Catalytic co-cracking of biomass and vacuum residue from distillation petroleum: Kinetic study and chemical characterization of liquid product
Name: KLEYTON PINTO DE OLIVEIRA
Publication date: 28/06/2024
Examining board:
Name |
Role |
|---|---|
| BRUNO QUIRINO ARAUJO | Coorientador |
| CLEOCIR JOSE DALMASCHIO | Examinador Interno |
| MARTA ALBUQUERQUE MACHADO | Presidente |
| VERÔNICA SANTOS DE MORAIS | Examinador Externo |
Summary: The accelerated energy consumption, along with the depletion of conventional fossil fuel reserves, has motivated the use of biomass as a promising alternative. The co processing of biomass and petroleum derived products is an alternative to improve the quality of the oil generated in the process, since it can mitigate the undesirable characteristics of both raw materials. In this study, the catalytic co-cracking reaction of biomass (B) with vacuum residue (RV) was first evaluated by thermogravimetric analysis (TGA), using HY zeolite as a catalyst. The Derivative Thermogravimetry (DTG) results showed the presence of a synergistic effect between both raw materials during co-processing. Furthermore, the introduction of the catalyst in the B:RV mixture led to the emergence of a new thermal event, which suggests a change in the reaction mechanism. The reaction kinetics were studied using the Coats & Redfern kinetic model. For the samples containing pure raw materials (RV, RV:HY, B and B:HY), it was observed that the cracking reaction is controlled by diffusion, with the one-dimensional model presenting the best fit (R2 between 0.9888 and 0.9937). For the samples containing the mixture of biomass and vacuum residue (B:RV and B:RV:HY), it was noted that the reaction is controlled by the first-order chemical reaction. From the activation energy determination, it was found that the use of the catalyst reduced its value. Thus, the decrease for RV was from 116 kJ/mol to 87 kJ/mol, for biomass it was from 83 kJ/mol to 76 kJ/mol and for the mixture B:RV it was from 50 kJ/mol to 47 kJ/mol. The co-cracking reaction was also carried out in a bench reaction unit, where it was found that the addition of RV to the biomass (sample B:RV) maintained the conversion, at around 20%, significantly increasing the liquid yield (from 59.18% to 71.84%). The addition of the catalyst to the B:RV mixture (sample B:RV:HY) decreased the liquid yield (58.27%) and increased the solid (29.45%) and gas (12.27%) yields, which can be attributed to the deposition of coke on the catalyst surface and the greater cracking degree of volatiles into much lighter molecules. The Gas Chromatography Mass Spectrometry (GC/MS) analysis showed that the mixture between RV and biomass was able to deoxygenate the compounds obtained from the cracking of pure biomass, and that the addition of HY zeolite in the B:RV mixture (sample B:RV:HY) contributed more effectively to this deoxygenation, leading to the production of hydrocarbons.
