Optimization analysis of hydrogen separation from an H2/CO2 gas mixture via a palladium membrane with a vacuum using response surface methodology

Author(s):  
Wei-Hsin Chen ◽  
Kuan-Hsiang Chen ◽  
Jenn-Kun Kuo ◽  
Ayyadurai Saravanakumar ◽  
Kit Wayne Chew
2017 ◽  
Vol 14 (1) ◽  
Author(s):  
M. A. Ahmad ◽  
N. K. A. Rashid ◽  
B. H. Hameed

Response surface methodology (RSM) was used to determine the optimum preparation conditions of polyetherimide based carbon molecular sieve (CMS) membranes. Two quadratic models were developed to correlate the pyrolysis temperature, pyrolysis time and polymer concentration to the responses; CO2 permeance and CO2/CH4permselectivity. According to the optimization analysis, the optimum preparation conditions were obtained by using pyrolysis temperature of 725°C, pyrolysis time of 3.0 h and polymer concentration of 8.52%, which resulted in CO2 permeance and CO2/CH4 permselectivity of 3.61×10–10 mol/m2.s.Pa and 4.35, respectively.


2021 ◽  
Vol 11 (24) ◽  
pp. 11638
Author(s):  
Bingbing Wang ◽  
Xiangjie Lu ◽  
Sha Tao ◽  
Yanzhao Ren ◽  
Wanlin Gao ◽  
...  

Carbon dioxide (CO2) enrichment in an agricultural environment has been shown to enhance the efficiency of crop photosynthesis, increasing crop yield and product quality. There is a problem of the excessive use of CO2 gas when the CO2 is enriched for crops, such as soybean and other field crops. Given the application of micro-nanobubbles (MNBs) in agricultural production, this research takes CO2 as the gas source to prepare the micro-nanobubble water by the dissolved gas release method, and the response surface methodology is used to optimize the preparation process. The results show that the optimum parameters, which are the gas–liquid ratio, generator running time, and inlet water temperature for the preparation of CO2 micro-nanobubble water, are 2.87%, 28.47 min, and 25.52 °C, respectively. The CO2 content in the MNB water prepared under the optimum parameters is 7.64 mg/L, and the pH is 4.08. Furthermore, the particle size of the bubbles is mostly 255.5 nm. With the extension of the storage time, some of the bubbles polymerize and spill out, but there is still a certain amount of nanoscale bubbles during a certain period. This research provides a new idea for using MNB technology to increase the content and lifespan of CO2 in water, which will slow the release and increase the utilization of CO2 when using CO2 enrichment in agriculture.


2017 ◽  
Vol 7 (2) ◽  
pp. 1504-1514
Author(s):  
A. Rastbood ◽  
Y. Gholipour ◽  
A. Majdi

The main objective of this paper is to optimize the geometrical and engineering characteristics of concrete segments of tunnel lining using Finite Element (FE) based Response Surface Methodology (RSM). Input data for RSM statistical analysis were obtained using FEM. In RSM analysis, thickness (t) and elasticity modulus of concrete segments (E), tunnel height (H), horizontal to vertical stress ratio (K) and position of key segment in tunnel lining ring (θ) were considered as input independent variables. Maximum values of Mises and Tresca stresses and tunnel ring displacement (UMAX) were set as responses. Analysis of variance (ANOVA) was carried out to investigate the influence of each input variable on the responses. Second-order polynomial equations in terms of influencing input variables were obtained for each response. It was found that elasticity modulus and key segment position variables were not included in yield stresses and ring displacement equations, and only tunnel height and stress ratio variables were included in ring displacement equation. Finally optimization analysis of tunnel lining ring was performed. Due to absence of elasticity modulus and key segment position variables in equations, their values were kept to average level and other variables were floated in related ranges. Response parameters were set to minimum. It was concluded that to obtain optimum values for responses, ring thickness and tunnel height must be near to their maximum and minimum values, respectively and ground state must be similar to hydrostatic conditions.


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