Stability of Li-LSX Zeolite in the Catalytic Pyrolysis of Non-Treated and Acid Pre-Treated Isochrysis sp. Microalgae

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.

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Upgrading of bio-oil from catalytic pyrolysis of pretreated rice husk over Fe-modified ZSM-5 zeolite catalyst

Fuel Processing Technology ◽

10.1016/j.fuproc.2018.03.002 ◽

2018 ◽

Vol 175 ◽

pp. 17-25 ◽

Cited By ~ 59

Author(s):

Shuping Zhang ◽

Houlei Zhang ◽

Xinzhi Liu ◽

Shuguang Zhu ◽

Linlin Hu ◽

...

Keyword(s):

Rice Husk ◽

Catalytic Pyrolysis ◽

Zeolite Catalyst ◽

Bio Oil

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Catalytic Pyrolysis of High Density Polyethylene on a HZSM-5 Zeolite Catalyst in a Conical Spouted Bed Reactor

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1567 ◽

2007 ◽

Vol 5 (1) ◽

Cited By ~ 7

Author(s):

Gorka Elordi ◽

Gartzen Lopez ◽

Roberto Aguado ◽

Martin Olazar ◽

Javier Bilbao

Keyword(s):

Atmospheric Pressure ◽

Catalytic Pyrolysis ◽

Zeolite Catalyst ◽

Catalyst Deactivation ◽

Gasoline Fraction ◽

Light Olefins ◽

Spouted Bed ◽

Product Analysis ◽

Commercial Gasoline ◽

On Line

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.

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Mechanistic Insights into Hydrodeoxygenation of Acetone over Mo/HZSM-5 Bifunctional Catalyst for the Production of Hydrocarbons

Energies ◽

10.3390/en15010053 ◽

2021 ◽

Vol 15 (1) ◽

pp. 53

Author(s):

Kai Miao ◽

Tan Li ◽

Jing Su ◽

Cong Wang ◽

Kaige Wang

Keyword(s):

Hydrogen Pressure ◽

Catalyst Deactivation ◽

Catalyst Activity ◽

Coke Formation ◽

Bifunctional Catalyst ◽

Acid Sites ◽

Coke Deposition ◽

Enhanced Production ◽

Bio Oil ◽

Catalytic Hydropyrolysis

Catalytic hydropyrolysis via the introduction of external hydrogen into catalytic pyrolysis process using hydrodeoxygenation catalysts is one of the major approaches of bio-oil upgrading. In this study, hydrodeoxygenation of acetone over Mo/HZSM-5 and HZSM-5 were investigated with focus on the influence of hydrogen pressure and catalyst deactivation. It is found that doped MoO3 could prolong the catalyst activity due to the suppression of coke formation. The influence of hydrogen pressure on catalytic HDO of acetone was further studied. Hydrogen pressure of 30 bar effectively prolonged catalyst activity while decreased the coke deposition over catalyst. The coke formation over the HZSM-5 and Mo/HZSM-5 under 30 bar hydrogen pressure decreased 66% and 83%, respectively, compared to that under atmospheric hydrogen pressure. Compared to the test with the HZSM-5, 35% higher yield of aliphatics and 60% lower coke were obtained from the Mo/HZSM-5 under 30 bar hydrogen pressure. Characterization of the spent Mo/HZSM-5 catalyst revealed the deactivation was mainly due to the carbon deposition blocking the micropores and Bronsted acid sites. Mo/HZSM-5 was proved to be potentially enhanced production of hydrocarbons.

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

International Journal of Chemical Engineering ◽

10.1155/2016/9148925 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Rui Zhang ◽

Li Li ◽

Zhichang Liu ◽

Xianghai Meng

Keyword(s):

Kinetic Model ◽

Crude Oil ◽

Catalytic Pyrolysis ◽

Zeolite Catalyst ◽

Catalyst Deactivation ◽

Arrhenius Equation ◽

Activation Energies ◽

Least Square ◽

Light Olefins ◽

Apparent Activation Energies

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.

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Process Simulation and Economic Evaluation of Bio-Oil Two-Stage Hydrogenation Production

Applied Sciences ◽

10.3390/app9040693 ◽

2019 ◽

Vol 9 (4) ◽

pp. 693

Author(s):

Xiaoyuechuan Ma ◽

Shusheng Pang ◽

Ruiqin Zhang ◽

Qixiang Xu

Keyword(s):

Process Simulation ◽

Catalyst Deactivation ◽

Catalyst Activity ◽

Fuel Oil ◽

Coke Deposition ◽

Two Stage ◽

Bio Oil ◽

Demonstration Plant ◽

Two Stages ◽

Optimal Reaction

Bio-oil hydrogenation upgrading process is a method that can convert crude bio-oil into high-quality bio-fuel oil, which includes two stages of mild and deep hydrogenation. However, coking in the hydrogenation process is the key issue which negatively affects the catalyst activity and consequently the degree of hydrogenation in both stages. In this paper, an Aspen Plus process simulation model was developed for the two-stage bio-oil hydrogenation demonstration plant which was used to evaluate the effect of catalyst coking on the bio-oil upgrading process and the economic performance of the process. The model was also used to investigate the effect of catalyst deactivation caused by coke deposition in the mild stage. Three reaction temperatures in the mild stage (250 °C, 280 °C, and 300 °C) were considered. The simulation results show that 45% yield of final product is obtained at the optimal reaction condition which is 280 °C for the mild stage and 400 °C for the deep stage. Economic analysis shows that the capital cost of industrial production is $15.2 million for a bio-oil upgrading plant at a scale of 107 thousand tons per year. The operating costs are predicted to be $1024.27 per ton of final product.

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