Production of Bio-Oils and Biochars from Olive Stones: Application of Biochars to the Esterification of Oleic Acid.

Autor: Sánchez-Borrego FJ; Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Seville, Spain., Barea de Hoyos-Limón TJ; Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Seville, Spain., García-Martín JF; Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Seville, Spain., Álvarez-Mateos P; Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Seville, Spain.
Jazyk: angličtina
Zdroj: Plants (Basel, Switzerland) [Plants (Basel)] 2021 Dec 27; Vol. 11 (1). Date of Electronic Publication: 2021 Dec 27.
DOI: 10.3390/plants11010070
Abstrakt: Olive stones are a by-product of the olive oil industry. In this work, the valorisation of olive stones through pyrolysis was attempted. Before pyrolysis, half of the samples were impregnated with sulphuric acid. Pyrolysis was carried out in a vertical tubular furnace with a ceramic support. The pyrolysis conditions assayed were: temperature between 400 and 600 °C, heating ramp between 5 and 20 °C∙min -1 , and inert gas flow rate between 50 and 300 mL Ar∙min -1 . Among them, temperature was the only parameter that influenced the pyrolysis product distribution. The most suitable temperature for obtaining biochar was 400 °C for both non-treated and pre-treated raw material, while for obtaining bio-oil, it was 600 °C for impregnated olive stones and 400 °C for the raw material. The impregnated olives stones led to bio-oils with much higher amounts of high-added-value products such as levoglucosenone and catechol. Finally, the biochars were impregnated with sulphuric acid and assayed as biocatalysts for the esterification of oleic acid with methanol in a stirred tank batch reactor at 60 °C for 30 min. Biochars from non-treated olive stones, which had lower specific surfaces, led to higher esterification yields (up to 96.2%).
Databáze: MEDLINE