scholarly journals Continuous-Flow Process for Glycerol Conversion to Solketal Using a Brönsted Acid Functionalized Carbon-Based Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 609 ◽  
Author(s):  
Vanesa Domínguez-Barroso ◽  
Concepción Herrera ◽  
María Ángeles Larrubia ◽  
Rafael González-Gil ◽  
Marina Cortés-Reyes ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Batch Reactor ◽  
High Surface ◽  
Molar Ratio ◽  
Fuel Additive ◽  
Flow Process ◽  
Glycerol Conversion ◽  
Structured Catalyst ◽  
Carbon Based

The acetalization of glycerol with acetone represents a strategy for its valorization into solketal as a fuel additive component. Thus, acid carbon-based structured catalyst (SO3H-C) has been prepared, characterized and tested in this reaction. The structured catalyst (L = 5 cm, d = 1 cm) showed a high surface density of acidic sites (2.9 mmol H+ g−1) and a high surface area. This catalyst is highly active and stable in the solketal reaction production in a batch reactor system and in a continuous downflow reactor, where several parameters were studied such as the variation of time of reaction, temperature, acetone/glycerol molar ratio (A/G) and weight hourly space velocity (WHSV). A complete glycerol conversion and 100% of solketal selectivity were achieved working in the continuous flow reactor equipped with distillation equipment when WHSV is 2.9 h−1, A/G = 8 at 57 °C in a co-solvent free operation. The catalyst maintained its activity under continuous flow even after 300 min of reaction.

Photocatalytic degradation of 2-propanol over TiO2-based thin films in a simulated pilot microreactor

2021 ◽  
Vol 02 ◽  
Author(s):  
Corrado Garlisi ◽  
Ahmed Yusuf ◽  
Giovanni Palmisano
Keyword(s):  
Thin Films ◽  
Gas Phase ◽  
Continuous Flow ◽  
Molecular Diffusion ◽  
Batch Reactor ◽  
High Surface ◽  
Operating Conditions ◽  
Flow Mode ◽  
Doped Tio2 ◽  
Kinetics Of

Background: Microreactor devices have attracted increasing attention over the last years due to their high surface-to-volume ratio which ensures a high heat and mass transfer, short molecular diffusion distance and greater spatial illumination homogeneity compared to traditional reactors. Objective: The aim of this study was to model the kinetics of photodegradation of 2-propanol over TiO2-based thin films in a gas-phase batch-reactor and simulate their performance in a microreactor device. Methods: The reaction was carried out in a gas-phase batch-reactor assessing the reactivity of a single-layer nitrogen (N)-doped TiO2 and a bilayer consisting of N-doped TiO2 as a bottom layer and copper (Cu)-doped TiO2 as a top layer. The kinetics of the photocatalytic process was modelled by Langmuir–Hinshelwood (LH) model. The constants obtained from LH model were used to simulate the performance of the photocatalysts in a microreactor operating in a continuous flow mode and investigating the effect of the volumetric flow rate (Q), initial concentration of pollutant (Co), number of microchannels (n) and microchannel length (l) on the photodegradation of 2-propanol. Results: N-Cu-TiO2 exhibited a higher reactivity but a lower to adsorption ability towards the target pollutant compared to N-TiO2. To maximize and leverage the advantages of microreactor, optimal operating conditions for a continuous flow mode, at steady state, should be moderately low Q and Co, long l and moderate n that minimizes flow maldistribution in parallel. Conclusion: The findings in this work could serve as a basis to design and fabricate efficient microreactors for the removal of VOC in air purification applications.

scholarly journals Heterogeneous catalytic reaction of glycerol with acetone for solketal production

2019 ◽  
Vol 268 ◽  
pp. 07004
Author(s):  
Hary Sulistyo ◽  
Indri Hapsari ◽  
Budhijanto ◽  
Wahyudi Budi Sediawan ◽  
Suprihastuti Sri Rahayu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Batch Reactor ◽  
Catalyst Loading ◽  
Fuel Additive ◽  
Proper Treatment ◽  
Heterogeneous Catalytic Reaction ◽  
Glycerol Conversion ◽  
Amberlyst 15 ◽  
Heterogeneous Catalytic ◽  
Catalyst Load

The rapid growth of biodiesel industries has also increased the production of glycerol as side product. Without proper treatment, glycerol may cause serious problem for the environment. Glycerol can be reacted with acetone to produce solketal as a fuel additive. The aim of this research was to study the glycerol ketalization with acetone using Amberlyst-15 as catalyst. Experiments were undertaken in a batch reactor. A set of experiment was conducted at varying temperature (35 to 60oC), initial mole ratio of acetone to glycerol (2 – 6) and catalyst loading (1,3,5 and 7% w/w). Sample was analyzed every 30 minutes. The results showed that optimal condition was achieved at temperature of 60 °C, initial mole ratio of acetone to glycerol of 3, and the catalyst load of 3%. The highest glycerol conversion achieved was 87.41 % at 60oC for 3 hours reaction. The Pseudo Steady State Hypothesis (PSSH) has been developed as rnet =k4.CG.CAC/1+k5.CG. Parameter estimation of k4 and k5 were evaluated from experimental data at various temperatures. It appears that the model predicted the experimental data well at high conversion (above 80 min) and showed relatively poor prediction below 80 min.

scholarly journals Selective Reduction of Ketones and Aldehydes in Continuous-Flow Microreactor—Kinetic Studies

Catalysts ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 221 ◽  
Author(s):  
Katarzyna Maresz ◽  
Agnieszka Ciemięga ◽  
Julita Mrowiec-Białoń
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Flow Characteristics ◽  
Selective Reduction ◽  
Kinetic Studies ◽  
Attractive Alternative ◽  
Batch Reactors ◽  
Flow Process ◽  
Micro Flow ◽  
Flow Microreactors

In this work, the kinetics of Meerwein–Ponndorf–Verley chemoselective reduction of carbonyl compounds was studied in monolithic continuous-flow microreactors. To the best of our knowledge, this is the first report on the MPV reaction kinetics performed in a flow process. The microreactors are a very attractive alternative to the batch reactors conventionally used in this process. The proposed micro-flow system for synthesis of unsaturated secondary alcohols proved to be very efficient and easily controlled. The microreactors had reactive cores made of zirconium-functionalized silica monoliths of excellent catalytic properties and flow characteristics. The catalytic experiments were carried out with the use of 2-butanol as a hydrogen donor. Herein, we present the kinetic parameters of cyclohexanone reduction in a flow reactor and data on the reaction rate for several important ketones and aldehydes. The lack of diffusion constraints in the microreactors was demonstrated. Our results were compared with those from other authors and demonstrate the great potential of microreactor applications in fine chemical and complex intermediate manufacturing.

The effect of several parameters on catalytic denitrification of water by the use of H2 in the presence of O2 over metal supported catalysts

2013 ◽  
Vol 68 (10) ◽  
pp. 2309-2315 ◽  
Author(s):  
C. P. Theologides ◽  
P. G. Savva ◽  
G. G. Olympiou ◽  
N. A. Pantelidou ◽  
B. K. Constantinou ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Catalytic Reduction ◽  
Supported Catalysts ◽  
Batch Reactor ◽  
Particle Diameter ◽  
Active Phase ◽  
Reaction Selectivity ◽  
Continuous Flow Reactor

The present paper involves a detailed study of the selective catalytic reduction of nitrates in aqueous mediums by the use of H2 in the presence of O2 over monometallic and bimetallic supported catalysts. In this study, an attempt has been made to improve the denitrification efficiency (XNO3−, SN2) of several catalysts by regulating some experimental parameters that are involved in the process. Therefore, the effects of the type of reactor (semi-batch reactor vs continuous flow reactor), the nature of the active phase (Pd, Cu, and Pd-Cu) and the particle size of γ-Al2O3 spheres (particle diameter = 1.8 mm and 3 mm) on catalytic activity and reaction selectivity, as well as the adsorption capacity of γ-Al2O3 spheres for nitrates, were examined. As the review indicates, most of the research has so far been conducted on batch or semi-batch reactors. This study successfully demonstrates the benefits of using a continuous flow reactor in terms of catalytic activity (XNO3−, %) and reaction selectivity (SN2, %). Another important aspect of this study is the crucial role of bimetallic Pd-Cu clusters for the prevention of NH4+ formation. Moreover, the use of 1.8 mm diameter γ-Al2O3 spheres as a support was proved to significantly enhance the catalytic performance of bimetallic Pd-Cu catalysts towards nitrate reduction compared to 3 mm diameter γ-Al2O3 spheres. This difference may be attributed to mass (NO3−, OH−) transfer effects (external mass transfer phenomena).

scholarly journals Solketal Production by Glycerol Acetalization Using Amberlyst-15 Catalyst

2020 ◽  
Vol 20 (1) ◽  
pp. 67
Author(s):  
Hary Sulistyo ◽  
Edwin Nur Huda ◽  
Tri Sarifah Utami ◽  
Wahyudi Budi Sediawan ◽  
Suprihastuti Sri Rahayu ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Cetane Number ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Fuel Additive ◽  
Stirrer Speed ◽  
Glycerol Conversion ◽  
Amberlyst 15 ◽  
Operation Conditions

Glycerol, as a by-product of biodiesel production, has recently increased due to the rapid growth of the biodiesel industry. Glycerol utilization is needed to increase the added value of glycerol. Glycerol can be converted to solketal, which can be used as a green fuel additive to enhance an octane or cetane number. Conversion of glycerol to solketal was conducted via acetalization reaction with acetone using amberlyst-15 as the catalyst. The objective of present study was to investigate the effect of some operation conditions on glycerol conversion. Furthermore, it also aimed to develop a kinetic model of solketal synthesis with amberlyst-15 resins. The experiment was conducted in a batch reactor, equipped with cooling water, thermometer, stirrer, and a water bath. The variables that have been investigated in the present work were reaction temperature, reactants molar ratio, catalyst loading, and stirrer speed for 3 hours of reaction time. Temperatures, reactants molar ratio, and stirrer speed appeared to have a significant impact on glycerol conversion, where the higher values led to higher conversion. On the other hand, in the presence of catalyst, the increase of catalyst loading has a less significant impact on glycerol conversion. The results showed that the highest glycerol conversion was 68.75%, which was obtained at 333 K, the reactant’s molar ratio was  4, the amount of catalyst was 1 wt%, and stirrer speed of 500 rpm. Based on the pseudo-homogeneous kinetic model, the resulting kinetic model suitable for this glycerol capitalization. The value of parameters k and Ea were 1.6135 108 min-1 and 62.226 kJ mol-1,respectively. The simulation model generally fits the experimental data reasonably well in the temperature range of 313-333 K.

Kinetics and Inhibition of Ferrous Sulfide Nucleation and Precipitation

2014 ◽  
Author(s):  
Qiliang ‘Luke’ Wang ◽  
Zhang Zhang ◽  
Amy Kan ◽  
Mason Tomson
Keyword(s):  
Flow Reactor ◽  
Production Systems ◽  
Batch Reactor ◽  
High Surface ◽  
Plug Flow ◽  
Oil Production ◽  
Rate Equations ◽  
Precipitation Kinetics ◽  
Severe Problem ◽  
Ferrous Sulfide

Abstract Ferrous sulfide (FeS) precipitation is a severe problem and the significance of this problem is increased in the shale gas and oil production due to the potentially increasing biologically and thermally induced sulfide production. Although FeS scale is ubiquitous, little is understood about its precipitation and inhibition properties due to experimental difficulties. In conventional research, we used a batch reactor to study the precipitation kinetics and inhibition of FeS formation. In order to assess scaling risk in pipes, a new plug flow reactor was developed under anoxic condition at different ionic strength (IS), pH and temperature to enable more reliable study of FeS precipitation kinetics at high surface to solution ratio. The precipitation kinetics of FeS is successfully fitted by a second/pseudo-first order rate equations for batch/plug flow systems. The rate of precipitation increases with increasing pH and temperature, and decreases with increasing IS. Commercial scale inhibitors, citrate, EDTA and other chelating agents have been tested for their inhibition effects on FeS precipitation. The new plug flow apparatus not only adds reliable data to the limited database of scaling kinetics in realistic flowing pipes, but also supplies a new method to study the effect of inhibitors in oil production systems. The research outcomes will contribute to the prediction of FeS scaling risk under different brine composition and well conditions.

scholarly journals Suitability of the Iraqi natural clay for the preparation of Al-Fe pillared-clays

2018 ◽  
Vol 162 ◽  
pp. 05017
Author(s):  
Faris Al-Ani ◽  
Ghayda Al-Kindi
Keyword(s):  
Batch Reactor ◽  
Organic Pollutant ◽  
High Surface ◽  
Pillared Clay ◽  
Molar Ratio ◽  
Silty Clay ◽  
Air Oxidation ◽  
Operation Condition ◽  
Iron Cation ◽  
X Ray

Some organic pollutant in aqueous wastewater inhabitant biological treatment, catalyst wet air oxidation is a method to treat this waste. Al-Fe pillared Iraqi clays with different Fe content were prepared. Aluminum was mixed with iron in different molar ratio Fe/Al (1:9- 2:8- 3:7- 4-6- 5:5) for each regions. These clays collected from different location in Iraq (Anbar, Erbil, Mosel, Baghdad, and Basra), the results of some properties studied for natural and pillared clay, from X-Ray- Fluorescence (XRF) show that iron cation replaces some Ca in the clay, and from X-Ray Diffraction (XRD) show the Calcite types of Iraqi clays. constructs clusters of active ingredient which dramatically clear on the catalytic surface for all catalyst types show through photos of catalysts by Scanning Electron Microscopy (SEM), the best molar ratio of Fe/Al in which give strong interaction between Fe and Al in the pillared were (0.5-0.4-0.3-0.3 and 0.2) for (Mosul-Basra -Anbar-Baghdad and Erbil) respectively. This ratio gives high surface area, and pore size in mesopore. It is concluded that clay and silty clay (Mosul clay) consider the best catalyst due to higher activity and stability through experiment of CWAO in batch reactor, with operation condition 150°C, 2.5 Mpa, Ccat equal to 7 mg/l.

scholarly journals Continuous Flow Friedel–Crafts Alkylation Catalyzed by Silica Supported Phosphotungstic Acid: An Environmentally Benign Process

2021 ◽  
Author(s):  
Zsófia Császár ◽  
Tatjána Juzsakova ◽  
Miklós Jakab ◽  
Szabolcs Balogh ◽  
Ágnes Szegedi ◽  
...  
Keyword(s):  
Flow Rate ◽  
Continuous Flow ◽  
Phosphotungstic Acid ◽  
Flow Reactor ◽  
Analytical Techniques ◽  
Catalyst System ◽  
Molar Ratio ◽  
Flow Mode ◽  
Reaction Conditions ◽  
Composite Catalysts

AbstractSix silica-supported phosphotungstic acid catalysts (PTA/SiO2) of different composition (20–70 wt% PTA content) have been synthesized and characterized by elemental analysis, BET, BJH, NH3-TPD methods, FT-IR spectroscopy of adsorbed pyridine and 1H MAS NMR techniques. The new composite catalysts were first applied in the Friedel–Crafts alkylation of toluene with 1-octene as a benchmark process under batch conditions in order to screen their activity and recyclability. The combined analytical techniques together with the catalytic studies enabled the identification of the main factors affecting the activity of the catalysts. Based on these preliminary experiments, the best performing catalyst system (50 wt% PTA/SiO2) was investigated in continuous flow mode using an in-house-made flow reactor. The thorough screening of the reaction conditions (temperature, toluene/1-octene molar ratio and flow rate) provided firm evidence that the 50 wt% PTA/SiO2 composite is highly active, selective and stable catalyst under mild reaction conditions even at elevated flow rate. Additionally, the catalyst used in the flow mode could successfully be regenerated and reused in the alkylation process.

scholarly journals The development and evaluation of a continuous flow process for the lipase-mediated oxidation of alkenes

2009 ◽  
Vol 5 ◽  
Author(s):  
Charlotte Wiles ◽  
Marcus J Hammond ◽  
Paul Watts
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Preliminary Investigation ◽  
Enzymatic Oxidation ◽  
High Yield ◽  
Reaction Conditions ◽  
Flow Process ◽  
Continuous Flow Reactor ◽  
Yield And Purity ◽  
Mediated Oxidation

We report the use of an immobilised form of Candida antarctica lipase B, Novozym® 435, in a preliminary investigation into the development of a continuous flow reactor capable of performing the chemo-enzymatic oxidation of alkenes in high yield and purity, utilising the commercially available oxidant hydrogen peroxide (100 volumes). Initial investigations focussed on the lipase-mediated oxidation of 1-methylcyclohexene, with the optimised reaction conditions subsequently employed for the epoxidation of an array of aromatic and aliphatic alkenes in 97.6 to 99.5% yield and quantitative purity.

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