scholarly journals Optimization in the Stripping Process of CO2 Gas Using Mixed Amines

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2202 ◽  
Author(s):  
Pao Chi Chen ◽  
Yan-Lin Lai

The aim of this work was to explore the effects of variables on the heat of regeneration, the stripping efficiency, the stripping rate, the steam generation rate, and the stripping factor. The Taguchi method was used for the experimental design. The process variables were the CO2 loading (A), the reboiler temperature (B), the solvent flow rate (C), and the concentration of the solvent (monoethanolamine (MEA) + 2-amino-2-methyl-1-propanol (AMP)) (D), which each had three levels. The stripping efficiency (E), stripping rate ( m ˙ CO 2 ), stripping factor (β), and heat of regeneration (Q) were determined by the mass and energy balances under a steady-state condition. Using signal/noise (S/N) analysis, the sequence of importance of the parameters and the optimum conditions were obtained, and the optimum operating conditions were further validated. The results showed that E was in the range of 20.98–55.69%; m ˙ CO 2 was in the range of 5.57 × 10−5–4.03 × 10−4 kg/s, and Q was in the range of 5.52–18.94 GJ/t. In addition, the S/N ratio analysis showed that the parameter sequence of importance as a whole was A > B > D > C, while the optimum conditions were A3B3C1D1, A3B3C3D2, and A3B2C2D2, for E, m ˙ CO 2 , and Q, respectively. Verifications were also performed and were found to satisfy the optimum conditions. Finally, the correlation equations that were obtained were discussed and an operating policy was discovered.

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 66
Author(s):  
Ziba Barati ◽  
Sajid Latif ◽  
Sebastian Romuli ◽  
Joachim Müller

In this study, the effect of enzymatic pre-treatment and the size of cassava tubers on mechanical peeling was examined. Cassava tubers were sorted based on their mass as small, medium and large. Viscozyme® L and an abrasive cassava peeling machine was used for the enzymatic pre-treatment and the mechanical peeling, respectively. Response surface methodology (RSM) was used to investigate the effect of the enzyme dose (0.5–1.9 mL g−1), incubation time (1.5–6 h), peeling time (1.5–4.5 min) and size of the tubers (small, medium and large) on the peeling process. Peeled surface area (PSA) and peel loss (PL) were measured as main responses in RSM. Results showed that the PSA and PL were significantly (p < 0.05) influenced by the enzyme dose, incubation time and peeling time. The size of tubers only had a significant impact on the PSA. The optimum operating conditions for different sizes of tubers were found and validated. Under optimum conditions, the PSA of the large tubers (89.52%) was significantly higher than the PSA of the medium and small tubers (p < 0.05). Application of enzymatic pre-treatment can improve the mechanical peeling process especially for larger cassava tubers.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Hany A. Khater ◽  
Amr A. Abdelraouf ◽  
Mohamed H. Beshr

Modeling of an alkaline electrolyzer and a proton exchange membrane fuel cell (PEMFC) is presented. Also, a parametric study is performed for both components in order to determine the effect of variable operating conditions on their performance. The aim of this study is to determine the optimum operating conditions when the electrolyzer and the PEMFC are coupled together as part of a residential solar powered stand-alone power system comprising photovoltaic (PV) arrays, an alkaline electrolyzer, storage tanks, a secondary battery, and a PEMFC. The optimum conditions are determined based on an economic study which is performed to determine the cost of electricity (COE) produced from this system so as to determine the lowest possible COE. All of the calculations are performed using a computer code developed by using MATLAB. The code is designed so that any user can easily change the data concerning the location of the system or the working parameters of any of the system's components to estimate the performance of a modified system. Cairo city in Egypt was used as the place at which the output of the system will be determined. It was found that the optimum operating temperature of the electrolyzer is 25∘C. Also, the optimum coupling pressure of the electrolyzer and the PEMFC is 4 bars. The operating temperature of the PEMFC had a slight effect on its performance while an optimum current density of 400 mA/cm2 was detected. By operating the fuel cell at optimum conditions, its efficiency was found to be 64.66% with a need of 0.5168 Nm3 (Nm3 is a m3 measured at temperature of 0∘C and pressure of 1 bar) of hydrogen to produce 1 kWh of electricity while its cogeneration efficiency was found to be 84.34%. The COE of the system was found to be 49 cents/kWh, at an overall efficiency of 9.87%, for an operational life of 20 years.


Author(s):  
Da-An Huh ◽  
Woo Ri Chae ◽  
Hong Lyuer Lim ◽  
Joung Ho Kim ◽  
Yoo Sin Kim ◽  
...  

Concerns about the widespread use of pesticides have been growing due to the adverse effects of chemicals on the environment and human health. It has prompted worldwide research into the development of a replacement to chemical disinfection of soil. The efficiency of steam sterilization, an alternative to chemical methods, has improved as technology has advanced, and the Agricultural Research and Extension Service in Korea recommends the use of steam sterilization. However, few studies have been conducted on the effects and operating conditions of high-temperature steam disinfection. In this study, we present the optimum operating conditions of a high-steam disinfector, to maximize the cost-effectiveness and removal efficiency of total nematodes and total bacteria in soil using the Box−Behnken design. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis, with coefficients of determination (R2) for each model of 0.9279, 0.9678, and 0.9979. The optimum conditions were found to be a steam temperature of 150.56 °C, running speed of 1.69 m/min, and spray depth of 15.0 cm, with a corresponding desirability value of 0.8367. In the model, these conditions cause the prediction of the following responses: nematode removal efficiency of 93.99%, bacteria removal efficiency of 97.49%, and oil consumption of 70.49 mL/m2. At the optimum conditions for the steam disinfector, the removal efficiencies of nematodes and bacteria were maximized, and the oil consumption was minimized. The results of our study can be used as basic data for efficient soil disinfection using high-temperature steam.


2011 ◽  
Vol 361-363 ◽  
pp. 785-788
Author(s):  
Xin Peng Bai ◽  
Xiao Lei Zhao ◽  
Zhi Yong Guo ◽  
Xiao Qin Liu

A simple and rapid blitzkrieg extraction procedure has been developed and optimized for hexane extraction yield from the noni (Morinda citrifolia L) seed. Several variables that could potentially affect the extraction efficiency, namely, solid: liquid ratio (g /mL), blitzkrieg extraction voltage (V), extracting time (s) have been optimized by means of response surface methodology (RSM). The optimum conditions were the ratio of material to liquid 95g/500mL, blitzkrieg extraction voltage 148V and extracting time 79s. Under the optimum operating conditions, the extraction yield was 10.42 %, a drastic reduction of the blitzkrieg extraction time (79 s vs. 8 h) was achieved, comparable with the reflux extraction.


TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 65-78 ◽  
Author(s):  
W.B.A. (SANDY) SHARP ◽  
W.J. JIM FREDERICK ◽  
JAMES R. KEISER ◽  
DOUGLAS L. SINGBEIL

The efficiencies of biomass-fueled power plants are much lower than those of coal-fueled plants because they restrict their exit steam temperatures to inhibit fireside corrosion of superheater tubes. However, restricting the temperature of a given mass of steam produced by a biomass boiler decreases the amount of power that can be generated from this steam in the turbine generator. This paper examines the relationship between the temperature of superheated steam produced by a boiler and the quantity of power that it can generate. The thermodynamic basis for this relationship is presented, and the value of the additional power that could be generated by operating with higher superheated steam temperatures is estimated. Calculations are presented for five plants that produce both steam and power. Two are powered by black liquor recovery boilers and three by wood-fired boilers. Steam generation parameters for these plants were supplied by industrial partners. Calculations using thermodynamics-based plant simulation software show that the value of the increased power that could be generated in these units by increasing superheated steam temperatures 100°C above current operating conditions ranges between US$2,410,000 and US$11,180,000 per year. The costs and benefits of achieving higher superheated steam conditions in an individual boiler depend on local plant conditions and the price of power. However, the magnitude of the increased power that can be generated by increasing superheated steam temperatures is so great that it appears to justify the cost of corrosion-mitigation methods such as installing corrosion-resistant materials costing far more than current superheater alloys; redesigning biomassfueled boilers to remove the superheater from the flue gas path; or adding chemicals to remove corrosive constituents from the flue gas. The most economic pathways to higher steam temperatures will very likely involve combinations of these methods. Particularly attractive approaches include installing more corrosion-resistant alloys in the hottest superheater locations, and relocating the superheater from the flue gas path to an externally-fired location or to the loop seal of a circulating fluidized bed boiler.


2020 ◽  
Vol 10 (10) ◽  
pp. 3566
Author(s):  
Mary Angélica Ferreira Vela ◽  
Juan C. Acevedo-Páez ◽  
Nestor Urbina-Suárez ◽  
Yeily Adriana Rangel Basto ◽  
Ángel Darío González-Delgado

The search for innovation and biotechnological strategies in the biodiesel production chain have become a topic of interest for scientific community owing the importance of renewable energy sources. This work aimed to implement an enzymatic transesterification process to obtain biodiesel from waste frying oil (WFO). The transesterification was performed by varying reaction times (8 h, 12 h and 16 h), enzyme concentrations of lipase XX 25 split (14%, 16% and 18%), pH of reaction media (6, 7 and 8) and reaction temperature (35, 38 and 40 °C) with a fixed alcohol–oil molar ratio of 3:1. The optimum operating conditions were selected to quantify the amount of fatty acid methyl esters (FAMEs) generated. The highest biodiesel production was reached with an enzyme concentration of 14%, reaction time of 8 h, pH of 7 and temperature of 38 °C. It was estimated a FAMEs production of 42.86% for the selected experiment; however, best physicochemical characteristics of biodiesel were achieved with an enzyme concentration of 16% and reaction time of 8 h. Results suggested that enzymatic transesterification process was favorable because the amount of methyl esters obtained was similar to the content of fatty acids in the WFO.


The Analyst ◽  
1999 ◽  
Vol 124 (5) ◽  
pp. 713-719 ◽  
Author(s):  
R. P. W. Scott ◽  
Thomas E. Beesley

1988 ◽  
Vol 110 (4) ◽  
pp. 472-481 ◽  
Author(s):  
D. C. Sun

A model of the metal V-belt drive (MBD), considering its detailed multiple-band and metal-block structure, and the ratio-change effect during its operation, is constructed and analyzed. A computational scheme is devised that adapts the analysis to the computation of the MBD’s performance for any specified drive-schedule. General performance characteristics of the MBD and an example illustrating its response to a given drive-schedule are presented. The use of the analysis and the computational scheme in the design of the MBD and in finding the optimum operating conditions is discussed.


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