scholarly journals Determination of exothermic batch reactor specific model parameters

2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.

2008 ◽  
Author(s):  
Rajesh Gupta

A simple empirical model for predicting the pyrolysis rate of fuel packed bed of a woodstove has been presented. The thermolytic behavior of the fuel bed has been approximated by a pseudo-first order reaction. The reaction rate constant has been determined as function of temperature. The effect of orientation of twigs in the fuel bed arrangement and twig diameter on the reaction rate constant has been analyzed. It has been concluded that the effect of twig orientation is insignificant while the peak magnitude of reaction rate constant increased with increasing twig diameter.


2014 ◽  
Vol 28 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Lech W. Szajdak ◽  
Jerzy Lipiec ◽  
Anna Siczek ◽  
Artur Nosalewicz ◽  
Urszula Majewska

Abstract The aim of this study was to verify first-order kinetic reaction rate model performance in predicting of leaching of atrazine and inorganic compounds (K+1, Fe+3, Mg+2, Mn+2, NH4 +, NO3 - and PO4 -3) from tilled and orchard silty loam soils. This model provided an excellent fit to the experimental concentration changes of the compounds vs. time data during leaching. Calculated values of the first-order reaction rate constants for the changes of all chemicals were from 3.8 to 19.0 times higher in orchard than in tilled soil. Higher first-order reaction constants for orchard than tilled soil correspond with both higher total porosity and contribution of biological pores in the former. The first order reaction constants for the leaching of chemical compounds enables prediction of the actual compound concentration and the interactions between compound and soil as affected by management system. The study demonstrates the effectiveness of simultaneous chemical and physical analyses as a tool for the understanding of leaching in variously managed soils.


2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.


1978 ◽  
Vol 41 (10) ◽  
pp. 774-780 ◽  
Author(s):  
M. P. DOYLE ◽  
E. H. MARTH

Bisulfite reacted with aflatoxin B1 and G1 resulting in their loss of fluorescence. The reaction was first order with rate depending on bisulfite (or the bisulfite and sulfite) concentration(s). Aflatoxin G1 reacted more rapidly with bisulfite than did aflatoxin B1. In the presence of 0.035 M potassium acid phthalate-NaOH buffer (pH 5.5) plus 1.3% (vol/vol) methanol at 25 C, the reaction rate constant for degradation of aflatoxin G1 was 2.23 × 10−2h− and that for aflatoxin B1 was 1.87 × 10−2h− when 50 ml of reaction mixture contained 1.60 g of K2SO3. Besides bisulfite concentrations, temperature influenced reaction rates. The Q10 for the bisulfite-aflatoxin reaction was approximately 2 while activation energies for degrading aflatoxin B1 and aflatoxin G1 were 13.1 and 12.6 kcal/mole, respectively. Data suggest that treating foods with 50 to 500 ppm SO2 probably would not effectively degrade appreciable amounts of aflatoxin. Treating foods with 2000 ppm SO2 or more and increasing the temperature might reduce aflatoxin to an acceptable level.


1979 ◽  
Vol 44 (4) ◽  
pp. 1246-1261 ◽  
Author(s):  
Josef Horák ◽  
František Jiráček ◽  
Ivan Šimůnek

The methods are proposed for studies on behaviour of periodically operated batch and semibatch reactors with the coupling between individual operating cycles and continuous reactors controlled by step changes of inlet quantities. The methods are based on numerical and graphical procedures. Examples are given on application of these methods to studies on the character and stability of steady cycles of the batch reactor with the closed bath of the coolant (heat carrier) at exothermic first order reaction. The reactor together with the bath of the coolant is operated autothermally.


1968 ◽  
Vol 46 (2) ◽  
pp. 191-197 ◽  
Author(s):  
A. T. C. H. Tan ◽  
A. H. Sehon

The pyrolysis of phenylmercaptoacetic acid was investigated by the toluene-carrier technique over the temperature range 760–835 °K. The main products of the decomposition were phenyl mercaptan, carbon dioxide, acetic acid, phenyl methyl sulfide, carbon monoxide, and dibenzyl.The overall decomposition was a first-order reaction with respect to phenylmercaptoacetic acid and could be represented by the two parallel steps:[Formula: see text]Reaction [1] was shown to be a homogeneous first-order dissociation process, and its rate constant was represented by the expression[Formula: see text]The activation energy of this reaction, i.e. 58 kcal/mole, was identified with D(C6H5S—CH2COOH).


2017 ◽  
Vol 8 (1) ◽  
pp. 214-222 ◽  
Author(s):  
Zhen Zheng ◽  
Peiyao Chen ◽  
Gongyu Li ◽  
Yunxia Zhu ◽  
Zhonghua Shi ◽  
...  

CBT-Cys click condensation reaction has a high second-order reaction rate constant and has found wide applicability in recent years.


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