Banca de QUALIFICAÇÃO: GISLANE PINHO DE OLIVEIRA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : GISLANE PINHO DE OLIVEIRA
DATE: 27/06/2024
TIME: 10:00
LOCAL: remoto
TITLE:
EVALUATION OF THE ENERGY POTENTIAL OF DIFFERENT BIOMASSES AND SELECTION OF LOW-COST OXYGEN CARRIERS WITH POTENTIAL APPLICATION IN THE CHEMICAL LOOPING PROCESS
KEY WORDS:
Chemical looping; mining ores and tailings; iG-CLC; semi-continuous reactor; continuous pilot plant; biomass
PAGES: 170
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SUMMARY:
Chemical looping technology is recognized as an energy-efficient approach for capturing and storing CO2. The pursuit for low-cost oxygen carriers (OC), for being used in chemical looping process, is driven by carriers’ loss incurred when solid fuels are employed. For this reason, this research focuses on the reactivity assessment characterization of various ores and mining wastes used as low-cost OC (Fe1, Fe2, Fe3, Mn, ReMn and ReNi). It also aims to characterize and select a suitable biomass with energetic potential to be applied on iG-CLC processes. The biomasses (BP, BLK and BRP) were characterized by immediate, elemental and thermogravimetric analyses, calorific value determination and analytical flash pyrolysis. OCs’ properties such as the chemical composition, crystalline phases, crush strength and attrition rate were also determined. The reactivity of the OCs was evaluated in a thermobalance with CH4, H2 and CO at 900 °C, and in a semi-continuous fluidized bed reactor with the same gases at 850, 900 and 950 °C. The performance of the selected OCs feeding the selected biomass was also evaluated at 900 °C in a fluidized bed reactor with variation of the oxygen-biomass ratio (O/C). The research ended with the evaluation of influence of fuel reactor temperature (TFR), air excess (λ) and oxygen-biomass ratio ( on CO2 capture efficiency ( on iG-CLC process conducted in a 0.5 kWh continuous pilot plant. The biomasses showed high calorific value (15-19 MJ/kg), high volatiles content (45-74%), high fixed carbon content (18-44%) and an ash content between 2 and 22%. BLK had high sulfur content (1.7%) while BP and BRP had less than 0.8%. The biomasses showed high amount of oxygenated (>50%) and nitrogenous (17-37%) volatile compounds. Only BLK showed sulfur volatile compounds (7%). The biomass ashes have revealed high K and Ca content, which can act as catalyst on gasification reactions or as slagging and fouling agents. Only BLK ash showed high S content. Slagging and fouling indices indicate the likeability of biomass ashes to develop slag and/or fouling (BP<BRP<BLK). Among the biomasses evaluated, BP was the most indicated for the application on iG-CLC processes, followed by BRP and BLK. All materials showed good attrition rate and crush resistance, except Mn, which was therefore subjected to calcination. Fe2, Fe3 and MnT1000 (manganese ore was calcined at 1000 °C) demonstrated favorable attributes: adequate crushing strength (>1 N), minimum attrition rate (<7%), good oxygen transport capacity (3.3%, 1.7% and 3.4%, respectively) and relatively high thermobalance reactivity. These materials also displayed excellent performance in a batch fluidized bed reactor with CO and H2, without agglomeration, good reoxidation rate, and lifetime ranging from 3000 for Fe2 and Fe3 to 10500 hours for MnT1000. Notably, due to the excellent performance of MnT1000 with CO and H2, it is a highly promising candidate for iG-CLC process application. The iG-CLC tests performed in a fluidized bed reactor indicate that an O/C>30 ratio promotes complete combustion of the gasification products, while values below 30 promote incomplete combustion. For values of 30>O/C>6 it is observed only CO formation, while 6>OC>2 results in CO and H2 formation and for OC<2 it is observed CO, H2 and CH4. Under O/C<2 conditions, the hematite phase of MnT1000 was reduced to Fe0. The iG-CLC tests made on the continuous plant indicate that increasing TFR or decreasing , increases the CO2 capture efficiency and the combustion efficiency, while the oxygen excess has no influence on the process.
COMMITTEE MEMBERS:
Interna - 1979301 - RENATA MARTINS BRAGA
Externo à Instituição - IÑAKI ADÁNEZ RUBIO
Externo à Instituição - JUAN ADÁNEZ ELORZA