Influence of Temperature and Residence Time on Torrefaction Coupled to Fast Pyrolysis for Valorizing Agricultural Waste

Torrefaction is a promising pretreatment technology for valorizing biomass and upgrading pyrolysis products. This study sets out an original procedure consisting of subjecting the biomass to torrefaction before fast pyrolysis to increased value-added compounds based on agricultural waste biomasses p...

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Bibliographic Details
Authors: Alcazar Ruiz, Angel, Dorado Fernández, Fernando, Sanchez-Silva, Luz
Format: article
Publication Date:2022
Country:España
Institution:Universidad de Castilla-La Mancha
Repository:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/30505
Online Access:http://hdl.handle.net/10578/30505
Access Level:Open access
Keyword:Torrefaction
Temperature
Residence time
Fast pyrolysis
Olive pomace
Almond shell
Torrefacción
Temperatura
Pirólisis rápida
Orujo de oliva
Cascara de almendra
Description
Summary:Torrefaction is a promising pretreatment technology for valorizing biomass and upgrading pyrolysis products. This study sets out an original procedure consisting of subjecting the biomass to torrefaction before fast pyrolysis to increased value-added compounds based on agricultural waste biomasses production. This study uses a combined biomass treatment consisting of torrefaction (280–320 °C) and subsequent fast pyrolysis (500 °C) using the same reactor. Under different torrefaction temperatures and residence times, olive pomace (OP) and almond shell (AS) have been evaluated. The study demonstrated OP rather than AS was thermally unstable. The highest total yield of carboxylic acids (mainly acetic acid) was obtained by means of torrefaction at 280 °C with a residence time of 20 s for OP, and at 300 °C and 20 s for AS. Higher torrefaction temperature and residence time promoted phenolic compounds production for OP. However, OP had a higher lignin content and inherent metals that promoted a catalytic reaction during the procedure. The highest yield (47.7%) was obtained using torrefaction at 320 °C with a residence time of 240 s. Overall, the torrefaction of biomass combined with fast pyrolysis constituted a very simple and efficient strategy for valorizing the conversion of agricultural waste biomass into value-added chemicals