Micro-batch reactor for catching intermediates and monitoring kinetics of rapid and exothermic homogeneous reactions

Experimental research of the kinetics of the decomposition process of Kovdorsky apatite with a size = 0.16 mm with sulfuric acid in a 1 dm3 batch reactor. Phosphoric acid with the concentration of 68.6 % wt and the sulfuric acid with the concentration of 12.3% wt in stoichiometric amount was introduces at the beginning of the process. The process was carried out at a ratio of liquid and solid phases 2.5:1 respectively at the boiling point of the mixture equal to 136 °C. The observing the progress was carried out according to the method of joint designation of sulfuric and phosphoric acids by titrimetric analysis. With methyl orange and then phenolphthalein 2 titration jumps were recorded, the first of which corresponded to the neutralization of sulfuric acid to Na2SO4 and phosphoric acid to NaH2PO4, the second to the neutralization of NaH2PO4 to Na2HPO4. The change in temperature of the reaction mixture was fixed during the process using a mercury thermometer. In the analysis of the derived experimental values of specified parameters that the boiling point decreases from 136 to 133.1 оС within 50 minutes during the process. A comparison of the reported values with the concentration values of sulfuric and phosphoric acids measured during the process shows that the change in boiling point of the reaction mixture is proportional to the change in the concentrations of sulfuric and phosphoric acids. This model is a closed system that provides thermal insulation and no loss of material balance. Thus, the kinetics of the decomposition of apatite with sulfuric acid at the boiling point can be monitored by the temperature change under specified conditions.

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Kinetics of Glycerol Biotransformation to Dihydroxyacetone by Immobilized Gluconobacter oxydans and Effect of Reaction Conditions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20071269 ◽

2007 ◽

Vol 72 (9) ◽

pp. 1269-1283 ◽

Cited By ~ 4

Author(s):

Jiří Raška ◽

František Skopal ◽

Karel Komers ◽

Jaroslav Machek

Keyword(s):

Yeast Extract ◽

Batch Reactor ◽

Gluconobacter Oxydans ◽

Poly Vinyl Alcohol ◽

Glycerol Concentration ◽

Reaction Conditions ◽

Extract Concentration ◽

Autocatalytic Model ◽

Kinetics Of ◽

Reaction Schemes

Biotransformation of glycerol to 1,3-dihydroxyacetone was carried out in an isothermal isochoric batch reactor with Gluconobacter oxydans immobilized in poly(vinyl alcohol) gel capsules. The reaction course was described with a three-step kinetic model. Two reaction schemes were proposed and compared with 8 kinetic experiments at 25 °C. The experimental dependences of glycerol and dihydroxyacetone concentrations on reaction time were simulated very well by the autocatalytic model. The effects of reaction temperature and initial concentrations of yeast extract and glycerol were studied. Temperature 25-30 °C, initial yeast extract concentration 2-4 g l-1 and initial glycerol concentration 20-50 g l-1 were found as optimal. The determined rate constants can be used to advantage for industrial production of dihydroxyacetone from glycerol.

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

Journal of Photocatalysis ◽

10.2174/2665976x02666210217085502 ◽

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.

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Precipitation

Bioseparations Science and Engineering ◽

10.1093/oso/9780195391817.003.0011 ◽

2015 ◽

Author(s):

Roger G. Harrison ◽

Paul W. Todd ◽

Scott R. Rudge ◽

Demetri P. Petrides

Keyword(s):

Coming Out ◽

Batch Reactor ◽

Protein Solubility ◽

Tubular Reactor ◽

Advantages And Disadvantages ◽

Long Term Storage ◽

Diffusion Limited ◽

Simple Scaling ◽

Separation Of Proteins ◽

Kinetics Of

Precipitation, which is the process of coming out of solution as a solid, is an important method in the purification of proteins that usually comes early in the purification process. Precipitation is frequently used in the commercial separation of proteins. The primary advantages of precipitation are that it is relatively inexpensive, can be carried out with simple equipment, can be done continuously, and leads to a form of the protein that is often stable in long-term storage. Since precipitation is quite tolerant of various impurities, including nucleic acids and lipids, it is used early in many bioseparation processes. The goal of precipitation is often concentration to reduce volume, although significant purification can sometimes be achieved. For example, all the protein in a stream might be precipitated and redissolved in a smaller volume, or a fractional precipitation might be carried out to precipitate the protein of interest and leave many of the contaminating proteins in the mother liquor. In this chapter the focus is first upon protein solubility, which is the basis of separations by precipitation. Then we discuss the basic concepts of particle formation and breakage and the distribution of precipitate particle sizes. The specific methods that can be used to precipitate proteins are treated next. The chapter concludes with methodology to use for the design of precipitation systems. After completing this chapter, the reader should be able to do the following: • Explain the various factors that influence protein solubility. • Use the Cohn equation to predict solution equilibria (precipitation recoveries). • Identify the distinct steps in the development of a precipitate. • Calculate mixing times in an agitated precipitator, the kinetics of diffusion-limited growth of particles, and the kinetics of particle-particle aggregation. • Perform particle balances as a function of particle size in a continuous-flow stirred tank reactor (CSTR). • Explain the methods used to cause precipitation. • Outline the advantages and disadvantages of the three basic types of precipitation reactor: the batch reactor, the CSTR, and the tubular reactor. • Implement simple scaling rules for a precipitation reactor.

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Modeling of kinetics of Cr(VI) sorption onto grape stalk waste in a stirred batch reactor

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2009.04.100 ◽

2009 ◽

Vol 170 (1) ◽

pp. 286-291 ◽

Cited By ~ 17

Author(s):

Carlos Escudero ◽

Nuria Fiol ◽

Jordi Poch ◽

Isabel Villaescusa

Keyword(s):

Batch Reactor ◽

Kinetics Of

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Kinetics of the Ozonation of Tetrabromobisphenol-A in Wastewater

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.2945 ◽

2011 ◽

Vol 383-390 ◽

pp. 2945-2950 ◽

Cited By ~ 1

Author(s):

Jie Zhang ◽

Shi Long He ◽

Mei Feng Hou ◽

Li Ping Wang ◽

Li Jiang Tian

Keyword(s):

Rate Constants ◽

Apparent Rate Constant ◽

Reaction Rate ◽

Batch Reactor ◽

Kinetic Studies ◽

Tetrabromobisphenol A ◽

First Order ◽

Reaction Rate Constants ◽

Pseudo First Order ◽

Kinetics Of

The kinetics of TBBPA degradation by ozonation in semi-batch reactor was studied. The reaction rate constants of TBBPA with O3 and •OH were measured by means of direct ozone attack and competition kinetics, and the values of which were 6.10 l/(mol•s), 4.8×109 l/(mol•s), respectively. Results of kinetic studies showed that TBBPA degradation by ozonation under the different conditions tested followed the pseudo-first-order. The values of apparent rate constant of TBBPA degradation increased with the increase of ozone dosage and pH, but decreased with the increase of initial TBBPA concentration.

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