Complex spatiotemporal patterns in an open-flow reactor

1994 ◽  
Vol 49 (6) ◽  
pp. 5207-5217 ◽  
Author(s):  
Massimo Sangalli ◽  
Hsueh-Chia Chang
Keyword(s):  
Flow Reactor ◽  
Spatiotemporal Patterns ◽  
Open Flow

scholarly journals Dissolution of atmospheric cobalt and zinc in seawater

2009 ◽  
Vol 6 (6) ◽  
pp. 10883-10910
Author(s):  
C.-E. Thuróczy ◽  
M. Boye ◽  
R. Losno
Keyword(s):  
Trace Metals ◽  
Primary Production ◽  
Elemental Composition ◽  
Flow Reactor ◽  
Light Irradiation ◽  
Open Flow ◽  
Atmospheric Inputs ◽  
The Impact ◽  
Voltammetric Methods

Abstract. Atmospheric dust inputs to the open ocean are major source of trace metals bioavailable for the phytoplankton after their dissolution in seawater. Among them, cobalt (Co) and zinc (Zn) are essential for the growth and for the distribution of major phytoplankton taxon such as coccolithophorids and diatoms. The solubility in seawater of Co and Zn present in atmospheric dusts was studied using an open-flow reactor with and without light irradiation. The analyses of cobalt and Zinc were conducted using voltammetric methods and the global elemental composition of dust determined by ICP-AES. This study highlights the role of the dust origin in revealing the solubility characteristics. Higher dust solubility was found for zinc as compared to cobalt. Cobalt in anthropogenic particles is much more soluble in seawater than in natural particles after 2 h of dissolution. Zinc showed opposite solubilities, higher in natural particles than in anthropogenics. This work is a contribution to ongoing studies which focus on the impact of atmospheric inputs of trace metals onto the primary production.

Oscillations and patterns in a model of simultaneous CO and C2H2 oxidation and NOx reduction in a cross-flow reactor

2015 ◽  
Vol 17 (9) ◽  
pp. 6458-6469 ◽  
Author(s):  
Otto Hadač ◽  
Martin Kohout ◽  
Jaromír Havlica ◽  
Igor Schreiber
Keyword(s):  
Flow Reactor ◽  
Heterogeneous Reaction ◽  
Nox Reduction ◽  
Tubular Reactor ◽  
Cross Flow ◽  
Spatiotemporal Patterns

Spatiotemporal patterns predicted by a model of a cross-flow tubular reactor with a complex heterogeneous reaction are linked to unstable reaction subnetworks identified in the mechanism.

scholarly journals Chaotic oscillations, dissipation and mirror symmetry breaking in a chiral catalytic network

2020 ◽  
Vol 22 (46) ◽  
pp. 27214-27223 ◽  
Author(s):  
David Hochberg ◽  
Antonio Sánchez Torralba ◽  
Federico Morán
Keyword(s):  
Symmetry Breaking ◽  
Entropy Production ◽  
Mirror Symmetry ◽  
Unit Volume ◽  
Flow Reactor ◽  
Chaotic Regime ◽  
Chaotic Oscillations ◽  
Open Flow ◽  
Catalytic Network

The entropy production per unit volume in the chaotic regime of a chiral hypercycle in an open-flow reactor.

Hydrogenolysis of glucose and fructose in glycol solutions over CuO-MgO-ZrO2 catalyst

2020 ◽  
pp. 48-55
Author(s):  
M.E. Sharanda ◽  
◽  
E.A. Bondarenko ◽  
Keyword(s):  
Ethylene Glycol ◽  
Propylene Glycol ◽  
Flow Reactor ◽  
General Trend ◽  
Raw Materials ◽  
Reaction Products ◽  
Renewable Raw Materials ◽  
High Partial Pressure ◽  
Zro2 Catalyst ◽  
Phase Process

Ethylene glycol and propylene glycol are important representatives of polyols. On an industrial scale, they are obtained from petrochemical raw materials. Within a decade, significant efforts were made for the producing of polyols from biologically renewable raw materials - carbohydrates. The general trend for carbohydrate hydrogenolysis includes application of liquid-phase process with the use of modified metal-oxide catalysts, at 120-120 ° C and pressure of 3MPa or above. So high pressure is used for the reason to increase hydrogen solubility, and also due to the high partial pressure of low boiling solvents. We supposed that usage of high boiling solvents could allow hydrogenolysis to be performed at the lower pressure. Ethylene glycol and propylene glycol are of particular interest as such kind of solvent since they are both the main products of glucose hydrogenolysis. In this work, the process of hydrogenolysis of glucose and fructose over Cu / MgO-ZrO2 catalyst have been studied at temperature range of 160-200 °C and a pressure of 0.1-0.3 MPa in a flow reactor. The solvents were simultaneously the target products of the reaction - ethylene glycol and / or propylene glycol. Gas chromatography and 13C NMR were used for the reaction products identification. It was found that the solubility of glucose in propylene glycol is 21 % by weight, and in ethylene glycol 62% by weight. It was pointed out that the process of hydrogenolysis can take place at a pressure close to atmospheric. Under these conditions, the conversion of hexoses reaches 96-100 %. The reaction products are preferably propylene glycol and ethylene glycol. The total selectivity for C3-2 polyols is 90-94 %, that is higher than in the hydrogenolysis of glucose in aqueous solution.

Conversion of fructose into methyl lactate over SnO2/Al2O3 catalystin flow regime

2020 ◽  
pp. 43-47
Author(s):  
S.V. Prudius ◽  
◽  
N.L. Hes ◽  
A.M. Mylin ◽  
V.V. Brei ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Practical Interest ◽  
Dimethyl Acetal ◽  
Racemic Mixture ◽  
Process Conditions ◽  
Impregnation Method ◽  
Aqueous Methanol ◽  
Methyl Lactate ◽  
Al2o3 Catalyst ◽  
Target Reaction

In recent years, numerous researchers have focused on the development of catalytic methods for processing of biomass-derived sugars into alkyl lactates, which are widely used as non-toxic solvents and are the starting material for obtaining monomeric lactide. In this work, the transformation of fructose into methyl lactate on Sn-containing catalyst in the flow reactor that may be of practical interest was studied. The supported Sn-containing catalyst was ob-tained by a simple impregnation method of granular γ-Al2O3. The catalytic ex-periments were performed in a flow reactor at temperatures of 160-190 °C and pressure of 3.0 MPa. The 1.6-9.5 wt.% fructose solutions in 80% aqueous methanol were used as a reaction mixture. It was found that addition to a reac-tion mixture of 0.03 wt.% potassium carbonate leads to the increase in selec-tivity towards methyl lactate on 15% at 100% conversion of fructose. Prod-ucts of the target reaction С6Н12О6 + 2СН3ОН = 2С4Н8О3 + 2Н2О were ana-lyzed using 13C NMR method. The following process conditions for obtaining of 65 mol% methyl lactate yield at 100% fructose conversion were found: use of 4.8 wt.% fructose solution in 80% methanol, 180 °С, 3.0 МПа and a load on catalyst 1.5 mmol C6H12O6/mlcat/h at contact time of 11 minutes. The cata-lyst productivity is 2.0 mmol C4H8O3/mlcat/h and the by-productі are 1,3-dihydroxyacetone dimethyl acetal (20%) and 5-hydroxymethylfurfural (10%). It should be noted that a racemic mixture of L- and D-methyl lactates has been obtained by conversion of D-fructose on the SnO2/Al2O3 catalyst. The SnO2/Al2O3 catalyst was found to be stable for 6 h while maintaining full fruc-tose conversion at 55–70% methyl lactate selectivity. After regeneration the catalyst completely restores the initial activity.

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