scholarly journals Biogas Dry Reforming for Hydrogen through Membrane Reactor Utilizing Negative Pressure

Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 194-209
Author(s):  
Akira Nishimura ◽  
Tomohiro Takada ◽  
Satoshi Ohata ◽  
Mohan Lal Kolhe
Keyword(s):  
Energy Source ◽  
Reaction Temperature ◽  
Negative Pressure ◽  
Membrane Reactor ◽  
Reaction Chamber ◽  
Dry Reforming ◽  
Molar Ratio ◽  
Effect Of Pressure ◽  
The Impact

Biogas, consisting of CH4 and CO2, is a promising energy source and can be converted into H2 by a dry reforming reaction. In this study, a membrane reactor is adopted to promote the performance of biogas dry reforming. The aim of this study is to investigate the effect of pressure of sweep gas on a biogas dry reforming to get H2. The effect of molar ratio of supplied CH4:CO2 and reaction temperature is also investigated. It is observed that the impact of psweep on concentrations of CH4 and CO2 is small irrespective of reaction temperature. The concentrations of H2 and CO increase with an increase in reaction temperature t. The concentration of H2, at the outlet of the reaction chamber, reduces with a decrease in psweep. It is due to an increase in H2 extraction from the reaction chamber to the sweep chamber. The highest concentration of H2 is obtained in the case of the molar ratio of CH4:CO2 = 1:1. The concentration of CO is the highest in the case of the molar ratio of CH4:CO2 = 1.5:1. The highest sweep effect is obtained at reaction temperature of 500 °C and psweep of 0.045 MPa.

Application of Response Surface Methodology for Optimization of Biodiesel Production from Microalgae Through Nanocatalytic Transesterification Process.

2021 ◽  
Author(s):  
Vaishali Mittal ◽  
Uttam Kumar Ghosh
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Process Parameters ◽  
Reaction Temperature ◽  
Methyl Esters ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Impregnation Method ◽  
The Impact

Abstract Production of biodiesel from microalgae is gaining popularity since it does not compromise food security or the global economy. This article reports biodiesel production with Spirulina microalgae through nanocatalytic transesterification process. The nanocatalyst calcium methoxide Ca(OCH3)2 was synthesized using wet impregnation method and utilized to carry out the transesterification process. The nanocatalyst was characterized to evaluate its structural and spectral characteristics using different characterization techniques such as Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Brunaeur-Emmett-Teller(BET) measurement for surface area. The result demonstrates that calcium methoxide Ca(OCH3)2 possesses a high catalytic activity compared to a heterogeneous catalyst such as calcium oxide (CaO). The impact of several process parameters such as reaction temperature, the molar ratio of methanol to oil, catalyst concentration, and reaction time used in the transesterification process was optimized by employing central composite design(CCD) based response surface methodology(RSM). The polynomial regression equation of second order was obtained for methyl esters. The model projected a 99% fatty acid methyl esters (FAME) yield for optimal process parameters of reaction time 3hrs,3 wt.% of Ca(OCH3)2 catalyst loading, 80°C reaction temperature, and 30:1 methanol to oil molar ratio.

Modeling of dry reforming of methane for hydrogen production at low temperatures using membrane reactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Cheng-Yang Lu ◽  
Rei-Yu Chein
Keyword(s):  
Reaction Temperature ◽  
Membrane Reactor ◽  
Catalyst Activity ◽  
Dry Reforming ◽  
Operating Conditions ◽  
Dry Reforming Of Methane ◽  
Membrane Thickness ◽  
Hydrogen Yield ◽  
Carbon Formation ◽  
Reactor Operation

Abstract The hydrogen removal and carbon formation effects in dense palladium (Pd)-based membrane reactors for dry reforming of methane (DRM) performance is numerically analyzed in this study. The steady-state membrane reactor operation is described using a three-dimensional, heterogeneous, non-isothermal mathematical model. Based on the numerical simulation results for reaction temperature and pressure varied in the 400–600 °C and 1–30 atm ranges, methane conversion and hydrogen yield were found enhanced using the membrane reactor. However, carbon formation, which affects catalyst activity and limits the benefits of using a membrane reactor is also enhanced. A parametric study using reaction pressure as the primary parameter for the membrane reactor operation found that the CH4 conversion, hydrogen yield, H2 recovery, and carbon formation can be enhanced by increasing the reaction temperature, inlet CO2/CH4 ratio, and sweep gas flow rate. With the enhanced H2 removal, carbon formation is also enhanced. Because membrane permeance is inversely proportional to the membrane thickness, membrane thickness can be used as a parameter to control the carbon formation under given operating conditions.

scholarly journals The Impact of Operating Conditions on the Performance of a CH4 Dry Reforming Membrane Reactor for H2 Production

2020 ◽  
Vol 2 (2) ◽  
pp. 1-19
Author(s):  
Akira Nishimura ◽  
◽  
Satoshi Ohata ◽  
Kaito Okukura ◽  
Eric Hu ◽  
...  
Keyword(s):  
Membrane Reactor ◽  
H2 Production ◽  
Dry Reforming ◽  
Operating Conditions ◽  
The Impact

Impact of Pulsed Electric Field on Glycerin Sedimentation from Biodiesel Production Process

2020 ◽  
Vol 846 ◽  
pp. 262-266
Author(s):  
Thanadol Hinthao ◽  
Tanakorn Wongwuttanasatian ◽  
Amnart Suksri
Keyword(s):  
Electric Field ◽  
Pulse Duration ◽  
Applied Voltage ◽  
Glass Tube ◽  
Pulsed Electric Field ◽  
Field Method ◽  
Reaction Chamber ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
The Impact

This research aims to study the impact of continuous pulsed electric field (PEF) on glycerin separation from Transesterification process. Transesterification process of biodiesel production using 100 ml vegetable oils with alcohol of 1:5 molar ratio together with potassium hydroxide (KOH) as catalyst 1 wt.% for the reaction. The designed glass tube reaction chamber is 250 ml contained with coaxial cylindrical electrodes. The applied voltage to an electrode was at 1 kV and frequency of 1 kHz with pulse duration of 500 μs and also 4 kHz with pulse duration of 125 μs. The results showed that the glycerin volume from transesterification process has rapidly sedimented with pulsed electric field method. It is much faster than using conventional gravity method. The sedimentation rate increases rapidly with an increasing in frequency of the applied voltage. The highest volume of glycerin sedimentation of 10.2 ml is by using pulsed electric field at 1 kV and 4 kHz.

scholarly journals Pawpaw (Carica papaya) Peel Waste as a Novel Green Heterogeneous Catalyst for Moringa Oil Methyl Esters Synthesis: Process Optimization and Kinetic Study

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5834
Author(s):  
Babatunde Oladipo ◽  
Tunde V Ojumu ◽  
Lekan M Latinwo ◽  
Eriola Betiku
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Carica Papaya ◽  
Methyl Esters ◽  
Molar Ratio ◽  
Coefficient Of Determination ◽  
Synthesis Process ◽  
Solid Base ◽  
X Ray ◽  
The Impact

This study evaluated pawpaw (Carica papaya) peel ash as a green solid base catalyst for Moringa oleifera oil methyl esters (MOOME) production. Taguchi orthogonal array approach was used to examine the impact of vital process input variables (calcined pawpaw peel (CPP) loading, reaction temperature, methanol-to-M. oleifera oil (MeOH:MOO) molar ratio and reaction time) on the MOOME yield. Catalytic potency potential of the CPP was evaluated by Fourier transform infrared (FTIR), Barrett-Joyner-Halenda (BJH), Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) methods. The results obtained indicate that the CPP consists of nanoparticles and alkaline elements K (23.89 wt.%), Ca (2.86 wt.%) and Mg (1.00 wt.%). The high values of coefficient of determination, R2 (0.9992) and adjusted R2 (0.9968) as well as the low value of the coefficient of variation (0.31%) for the model developed indicate it can be used to sufficiently describe the transesterification process. MOOME yield of 96.43 ± 0.10 wt.% was achieved at the optimum values of 3.5 wt.% CPP loading, 9:1 MeOH:MOO molar ratio, 35 °C reaction temperature and 40 min reaction time. The kinetic modeling of the transesterification process determined the reaction rate constant and overall reaction order as 0.20465 L·mol−1·s−1 and 2, respectively. The results of this study demonstrate both CPP and MOO are feasible renewable resources for MOOME production. The kinetic data generated may be useful in reactor design for the transesterification process.

scholarly journals Nitrate-dominated PM<sub>2.5</sub> and elevation of particle pH observed in urban Beijing during the winter of 2017

2020 ◽  
Vol 20 (8) ◽  
pp. 5019-5033 ◽  
Author(s):  
Yuning Xie ◽  
Gehui Wang ◽  
Xinpei Wang ◽  
Jianmin Chen ◽  
Yubao Chen ◽  
...  
Keyword(s):  
Atmospheric Aerosols ◽  
Ammonia Concentration ◽  
Historical Record ◽  
Molar Ratio ◽  
Effective Control ◽  
Nitrate Content ◽  
Chinese Government ◽  
Low Level ◽  
The Impact ◽  
Pollution Episodes

Abstract. The Chinese government has exerted strict emission controls to mitigate air pollution since 2013, which has resulted in significant decreases in the concentrations of air pollutants such as SO2. Strict pollution control actions also reduced the average PM2.5 concentration to the low level of 39.7 µg m−3 in urban Beijing during the winter of 2017. To investigate the impact of such changes on the physiochemical properties of atmospheric aerosols in China, we conducted a comprehensive observation focusing on PM2.5 in Beijing during the winter of 2017. Compared with the historical record (2014–2017), SO2 decreased to the low level of 3.2 ppbv in the winter of 2017, but the NO2 level was still high (21.4 ppbv in the winter of 2017). Accordingly, the contribution of nitrate (23.0 µg m−3) to PM2.5 far exceeded that of sulfate (13.1 µg m−3) during the pollution episodes, resulting in a significant increase in the nitrate-to-sulfate molar ratio. The thermodynamic model (ISORROPIA II) calculation results showed that during the PM2.5 pollution episodes particle pH increased from 4.4 (moderate acidic) to 5.4 (more neutralized) when the molar ratio of nitrate to sulfate increased from 1 to 5, indicating that aerosols were more neutralized as the nitrate content elevated. Controlled variable tests showed that the pH elevation should be attributed to nitrate fraction increase other than crustal ion and ammonia concentration increases. Based on the results of sensitivity tests, future prediction for the particle acidity change was discussed. We found that nitrate-rich particles in Beijing at low and moderate humid conditions (RH: 20 %–50 %) can absorb twice the amount of water that sulfate-rich particles can, and the nitrate and ammonia with higher levels have synergetic effects, rapidly elevating particle pH to merely neutral (above 5.6). As moderate haze events might occur more frequently under abundant ammonia and nitrate-dominated PM2.5 conditions, the major chemical processes during haze events and the control target should be re-evaluated to obtain the most effective control strategy.

The Impact of Negative-Pressure Wound Therapy with Instillation Compared with Standard Negative-Pressure Wound Therapy

2014 ◽  
Vol 133 (3) ◽  
pp. 709-716 ◽  
Author(s):  
Paul J. Kim ◽  
Christopher E. Attinger ◽  
John S. Steinberg ◽  
Karen K. Evans ◽  
Kelly A. Powers ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Negative Pressure Wound Therapy ◽  
Wound Therapy ◽  
The Impact

scholarly journals Rapid and Efficient Synthesis ofω-Alkylenediphosphoric Acids from Phosphorus Oxychloride

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Dalila Meziane ◽  
Abdelhamid Elias ◽  
Erwann Guénin
Keyword(s):  
Microwave Irradiation ◽  
Reaction Temperature ◽  
Phosphorus Oxychloride ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Selective Method

The aim of this investigation was to develop an efficient, rapid, and selective method for the synthesis ofω-alkylenediphosphoric acids (HO)2(O)P-O-CH2n-O-P(O)(OH)2from reaction of several diols with phosphorus oxychloride. The reaction was investigated using three methodologies: (i) presence of a base, (ii) classical heating, and (iii) use of microwave irradiation. Influence of reaction temperature and molar ratio of reagents, as well as the nature of the solvent, was studied using these three different methods.

The impact of menopausal status on cardiac responses to exercise training and lower body negative pressure

Maturitas ◽  
2017 ◽  
Vol 103 ◽  
pp. 91
Author(s):  
Amanda Q.X. Nio ◽  
Eric J. Stöhr ◽  
Samantha Rogers ◽  
Rachel Mynors-Wallis ◽  
Jane M. Black ◽  
...  
Keyword(s):  
Exercise Training ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Menopausal Status ◽  
Lower Body ◽  
Cardiac Responses ◽  
The Impact

scholarly journals The influence of physical parameters on the in-situ metal carbonyl complex formation studied with the Fast On-line Reaction Apparatus (FORA)

2021 ◽  
Vol 109 (4) ◽  
pp. 261-281
Author(s):  
Yves Wittwer ◽  
Robert Eichler ◽  
Dominik Herrmann ◽  
Andreas Türler
Keyword(s):  
Gas Flow ◽  
Metal Carbonyl ◽  
Fission Products ◽  
Reaction Chamber ◽  
Single Atom ◽  
Physical Parameters ◽  
Carbonyl Complex ◽  
Reaction Conditions ◽  
On Line ◽  
The Impact

Abstract The Fast On-line Reaction Apparatus (FORA) was used to investigate the influence of various reaction parameters onto the formation and transport of metal carbonyl complexes (MCCs) under single-atom chemistry conditions. FORA is based on a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes. Those are recoiling from the spontaneous fission source into a reaction chamber flushed with a gas-mixture containing CO. Upon contact with CO, fission products form volatile MCCs which are further transported by the gas stream to the detection setup, consisting of a charcoal trap mounted in front of a HPGe γ-detector. Depending on the reaction conditions, MCCs are formed and transported with different efficiencies. Using this setup, the impact of varying physical parameters like gas flow, gas pressure, kinetic energy of fission products upon entering the reaction chamber and temperature of the reaction chamber on the formation and transport yields of MCCs was investigated. Using a setup similar to FORA called Miss Piggy, various gas mixtures of CO with a selection of noble gases, as well as N2 and H2, were investigated with respect to their effect onto MCC formation and transport. Based on this measurements, optimized reaction conditions to maximize the synthesis and transport of MCCs are suggested. Explanations for the observed results supported by simulations are suggested as well.

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