scholarly journals Nine-Lump Kinetic Study of Catalytic Pyrolysis of Gas Oils Derived from Canadian Synthetic Crude Oil

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Rui Zhang ◽  
Li Li ◽  
Zhichang Liu ◽  
Xianghai Meng

Catalytic pyrolysis of gas oils derived from Canadian synthetic crude oil on a kind of zeolite catalyst was conducted in a confined fluidized bed reactor for the production of light olefins. The overall reactants and products were classified into nine species, and a nine-lump kinetic model was proposed to describe the reactions based on appropriate assumptions. This kinetic model had 24 rate constants and a catalyst deactivation constant. The kinetic constants at 620°C, 640°C, 660°C, and 680°C were estimated by means of nonlinear least-square regression method. Preexponential factors and apparent activation energies were then calculated according to the Arrhenius equation. The apparent activation energies of the three feed lumps were lower than those of the intermediate product lumps. The nine-lump kinetic model showed good calculation precision and the calculated yields were close to the experimental ones.

Author(s):  
Gorka Elordi ◽  
Gartzen Lopez ◽  
Roberto Aguado ◽  
Martin Olazar ◽  
Javier Bilbao

HDPE has been pyrolysed at 450 °C and 500 °C using HZSM-5 zeolite as a catalyst. Batch runs have been carried out at atmospheric pressure in a conical spouted bed reactor. Product analysis has been carried out by means of a GC, connected on-line with a thermostated line. The degradation rate of the plastic is slightly faster at 500 °C than at 450 °C and much faster than thermal pyrolysis in both cases. Products have been grouped into five lumps: the lump of light olefins, C2-C4; light alkanes, C1-C4; the gasoline fraction, C5-C11 compounds; C11+ hydrocarbons; and the coke deposited on the catalyst. An HZSM-5 catalyst is appropriate to obtain light olefins; about 55 wt% in both cases. The yield of gasoline fraction is also considerable and although its composition is not suitable for commercial gasoline, is interesting for its use in petrochemistry. The catalyst deactivation rate is low.


Author(s):  
Diana Mier ◽  
Andrés Tomás Aguayo ◽  
Alaitz Atutxa ◽  
Ana G Gayubo ◽  
Javier Bilbao

A study has been carried out on the effect of acid catalyst properties and operating conditions (methanol/n-butane ratio in the feed, temperature, space time, time on stream) on the yield of light olefins (C2-C4) in the simultaneous cracking of n-butane and methanol. The operation has been carried out in an isothermal fixed bed reactor in the 400-575 °C range, using catalysts prepared based on HZSM-5 zeolites (with different Si/Al ratio), HY, Ni/HZSM-5 and SAPO-18. The results are evidence of a synergism between the transformation reactions of both reactants, whose consequence is an increase in the yield of olefins that correspond to the transformation of methanol and the cracking of n-butane. Furthermore, catalyst deactivation by coke is significantly attenuated compared to the corresponding transformation of methanol. Based on the effect of operating conditions on product distribution, a kinetic model is proposed by combining the schemes corresponding to the transformation of individual components.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 959 ◽  
Author(s):  
Nur Adilah Abd Rahman ◽  
Javier Fermoso ◽  
Aimaro Sanna

This paper investigates the use of Li-LSX-zeolite catalyst over three regeneration cycles in presence of non-treated and acid pre-treated Isochrysis sp. microalgae. The spent and regenerated catalysts were characterised by surface analysis, elemental analysis (EA), SEM-EDS, and XRD to correlate their properties with the bio-oil yield and quality. The acid pre-treatment removed alkali metals, reducing gas yield in favour of bio-oil, but, at the same time, led to catalyst deactivation by fouling. Differently, the non-treated microalgae resulted in a bio-oil enriched in C and H and depleted in O, compared to the pre-treated ones, denoting higher deoxygenation activity. After 3 pyrolysis/regeneration cycles, the analyses suggest that there are no major changes on catalyst using non-treated microalgae. Regeneration at 700 °C has been shown to be able to remove most of the coke without damaging the Li-LSX zeolite structure. In summary, Li-LSX zeolite was effective in maintaining deoxygenation activity over three cycles in the pyrolysis of non-treated Isochrysis microalgae, while the algae pre-treatment with sulphuric acid was detrimental on the catalyst activity.


Author(s):  
Mallaiah Mekala

AbstractThe reaction of isopropyl alcohol with acetic acid was carried out in an isothermal batch reactor in presence of solid resin catalyst to produce isopropyl acetate and water. A novel solid resin catalyst Indion 140 was used in the present study. The temperature of reaction mixture was maintained in the range of 333.15 – 363.15 K. The effects of reaction temperature, catalyst loading, mole ratio, size of catalyst, agitation speed were investigated on acetic acid conversion. Further, pseudo-homogeneous kinetic model was developed for the catalyzed reaction. The forward reaction rate constants and activation energies were determined from the Arrhenius plot. The forward and backward activation energies are found to 53,459 J/mol and 54,748 J/mol, respectively. The heat of reaction is −1.289 kJ/mol with Indion 140 catalyst. The mathematical equation was developed for frequency factor as function of the catalyst loading and found that it follows a linear relationship between frequency factor and catalyst loading. The simulations were performed for pseudo homogeneous kinetic model and found that the model is able to predict the experimental data very well. The developed kinetic equation is useful for the simulation of a reactive distillation column for the synthesis of isopropyl acetate.


2021 ◽  
Vol 10 (1) ◽  
pp. 011-020
Author(s):  
Luyao Kou ◽  
Junjing Tang ◽  
Tu Hu ◽  
Baocheng Zhou ◽  
Li Yang

Abstract Generally, adding a certain amount of an additive to pulverized coal can promote its combustion performance. In this paper, the effect of CaO on the combustion characteristics and kinetic behavior of semi-coke was studied by thermogravimetric (TG) analysis. The results show that adding proper amount of CaO can reduce the ignition temperature of semi-coke and increase the combustion rate of semi-coke; with the increase in CaO content, the combustion rate of semi-coke increases first and then decreases, and the results of TG analysis showed that optimal addition amount of CaO is 2 wt%. The apparent activation energy of CaO with different addition amounts of CaO was calculated by Coats–Redfern integration method. The apparent activation energy of semi-coke in the combustion reaction increases first and then decreases with the increase in CaO addition. The apparent activation energies of different samples at different conversion rates were calculated by Flynn–Wall–Ozawa integral method. It was found that the apparent activation energies of semi-coke during combustion reaction decreased with the increase in conversion.


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