scholarly journals Continuous isomerization of glucose to fructose using activated hydrotalcite catalyst: Effects of reaction conditions

2021 ◽  
Author(s):  
Sadra Souzanchi ◽  
Laleh Nazari ◽  
Venkat Kasanneni ◽  
Zhongchao Tan ◽  
Charles Xu
Keyword(s):  
Reaction Temperature ◽  
Flow Rate ◽  
Retention Time ◽  
Catalyst Activity ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Bet Surface Area ◽  
Isomerization Reaction ◽  
Catalyst Loading ◽  
Calcined Hydrotalcite

Isomerization of glucose to fructose was studied over activated hydrotalcite as a catalyst in a continuous-flow tubular reactor. The synthetic hydrotalcite (HT), calcined hydrotalcite (HT-C) and activated hydrotalcite (calcined-rehydrated hydrotalcite (HT-C-R)) were characterized by TGA, XRD, BET surface area, and FT-IR analyses. The effects of operating conditions, including reaction temperature and retention time (in terms of both catalyst loading and feeding flow rate) on the isomerization reaction, were investigated. Glucose conversion and fructose selectivity were found to be more strongly dependent on retention time than reaction temperature. The fructose yield was mostly dependent on the feeding flow rate, and its maximum value of 18% corresponded to the lowest flow rate of 0.5 ml/min. The regenerated hydrotalcite catalyst showed that the catalyst activity could be restored through the calcination-rehydration process, and it showed good potential for recycling and reusability.

Application of Taguchi Optimization Method in Improving the Selectivity of Dihydroxystearic Acid

2015 ◽  
Vol 1113 ◽  
pp. 703-709 ◽  
Author(s):  
Siti Khatijah Jamaludin ◽  
Ku Halim Ku Hamid ◽  
Hazimah Abu Hassan ◽  
Ayub Md Som ◽  
Zulina Maurad ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Oleic Acid ◽  
Taguchi Method ◽  
Formic Acid ◽  
Reaction Temperature ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Dihydroxystearic Acid ◽  
Catalyst Loading ◽  
Taguchi Optimization

Dihydroxystearic acid (DHSA) is perceived to be of significant value to various types of industries, especially the oleochemical industry. It is produced by reacting palm-based crude oleic acid (OA) with formic acid and hydrogen peroxide through thein situepoxidation-dihydroxylation, a multistep reaction process. Optimization of the reaction’s operating conditions with respect to the selectivity of DHSA was conducted via the Taguchi method of optimization. The selectivity of DHSA was determined based on gas chromatography (GC) analysis. The signal-to-noise (S/N) ratio analysis procedure in Taguchi method revealed that the optimum operating conditions for the production of crude DHSA with respect to its selectivity were found to be: catalyst (sulphuric acid) loading at 0.5 gm, formic acid-to-oleic acid unsaturation mole ratio of 1:1, hydrogen peroxide-to-oleic acid unsaturation mole ratio of 0.75:1 and reaction temperature: 85°C. ANOVA tested at 90% confidence level revealed that reaction temperature and catalyst loading highly affect the selectivity of DHSA. The selectivity of DHSA was improved to 97.2% by applying the optimum operating conditions as obtained by Taguchi method.

scholarly journals Removal of methyl orange by heterogeneous fenton process using iron dispersed on alumina pillared bentonite pellet

2020 ◽  
Vol 23 (2) ◽  
pp. First
Author(s):  
Ngo Thi Thuan ◽  
Tran Tien Khoi ◽  
Nguyen Thi My Chi ◽  
Nguyen Ngoc Vinh
Keyword(s):  
Methyl Orange ◽  
Surface Area ◽  
Dye Degradation ◽  
Catalyst Activity ◽  
Cod Removal ◽  
Bet Surface Area ◽  
Catalyst Loading ◽  
Fenton Process ◽  
Heterogeneous Fenton ◽  
X Ray

Introduction: Heterogeneous Fenton is one of the Advanced Oxidation Processes (AOPs) and has been proven to be effective on azo dye degradation. However, a low-cost catalyst and factors affecting the processes of this system were further investigated. Methods: In this study, pellets of iron alumina pillared bentonite (PFeAPB) were prepared by dispersing iron ions on alumina pillared bentonite pellet. Catalyst activity and lifetime were investigated via efficiencies of Methyl Orange (MO) decolorization and Chemical Oxygen Demand (COD) removal, a typical dye type of textile wastewater. Characteristics of the PFeAPB catalyst were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, and X-ray fluorescence (XRF). Results: Results of batch experiments showed that specific surface area of the PFeAPB catalyst was 111.22 m2/g higher than its precursor by 2 times (57.79 m2/g). Goethite, Hematite and Maghemite phases with approximately 11.5% of iron elements containing in the catalyst were detected via XRD and XRF. Experimental conditions of pH, initial MO solution, Hydrogen Peroxide concentration, reaction time and catalyst loading were 2.0 ± 0.1, 12.7 mmol/L, 150 min and 20 g/L, respectively, to achieve 88.68 ± 5.69% of MO decolorization and 50.27 ± 6.05% of COD removal while dissolved iron in this heterogeneous Fenton process was below standard limit (2 ppm). Catalyst activity decreased by 5.22% in decolorization efficiency after the two first reusages. Conclusion: These primary results showed the potential of applying PFeAPB catalyst in heterogeneous Fenton process with low iron leaching into water.  

Mathematical Modeling of Carbon Nanotubes Formation in Fluidized Bed Chemical Vapor Deposition

2017 ◽  
Vol 15 (2) ◽  
Author(s):  
Firoozeh Danafar ◽  
Said S. Elnashaie ◽  
Hassan Hashemipour ◽  
Mohammad Ali Rostamizadeh
Keyword(s):  
Mathematical Modeling ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Fluidized Bed ◽  
Vapor Deposition ◽  
Active Sites ◽  
Catalyst Activity ◽  
Chemical Vapor ◽  
Operating Conditions ◽  
Catalyst Loading

Abstract This study investigates mathematical modeling of carbon nanotubes (CNTs) formation on catalyst particulate in a fluidized bed chemical vapor deposition (FBCVD) reactor. The mass of CNTs formed corresponds to the catalyst activity directly. The catalyst deactivation occurs as active sites are occupied by CNTs and thus causes unsteady state behavior of the process. The effects of catalyst loading (as bed height) as well as reaction temperature on the reaction progressing were investigated. The model, validated with our experimental data, indicates a good accuracy to predict the yield of CNTs formation for a given operating conditions. The model presented also can predict the optimized time as well as the suitable amount of catalyst loading to produce CNTs for a given reactor conditions.

scholarly journals Production of Biodiesel from Waste Cooking Oil and Its Performance on Four Strokes IC Engine

2018 ◽  
Vol 7 (4.5) ◽  
pp. 303
Author(s):  
B. S V S R Krishna ◽  
Shivaraj B K
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Waste Cooking Oil ◽  
Operating Conditions ◽  
Biodiesel Production ◽  
Catalyst Loading ◽  
Plant Oil ◽  
Alkaline Catalyst ◽  
Ic Engine ◽  
Cooking Oil

Majority of biodiesel is produced from plant oil (Jatropha, Pongamia, Mahua, Neem, Cotton seed oil etc.), which requires large land area to grow. The major drawback of production of biodiesel in large scale is the cost of raw materials. One of the satisfactory methods to limit the Biodiesel (Methyl esters) production cost is to employ low price/quality raw material, for instance biodiesel production using waste cooking oil (WCO). Simultaneously solves the disposal problem of waste cooking oil. This is socioeconomic and environment friendly and it does not compete with fresh food oil resources. Waste cooking oil collected from different hotels in and around Manipal/Udupi of Karnataka, India. Transesterification reaction of WCO with methanol in presence of alkaline catalyst KOH has been accomplished in transesterification reactor. Experiments have been carried out at different operating conditions viz. catalyst loading (over the range of 0.4 to 3 wt %), oil to methanol ratio (1:3, 1:5, 1:6, 1:8, 1:9, 1:10 and 1:12), reaction temperature (50, 60 and 70 ºC) and reaction time (40, 50, 60, 70, 80 and 90 minutes) to identify optimized conditions for preparation of biodiesel. At these conditions gave that maximum yield (~91.60 %) of biodiesel at catalyst loading of 0.85 wt %, oil to methanol ratio of 1:8, reaction temperature of 60 ºC and reaction time of 60 minutes. Biodiesel properties at different blends (B100, B30, B20, and B5) as prescribed by ASTM D6751-12 methods have been carried out. Its performance and emission test on diesel engine were also carried out.  

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 Optimization the Process of Chemically Modified Carbon Nanofiber Coated Monolith via Response Surface Methodology for CO2 Capture

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1775 ◽  
Author(s):  
Mohamad Rasool Malekbala ◽  
Soroush Soltani ◽  
Suraya Abdul Rashid ◽  
Luqman Chuah Abdullah ◽  
Umer Rashid ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Co2 Capture ◽  
Carbon Nanofiber ◽  
Co2 Adsorption ◽  
Operating Conditions ◽  
Co2 Uptake ◽  
Operating Pressure

In the present study, a sequence of experiments was performed to assess the influence of the key process parameters on the formation of a carbon nanofiber-coated monolith (CNFCM), using a four-level factorial design in response surface methodology (RSM). The effect of reaction temperature, hydrocarbon flow rate, catalyst and catalyst promoter were examined using RSM to enhance the formation yield of CNFs on a monolith substrate. To calculate carbon yield, a quadratic polynomial model was modified through multiple regression analysis and the best possible reaction conditions were found as follows: a reaction temperature of 800 °C, furfuryl alcohol flow of 0.08525 mL/min, ferrocene catalyst concentration of 2.21 g. According to the characterization study, the synthesized CNFs showed a high graphitization which were uniformly distributed on a monolith substrate. Besides this, the feasibility of carbon dioxide (CO2) adsorption from the gaseous mixture (N2/CO2) under a range of experimental conditions was investigated at monolithic column. To get the most out of the CO2 capture, an as-prepared sample was post-modified using ammonia. Furthermore, a deactivation model (DM) was introduced for the purpose of studying the breakthrough curves. The CO2 adsorption onto CNFCM was experimentally examined under following operating conditions: a temperature of 30–50 °C, pressure of 1–2 bar, flow rate of 50–90 mL/min, and CO2 feed amount of 10–40 vol.%. A lower adsorption capacity and shorter breakthrough time were detected by escalating the temperature. On the other hand, the capacity for CO2 adsorption increased by raising the CO2 feed amount, feed flow rate, and operating pressure. The comparative evaluation of CO2 uptake over unmodified and modified CNFCM adsorbents confirmed that the introduced modification procedure caused a substantial improvement in CO2 adsorption.

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

Analysis of NiMoP/γ-Al2O3 Catalyst Preparation with Impregnation and Microwave Polyol Methods for Bio-Jet Production

2020 ◽  
Vol 1000 ◽  
pp. 257-264
Author(s):  
Bambang Heru Susanto ◽  
Joshua Raymond Valentino Siallagan
Keyword(s):  
Coconut Oil ◽  
Catalyst Preparation ◽  
Operating Conditions ◽  
Catalyst Loading ◽  
Impregnation Method ◽  
Conversion Yield ◽  
Jet Production ◽  
Cracking Process ◽  
Catalyst Impregnation ◽  
Rate Conversion

Bio-Jet could be produced by the synthesis of vegetable oil through the hydrodeoxygenation, decarboxylation, decarbonization, and catalytic cracking process. Physical characteristics, activities, and selectivity of the catalyst used will determine the rate, conversion, and yield of the reaction that being carried out. This study aims to compare and obtain the best characteristics of NiMoP/γ-Al2O3 catalysts synthesized using two types of preparation, impregnation and microwave polyol methods, which will be used for bio-jet production. The impregnation method takes more than 24 hours for catalyst preparation, while microwave polyols that use microwaves can synthesize catalysts faster. Both catalysts have almost the same loading on the weight of the catalyst, which in the microwave polyol method has a more dispersed promotor and active site, although the crystallinity level is deficient and tends to be amorphous compared to the impregnation method with high crystallinity. In bio-jet synthesis reaction with operating conditions of 5% catalyst loading by comparison to Coconut Oil, 400°C, and 15 bar, the conversion, yield, and selectivity of catalyst impregnation were 91.705%, 47.639%, and 84.511%, while microwave polyol catalysts were 90.296%, 42.752%, and 82.517%, respectively. In conclusion, microwave polyol provides a more effective and efficient preparation method.

scholarly journals Chemical–Electrochemical Process Concept for Lead Recovery from Waste Cathode Ray Tube Glass

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1546
Author(s):  
Árpád Imre-Lucaci ◽  
Melinda Fogarasi ◽  
Florica Imre-Lucaci ◽  
Szabolcs Fogarasi
Keyword(s):  
Flow Rate ◽  
Current Density ◽  
Complete Recovery ◽  
Electrochemical Process ◽  
Operating Conditions ◽  
General Effect ◽  
Optimal Operating ◽  
Recirculation Flow ◽  
Lead Recovery ◽  
Cathode Ray Tube

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.

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