The thermo-catalytic decomposition (TCD) of methane has attracted the attention of numerous resea... more The thermo-catalytic decomposition (TCD) of methane has attracted the attention of numerous researchers’ around the world as an ideal approach for hydrogen production, which in turns, can be used as an appropriate feeding gas in fuel cells operating at low temperatures. The TCD of methane is capable to produce a valuable by–product, pure carbon, which can excessively alleviate the total cost of the process. In this study, we report TCD of methane over 30% Ni supported Y zeolite catalyst at 550 and 600 °C was conducted in a fixed bed reactor and the yield of hydrogen from the reactor was analyzed by GC. As can be observed that, the TCD of methane over Ni-supported Y zeolite showed maximum conversion (31 and 15.90 % at 600 and 550 °C, respectively) at the initial stages and on stream of reaction time, it decreased gradually; and ultimately, deactivated the catalyst completely. The cause for this is the formation of encapsulating carbon on Ni active sites which deactivates the catalyst over the course of reaction time. Hydrogen production rate, carbon accumulation (CA) and carbon formation rate (CFR) were investigated at three representative times for both temperatures. The CFR analysis showed that the growth of filamentous carbon was steady-state at the first stage and then reduced to a relic activity and it remains constant during the rest of the reaction. The descriptive dissemination of methane TCD over Ni-supported Y zeolite has been speculated in this paper.
Catalytic characteristics of activated carbon manufactured from palm shell (ACPS) for methane dec... more Catalytic characteristics of activated carbon manufactured from palm shell (ACPS) for methane decomposition was studied using a thermobalance by measuring thee mass gain with time. A reaction order of 0.5 is obtained for methane decomposition over the activated ...
This study reports the hydrodeoxygenation (HDO) of stearic acid (SA) into paraffinic biofuel with... more This study reports the hydrodeoxygenation (HDO) of stearic acid (SA) into paraffinic biofuel with synthesized palladium-oxalate zeolite supported catalyst (PdOx/Zeol). The PdOx/Zeol was synthesized via the functionalization of dihydrogen tetrachloropalladate (II) with aqueous oxalic acid (OxA) to form the polynuclear palladium(II) oxalate (PdOx), which was supported on zeolite. The SEM and XRD characterization results showed that the zeolite support is highly crystalline but loss some degree of crystallinity in the PdOx/Zeol sample after PdOx incorporation. The activity of the PdOx/Zeol tested on the HDO of SA showed that temperature, pressure, gas flow rate, and PdOx/Zeol loading have significant effects on the HDO process, and their best observed conditions were 360 °C, 20 bar, 100 mL/min, and 25 mg, respectively to achieve 92% biofuel production from 35 g SA. The biofuel product distribution showed 71% n-C18H38, 18% iso-C18H38, and 3% C17H36. The presence of iso-C18H38, which is an excellent biofuel value-added-component due to its low freezing point, was ascribed to the functionalization of Pd with OxA, which increases PdOx/Zeol acidity. The results showed that PdOx/Zeol is a prospective catalyst toward further research and commercialization of HDO process of SA.
catalytic hydrodeoxygenation reaction (HDO). Firstly, thermodynamic simulation studies were carri... more catalytic hydrodeoxygenation reaction (HDO). Firstly, thermodynamic simulation studies were carried out using Aspen Hysys® to establish the process feasibility. The catalyst precursor, molybdenum oxalate (MoOx) was prepared from the reaction of Bis(acetylacetonato)dioxomolybdenum (VI) and oxalic acid in both acidic (pH 2) and basic (pH 10) environment using HF and NaOH as buffers, respectively and incorporated into Al2O3 support. The catalysts characterization results showed that polymeric molybdates [Mo2O5(OH)(C2O4)2]3- and monomeric molybdates [MoO2(OH)2(C2O4)2]4- are the Mo species present on the acidified MoOx/Al2O3 and basic MoOx/Al2O3, respectively according to the Raman spectroscopy and x-ray diffraction. The HDO of SB at 370 °C and 1 bar showed that the basic MoOx/Al2O3 has higher conversion of about 98% nC18 while the acidified MoOx/Al2O3 has comparably lower conversion of 92% nC18 within 35 min of reaction time, but the acidified MoOx/Al2O3 showed higher selectivity of 42% for the production of iso-paraffins (iC18) compared to 34% obtained for the basic MoOx/Al2O3. The high iC18 production was ascribed to the acidity of MoOx/Al2O3 (pH 2) catalyst due to fluoride ion functionalization. This result is encouraging for further research towards industrialization.
Thermocatalytic decomposition of methane (TCD) is a fully green single step technology for produc... more Thermocatalytic decomposition of methane (TCD) is a fully green single step technology for producing hydrogen and nano-carbon. This review studying all development in laboratory-scale research on TCD, especially the recent advances like co-feeding effect and catalyst regeneration for augmenting the productivity of the whole process. Although a great success on the laboratory-scale has been fulfilled, TCD for greenhouse gas (GHG) free hydrogen production is still in its infancy. The need for commercialization of TCD is greater than ever in the present situation of huge GHG emission. TCD usually examined over various kind of catalysts, such as monometallic, bimetallic, trimetallic, combination of metal–metal oxide, carbonaceous and/or metal doped carbon catalysts. Deactivation of catalysts is the prime drawback found in TCD process. Catalyst regeneration and co-feeding of methane with other hydrocarbon are the two solutions put forwarded in accordance to overcome deactivation hurdle. Higher amount of co-feed hydrocarbon in situ produce more amount of highly active carbonaceous deposits which assist further methane decomposition to produce additional hydrogen to a great extent. The methane conversion rate increases with increase in the temperature and decreases with the flow rate in the co-feeding process in a similar manner as observed in normal TCD. The presence of co-components in the post-reaction stream is a key challenge tackled in the co-feeding and regeneration. Hence, this review hypothesizing the integration of hydrogen separation membrane in to methane decomposition reactor for online hydrogen separation.
This review will explore the influences of the active metal, support, promoter, preparation metho... more This review will explore the influences of the active metal, support, promoter, preparation methods, calcination temperature, reducing environment, particle size and reactor choice on catalytic activity and carbon deposition for the dry reforming of methane. Bimetallic (Ni-Pt, Ni-Rh, Ni-Ce, Ni-Mo, Ni-Co) and monometallic (Ni) catalysts are preferred for dry reforming compared to noble metals (Rh, Ru and Pt) due to their low-cost Investigation of support materials indicated that ceria zirconia mixtures, ZrO2 with alkali metals (Mg2+, Ca2+, Y2+) addition, MgO, SBA-15, ZSM-5, CeO2, BaTiO3 and Ca0.8Sr0.2TiO3 showed improved catalytic activities and decreased carbon deposition. The modifying effects of cerium (Ce), magnesium (Mg) and yttrium (Y) were significant for dry reforming of methane. MgO, CeO2 and La2O3 promoters for metal catalysts supported on mesoporous materials had the highest catalyst stability among all the other promoters. Preparation methods played an important role in the synthesis of smaller particle size and higher dispersion of active metals. Calcination temperature and treatment duration imparted significant changes to the morphology of catalysts as evident by XRD, TPR and XPS. Catalyst reduction in different environments (H-2, He, H-2/He, O-2/He, H-2-N-2 and CH4/O-2) indicated that probably the mixture of reducing agents will lead to enhanced catalytic activities. Smaller particle size (<15 nm) had a significant influence on the suppression of carbon deposition and catalytic activity. Fluidized bed reactor exhibited the highest activity and stability, lower carbon deposition and higher conversion compared to a fixed-bed reactor. Moreover, membrane reactor, solar reactor, high-pressure reactor and microreactor were also investigated with specific features such as: pure H-2 production, detailed reaction information with enhanced safety, higher pressure applications and dry reforming reaction with/without catalyst under sunlight The study of parameters would improve the understanding of various preparation and reaction conditions leading to various catalytic activities. (C) 2015 Elsevier Ltd. All rights reserved. http://www.sciencedirect.com/science/article/pii/S1364032115001148http://ac.els-cdn.com/S1364032115001148/1-s2.0-S1364032115001148-main.pdf?_tid=ec2ec800-f3a1-11e4-b188-00000aab0f6b&acdnat=1430883930_9baf6dd90ba614a8cd97dbd610689158
The thermo-catalytic decomposition (TCD) of methane has attracted the attention of numerous resea... more The thermo-catalytic decomposition (TCD) of methane has attracted the attention of numerous researchers’ around the world as an ideal approach for hydrogen production, which in turns, can be used as an appropriate feeding gas in fuel cells operating at low temperatures. The TCD of methane is capable to produce a valuable by–product, pure carbon, which can excessively alleviate the total cost of the process. In this study, we report TCD of methane over 30% Ni supported Y zeolite catalyst at 550 and 600 °C was conducted in a fixed bed reactor and the yield of hydrogen from the reactor was analyzed by GC. As can be observed that, the TCD of methane over Ni-supported Y zeolite showed maximum conversion (31 and 15.90 % at 600 and 550 °C, respectively) at the initial stages and on stream of reaction time, it decreased gradually; and ultimately, deactivated the catalyst completely. The cause for this is the formation of encapsulating carbon on Ni active sites which deactivates the catalyst over the course of reaction time. Hydrogen production rate, carbon accumulation (CA) and carbon formation rate (CFR) were investigated at three representative times for both temperatures. The CFR analysis showed that the growth of filamentous carbon was steady-state at the first stage and then reduced to a relic activity and it remains constant during the rest of the reaction. The descriptive dissemination of methane TCD over Ni-supported Y zeolite has been speculated in this paper.
Catalytic characteristics of activated carbon manufactured from palm shell (ACPS) for methane dec... more Catalytic characteristics of activated carbon manufactured from palm shell (ACPS) for methane decomposition was studied using a thermobalance by measuring thee mass gain with time. A reaction order of 0.5 is obtained for methane decomposition over the activated ...
This study reports the hydrodeoxygenation (HDO) of stearic acid (SA) into paraffinic biofuel with... more This study reports the hydrodeoxygenation (HDO) of stearic acid (SA) into paraffinic biofuel with synthesized palladium-oxalate zeolite supported catalyst (PdOx/Zeol). The PdOx/Zeol was synthesized via the functionalization of dihydrogen tetrachloropalladate (II) with aqueous oxalic acid (OxA) to form the polynuclear palladium(II) oxalate (PdOx), which was supported on zeolite. The SEM and XRD characterization results showed that the zeolite support is highly crystalline but loss some degree of crystallinity in the PdOx/Zeol sample after PdOx incorporation. The activity of the PdOx/Zeol tested on the HDO of SA showed that temperature, pressure, gas flow rate, and PdOx/Zeol loading have significant effects on the HDO process, and their best observed conditions were 360 °C, 20 bar, 100 mL/min, and 25 mg, respectively to achieve 92% biofuel production from 35 g SA. The biofuel product distribution showed 71% n-C18H38, 18% iso-C18H38, and 3% C17H36. The presence of iso-C18H38, which is an excellent biofuel value-added-component due to its low freezing point, was ascribed to the functionalization of Pd with OxA, which increases PdOx/Zeol acidity. The results showed that PdOx/Zeol is a prospective catalyst toward further research and commercialization of HDO process of SA.
catalytic hydrodeoxygenation reaction (HDO). Firstly, thermodynamic simulation studies were carri... more catalytic hydrodeoxygenation reaction (HDO). Firstly, thermodynamic simulation studies were carried out using Aspen Hysys® to establish the process feasibility. The catalyst precursor, molybdenum oxalate (MoOx) was prepared from the reaction of Bis(acetylacetonato)dioxomolybdenum (VI) and oxalic acid in both acidic (pH 2) and basic (pH 10) environment using HF and NaOH as buffers, respectively and incorporated into Al2O3 support. The catalysts characterization results showed that polymeric molybdates [Mo2O5(OH)(C2O4)2]3- and monomeric molybdates [MoO2(OH)2(C2O4)2]4- are the Mo species present on the acidified MoOx/Al2O3 and basic MoOx/Al2O3, respectively according to the Raman spectroscopy and x-ray diffraction. The HDO of SB at 370 °C and 1 bar showed that the basic MoOx/Al2O3 has higher conversion of about 98% nC18 while the acidified MoOx/Al2O3 has comparably lower conversion of 92% nC18 within 35 min of reaction time, but the acidified MoOx/Al2O3 showed higher selectivity of 42% for the production of iso-paraffins (iC18) compared to 34% obtained for the basic MoOx/Al2O3. The high iC18 production was ascribed to the acidity of MoOx/Al2O3 (pH 2) catalyst due to fluoride ion functionalization. This result is encouraging for further research towards industrialization.
Thermocatalytic decomposition of methane (TCD) is a fully green single step technology for produc... more Thermocatalytic decomposition of methane (TCD) is a fully green single step technology for producing hydrogen and nano-carbon. This review studying all development in laboratory-scale research on TCD, especially the recent advances like co-feeding effect and catalyst regeneration for augmenting the productivity of the whole process. Although a great success on the laboratory-scale has been fulfilled, TCD for greenhouse gas (GHG) free hydrogen production is still in its infancy. The need for commercialization of TCD is greater than ever in the present situation of huge GHG emission. TCD usually examined over various kind of catalysts, such as monometallic, bimetallic, trimetallic, combination of metal–metal oxide, carbonaceous and/or metal doped carbon catalysts. Deactivation of catalysts is the prime drawback found in TCD process. Catalyst regeneration and co-feeding of methane with other hydrocarbon are the two solutions put forwarded in accordance to overcome deactivation hurdle. Higher amount of co-feed hydrocarbon in situ produce more amount of highly active carbonaceous deposits which assist further methane decomposition to produce additional hydrogen to a great extent. The methane conversion rate increases with increase in the temperature and decreases with the flow rate in the co-feeding process in a similar manner as observed in normal TCD. The presence of co-components in the post-reaction stream is a key challenge tackled in the co-feeding and regeneration. Hence, this review hypothesizing the integration of hydrogen separation membrane in to methane decomposition reactor for online hydrogen separation.
This review will explore the influences of the active metal, support, promoter, preparation metho... more This review will explore the influences of the active metal, support, promoter, preparation methods, calcination temperature, reducing environment, particle size and reactor choice on catalytic activity and carbon deposition for the dry reforming of methane. Bimetallic (Ni-Pt, Ni-Rh, Ni-Ce, Ni-Mo, Ni-Co) and monometallic (Ni) catalysts are preferred for dry reforming compared to noble metals (Rh, Ru and Pt) due to their low-cost Investigation of support materials indicated that ceria zirconia mixtures, ZrO2 with alkali metals (Mg2+, Ca2+, Y2+) addition, MgO, SBA-15, ZSM-5, CeO2, BaTiO3 and Ca0.8Sr0.2TiO3 showed improved catalytic activities and decreased carbon deposition. The modifying effects of cerium (Ce), magnesium (Mg) and yttrium (Y) were significant for dry reforming of methane. MgO, CeO2 and La2O3 promoters for metal catalysts supported on mesoporous materials had the highest catalyst stability among all the other promoters. Preparation methods played an important role in the synthesis of smaller particle size and higher dispersion of active metals. Calcination temperature and treatment duration imparted significant changes to the morphology of catalysts as evident by XRD, TPR and XPS. Catalyst reduction in different environments (H-2, He, H-2/He, O-2/He, H-2-N-2 and CH4/O-2) indicated that probably the mixture of reducing agents will lead to enhanced catalytic activities. Smaller particle size (<15 nm) had a significant influence on the suppression of carbon deposition and catalytic activity. Fluidized bed reactor exhibited the highest activity and stability, lower carbon deposition and higher conversion compared to a fixed-bed reactor. Moreover, membrane reactor, solar reactor, high-pressure reactor and microreactor were also investigated with specific features such as: pure H-2 production, detailed reaction information with enhanced safety, higher pressure applications and dry reforming reaction with/without catalyst under sunlight The study of parameters would improve the understanding of various preparation and reaction conditions leading to various catalytic activities. (C) 2015 Elsevier Ltd. All rights reserved. http://www.sciencedirect.com/science/article/pii/S1364032115001148http://ac.els-cdn.com/S1364032115001148/1-s2.0-S1364032115001148-main.pdf?_tid=ec2ec800-f3a1-11e4-b188-00000aab0f6b&acdnat=1430883930_9baf6dd90ba614a8cd97dbd610689158
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Papers by Hazzim Abbas
out using Aspen Hysys® to establish the process feasibility. The catalyst precursor, molybdenum
oxalate (MoOx) was prepared from the reaction of Bis(acetylacetonato)dioxomolybdenum (VI) and
oxalic acid in both acidic (pH 2) and basic (pH 10) environment using HF and NaOH as buffers,
respectively and incorporated into Al2O3 support. The catalysts characterization results showed
that polymeric molybdates [Mo2O5(OH)(C2O4)2]3- and monomeric molybdates [MoO2(OH)2(C2O4)2]4-
are the Mo species present on the acidified MoOx/Al2O3 and basic MoOx/Al2O3, respectively
according to the Raman spectroscopy and x-ray diffraction. The HDO of SB at 370 °C and 1 bar
showed that the basic MoOx/Al2O3 has higher conversion of about 98% nC18 while the acidified
MoOx/Al2O3 has comparably lower conversion of 92% nC18 within 35 min of reaction time, but the
acidified MoOx/Al2O3 showed higher selectivity of 42% for the production of iso-paraffins (iC18)
compared to 34% obtained for the basic MoOx/Al2O3. The high iC18 production was ascribed to the
acidity of MoOx/Al2O3 (pH 2) catalyst due to fluoride ion functionalization. This result is encouraging
for further research towards industrialization.
out using Aspen Hysys® to establish the process feasibility. The catalyst precursor, molybdenum
oxalate (MoOx) was prepared from the reaction of Bis(acetylacetonato)dioxomolybdenum (VI) and
oxalic acid in both acidic (pH 2) and basic (pH 10) environment using HF and NaOH as buffers,
respectively and incorporated into Al2O3 support. The catalysts characterization results showed
that polymeric molybdates [Mo2O5(OH)(C2O4)2]3- and monomeric molybdates [MoO2(OH)2(C2O4)2]4-
are the Mo species present on the acidified MoOx/Al2O3 and basic MoOx/Al2O3, respectively
according to the Raman spectroscopy and x-ray diffraction. The HDO of SB at 370 °C and 1 bar
showed that the basic MoOx/Al2O3 has higher conversion of about 98% nC18 while the acidified
MoOx/Al2O3 has comparably lower conversion of 92% nC18 within 35 min of reaction time, but the
acidified MoOx/Al2O3 showed higher selectivity of 42% for the production of iso-paraffins (iC18)
compared to 34% obtained for the basic MoOx/Al2O3. The high iC18 production was ascribed to the
acidity of MoOx/Al2O3 (pH 2) catalyst due to fluoride ion functionalization. This result is encouraging
for further research towards industrialization.