scholarly journals Simultaneous effect of cathode potentials and magnetite concentrations on methanogenesis of acetic acid under different ammonia conditions

2021 ◽  
Vol 27 (6) ◽  
pp. 210317-0
Author(s):  
Arma Yulisa ◽  
Joonyeob Lee ◽  
Sang Hyeok Park ◽  
Seokhwan Hwang
Keyword(s):  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Total Ammonia ◽  
External Power ◽  
Biodegradation Product ◽  
Face Centered ◽  
The Stability ◽  
Acetate Degradation ◽  
Composite Face ◽  
Central Composite

Electromethanogenesis (EM) is a system that facilitates direct interspecies electron transfer (DIET) in anaerobic digestion (AD) by providing an external power supply to favor desired reactions. Substrates of AD commonly contain ammonia (NH3) as biodegradation product of nitrogen-rich compounds that can deteriorate the stability of AD process. Optimized cathode potential (VCAT) and magnetite (Mag) concentration ([Mag]) are expected to improve AD efficiency in the presence of NH3. Response surface analysis with central composite face-centered design was used in this study to investigate the effect of VCAT and [Mag] under different total ammonia nitrogen concentration ([TAN]). Highest cumulative methane production was achieved at VCAT = -737.4 mV, [Mag] = 18.2 mM, and [TAN] = 1.5 g/L; highest acetate degradation rate was achieved at VCAT = 757.6 mV, [Mag] = 21.4 mM, and [TAN] = 1.5 g/L. The study demonstrated that VCAT promotes either microbial growth or electrochemical NH3 removal. A Shift from acetoclastic to hydrogenotrophic pathway was also observed by the increase of hydrogenotrophic methanogen populations at the end of experiment. This study is beneficial for process control of AD under different NH3 conditions.

scholarly journals OPTIMIZING THE PROCESS OF TRANSFORMING COFFEE HUSKS INTO BIOCHAR BY MEANS OF HYDROTHERMAL CARBONIZATION

2018 ◽  
Vol 54 (4B) ◽  
pp. 138
Author(s):  
Tran Thi Hien
Keyword(s):  
Maximum Yield ◽  
Hydrothermal Carbonization ◽  
Optimal Conditions ◽  
Coffee Husk ◽  
Optimal Value ◽  
Face Centered ◽  
Composite Face ◽  
Temperature Time ◽  
Central Composite ◽  
Water Ratio

The conditions of the hydrothermal carbonization process to produce biochar from coffee husk will be optimized for maximum yield. Besides, response surface methodology (RSM) and central composite face-centered (CCF) method will be used in designing experiments. Also, the optimal value of factors such as temperature, time and biomass: water ratio which can provide a maximum yield of biochar will be worked out using Modde 5.0. As a result, the optimal conditions for maximum yield of biochar was obtained as temperature of 180 oC, 3.5 h and biomass: water ratio of 15 %. It can also be concluded that temperature has greater impact on the transformation of biochar than time and biomass: water ratio.

Liquefaction of almond husk for assessment as feedstock to obtain valuable bio-oils

2019 ◽  
Vol 91 (7) ◽  
pp. 1177-1190
Author(s):  
Maria Margarida Mateus ◽  
Sandro Matos ◽  
Dinis Guerreiro ◽  
Paulo Debiagi ◽  
Daniela Gaspar ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Reaction Model ◽  
Effect Of Temperature ◽  
Acid Catalyzed ◽  
Face Centered ◽  
Liquefaction Process ◽  
Favorable Conditions ◽  
Almond Husk ◽  
Composite Face ◽  
Central Composite

Abstract Almond husk liquefaction can be envisaged as an alternative to fossil sources which are becoming exhausted. Lately, the polyols obtain from the lignocellulosic biomass have been under investigation for the production of sustainable chemicals, fuel, materials or other commodities. Within this context, acid-catalyzed liquefaction of such lignocellulosic biomass has been successfully used to access highly functionalized compounds that can be used to replace those produced from petroleum. Almond shells waste can be considered to be part of the lignocellulosic biomass. Its main constituents of are cellulose, hemicellulose, and lignin. In this assay, the biochemical composition of almond husk was estimated based on atomic mass balances, and at the same time, the pyrolysis outcome was also estimated using a kinetic model using some reference compounds. In order to evaluate the use of almond waste as a substrate for acid-catalyzed liquefaction, the most favorable conditions of the liquefaction process were investigated. To better understand the liquefaction process, response surface methodology, in particular, central composite face-centered factorial design was used to set an array of 17 experiments including three replications at the center point leading to the development of a reaction model for further prediction and optimization of the liquefaction outcome. The effect of temperature (120–150 °C), time (20–200 min) and catalyst amount (0.5–5 wt. %) was investigated and a predictive model established.

scholarly journals Investigation on Fabrication of SS316 Gear by Wire-EDM

2021 ◽  
Vol 346 ◽  
pp. 01044
Author(s):  
Kapil Gupta
Keyword(s):  
Low Cost ◽  
Equal Importance ◽  
Dimensional Deviation ◽  
Cutting Rate ◽  
Predicted Values ◽  
Face Centered ◽  
Traditional Manufacturing ◽  
High Level ◽  
Composite Face ◽  
Central Composite

Manufacturing of miniature gears with good accuracy and quality, and at low cost is a challenging task for traditional manufacturing processes. Wire-cut electric discharge machining (WEDM) has the capacity to machine any conductive material to fabricate typical shaped products like gears with high level of accuracy and quality. In present research, stainless steel (SS) alloy 316 is used to fabricate miniature gears by WEDM. The experimental array is designed according to Response Surface Methodology (RSM) based central composite face centered (CCFC). Four input parameters namely servo feed (SF), duty factor (DF), servo voltage (SV) and wire feed (WF) with three levels each are used for experimental array to investigate the process performance in terms of cutting rate (CR), and product i.e. gear quality in terms of mean roughness depth (Rz) and dimensional deviation (DD). After WEDM parameter optimization, confirmation experiments are performed at the parametric setting by considering equal importance to all response variables. A very close agreement between the experimental and predicted values have been observed.

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