scholarly journals Reaction Kinetics in Conversion Process of Pineapple Leaves into Glucose

REAKTOR ◽  
2018 ◽  
Vol 18 (03) ◽  
pp. 155 ◽  
Author(s):  
Muhaimin Muhaimin ◽  
Beta Wulan Febriana ◽  
Septian Arfan

Abstract This research aimed to determine the reaction kinetics in the process of hydrolysis of pineapple leaves. The experiment was carried out at the temperature (60, 90, and 120 oC) and variation of acid catalyst concentration (0.1; 0.5 and 1 M) by observation reaction time every 30 min. The kinetics model of hydrolysis reactions of pineapple leaves has shown first order reaction with activation energy value to find the concentration of sulfuric acid successively: 0.1 M; -15420 KJ/mol; 0,5 M; 3173.8 KJ/mol; 1 M; 100.53 KJ/mol. The reaction rate constant which produced the highest glucose level was on the use of sulfuric acid at a concentration of 0.1 M at a temperature of 120 oC with glucose levels produced between 26.366.039 ppm to 155.510.778 ppm with k = 0.0106/min. Keywords: glucose; hydrolysis; kinetic model; pineapple leaves

EKUILIBIUM ◽  
2013 ◽  
Vol 12 (1) ◽  
Author(s):  
Enny Kriswiyanti

<p>Abstract : Sweet sorghum stem residues contains high enough cellulose (36.92%)so it can be<br />hydrolyzed to glucose. In this research, hydrolysis of cellulose is carried out using hydrochloric<br />acid catalyst. This research aims to determine the effect of acid catalyst concentration and<br />agitation speed on the resulting reduction of glucose levels and determine the reaction rate<br />constant of hydrolysis of sweet sorghum stem residues. The observed variables were the<br />concentration of hydrochloric acid catalyst (0.5 N, 1 N, 1.5 N, 2 N) and the agitation speed (150<br />rpm, 200 rpm, 250 rpm, 300 rpm). Glucose samples were analyzed by using the Lane-Eynon<br />method. Data analysis showed the higher concentration of hydrochloric acid (HCl) and the<br />agitation speed, the levels of reduced glucose that is formed is also higher. In this study by<br />assuming a first order reaction, the reaction rate constants obtained at variable concentrations of<br />hydrochloric acid catalyst ranged from 0.0010 to 0.0033 / minute and at agitation speeds variable<br />ranged from 0.0023 to 0.0030 / minute.<br />Keywords : sweet sorghum stem residues, hydrochloric acid, hydrolysis, cellulose</p>


2015 ◽  
Vol 8 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Olga V. Yatsenkova ◽  
◽  
Anna I. Chudina ◽  
Nikolay V. Chesnokov ◽  
Andrey M. Skripnikov ◽  
...  

2012 ◽  
Vol 19 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Marta Siemieniec ◽  
Hanna Kierzkowska-Pawlak ◽  
Andrzej Chacuk

Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique The pseudo-first-order rate constants (kOV) for the reactions between CO2 and diethanolamine have been studied using the stopped-flow technique in an aqueous solution at 293, 298, 303 and 313 K. The amine concentrations ranged from 167 to 500 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. Both the zwitterion and termolecular mechanisms were applied to correlate the experimentally obtained rate constants. The values of SSE quality index showed a good agreement between the experimental data and the corresponding fit by the use of both mechanisms.


2012 ◽  
Vol 550-553 ◽  
pp. 484-487 ◽  
Author(s):  
Chong Wen Jiang ◽  
Can Chen Bai ◽  
Hao Xiao

This study focuses on kinetics of straw hydrolysis using sulfuric acid catalyst to produce fermentable sugars. The result shows the degradation of sugars is encountered during the hydrolysis of straw biomass. A consecutive first-order reactions kinetic model is proposed and the kinetic model well agrees with the experimental data. It turns out that rate of sugar formation and degradation is small at lower experimental temperature. The reactions rates constant k1 including the formation of sugar begins to increase rapidly when the Fe2+concentration increases from 0.125 to 0.500molL-1. However, the rate constant k2 relevant with the degradation of sugar varies unsensibly below 0.375molL-1 Fe2+and it is accelerated as the Fe2+concentration increases to 0.500molL-1. Thus the optimum yield is obtained at 0.375molL-1 Fe2+concentration.


Buletin Palma ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 51
Author(s):  
Linda Trivana ◽  
Steivie Karouw

<p>An accurate kinetic data has been considered as main substance in hydrolysis reaction. This research was conducted at the laboratory of processing of Indonesian Palm Crops Research Institute (IPRI) during June-July 2015. The objective of the research was to obtain the optimum condition of hydrolysis of VCO and the data of reaction kinetics (the reaction rate constant (k), the activation energy (Ea), and the reaction kinetics equation). Virgin coconut oil hydrolysis was done in two stages, the first step was the determination of the ratio of VCO:water (1:3; 1:6; 1:9; 1:12), the second step was the evaluation of reaction temperatures (60°C, 70°C, and 80°C). The determination of the optimum condition was based on the result of free fatty acid content and the values of the reaction rate constant. The free fatty acid content was measured by acid-base titration, meanwhile the reaction rate constant was determined by the equation –ln(1-XA)=kt. The results showed that the hydrolysis of VCO using ratio of VCO:water 1:12 produced higher content of FFA (0.11%) compared than others. The ratio of VCO:water 1:12 was then used to obtain the optimum temperature of hydrolysis. The optimum temperature of hydrolysis was 80°C with 0.14% of FFA, the reaction conversion was 0.88, and the reaction rate constant was 0.27 hour-1. The water consentration and reaction temperature influenced the FFA content, reaction conversion, and the reaction rate constant. The best condition of VCO hydrolysis using 1% of hydrochloride acid catalyst was on ratio of VCO:water 1:12, reaction temperature 80°C for 8 hours. The relationship between the reaction rate constant and temperature, follow Arrhenius equation k = 1,62 x 1015 e -25831/RT. Free fatty acid and glycerol are extensively used as raw materials in the manufacture of products such as detergents, cosmetics, surfactants, and pharmaceuticals.</p><p align="center"><strong>ABSTRAK</strong></p><p>Hidrolisis dapat berjalan baik apabila menggunakan data kinetika yang tepat untuk mendapatkan produk yang diinginkan. Penelitian ini dilaksanakan di Laboratorium Pengolahan Hasil, Balai Penelitian Tanaman Palma pada bulan Juni-Juli 2015. Penelitian bertujuan menentukan kondisi optimum hidrolisis Virgin Coconut Oil (VCO) secara kimiawi dengan katalis HCl dan mendapatkan data kinetika reaksi, yaitu konstanta kecepatan reaksi (k), energi aktivasi (Ea), dan rumusan persamaan kinetika reaksi. Hidrolisis VCO dilakukan 2 tahap, yaitu tahap pertama penentuan rasio VCO:air (1:3; 1:6; 1:9; dan 1:12) dipilih yang menghasilkan kadar ALB terbesar, dilanjutkan pada tahap kedua, yaitu penentuan suhu reaksi (60°C, 70°C, dan 80°C). Penentuan kondisi optimum berdasarkan kadar asam lemak bebas yang dihasilkan dan nilai konstanta kecepatan reaksi. Kadar asam lemak bebas ditentukan dengan titrasi asam-basa, sedangkan konstanta kecepatan reaksi menggunakan rumus persamaan kecepatan reaksi -ln(1-XA)=kt. Hidrolisis VCO menggunakan rasio VCO:air (1:12) menghasilkan kadar asam lemak bebas (ALB) yang lebih tinggi (0,11%), selanjutnya digunakan untuk penentuan suhu optimum hidrolisis. Suhu hidrolisis optimum adalah 80°C dengan kadar ALB sebesar 0,14%, konversi reaksi 0,88 dan konstanta kecepatan reaksi 0,27 jam-1. Konsentrasi air dan suhu reaksi berpengaruh terhadap kadar ALB, konversi reaksi, dan konstanta kecepatan reaksi. Hidrolisis VCO dengan katalis HCl 1% terbaik pada rasio VCO:air 1:12, suhu reaksi 80°C selama 8 jam. Hubungan konstanta kecepatan reaksi dengan suhu reaksi mengikuti persamaan Arrhenius k = 1,62 x 1015 e -25831/RT. Asam lemak bebas dan gliserol hasil hidrolisis banyak digunakan sebagai bahan baku dalam industri deterjen, kosmetik, surfaktan, dan obat-obatan.</p><p> </p>


1985 ◽  
Vol 50 (4) ◽  
pp. 845-853 ◽  
Author(s):  
Miloslav Šorm ◽  
Miloslav Procházka ◽  
Jaroslav Kálal

The course of hydrolysis of an ester, 4-acetoxy-3-nitrobenzoic acid catalyzed with poly(1-methyl-3-allylimidazolium bromide) (IIa), poly[l-methyl-3-(2-propinyl)imidazolium chloride] (IIb) and poly[l-methyl-3-(2-methacryloyloxyethyl)imidazolium bromide] (IIc) in a 28.5% aqueous ethanol was investigated as a function of pH and compared with low-molecular weight models, viz., l-methyl-3-alkylimidazolium bromides (the alkyl group being methyl, propyl, and hexyl, resp). Polymers IIb, IIc possessed a higher activity at pH above 9, while the models were more active at a lower pH with a maximum at pH 7.67. The catalytic activity at the higher pH is attributed to an attack by the OH- group, while at the lower pH it is assigned to a direct attack of water on the substrate. The rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid is proportional to the catalyst concentration [IIc] and proceeds as a first-order reaction. The hydrolysis depends on the composition of the solvent and was highest at 28.5% (vol.) of ethanol in water. The hydrolysis of a neutral ester, 4-nitrophenyl acetate, was not accelerated by IIc.


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.


2011 ◽  
Vol 312-315 ◽  
pp. 364-369 ◽  
Author(s):  
Seyed Amir Bahrani ◽  
Catherine Loisel ◽  
Jean Yves Monteau ◽  
Sid Ahmed Rezzoug ◽  
Zoulikha Maache-Rezzoug

Two hydrothermal treatment processes (DV-HMT and DIC treatment) were investigated on standard maize starch for three processing temperatures; 100, 110 and 120°C. The gravimetric change of starch powder during the treatment was analyzed by a simultaneous water diffusion and starch reaction model. The effective diffusivity coefficient (Deff) and reaction rate constant (k) were estimated by minimizing the error between experimental and analytical results. The values of Deff and k clearly increased with temperature. The degree of starch melting was evaluated for the two treatments using the first-order reaction model as a function of processing time. The results suggest that the absorption process is controlled by water–starch reactivity that induces melting phenomenon of starch crystallites, which progresses when temperature increases. The two hydrothermal treatments considerably differ: DIC being more prone to water absorption as demonstrated by the values of Deff and k.


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.


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