scholarly journals Numerical study of H2S-H2O-air mixture conversion to hydrogen via activation of air by an electric discharge

2018 ◽  
Vol 209 ◽  
pp. 00015
Author(s):  
Ilya Arsentiev ◽  
Vera Savelieva ◽  
Nataliya Titova
Keyword(s):  
Mole Fraction ◽  
Electrical Discharge ◽  
Flow Reactor ◽  
Numerical Study ◽  
Energy Requirement ◽  
Plug Flow ◽  
Relative Yield ◽  
Hydrogen Yield ◽  
Input Energy ◽  
Specific Energy Requirement

The numerical analysis of H2 production during partial oxidation of H2S–H2O–air in a plug-flow reactor at a rather low temperature (T 0=500 K) was conducted. For the reforming process promotion, the oxidizer (air) was activated by an electrical discharge with different values of reduced electric field E/N and input energy E s. It was shown that a significant hydrogen yield in a flow reactor can be obtained only after mixture ignition. The ignition delay length turned out to be minimal at E/N~4–10 and 120–150 Td, when O2(a1Δg) mole fraction in the discharge products is maximal. If the H2S–H2O–air mixture ignites inside the flow reactor, the H2 mole fraction and its relative yield do not depend on E/N. The relative hydrogen yield increases monotonically with an increase of H2O amount. The specific energy requirement for H2 production in considered process was evaluated.

scholarly journals The Effect of Mg and Zn Dopants on Pt/Al2O3 for the Dehydrogenation of Perhydrodibenzyltoluene

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 490
Author(s):  
Rudaviro Garidzirai ◽  
Phillimon Modisha ◽  
Innocent Shuro ◽  
Jacobus Visagie ◽  
Pieter van Helden ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Flow Reactor ◽  
Plug Flow ◽  
Optical Emission ◽  
Catalytic Performance ◽  
Emission Spectrometry ◽  
Hydrogen Yield ◽  
X Ray ◽  
Temperature Programmed

The effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst were investigated for dehydrogenation of perhydrodibenzyltoluene (H18-DBT) as a liquid organic hydrogen carrier. Al2O3 supports were modified with Mg and Zn to produce Mg-Al2O3 and Zn-Al2O3 with a target loading of 3.8 wt.% for dopants. The modified supports were impregnated with chloroplatinic acid solution to produce the catalysts Pt/Al2O3, Pt/Mg-Al2O3 and Pt/Zn-Al2O3 of 0.5 wt.% Pt loading. Thereafter, the catalysts were characterised using inductively coupled plasma- optical emission spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, hydrogen temperature-programmed reduction, carbon-monoxide pulse chemisorption, ammonia temperature-programmed desorption, X-ray diffraction and transmission electron microscopy. The dehydrogenation experiments were performed using a horizontal plug flow reactor system and the catalyst time-on-stream was 22 h. Pt/Mg-Al2O3 showed the highest average hydrogen flowrate of 29 nL/h, while an average of 27 nL/h was obtained for both Pt/Al2O3 and Pt/Zn-Al2O3. This has resulted in a hydrogen yield of 80% for Pt/Mg-Al2O3, 71% for Pt/Zn-Al2O3 and 73% for Pt/Al2O3. In addition, the conversion of H18-DBT ranges from 99% to 92%, Pt 97–90% and 96–90% for Pt/Mg-Al2O3, Pt/Zn-Al2O3 and Pt/Al2O3, respectively. Following the latter catalyst order, the selectivity to dibenzyltoluene (H0-DBT) ranges from 78% to 57%, 75–51% and 71–45%. Therefore, Pt/Mg-Al2O3 showed improved catalytic performance towards dehydrogenation of H18-DBT.

Energetic relationships for crushing of soil clods

2006 ◽  
Vol 2 (1) ◽  
pp. 51-72
Author(s):  
István Patay ◽  
Virág Sándor
Keyword(s):  
Moisture Content ◽  
Specific Energy ◽  
Soil Moisture Content ◽  
Energy Requirement ◽  
Clay Content ◽  
Clay Soils ◽  
Rigid Support ◽  
Soil Plasticity ◽  
Specific Energy Requirement ◽  
The Relationship

Clod crushing is a principal problem with soils of high clay content. Therefore, there is a need for determining the conditions for clod breaking and clod crushing. The objective of the work was to develop a special purpose tool for single clod breaking both by rigid support of the clod and by a single clod supported by soil and to develop a machine for clod crushing. Furthermore, the purpose was to determine the relationship between the specific energy requirement for clod crushing in the function of soil plasticity and the soil moisture content by the means of the developed tool and machine. The main result of the experiments is summarized in a 3D diagram where the specific energy requirement for soil clod crushing is given in the function of the moisture content and the plasticity index for different clay soils.

A stochastic model for two-station hydraulics exhibiting transient impact

1997 ◽  
Vol 36 (5) ◽  
pp. 19-26 ◽  
Author(s):  
J. L. Jacobsen ◽  
H. Madsen ◽  
P. Harremoès
Keyword(s):  
Parameter Estimation ◽  
Flow Reactor ◽  
Deterministic Model ◽  
Plug Flow ◽  
Stochastic Methods ◽  
Sewer System ◽  
Statistical Tool ◽  
Water Level Variation ◽  
Deterministic Description ◽  
Linear Reservoir

The objective of the paper is to interpret data on water level variation in a river affected by overflow from a sewer system during rain. The simplest possible, hydraulic description is combined with stochastic methods for data analysis and model parameter estimation. This combination of deterministic and stochastic interpretation is called grey box modelling. As a deterministic description the linear reservoir approximation is used. A series of linear reservoirs in sufficient number will approximate a plug flow reactor. The choice of number is an empirical expression of the longitudinal dispersion in the river. This approximation is expected to be a sufficiently good approximation as a tool for the ultimate aim: the description of pollutant transport in the river. The grey box modelling involves a statistical tool for estimation of the parameters in the deterministic model. The advantage is that the parameters have physical meaning, as opposed to many other statistically estimated, empirical parameters. The identifiability of each parameter, the uncertainty of the parameter estimation and the overall uncertainty of the simulation are determined.

Efficient Production of Light Olefin Based on Methanol Dehydration: Simulation and Design Improvement

2020 ◽  
Vol 23 ◽  
Author(s):  
S. Majid Abdoli ◽  
Mahsa Kianinia
Keyword(s):  
Dimethyl Ether ◽  
Flow Reactor ◽  
New Technology ◽  
Plug Flow ◽  
Light Olefins ◽  
Efficient Production ◽  
Actual Process ◽  
Light Olefin ◽  
Aspen Hysys ◽  
Improved Design

Background: Ethylene, propylene, and butylene as light olefins are the most important intermediates in the petrochemical industry worldwide. Methanol to olefins (MTO) process is a new technology based on catalytic cracking to produce ethylene and propylene from methanol. Aims and Objective: This study aims to simulate the process of producing ethylene from methanol by using Aspen HYSYS software from the initial design to the improved design. Methods: Ethylene is produced in a two-step reaction. In an equilibrium reactor, the methanol is converted to dimethyl ether by an equilibrium reaction. The conversion of the produced dimethyl ether to ethylene is done in a conversion reactor. Changes have been made to improve the conditions and get closer to the actual process design done in the industry. The plug flow reactor has been replaced by the equilibrium reactor, and the distillation column was employed to separate the dimethyl ether produced from the reactor. Result and Conclusion: The effect of the various parameters on the ethylene production was investigated. Eventually, ethylene is

Enhancing Fenton-like oxidation of crystal violet over Fe/ZSM-5 in a plug flow reactor

2021 ◽  
Author(s):  
Sara Modarresi-Motlagh ◽  
Fatemeh Bahadori ◽  
Mohammad Ghadiri ◽  
Arash Afghan
Keyword(s):  
Crystal Violet ◽  
Flow Reactor ◽  
Plug Flow ◽  
Plug Flow Reactor

Experimental and numerical study of biomass flash pyrolysis in an entrained flow reactor

2010 ◽  
Vol 101 (10) ◽  
pp. 3678-3684 ◽  
Author(s):  
Shaozeng Sun ◽  
Hongming Tian ◽  
Yijun Zhao ◽  
Rui Sun ◽  
Hao Zhou
Keyword(s):  
Flow Reactor ◽  
Numerical Study ◽  
Flash Pyrolysis ◽  
Entrained Flow ◽  
Entrained Flow Reactor

Anaerobic digestion of pineapple pulp and peel in a plug-flow reactor

2012 ◽  
Vol 110 ◽  
pp. 40-47 ◽  
Author(s):  
Pimjai Namsree ◽  
Worakrit Suvajittanont ◽  
Chureerat Puttanlek ◽  
Dudsadee Uttapap ◽  
Vilai Rungsardthong
Keyword(s):  
Anaerobic Digestion ◽  
Flow Reactor ◽  
Plug Flow ◽  
Plug Flow Reactor ◽  
Pineapple Pulp

Autothermal Reforming of Propane Over Ni Catalysts Supported on a Variety of Perovskites

2007 ◽  
Vol 7 (11) ◽  
pp. 4013-4016 ◽  
Author(s):  
SeungSoo Lim ◽  
DongJu Moon ◽  
JongHo Kim ◽  
YoungChul Kim ◽  
NamCook Park ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Storage Capacity ◽  
Flow Reactor ◽  
Oxygen Storage Capacity ◽  
Autothermal Reforming ◽  
Oxygen Storage ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Ni Catalysts ◽  
Atmospheric Flow

Autothermal reforming of propane for hydrogen over Ni catalysts supported on a variety of perovskites was performed in an atmospheric flow reactor. Perovskite is known for its higher thermal stability and oxygen storage capacity, but catalytic activity of itself is low. A sites of the ABO3 structured perovskites were occupied by La while B sites by one of Fe, Co, Ni, and Al by citrate method. The composition of the reactant mixture was H2O/C/O2 = 8.96/1.0/1.1. The changes in the states of the catalysts after reaction were analyzed by XRD, TPD, and TGA. Ni/LaAlO3 catalyst maintained the perovskite structure after reaction. It showed higher hydrogen yield and thermal stability compared to those of the catalysts with Fe, Co, or Ni in B sites. Catalysts prepared by deposition-precipitation (DP) method showed higher activity than those prepared by impregnation method, presumably due to the smaller sizes of the NiO crystal particles.

Sign in / Sign up

Export Citation Format

Share Document