Nombre: KELLY COSTA CABRAL SALAZAR RAMOS MOREIRA
Tipo: MSc dissertation
Fecha de publicación: 12/03/2020
Supervisor:
Nombre |
Rol |
|---|---|
| TAISA SHIMOSAKAI DE LIRA | Advisor * |
Junta de examinadores:
| Nombre |
Rol |
|---|---|
| KÁSSIA GRACIELE DOS SANTOS | External Examiner * |
| TAISA SHIMOSAKAI DE LIRA | Advisor * |
| THIAGO PADOVANI XAVIER | External Examiner * |
Resumen: Lignocellulosic material, the main waste component, has been identified as an alternative source to fossil fuels when used as biomass in thermal recovery processes such as pyrolysis. The macadamia, a high-added value nut, generates a large amount of waste in its production process, such as the walnut carpel. Among the forms of waste treatment, the pyrolysis is able to transform biomass into solid, liquid and/or gaseous products by heating in the absence of O2. The liquid product contains a bio-oil with great potential for fuel production, but it can present a high degree of oxygenation, reducing its quality. This problem can be corrected or minimized with the use of catalysts. The clinoptilolite, a low-cost natural zeolite, has been investigated for its catalytic effect on pyrolysis product yield, which can be modified to enhance its catalytic capacity. Thus, the biomass and catalyst, in its natural and activated form, were characterized. The mineral characterization proved its activation and the improvement of zeolite adsorption and catalysis capacity after modification. The reactions kinetic and thermodynamic parameters were evaluated by isoconversional models of Ozawa, Kissinger, Starink and KAS from thermogravimetric data, which presented an activation energy in the range of 137,41 to 146,63 KJ/mol and proved the product favoring. In addition, the master plot method application allowed the identification of diffusion and nucleation mechanisms at the beginnig of lignocellulosic thermal degradation process. The experimental designs for fixed bed pyrolysis of macadamia carpel were carried out in the presence and absence of catalysts and showed the increase of liquid produced from catalytic pyrolysis, especially when activated clinoptilolite was used, with 58,20% yield. The data statistical treatment proved the significant influence of temperature on the liquid yield, such as the catalyst concentration. The best conditions of temperature, heating rate and catalyst concentration for macadamia carpel pyrolysis were estimated from the desirability function, being 873,15 K, 50 K/min and 20% of activated clinoptilolite.
