Banca de QUALIFICAÇÃO: MÁGNO KLEBSON AUGUSTINHO SENA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MÁGNO KLEBSON AUGUSTINHO SENA
DATE: 17/08/2026
TIME: 08:30
LOCAL: Online
TITLE:

HYDROXYAPATITE CATALYSTS FOR HYDROCARBON PRODUCTION VIA CATALYTIC PYROLYSIS AND HEFA ROUTE: CONTRIBUTIONS TO THE DEVELOPMENT OF SUSTAINABLE AVIATION FUELS (SAF).

KEY WORDS:

 sustainable aviation fuel; waste cooking oil; hydroxyapatite; nickel; catalytic pyrolysis; HEFA-SPK; deoxygenation.

PAGES: 180
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

Greenhouse gas emissions associated with the burning of fossil fuels are driving the search for renewable fuels, and the aviation sector finds in catalytic pyrolysis and in the HEFA-SPK route two alternatives for its decarbonization. This work investigated the conversion of waste cooking oil (WCO), a low-cost residual feedstock, into renewable hydrocarbons through these two pathways, using nickel-impregnated hydroxyapatite (HAP) as catalyst. HAP was synthesized, impregnated with 10 and 20% nickel, and calcined, then characterized by XRD, XRF, TGA/DTG, FTIR, SEM, and n-butylamine desorption for acidity measurement. The density of strong acid sites was 289.0, 345.5, and 256.2 μmol·g⁻¹ for HAP, 10NiHAP, and 20NiHAP, respectively. The kinetic behavior of WCO degradation was described by the Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) models, which revealed a systematic reduction of the apparent activation energy (Ea) in the presence of the catalysts. According to the KAS model, Ea decreased from 160.354 kJ·mol⁻¹ for pure WCO to 144.972, 147.992, and 144.538 kJ·mol⁻¹ for WCO/HAP, WCO/10NiHAP, and WCO/20NiHAP; according to OFW, the decrease was from 172.110 to 156.744, 159.893, and 152.170 kJ·mol⁻¹, in the same order. The thermodynamic parameters of enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS) proved favorable. In pyrolysis, the hydrocarbon yield was 30% in the thermal process and 24%, 40%, and 35% in the catalytic process over HAP, 10NiHAP, and 20NiHAP. The bio-jet fraction corresponded to 41% over HAP, with the remaining 59% above C16; over the catalysts with 10 and 20% nickel, this fraction reached 61% and 48%, with green diesel accounting for 39% and 52%, respectively. In hydroprocessing via the HEFA-SPK route, carried out at 380 °C and 30 bar of H₂ in an Amar Equipment PVT. LTD model A1425 reactor, the catalyst with 10% nickel provided a conversion of 65.09% and a selectivity of 49.16% for n-alkanes in the C8 to C16 range. The results indicate that nickel-impregnated hydroxyapatite is a promising catalyst for the deoxygenation of waste cooking oil, with performance and stability compatible with the production of renewable paraffinic hydrocarbons in the aviation fuel range, both by catalytic pyrolysis and by hydroprocessing.

COMMITTEE MEMBERS:
Interna - 2140818 - AMANDA DUARTE GONDIM
Presidente - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Interna - 2140775 - LIVIA NUNES CAVALCANTI
Externa à Instituição - MARCELA NASCIMENTO BARBOSA - F.M.Nassau
Externo à Instituição - PEDRO NOTHAFT ROMANO - UFRJ