equilibrium calculation.A rigorous model for hydrogen permeation through mixed proton-electron conducting ceramic membranes was also developed based on non-equilibrium thermodynamics. The results from the simulation work confirm that the hydrogen flux increases with increasing partial pressure of hydrogen. The presence of steam in the permeate side can have a small negative effect on the hydrogen flux, in the order of 10%. When the steam partial pressure is greater than 1 atm, the hydrogen flux becomes independent of the steam pressure.
Gas Technology Institute is developing a novel concept of membrane reactor coupled with a gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates.Hydrogen permeation data for several perovskite membranes BCN (BaCe 0.9 Nd 0.1 O 3-x ), SCE (SrCe 0.9 Eu 0.1 O 3 ) and SCTm (SrCe 0.95 Tm 0.05 O 3 ) have been successfully obtained for temperatures between 800 and 950 o C and pressures from 1 to 12 bar in this project. However, it is known that the cerate-based perovskite materials can react with CO 2 . Therefore, the stability issue of the proton conducting perovskite materials under CO 2 or H 2 S environments was examined. Tests were conducted in the Thermo Gravimetric Analyzer (TGA) unit for powder and disk forms of BCN and SCE. Perovskite materials doped with zirconium (Zr) are known to be resistant to CO 2 . The results from the evaluation of the chemical stability for the Zr doped perovskite membranes are presented.During this reporting period, flowsheet simulation was also performed to calculate material and energy balance based on several hydrogen production processes from coal using high temperature membrane reactor (1000 o C), low temperature membrane reactor (250 o C), or conventional technologies. The results show that the coal to hydrogen process employing both the high temperature and the low temperature membrane reactors can increase the hydrogen production efficiency (cold gas efficiency) by more than 50% compared to the conventional process. Using either high temperature or low temperature membrane reactor process also results in an increase of the cold gas efficiencies as well as the thermal efficiencies of the overall process.
Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates.To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit has been constructed in this project. The unit is designed to operate at temperatures up to 1100 o C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. Several perovskite membranes based on the formulations of BCN (BaCe 0.8 Nd 0.2 O 3-x ) and BCY (BaCe 0.8 Y 0.2 O 3-x ) were prepared by GTI and successfully tested in the new permeation unit.During this reporting period, two different types of membranes, Eu-doped SrCeO 3 (SCE) and SrCe 0.95 Tm 0.05 O 3 (SCTm) provided by the University of Florida and the University of Cincinnati, respectively were tested in the high pressure permeation unit. The SCTm membrane, with a thickness of 1.7 mm, showed the highest hydrogen permeability among the perovskite membranes tested in this project so far. The hydrogen flux measured for the SCTm membrane was close to 0.8 cc/min/cm 2 at a hydrogen feed pressure of about 4 bar at 950 o C. SEM and EDX analysis for the tested SCTm membrane showed a separate Ce-rich phase deposited along the grain boundaries in the region towards the feed side of the membrane. No such phase separation was observed towards the permeate side. Partial reduction of the SCTm perovskite material by the high pressure hydrogen, especially in the feed side of the membrane, was postulated to be the possible reason for the phase separation. Further investigation of the stability issue of the perovskite membrane is needed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.