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.

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.

Effects of Several Metals Species on Steam Gasification Behavior of Lignite from Inner Mongolia

2014 ◽  
Vol 953-954 ◽  
pp. 1176-1179
Author(s):  
Yang Li ◽  
Yan Peng Ban ◽  
Quan Sheng Liu ◽  
Meng Zhang ◽  
Ke Duan Zhi ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Metal Catalyst ◽  
Gasification Reactivity ◽  
Char Reactivity ◽  
Shift Reaction ◽  
Water Gas ◽  
Catalytic Effects ◽  
Gasification Temperature

The purpose of this study is to investigate the catalytic effects of different metals in Shengli lignite on the char reactivity. The pyrolysis of Shengli lignite and various metal catalyst loaded coal was investigated in a small fixed-bed reactor, and the gasification activity with steam for different chars was compared as well. The results show that Fe, Ni, Ca and K could effectively lowering the gasification temperature, enhancing the gasification reactivity of SL char. Alkali (K) and alkaline earth (Ca) could be feasibly used as catalysis for the catalytic steam gasification at relatively low temperatures (550~700°C) to produce gases with high H2 (63.2~63.8 v%) and low CO (below 0.9%), and promoting the carbon-water reaction, the water-gas shift reaction to some extent.

Enhanced Yield of Hydrogen From Wastes Using High Temperature Steam Gasification

2005 ◽  
Vol 128 (3) ◽  
pp. 179-185 ◽  
Author(s):  
W. Jangsawang ◽  
A. Klimanek ◽  
Ashwani K. Gupta
Keyword(s):  
Carbon Monoxide ◽  
Fixed Bed ◽  
Calculated Data ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Effect Of Temperature ◽  
Gas Composition ◽  
Wood Pellets ◽  
Feed Composition ◽  
High Yields

Equilibrium calculations using the element potential method have been used to determine optimum conditions for the gasification of wood pellets and to understand the limitations and influence of preheated gasifying agent on the product gas composition. The calculations were carried out under isobaric (1 atm) and isothermal conditions using cellulose as the waste fuel. For each isothermal case results were obtained for the effect of feed gas composition. Various mixtures of steam/cellulose [mol/mol] and oxygen/steam [mol/mol] were examined to determine conditions for high yields of H2 and CO at a given temperature. The yield of hydrogen and carbon monoxide with different input feed composition and temperature of the process are therefore considered. The results showed strong effect of temperature on hydrogen and carbon monoxide yield in the gasified product stream. High temperatures resulted in high yields of hydrogen. Pure steam resulted in higher yields of hydrogen than steam-air gasifying agent. The experimental results using a fixed bed reactor showed good trends with the calculated data. These results assist in the design and development of enhanced hydrogen production from steam gasification of wastes.

scholarly journals Thermochemical Heat Storage in a Lab-Scale Indirectly Operated CaO/Ca(OH)2 Reactor—Numerical Modeling and Model Validation through Inverse Parameter Estimation

2021 ◽  
Vol 11 (2) ◽  
pp. 682
Author(s):  
Gabriele Seitz ◽  
Farid Mohammadi ◽  
Holger Class
Keyword(s):  
Numerical Model ◽  
Gas Flow ◽  
Reaction Rate ◽  
Heat Storage ◽  
Bulk Material ◽  
Fixed Bed ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Thermochemical Heat Storage ◽  
Speed Up

Calcium oxide/Calcium hydroxide can be utilized as a reaction system for thermochemical heat storage. It features a high storage capacity, is cheap, and does not involve major environmental concerns. Operationally, different fixed-bed reactor concepts can be distinguished; direct reactor are characterized by gas flow through the reactive bulk material, while in indirect reactors, the heat-carrying gas flow is separated from the bulk material. This study puts a focus on the indirectly operated fixed-bed reactor setup. The fluxes of the reaction fluid and the heat-carrying flow are decoupled in order to overcome limitations due to heat conduction in the reactive bulk material. The fixed bed represents a porous medium where Darcy-type flow conditions can be assumed. Here, a numerical model for such a reactor concept is presented, which has been implemented in the software DuMux. An attempt to calibrate and validate it with experimental results from the literature is discussed in detail. This allows for the identification of a deficient insulation of the experimental setup. Accordingly, heat-loss mechanisms are included in the model. However, it can be shown that heat losses alone are not sufficient to explain the experimental results. It is evident that another effect plays a role here. Using Bayesian inference, this effect is identified as the reaction rate decreasing with progressing conversion of reactive material. The calibrated model reveals that more heat is lost over the reactor surface than transported in the heat transfer channel, which causes a considerable speed-up of the discharge reaction. An observed deceleration of the reaction rate at progressed conversion is attributed to the presence of agglomerates of the bulk material in the fixed bed. This retardation is represented phenomenologically by mofifying the reaction kinetics. After the calibration, the model is validated with a second set of experimental results. To speed up the calculations for the calibration, the numerical model is replaced by a surrogate model based on Polynomial Chaos Expansion and Principal Component Analysis.

scholarly journals Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3347
Author(s):  
Arslan Mazhar ◽  
Asif Hussain Khoja ◽  
Abul Kalam Azad ◽  
Faisal Mushtaq ◽  
Salman Raza Naqvi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Dry Reforming Of Methane ◽  
Catalyst Stability ◽  
Feed Ratio ◽  
Catalyst Loading ◽  
Impregnation Method

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

Effects of Zn on Pyrolysis Characteristics of Shenhua Lignite

2014 ◽  
Vol 1008-1009 ◽  
pp. 247-251
Author(s):  
Wipawan Sangsanga ◽  
Chuan Na ◽  
Jin Xiao Dou ◽  
Jiang Long Yu
Keyword(s):  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Coal Pyrolysis ◽  
Pyrolysis Gas ◽  
Gaseous Products ◽  
Pyrolysis Characteristics ◽  
Maximum Value ◽  
Product Gas ◽  
Zn Content ◽  
Catalytic Effects

The catalytic effects of Zn on the release of the gaseous products during pyrolysis of Shenhua lignite was investigated by using a fixed-bed quartz reactor. The product gas compositions from the coal pyrolysis were analyzed by a gas chromatography (GC). Experimental results show that Zn had noticeable catalytic effects on lignite pyrolysis. With the increase in Zn content, lignite weight loss increases during pyrolysis. However, there was an optimum content for amount Zn into the coal. Pyrolysis temperature had a great impact on the composition of pyrolysis gas. As the pyrolysis temperature increased, char yield decreased and gas yield increased. There existed a temperature that tar yield reached its maximum value.

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

Catalytic steam gasification of pig compost for hydrogen-rich gas production in a fixed bed reactor

2013 ◽  
Vol 133 ◽  
pp. 127-133 ◽  
Author(s):  
Jingbo Wang ◽  
Bo Xiao ◽  
Shiming Liu ◽  
Zhiquan Hu ◽  
Piwen He ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Gas Production ◽  
Steam Gasification ◽  
Fixed Bed Reactor

scholarly journals Hydrogen Production From Steam Gasification of Palm Kernel Shell Using Sequential Impregnation Bimetallic Catalysts

2021 ◽  
Vol 14 ◽  
pp. 58-62
Author(s):  
Anita Ramli ◽  
Siti Eda Eliana Misi ◽  
Mas Fatiha Mohamad ◽  
Suzana Yusup
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Palm Kernel ◽  
Steam Gasification ◽  
Impregnation Method ◽  
Ni Catalysts ◽  
Palm Kernel Shell ◽  
Calcination Temperatures ◽  
Zeolite Β ◽  
Metal Addition

Zeolite β supported bimetallic Fe and Ni catalysts have been prepared using sequential impregnation method and calcined at temperatures between 500-700 ºC. The catalytic activity of these catalysts in a steam gasification of palm kernel shell was tested in a fixed-bed quartz micro-reactor at 700 ºC. Both Fe and Ni active metals present in FeNi/BEA and NiFe/BEA catalysts are corresponding to Fe2O3 and NiO. Different calcination temperatures and different sequence in metal addition have a significant effect to the catalytic activity where FeNi/BEA (700) shows the highest hydrogen produced than other catalysts.

Steam gasification of selected energy crops in a fixed bed reactor

2010 ◽  
Vol 35 (2) ◽  
pp. 397-404 ◽  
Author(s):  
Adam Smoliński ◽  
Krzysztof Stańczyk ◽  
Natalia Howaniec
Keyword(s):  
Fixed Bed ◽  
Energy Crops ◽  
Steam Gasification ◽  
Fixed Bed Reactor
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