scholarly journals Thermal and Catalytic Cracking of Toluene Using Char from Commercial Gasification Systems

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3764 ◽  
Author(s):  
Cordioli ◽  
Patuzzi ◽  
Baratieri
Keyword(s):  
Catalytic Activity ◽  
Removal Efficiency ◽  
Catalytic Cracking ◽  
Biomass Gasification ◽  
Catalytic Performance ◽  
Heavy Hydrocarbons ◽  
Tar Removal ◽  
Toluene Removal ◽  
Degradation Tests ◽  
Pyrolytic Char

Tar formation hinders the development of biomass gasification technologies. The use of pyrolytic char as a catalyst for removing tar has been widely investigated; its large specific surface area and pores distribution make it a good candidate for the cracking of heavy hydrocarbons. The present work assesses the catalytic activity of char from a commercial gasifier. Thermal degradation tests in N2 and in CO2 proved that the char is suitable for high-temperature applications (catalytic cracking) and showed release of CO and H2, which might affect the catalytic performance of the char when used for tar removal applications. For inspecting the potential of the char for tar removal, toluene was chosen as model tar. Through GC-FID, toluene removal efficiency and the amount of benzene produced from its decomposition were evaluated. Tests up to 1273 K resulted in tar removal efficiencies as high as 99.0%, and empty reactor tests allowed for discerning the effects of thermal and catalytic cracking. The catalytic activity of the char was more pronounced at 1173 K, as char increased the toluene removal efficiency from 39.9% (empty reactor) to 60.3%. The results confirmed that gasification char, like pyrolytic char, has a high potential for catalytic tar removal applications.

scholarly journals The Removal of Biomass Tar Derived Producer Gas by Means of Thermal and Catalytic Cracking Methods

2021 ◽  
Vol 88 (2) ◽  
pp. 147-156
Author(s):  
Hafnee Lateh ◽  
Juntakan Taweekun ◽  
Kittinan Maliwan ◽  
Zainal Alimuddin Zainal Alauddin ◽  
Sukritthira Rattanawilai
Keyword(s):  
Heat Transfer ◽  
Removal Efficiency ◽  
Catalytic Cracking ◽  
Carbon Deposition ◽  
Catalyst Surface ◽  
Biomass Gasification ◽  
Producer Gas ◽  
Tar Removal ◽  
Biomass Tar ◽  
Microwave Assistance

Tar derived from biomass gasification system needs to be eliminated before applying biomass producer gas for avoiding equipment and its gas problems. In this study, thermal and catalytic cracking methods of biomass tar along with microwave assistance in heat transfer were experimented at various temperatures during 650-1,200 °C and residence at 0.24-0.5 s. The results present that high tar removal efficiency by approximately 90 % under thermal cracking treatment and about 98 % with catalytic cracking method. It also shows that the catalytic cracking especially modified catalyst could be lowered carbon deposition on catalyst surface.

scholarly journals A diffusion anisotropy descriptor links morphology effects of H-ZSM-5 zeolites to their catalytic cracking performance

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaoliang Liu ◽  
Jing Shi ◽  
Guang Yang ◽  
Jian Zhou ◽  
Chuanming Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Cracking ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Time Resolved ◽  
Cracking Performance ◽  
Morphology Effect ◽  
Ft Ir ◽  
The Difference ◽  
Dynamics Simulations

AbstractZeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C4 olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.

scholarly journals Preparation and performance study of mixed metal oxide catalyst for catalytic removal of toluene

2021 ◽  
Vol 252 ◽  
pp. 02080
Author(s):  
Hongbo Liu ◽  
Zhiyong Huang ◽  
Wenhao Huang ◽  
Chong Li
Keyword(s):  
Low Temperature ◽  
Metal Oxide ◽  
Removal Efficiency ◽  
Catalytic Performance ◽  
Mixed Metal Oxide ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Mixed Metal ◽  
Toluene Removal ◽  
Catalytic Removal

As important pollutant in VOCs, toluene has serious impact on people's health and ed by using hydrotalcite as precursor due to the characteristics of its unique composition and controllable structure. Thus the technical problems of difficult control of structure and high cost of nano catalyst were solved. The mixed metal oxide was used as catalyst for toluene removal and its catalytic performance was studied. The results show that the hydrotalcite precursor with good structure can be obtained by both co-precipitation and hydrothermal method. The well-structured precursor can be synthesized in the range of mole ratios of 0:2:1 to 2:0:1 by different methods. When the reaction temperature is above 80 °C, the reaction speed is fast and the crystalline of hydrotalcite is high. The removal efficiency of toluene by catalyst assisted low temperature plasma is better than that of single low temperature plasma. The best catalytic removal efficiency of toluene is 42.10%, which is 1.8 times higher than that of single low temperature plasma. The order of catalytic performance of different catalysts and low temperature plasma for toluene removal is as follows: Zn-Mg-Al > Cu-Mg-Al > Mg-Al > Co-Mg-Al.

Recent Progress in Biomass Tar Catalytic Cracking Method Research

2012 ◽  
Vol 608-609 ◽  
pp. 448-452 ◽  
Author(s):  
Jun Tao ◽  
Qiang Lu ◽  
Chang Qing Dong ◽  
Xiao Ze Du
Keyword(s):  
Environmental Pollution ◽  
Low Temperatures ◽  
Catalytic Cracking ◽  
Recent Progress ◽  
Biomass Gasification ◽  
Tar Removal ◽  
Advantages And Disadvantages ◽  
Key Issues ◽  
Biomass Tar ◽  
The Common

A major problem in the current biomass gasification systems is the formation of tar. The condensed tar at low temperatures may cause blockage and pollution of downstream equipments, as well as environmental pollution. Therefore, the removal and conversion of tar are the key issues for biomass gasification. At present, the common methods of tar removal are mainly mechanism methods, thermal cracking and catalytic cracking. In this paper, the catalytic cracking method and its advantages and disadvantages are discussed.

scholarly journals Diffusion anisotropy descriptor revealing morphology effect of H-ZSM-5 zeolite for olefin catalytic cracking

2021 ◽  
Author(s):  
Xiaoliang Liu ◽  
Jing Shi ◽  
Guang Yang ◽  
Jian Zhou ◽  
Chuanming Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Cracking ◽  
Quantitative Description ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Diffusion Anisotropy ◽  
Dynamic Simulations ◽  
Time Resolved ◽  
Zeolite Catalysis ◽  
Morphology Effect

Abstract Zeolite morphology is vital in determining catalytic activity, selectivity and stability in zeolite catalysis, while quantitative description of morphology effect is great challenging but highly desirable. Herein, a descriptor to elucidate the morphology effect is proposed by revealing the diffusion anisotropy in straight and sinusoidal channels of H-ZSM-5 zeolite for olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar nano-sheet morphology were precisely synthesized in which only the length in c-axis varies. It is unexpectedly demonstrated that the catalytic activity and stability can be obviously improved by employing samples with longer length in c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamic simulations, we revealed that the difference in catalytic performance can be attributed to the intracrystalline diffusive propensity in different channels. This work not only provides a clear descriptor revealing morphology effect, but also offers deep insight into design of highly effective zeolite catalysts for olefin catalytic cracking.

scholarly journals Investigation of ZrMnFe/Sepiolite Catalysts on Toluene Degradation in a One-Stage Plasma-Catalysis System

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Jianqi Liu ◽  
Xin Liu ◽  
Jiayao Chen ◽  
Xianying Li ◽  
Tianpeng Ma ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Carbon Balance ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Toluene Degradation ◽  
Plasma Catalysis ◽  
Efficient Catalyst ◽  
Toluene Removal ◽  
Co2 Selectivity ◽  
Constant Energy Density

Toluene removal by double dielectric barrier charge (DDBD) plasma combined with a ZrMnFe/Sepiolite (SEP) catalyst was investigated and compared with the results from Fe/SEP, Mn/SEP and MnFe/SEP ones. All the catalysts were prepared by the impregnation method and characterized by XRD, BET, ICP, SEM, TEM, H2-TPR and XPS. The effect of catalysts on toluene degradation efficiency, carbon balance, CO2 selectivity and residual O3 concentration was studied. The experimental results indicated that the ZrMnFe/SEP catalyst presented the best catalytic performance. This is because of the high content of lattice oxygen contained in its surface, owing to the addition of Zr. When the SIE was 740 J/L, the highest toluene removal efficiency (87%), carbon balance (93%) and CO2 selectivity (51%) were obtained. The ZrMnFe/SEP catalyst had a better ozone inhibition effect than other catalysts. The catalyst has good stability, which the toluene removal efficiency, carbon balance and CO2 selectivity did not decrease significantly after 36 h of work at a constant energy density. The results indicated that the ZrMnFe/SEP catalyst is an efficient catalyst for degradation of toluene by plasma-catalyst measures.

scholarly journals Nanostructure Design and Catalytic Performance of Mo/ZnAl-LDH in Cationic Orchid X-BL Removal

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2390 ◽  
Author(s):  
Yin Xu ◽  
Tingjiao Liu ◽  
Yang Li ◽  
Yun Liu ◽  
Fei Ge
Keyword(s):  
Catalytic Activity ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Air Oxidation ◽  
Preparation Methods ◽  
Temperature And Pressure ◽  
Co Precipitation ◽  
Double Hydroxide

The nanostructure of ZnAl-layered double hydroxide (ZnAl-LDH) was designed to promote the catalytic performance of Mo-based ZnAl-LDH (Mo/ZnAl-LDH) catalysts, in a catalytic wet air oxidation (CWAO) process, under room temperature and pressure, in degradation of dye wastewater. Four most commonly used preparation methods, traditional precipitation (TP), hydrothermal synthesis (HS), sol-gel (SG), and urea co-precipitation (UC) were employed to prepare the ZnAl-LDH. The resulting Mo/ZnAl-LDH samples were contrasted through surface area, crystal structure, chemical state, and morphology. The degradation of cationic orchid X-BL, under room temperature and pressure, was developed to determine the catalytic activity of these Mo/ZnAl-LDH samples. The results showed that the nanostructure of ZnAl-LDH, prepared by HS, enhanced the adhesion of the catalytic active component, thus Mo/ZnAl-LDH had the highest catalytic activity of 84.2% color removal efficiency and 73.9% total organic carbon removal efficiency. Specific Mo species, such as Na2Mo2O7, Mo dispersion, and O2− ions were proved to be related with catalytic performance. These findings preliminarily clarified that LDHs preparation methods make a difference in the performance of Mo/LDHs.

Investigation of 64%Ni on SiO2-Al2O3 Catalyst as Tar Removal Catalysts for Biomass Gasification

2009 ◽  
Author(s):  
Viboon Sricharoenchaikul ◽  
Sildara Thassanaprichayanont ◽  
Duangduen Atong
Keyword(s):  
Reaction Temperature ◽  
Fixed Bed ◽  
Complex Mixture ◽  
Biomass Gasification ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Tar Removal ◽  
Interesting Approach ◽  
Shift Reaction ◽  
Al2o3 Catalyst

Biomass gasification is a recognized process that may generate synthesis gas (H2+CO) from renewable resources. During gasification, a complex mixture of condensable hydrocarbons or tar compounds form; this can interfere with downstream utilization technologies and also reduce gasification efficiency. Catalytic tar conversion of these compounds to additional product gas is technically and economically interesting approach to reduce or to eliminate tar in product stream. In this paper, 64% Ni on SiO2-Al2O3 catalyst was used as tar removal catalyst. The catalytic performance of this catalyst was evaluated by the conversion of benzene as a model of tar component using a fixed bed reactor. The process variables including reaction temperature 500, 600 and 700°C, Amount of steam added in the cracking and reforming reactions of 1.44 and 2.88 vol.%. The reactor effluent was analyzed by on-line FTIR for CO, CO2, CH4, and other hydrocarbons. Part of the gas product was collected in sample vials for concurrent analysis by GC. The results indicated that the highest conversion of benzene and superior ratio of [CO] to [CO2] may be obtained from at 700°C reaction temperature and 1.44% volume of H2O where 91.2% conversion and ratio of 18.1 may be obtained, respectively. Generally, the distribution of produced gas was greater than the data predicted by equilibrium calculation according to water-gas shift reaction.

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