Banca de QUALIFICAÇÃO: TACIANA CARNEIRO CHAVES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : TACIANA CARNEIRO CHAVES
DATE: 25/04/2022
TIME: 09:00
LOCAL: Sala do Conselho do CTEC
TITLE:

Anaerobic co-digestion of sugarcane vinasse and molasses for the production of H2, CH4 and high added value organic acids

KEY WORDS:

Anaerobic Digestion; Acidogenic fermentation; Inhibition of methanogenesis; Chain elongation.

PAGES: 96
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

Industrial by-products are materials abundant in carbohydrates, lipids, and proteins representing alternative sources of renewable energy that have been gaining prominence nowadays. By-products from the sugarcane agroindustry, such as vinasse and sugarcane molasses, are rich in organic matter and, therefore, can be converted into hydrogen, organic acids, and methane during anaerobic digestion stages. It is possible to inhibit methanogenesis and favor the production of only H₂ and acids controlling specific operational parameters. Besides that, the chain elongation of carboxylic acids to form caproic acid can aggregate more value to the process. In this context, the objective of this study is to use the co-fermentation of vinasse and molasses to produce hydrogen, caproic acid, and methane. In a first phase (F1), from the implementation of the Simplex Lattice experimental design using batch tests, the synergistic and antagonistic effects of vinasse (V) and molasses (M) on the co digestion of the mixture were evaluated in search of the best proportion (V₁₀₀/M₀, V₇₅/M₂₅, V₅₀/M₅₀, V₂₅/M₇₅, V₀/M₁₀₀) for hydrogen production. In F1, the results showed carbohydrate removal efficiency between 46.49 and 74.75%, COD between 13.49 and 26.53%, and SVT between 41.58 and 50.93%. The use of vinasse at a proportion of 75% or more caused instability in the production of H₂. The condition V₅₀/M₅₀ presented maximums of 595.63 mL-H₂/(g-COD_apl) and 50.63 mL-H₂/(g-COD_apl.d). According to Tukey's test, these results are statistically similar to those observed in V₂₅/M₇₅ and V₀/M₁₀₀. The mixing design revealed that vinasse and molasses interacted synergistically in the mixtures and resulted in highly significant quadratic models (p ≤ 0.05) and with good fits (R² equal to 0.98 and 0.92 for yield and production rate, respectively). After the F1 results, a second phase (F2) will also be carried out in batch reactors, aiming at the production of hydrogen and caproic acid, where two types of methanogenesis inhibition will be tested (thermal treatment and chloroform 0.05% v/v) and two-electron donors (ethanol and lactate) to promote chain elongation of the acids produced in acidogenesis. Finally, the third phase will analyze two continuous and series anaerobic fluidized bed reactors (AFBR) for the sequential generation of hydrogen and methane. AFBR will be operated at room temperature and under a progressive increase in the volumetric organic load, through the implementation of two HRTs.

BANKING MEMBERS:
Externa à Instituição - MÉLIDA DEL PILAR ANZOLA ROJAS - USP
Externa ao Programa - 1272239 - DANIELE VITAL VICH
Interno - 1774383 - EDUARDO LUCENA CAVALCANTE DE AMORIM
Presidente - 1456420 - RENATA MARIA ROSAS GARCIA ALMEIDA