Synthesis of novel catalysts for hydrodeoxygenation of bio-oil: guaiacol as a model component

Abstract

In this work, NiMo/Support catalysts have been prepared by impregnation technique and evaluated for hydrodeoxygneation (HDO) reaction of guaiacol (GUA) aiming at the identification of active catalysts. Among various catalysts, NiMo/TiO 2 was chosen to understand the influence of reaction parameters, such as temperature, reaction time, H 2 pressure, and quantity of the catalyst. The influence of the metal components on guaiacol conversion is determined by comparing mono (Ni and Mo) metals deposited TiO 2 . These results signify the alloying nature of metal components. GCMS results showed that phenol is a major component in all the conditions. As there is an increase in the temperature (200, 250, 300, 350C), reaction time (1, 5, 8, 24 h), H 2 /guaiacol molar feed ratio (0, 1:2, 1:1, and 2:1), and catalyst amount (0, 25, 50, 100 mg), the conversion has increased significantly while maintaining the high selectivity to HDO products without ring opening reactions. Under optimized conditions (350C and 2:1 of H 2 :guaiacol ratio), 98% guaiacol is converted on NiMo/TiO 2 resulting phenol, poly methyl substituted phenols, and traces of cyclohexanone and benzene. It is remarkable that a low amount of catechol dimethyl ether and no indication of catechol and creosol were detected.

Hidrodesoxigenação de bio-óleos utilizando catalisadores de níquel e molibdênio suportados em sílica mesoporosa SBA-15.

“…Os resultados de seletividade para os catalisadores utilizados também mostram que a proporção de produtos não oxigenados diminui com a temperatura, em favor da produção de compostos como o fenol, o-cresol e outros monoxigenados como anisol e cicloexanol. Estes resultados indicam que a quebra das ligações C-OH e C-OCH3 não está favorecida a altas temperaturas, como já foi reportado em outros estudos (AQSHA et al, 2015;XU et al, 2016). O fenol é o principal produto do grupo de produtos oxigenados, com seletividade variando de 10,5 a 34,2 % entre 200 e 300 °C para o caso do catalisador de SBA-15 e de 16,3 a 41,3 % para o catalisador de alumina.…”