Effect of concentration and gas flow rate on the removal of gas-phase trichloroethylene in a novel packed biofilter

The rate of response of CeO2−δ to changes in gas composition can be systematically manipulated via changes to gas flow rate or material specific surface area.

Download Full-text

Kinetic Aspects of Phosphorus Removal from Electromagnetically Levitated 600 MPa Steel Droplets

Metals ◽

10.3390/met11091460 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1460

Author(s):

Qi Jiang ◽

Guifang Zhang ◽

Yindong Yang ◽

Alexander McLean ◽

Lei Gao

Keyword(s):

Gas Phase ◽

Flow Rate ◽

Phosphorus Removal ◽

Gas Flow ◽

Electromagnetic Levitation ◽

Effect Of Temperature ◽

Gas Flow Rate ◽

Electromagnetically Levitated ◽

Rate Controlling Step ◽

Good Agreement

A kinetic model was developed to study the dephosphorization of 600 MPa steel droplets under electromagnetic levitation conditions. The relationships which were derived from the model between dephosphorization and the influence of temperature and gas flow rate were in good agreement with experimental data. Both temperature and gas flow rate were conducive to the evaporation of phosphorus, with the effect of temperature having a greater influence than that of the gas velocity. The results show that the rate-controlling step for the dephosphorization process was diffusion within the gas phase. This work aims to provide a theoretical basis for process optimization during the dephosphorization of 600 MPa steel.

Download Full-text

Effect of Carrier Gas Flow Rate in Thermal Desorption Process of PCBs Contaminated Soil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.878.731 ◽

2014 ◽

Vol 878 ◽

pp. 731-738 ◽

Cited By ~ 3

Author(s):

Si Hong Bai ◽

Zhi Fu Qi ◽

Jie Liu ◽

Tong Chen ◽

Sheng Yong Lu ◽

...

Keyword(s):

Mass Transfer ◽

Thermal Treatment ◽

Gas Phase ◽

Thermal Desorption ◽

Flow Rate ◽

Gas Flow ◽

Gas Flow Rate ◽

Desorption Process ◽

Carrier Gas ◽

Carrier Gas Flow

A real PCBs contaminated soil was heated at 500°C using pure nitrogen as carrier gas under different flow rate to investigate the influence of carrier gas flow rate on the thermal desorption process. After 1 hour thermal treatment, the residual PCBs in soil decreased and the removal efficiency (RE) of PCBs is up to 95.1%. The distributions of PCBs in soil under different flow rate were identical. The World Health Organization toxic equivalency quantity (WHO TEQ) of PCBs in soil got its lowest value at 400Nml/min. Tetra-and higher chlorinated PCBs desorbed to carrier gas increased with increased flow rate, while the total amount of PCBs, Tri-and lower chlorinated PCBs first increased then decreased. The distributions of PCBs in carrier gas became more closely to the raw soil with increased flow rate. The TEQ of PCBs in carrier gas increased with increased flow rate. Increased flow rate enhanced the mass transfer of PCBs in the soil but shortened the preheating time of carrier gas and the retention time of carries gas, weakening the mass transfer and degradation process in gas phase. The RE of WHO TEQ of PCDDs in treated soil decreased from 86.7% to 83.2% with increased flow rate while the RE of WHO TEQ of PCDFs decreased from 85.4% to 70.0%. After thermal treatment process, the total amount of PCDD/Fs TEQ in soil and carrier gas increase from 43.8% to 18.6% times of that in raw soil. Considering removal efficiency of PCBs and PCDD/Fs and generation of PCDD/Fs in soil and gas phase, an optimized flow rate should be set at about 400Nml/min.

Download Full-text

Numerical Simulation of Gas Phase Reaction for Epitaxial Chemical Vapor Deposition of Silicon Carbide by Methyltrichlorosilane in Horizontal Hot-Wall Reactor

Materials ◽

10.3390/ma14247532 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7532

Author(s):

Botao Song ◽

Bing Gao ◽

Pengfei Han ◽

Yue Yu ◽

Xia Tang

Keyword(s):

Silicon Carbide ◽

Chemical Vapor Deposition ◽

Gas Phase ◽

Flow Rate ◽

Vapor Deposition ◽

Gas Flow ◽

Consumption Rate ◽

Chemical Vapor ◽

Phase Reaction ◽

Gas Flow Rate

Methyltrichlorosilane (CH3SiCl3, MTS) has good performance in stoichiometric silicon carbide (SiC) deposition and can be facilitated at relatively lower temperature. Simulations of the chemical vapor deposition in the two-dimensional horizontal hot-wall reactor for epitaxial processes of SiC, which were prepared from MTS-H2 gaseous system, were performed in this work by using the finite element method. The chemistry kinetic model of gas-phase reactions employed in this work was proposed by other researchers. The total gas flow rate, temperature, and ratio of MTS/H2 were the main process parameters in this work, and their effects on consumption rate of MTS, molar fraction of intermediate species and C/Si ratio inside the hot reaction chamber were analyzed in detail. The phenomena of our simulations are interesting. Both low total gas flow rate and high substrate temperature have obvious effectiveness on increasing the consumption rate of MTS. For all cases, the highest three C contained intermediates are CH4, C2H4 and C2H2, respectively, while the highest three Si/Cl contained intermediates are SiCl2, SiCl4 and HCl, respectively. Furthermore, low total gas flow results in a uniform C/Si ratio at different temperatures, and reducing the ratio of MTS/H2 is an interesting way to raise the C/Si ratio in the reactor.

Download Full-text

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

Energy Technologies & Resource Saving ◽

10.33070/etars.3.2017.01 ◽

2017 ◽

pp. 3-18 ◽

Cited By ~ 1

Author(s):

B.S. Soroka ◽

V.V. Horupa

Keyword(s):

Natural Gas ◽

Flow Rate ◽

Gas Flow ◽

Renewable Energy Sources ◽

Combustion Process ◽

Orifice Diameter ◽

Firing Process ◽

Gas Flow Rate ◽

Gas Combustion ◽

Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

Download Full-text

Sputtering Deposition of VO$lt;inf$gt;2$lt;/inf$gt; Film Using Plasma Emission Monitor as Reactive Gas Flow Rate Feedback Control

Journal of Inorganic Materials ◽

10.15541/jim20150302 ◽

2015 ◽

Vol 30 (11) ◽

pp. 1228 ◽

Cited By ~ 2

Author(s):

WANG Xiao ◽

YAN Lu ◽

LI Ying ◽

CAO Yun-Zhen

Keyword(s):

Feedback Control ◽

Flow Rate ◽

Gas Flow ◽

Plasma Emission ◽

Gas Flow Rate ◽

Sputtering Deposition ◽

Rate Feedback ◽

Reactive Gas

Download Full-text

Analytical methods for determination of aerosols by means of membrane ultrafilters. VIII. Determination of the mean pore size by gas flow rate measurements

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19661152 ◽

1966 ◽

Vol 31 (3) ◽

pp. 1152-1161 ◽

Cited By ~ 5

Author(s):

V. Hampl ◽

K. Spurný

Keyword(s):

Pore Size ◽

Flow Rate ◽

Analytical Methods ◽

Gas Flow ◽

Gas Flow Rate ◽

The Mean

Download Full-text

On the Influence of Fluctuating Flow Rate Upon the Performance and Behaviour of Isothermal Reacting Systems

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19980881 ◽

1998 ◽

Vol 63 (6) ◽

pp. 881-898

Author(s):

Otakar Trnka ◽

Miloslav Hartman

Keyword(s):

Flow Rate ◽

Gas Flow ◽

Fluidized Bed Reactor ◽

Computational Techniques ◽

Continuous Stirred Tank Reactor ◽

Gas Flow Rate ◽

Solid Reaction ◽

Continuous Stirred Tank ◽

And Performance ◽

Reacting Systems

Three simple computational techniques are proposed and employed to demonstrate the effect of fluctuating flow rate of feed on the behaviour and performance of an isothermal, continuous stirred tank reactor (CSTR). A fluidized bed reactor (FBR), in which a non-catalytic gas-solid reaction occurs, is also considered. The influence of amplitude and frequency of gas flow rate fluctuations on reactant concentrations at the exit of the CSTR is shown in four different situations.

Download Full-text