Banca de QUALIFICAÇÃO: ANDERSON LUIZ SOARES LEAO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANDERSON LUIZ SOARES LEAO
DATA : 15/04/2019
HORA: 10:30
LOCAL: Auditório do NUPPRAR
TÍTULO:

USE OF ALKALINE LIGNIN IN PORTLAND CLASS G CEMENT PASTS AS AN ADDITIVE FOR INCREASING RESISTANCE TO THE CARBONATING PROCESS.

PALAVRAS-CHAVES:

Portland Cement, CO2, Carbonation, reactivity

PÁGINAS: 83
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Portland cement is a binder used globally in oil wells, as well as carbon capture and storage (CCS) and Carbon Capture and Storage (CCS) wells. Portland cement is highly reactive with carbon dioxide, a substance found on a large scale in the most diverse types of oil reservoirs, including pre-salt formations. The reactions of the Portland cement with the CO2 result in the formation of carbonates and bicarbonates, causing the degradation of the cement and consequent loss of mechanical resistance. Alkaline lignin is a natural polymer that has a long three-dimensional chain with active functional groups that change the surface energies and interactions of certain cement phases with CO2. In this study, SIGMA alkaline lignin was added in formulations with Portland Class G, at concentrations of 0.3% and 0.5% by weight of cement, and exposed for 90 days to the autoclave reactor under conditions of 2200 psi (149.7 ATM) CO2 and 70 ° C and compared to the standard formulation without lignin. Results of pH, x-ray diffraction, infrared, electron microscopy and thermogravimetric analyzes showed that the addition of lignin improved the cement resistance to reactions with CO2, reducing the advance of the carbonation front. The hydrated phases Aft and C-S-H presented significant interactions with the additive. The samples with 0.5% wt of additive presented in the longitudinal section an average of 87% preservation in the alkalinity and, the standard samples, average of 65% preservation of the alkalinity. The XRD results show a significant reduction in the formation of aragonite and carbonation of the hydrated calcium silicates in the samples with lignin. The additive does not appear to change the consumption of Ca(OH)2 in the carbonation process.

MEMBROS DA BANCA:
Presidente - 349770 - DULCE MARIA DE ARAUJO MELO
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externo ao Programa - 2302898 - ELEDIR VITOR SOBRINHO