scholarly journals Experimental and Kinetic Studies on Steam Gasification of a Biomass Char

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7229
Author(s):  
Shengguo Zhao ◽  
Liang Ding ◽  
Yun Ruan ◽  
Bin Bai ◽  
Zegang Qiu ◽  
...  
Keyword(s):  
Kinetic Modeling ◽  
Catalytic Effect ◽  
Steam Gasification ◽  
Magnetic Suspension ◽  
Fixed Bed Reactor ◽  
Pore Model ◽  
Gasification Rate ◽  
Biomass Char ◽  
The Impact ◽  
Random Pore Model

The maximum gasification rate of corn stalk char (CSC) appeared at high conversion range, and its quite different gasification behaviors from other carbonaceous materials are all derived from the catalytic effect of alkali and alkali earth metals (AAEMs), so it is necessary to study the effect of AAEMs and gasification kinetics of such biomass char. However, there are few systematic discussions about this effect and kinetic modeling. Thus, in this study, CSC samples were prepared in a fast pyrolysis fixed-bed reactor, and its gasification experiments were conducted on a pressurized magnetic suspension balance at various total pressures (0.1–0.7 MPa), steam concentrations (10–70 vol.%) and temperatures (725–900 °C). Moreover, a water-leached CSC (H2O-CSC) was also prepared to evaluate the impact of AAEMs on the gasification performance of CSC, and some well-known models were adopted to describe the gasification behaviors. On the basis of these results, the effect of primary AAEMs on the gasification behaviors of CSC and gasification kinetic modeling were obtained. Results showed total pressure had no obvious influence on the gasification rate of CSC, and the reaction order varied at 0.43–0.55 with respect to steam partial pressures. In addition, the modified random pore model (MRPM) and Langmuir–Hinshelwood (L-H) model were satisfactorily applied to predict the gasification behaviors of CSC. The catalytic effect of AAEMs on CSC gasification was weakened due to water-leaching treatment. A random pore model (RPM) could describe the gasification behavior of H2O-CSC well, followed by grain model (GM) and volumetric model (VM).

CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels

2009 ◽  
Author(s):  
Mayank Kumar ◽  
Cheng Zhang ◽  
Rory F. D. Monaghan ◽  
Simcha L. Singer ◽  
Ahmed F. Ghoniem
Keyword(s):  
Cfd Simulation ◽  
Quantitative Description ◽  
Core Model ◽  
Diffusion Control ◽  
Shrinking Core Model ◽  
Carbon Conversion ◽  
Pore Model ◽  
Shrinking Core ◽  
The Impact ◽  
Random Pore Model

In this work, we use a CFD package to model the operation of a coal gasifier with the objective of assessing the impact of devolatilization and char consumption models on the accuracy of the results. Devolatilization is modeled using the Chemical Percolation Devolitilization (CPD) model. The traditional CPD models predict the rate and the amount of volatiles released but not their species composition. We show that the knowledge of devolatilization rates is not sufficient for the accurate prediction of char consumption and a quantitative description of the devolatilization products, including the chemical composition of the tar, is needed. We incorporate experimental data on devolatilization products combined with modeling of the tar composition and reactions to improve the prediction of syngas compositions and carbon conversion. We also apply the shrinking core model and the random pore model to describe char consumption in the CFD simulations. Analysis of the results indicates distinct regimes of kinetic and diffusion control depending on the particle radius and injection conditions for both char oxidation and gasification reactions. The random pore model with Langmuir-Hinshelwood reaction kinetics are found to be better at predicting carbon conversion and exit syngas composition than the shrinking core model with Arrhenius kinetics. In addition, we gain qualitative and quantitative insights into the impact of the ash layer surrounding the char particle on the reaction rate.

A Modified Random Pore Model for Gasification Kinetics of Coal Char and Biomass Char

2015 ◽  
pp. 841-848
Author(s):  
Guang-wei Wang ◽  
Jian-liang Zhang ◽  
Wei-wei Geng ◽  
Jiu-gang Shao
Keyword(s):  
Coal Char ◽  
Pore Model ◽  
Biomass Char ◽  
Kinetics Of ◽  
Random Pore Model

A Modified Random Pore Model for Gasification Kinetics of Coal Char and Biomass Char

2015 ◽  
pp. 841-848
Author(s):  
Guang-Wei Wang ◽  
Jian-Liang Zhang ◽  
Wei-Wei Geng ◽  
Jiu-gang Shao
Keyword(s):  
Coal Char ◽  
Pore Model ◽  
Biomass Char ◽  
Kinetics Of ◽  
Random Pore Model

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

Languages on Stage: Linguistic Pluralism and Community Formation in the Nineteenth-Century Parsi Theatre

2003 ◽  
Vol 37 (2) ◽  
pp. 381-405 ◽  
Author(s):  
Kathryn Hansen
Keyword(s):  
Catalytic Effect ◽  
Community Formation ◽  
Economic Base ◽  
Modern Drama ◽  
Dominant Form ◽  
Middle Classes ◽  
Indian Cinema ◽  
The Masses ◽  
Commercial Organization ◽  
The Impact

The Parsi theatre was the dominant form of dramatic entertainment in urban India from the 1860s to the 1930s. Named for its Bombay-based pioneers, the Parsi theatre blended certain European practices of stagecraft and commercial organization with Indic, Persian, and English stories, music, and poetry. Through the impact of its touring companies, it had a catalytic effect on the development of modern drama and regional theatre throughout South and Southeast Asia. Moreover, Parsi theatre is widely credited with contributing to popular Indian cinema its genres, aesthetic, and economic base. With Hindi films now the major cultural signifier for the middle classes and the ‘masses’ in South Asia and its diaspora, documentation and evaluation of the Parsi theatre is much needed, especially to connect it convincingly to the cinematic medium that followed.

scholarly journals Understanding the Impact of Hydrogen Activation by SrCe0.8Zr0.2O3−δ Perovskite Membrane Material on Direct Non-Oxidative Methane Conversion

2022 ◽  
Vol 9 ◽  
Author(s):  
Sichao Cheng ◽  
Su Cheun Oh ◽  
Mann Sakbodin ◽  
Limei Qiu ◽  
Yuxia Diao ◽  
...  
Keyword(s):  
Methane Conversion ◽  
Membrane Reactor ◽  
Membrane Reactors ◽  
Fixed Bed Reactor ◽  
Perovskite Oxide ◽  
Oxide Material ◽  
Hydrogen Activation ◽  
Permeable Membrane ◽  
The Impact

Direct non-oxidative methane conversion (DNMC) converts methane (CH4) in one step to olefin and aromatic hydrocarbons and hydrogen (H2) co-product. Membrane reactors comprising methane activation catalysts and H2-permeable membranes can enhance methane conversion by in situ H2 removal via Le Chatelier's principle. Rigorous description of H2 kinetic effects on both membrane and catalyst materials in the membrane reactor, however, has been rarely studied. In this work, we report the impact of hydrogen activation by hydrogen-permeable SrCe0.8Zr0.2O3−δ (SCZO) perovskite oxide material on DNMC over an iron/silica catalyst. The SCZO oxide has mixed ionic and electronic conductivity and is capable of H2 activation into protons and electrons for H2 permeation. In the fixed-bed reactor packed with a mixture of SCZO oxide and iron/silica catalyst, stable and high methane conversion and low coke selectivity in DNMC was achieved by co-feeding of H2 in methane stream. The characterizations show that SCZO activates H2 to favor “soft coke” formation on the catalyst. The SCZO could absorb H2in situ to lower its local concentration to mitigate the reverse reaction of DNMC in the tested conditions. The co-existence of H2 co-feed, SCZO oxide, and DNMC catalyst in the present study mimics the conditions of DNMC in the H2-permeable SCZO membrane reactor. The findings in this work offer the mechanistic understanding of and guidance for the design of H2-permeable membrane reactors for DNMC and other alkane dehydrogenation reactions.

scholarly journals STEAM GASIFICATION OF SOME MONGOLIAN COALS

2017 ◽  
pp. 48-51
Author(s):  
Tungalagtamir B ◽  
Enkhtsetseg E ◽  
Chao Lumen ◽  
Narantsetseg M ◽  
Avid B ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Bituminous Coal ◽  
Steam Gasification ◽  
Coal Deposits ◽  
Gasification Rate ◽  
Product Gas ◽  
N2 Atmosphere ◽  
Carbon Dioxide Concentrations ◽  
Stainless Steel Reactor ◽  
Scale Reactor

The gasification tests for the Alagtolgoi and Ailbayan coal deposits were conducted in the temperature up to 850°C using bench scale reactor in order to evaluate product gas composition. Prior to the gasification experiments, the raw coal was pyrolysed in a stainless steel reactor under N2 atmosphere at a temperature of 500°C for 1 h. General behavior of the coal conversion was quite similar for both coals. The gasification tests show that an increase in temperature enhances the formation of hydrogen, carbon dioxide and carbon monoxide. The highest yield of hydrogen and carbon dioxide concentrations of the Ailbayan coal are achieved at temperature of 850°C, which were 2.859 mmol⋅g-1⋅min-1 and 1.054 mmol⋅g-1⋅min-1 respectively. However maximum rate of hydrogen for Alagtolgoi subbituminous coal reached around 800°C. Overall results show that the maximum gasification rate is reached earlier for subbituminous coal than for bituminous coal, but product gas evolution was higher for the investigated bituminous coal.

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

Reactivation of the Spent Residue Fluid Catalytic Cracking (RFCC) Catalyst through Acid Treatment for Palm Oil Cracking to Biofuels

Teknik ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 218-225
Author(s):  
Rahma Amalia ◽  
Teguh Riyanto ◽  
Istadi Istadi
Keyword(s):  
Palm Oil ◽  
Catalytic Cracking ◽  
Acid Treatment ◽  
Catalytic Performance ◽  
Gasoline Fraction ◽  
Fluid Catalytic Cracking ◽  
Fixed Bed Reactor ◽  
X Ray ◽  
Oil Cracking ◽  
The Impact

This work discusses the treated spent Residue Fluid Catalytic Cracking (RFCC) catalysts using sulfuric or citric acids to examine the impact of acid treatment on the catalyst physicochemical properties and structural characteristics. The catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and Brunauer−Emmett−Teller-Barrett−Joyner−Halenda (BET-BJH) methods. The catalytsts were performed in a continuous fixed-bed reactor for catalytic cracking of palm oil. Changes of the catalyst characteristics and catalytic performance testing of the catalyst after the acid treatment for palm oil cracking process were discussed. It was found that the acid treatment on the spent RFCC catalyst can increase the surface area and pore volume of catalysts as well as the crystallinity. The closed pores in the spent RFCC are opened by acid treatment by eliminating heavy metals. Concerning to the catalytic performance, the acid-treated catalysts had better performance than the non-treated catalyst, which could increase selectivity of the kerosene-diesel range fraction from 47.89% to 55.41%. It was interested, since the non-treated catalyst could not produce gasoline fraction, while the acid-treated catalsysts could produce gasoline fraction at selectivity range of 0.57 – 0.84%. It was suggested that both sulfuric or citric acids treatment could increase the cracking performance of spent RFCC catalyst by shifting the product to lower hydrocarbons.

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