SER Process Variable Evaluation for the Production of Hydrogen using Calcined Dolomite

2011 ◽  
Vol 14 (2) ◽  
pp. 121-126
Author(s):  
A. Lopez-Ortiz ◽  
V. Collins-Martinez ◽  
D. P. Harrison
Keyword(s):  
Fixed Bed ◽  
Catalyst Particle ◽  
Process Variable ◽  
Fixed Bed Reactor ◽  
Particle Sizes ◽  
Gas Composition ◽  
Co2 Diffusion ◽  
Production Of Hydrogen ◽  
Kinetic Effects ◽  
Co2 Absorbent

Reaction performance of the sorption enhanced reforming (SER) process for the production of hydrogen was studied using commercial dolomite as inexpensive solid CO2 absorbent. The combined reforming, shift, and CO2 separation reactions were studied using a laboratory-scale fixed-bed reactor as a function of temperature, feed gas composition, dolomite type, and dolomite and catalyst particle sizes. Reactor was loaded with a mixture of calcined dolomite (≈ 23g) and a commercial reforming catalyst (NiO/Al2O3, ≈ 10g). Temperature was varied from 550 to 650°C at 15 atm. Feed gas composition was varied from 6 to 20% CH4/balance N2 and steam, with a feed H2O/CH4 ratio = 4. Two sources of dolomite were used; Rockwell and Stonelite. Particle sizes of dolomite and catalyst were 75>dp>150 μm and 300>dp>425 μm, respectively and were inversely varied. Results show that at 550°C Ca(OH)2 formation is possible, thus reducing the available CaO for carbonation, negatively affecting the performance of the SER system, while 650°C reached the SER thermodynamic equilibrium (TE). The use of dolomite approached the TE of the feed gas compositions studied, disregarding of its source. Kinetic effects observed in the tests suggest that small dolomite and large catalyst particles favor the decrease of CO2 diffusion effects.

The Mo Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

2012 ◽  
Vol 229-231 ◽  
pp. 126-129 ◽  
Author(s):  
Yan Gao ◽  
Tao Luan ◽  
Tao Lv ◽  
Hong Ming Xu
Keyword(s):  
High Temperature ◽  
Fixed Bed ◽  
Catalytic Efficiency ◽  
Fixed Bed Reactor ◽  
Exhaust Gas ◽  
Impregnation Method ◽  
Gas Composition ◽  
Loading Effect ◽  
Tio2 Catalyst ◽  
Temperature Window

The V(1)-W(4.5)-Mo(x)/TiO2 catalysts was prepared by the incipient dry impregnation method. The catalyst samples were ground and sieved for 0.3~0.6 mm. The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of Mo enhanced the catalytic efficiency of V(1)-W(4.5)-Mo(x)/TiO2 catalysts at low temperature region, while lessened that at high temperature, especially at the temperature above 400 °C. Increasing the loading of Mo from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 78% to 99% and enlarged the temperature window of the catalyst. The acceptable NO conversion (>60%) was attained at temperature as low as 240 °C for V(1)-W(4.5)-Mo(7.5)/TiO2 catalyst. The presence of Mo promoted the N2O generation. The V(1)-W(4.5)-Mo(0)/TiO2 catalyst showed higher catalytic selectivity for NO compared to the catalysts loading Mo.

The W Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

2013 ◽  
Vol 774-776 ◽  
pp. 743-746 ◽  
Author(s):  
Ji Wei Peng ◽  
Tao Luan ◽  
Yan Gao
Keyword(s):  
High Temperature ◽  
Fixed Bed ◽  
Catalytic Efficiency ◽  
Fixed Bed Reactor ◽  
Exhaust Gas ◽  
Gas Composition ◽  
High Temperature Region ◽  
Loading Effect ◽  
Scr Catalysts ◽  
Temperature Window

The SCR catalysts were produced with V2O5, WO3, MoO3and anatase type TiO2. The catalyst samples were ground and sieved for 0.3~0.6mm.The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of W enhanced the catalytic efficiency of V(1)-W(x)-Mo (4.5)/TiO2catalysts at high temperature region, while lessened that at low temperature. Increasing the loading of W from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 88% to 99% and enlarged the temperature window of the catalyst. The presence of W promoted the N2O generation. The V(1)-W(4.5)-Mo (4.5)/TiO2catalyst showed higher catalytic selectivity for NO compared to the catalysts loading W.

Effects of Zn on Steam Gasification Characteristics of Shenhua Lignite Char

2014 ◽  
Vol 1008-1009 ◽  
pp. 252-256
Author(s):  
Wipawan Sangsanga ◽  
Jin Xiao Dou ◽  
Zhe Lei Tong ◽  
Jiang Long Yu
Keyword(s):  
Gas Chromatography ◽  
Catalytic Activity ◽  
Fixed Bed ◽  
Steam Gasification ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Gas Composition ◽  
Gaseous Products ◽  
Lignite Char ◽  
Catalytic Effects

The catalytic effects of Zn on the yield of the gaseous products during steam gasification of lignite char were investigated by using a fixed-bed reactor. The gas composition was measured using a gas chromatography (GC). The experimental results show that Zn has catalytic effects on steam gasification and increased the yield of H2. There was an optimum content of Zn implanted into the coal above which zinc does not show further catalytic activity.

scholarly journals Integrated Ozonation-Enzymatic Hydrolysis Pretreatment of Sugarcane Bagasse: Enhancement of Sugars Released to Expended Ozone Ratio

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1274 ◽  
Author(s):  
Daryl Rafael Osuna-Laveaga ◽  
Octavio García-Depraect ◽  
Ramiro Vallejo-Rodríguez ◽  
Alberto López-López ◽  
Elizabeth León-Becerril
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugarcane Bagasse ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Particle Sizes ◽  
Combined Effects ◽  
Sugar Release ◽  
The Relationship ◽  
Ozonation Process

The combined effects of three key ozonation process parameters on the integrated ozonation-enzymatic hydrolysis pretreatment of sugarcane bagasse (SCB) were investigated, with emphasis on the relationship between sugar release and ozone consumption. A lab-scale fixed bed reactor was employed for ozonation at varying ozone doses (50, 75 and 100 mg O3/g SCB), particle sizes (420, 710 and 1000 µm) and moisture contents (30, 45 and 60% w/w) in multifactorial experiments, keeping a residence time of 30 min. The ozonated SCB showed a reduction in the content of acid-insoluble lignin from 26.6 down to 19.1% w/w, while those of cellulose and hemicellulose were retained above 45.5 and 13.6% w/w, with recoveries of 100–89.9 and 83.5–72.7%, respectively. Ozone-assisted enzymatic hydrolysis allowed attaining glucose and xylose yields as high as 45.0 and 37.8%, respectively. The sugars released/ozone expended ratio ranged between 2.3 and 5.7 g sugars/g O3, being the higher value achieved with an applied ozone input of 50 mg O3/g SCB and SCB with 420 µm particle size and 60% moisture. Such operating conditions led to efficient ozone utilization (<2% unreacted ozone) with a yield of 0.29 g sugars/g SCB. Overall, the amount of sugars released relative to the ozone consumed was improved, entailing an estimated cost of ozonation of USD 34.7/ton of SCB, which could enhance the profitability of the process.

Regeneration of Iron Oxide Sorbent Used for Hot Gas Desulfurization

2011 ◽  
Vol 396-398 ◽  
pp. 1170-1173
Author(s):  
Hui Ling Fan ◽  
Hong Sheng Guo ◽  
Li Tong Liang ◽  
Fang Shen ◽  
Jian Ying Lin ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Red Mud ◽  
Fixed Bed ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Gas Composition ◽  
Hot Gas ◽  
Regeneration Condition ◽  
Hot Gas Desulfurization

Iron oxide sorbent was prepared from red mud and the regeneration behaviors were investigated in a fixed bed reactor. Regeneration parameters including temperature and concentration of oxygen have been considered in order to obtain a suitable regeneration condition. XRD and SEM techniques were used to characterize the fresh and regenerated sorbents. The experimental results show that the sulfided sorbent could be regenerated efficiently using a gas composition of 2% O2-15% H2O- balance N2, at the temperature of 700 °C.

scholarly journals Synthesis of carbon nanotube using ferrocene as carbon source and catalyst in a vertical structured catalyst reactor

2018 ◽  
Vol 67 ◽  
pp. 03038 ◽  
Author(s):  
Praswasti PDK Wulan ◽  
Ghassan Tsabit Rivai
Keyword(s):  
Carbon Nanotube ◽  
Carbon Source ◽  
Gas Phase ◽  
Carbon Deposition ◽  
Fixed Bed ◽  
Catalyst Particle ◽  
Fixed Bed Reactor ◽  
Structured Catalyst ◽  
Catalyst Particle Size

Development of nano-carbon technology in the world has recently occurred due to its excellent electric, thermal, and mechanical properties and it diverse of applications such as electronics, biology, and material. Fixed bed reactor run into blocked due to carbon deposition on the catalyst that cause pressure drop enhancement. Whereas, application of fluidized bed reactor as an alternative of prior reactor have some trouble for complicated of feed flow control that can cause change of catalyst particle size during reaction since agglomeration and adhesion of nanoparticles transpire. Synthesis of carbon nanotube material used a vertical structured catalyst gauze reactor with double furnace system to maintain the catalyst and carbon source in the form of gas phase. This will lead growth of CNT on the surface of the substrate proved by SEM and XRD characterization. Furnace 1 used to ferrocene vaporizer at 400°C and furnace 2 provide substrate placement for CNT growth at 850°C. CNTs characterization confirmed yield and CNT diameter 29.33% and 11.38 nm respectively. Characterization of SEM show that CNT grows on stainless steel type 316 substrate preferable with oxidative heat treatment. Nevertheless, CNTs product still contain many of impurities such as Fe3O4, Fe2O3, Fe3C, hexagonal graphite, and amorphous carbon.

scholarly journals Solar-Driven Thermochemical Water-Splitting by Cerium Oxide: Determination of Operational Conditions in a Directly Irradiated Fixed Bed Reactor

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2451 ◽  
Author(s):  
Lucía Arribas ◽  
José González-Aguilar ◽  
Manuel Romero
Keyword(s):  
Water Splitting ◽  
Cerium Oxide ◽  
Radiation Power ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Solar Simulator ◽  
Operational Conditions ◽  
Concentrated Solar Energy ◽  
Production Of Hydrogen ◽  
Temperature Levels

Concentrated solar energy can be transformed into electricity, heat or even solar fuels, such as hydrogen, via thermochemical routes with high exergetic efficiency. In this work, a specific methodology and experimental setup are described, developed to assess the production of hydrogen by water splitting making use of commercial cerium oxide, ceria (CeO2), in a solarized reactor. A fixed bed reactor, directly irradiated by a 7 kWe high flux solar simulator (HFSS) was used. Released H2 and sample temperature levels were continuously monitored. Three tests were carried out consisting of three consecutive redox cycles each, with irradiances in the range of 1017–2034 kWm−2. It was necessary to achieve a compromise between sample temperatures (higher temperatures lead to higher reduction rates) and sample stability, since absorbed radiation can degrade a sample at lower temperature (1280–1480 °C) than in a conventional infrared oven (T > 2000 °C). Irradiating the surface of the sample with an irradiance of 2034 kWm−2 (270 W of total radiation power) during 9.5 min eventually degraded the sample, resulting in a conversion into stoichiometrically reduced oxide (Ce2O3) of 11%. A similar conversion was achieved (9.7%) after 2 min of irradiation at 270 W (100% of radiation), but without irreversibly damaging the sample.

Production of Hydrogen and Syngas via Steam Gasification of Glycerol in a Fixed-Bed Reactor

2008 ◽  
Vol 49 (1-2) ◽  
pp. 59-67 ◽  
Author(s):  
T. Valliyappan ◽  
D. Ferdous ◽  
N. N. Bakhshi ◽  
A. K. Dalai
Keyword(s):  
Fixed Bed ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Production Of Hydrogen

Steam Gasification of Biochar Derived from Fast Pyrolysis for Hydrogen-Rich Gas Production

2013 ◽  
Vol 830 ◽  
pp. 477-480 ◽  
Author(s):  
Wei Qing Zeng ◽  
Ling Jun Zhu ◽  
Qi Wang
Keyword(s):  
Carbon Number ◽  
Fast Pyrolysis ◽  
Fixed Bed ◽  
Gas Production ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Hydrogen Yield ◽  
Low Carbon ◽  
Production Of Hydrogen ◽  
Pyrolysis Of Biomass

Steam gasification of biochar from fast pyrolysis of biomass was conducted in a fixed bed reactor. The experiments were carried out at temperature of 700, 750, 800 °C with steam flow rate of 0.1 g/min and reaction time of 3 h. The gas products mainly included H2, CO, CO2and some hydrocarbons with low carbon number. The results showed that the conversion of biochar at 700, 750, 800 °C was 68, 78, 96 wt%, respectively, and high gasification temperature favored the production of hydrogen-rich gases. The hydrogen yield increased with temperature rising and reached the maximum of 35.70 mol/kg with a hydrogen concentration of 74 V% at 800 °C.

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