Use of activated carbons for detoxification of a lignocellulosic hydrolysate: Statistical optimisation

• Published in: Journal of environmental management Vol. 296; p. 113320
• Main Authors: Arminda, Mamaní, Josúe, Castilla, Cristina, Deiana, Fabiana, Sardella, Yolanda, Maturano
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.10.2021
• Subjects: Activated carbon; Adsorption; Detoxification; Integral valorization; Olive tree pruning; Olive tree pruning; Integral valorization; Adsorption; Activated carbon; Detoxification
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2021.113320

In order to improve bioethanol production from hydrolysates from olive tree pruning residues the present study assessed a detoxification method using the same waste material. The objective was to develop optimal removal without diminishing fermentable sugars. A statistical optimisation study was performed for the production of activated carbons using the same olive tree pruning residue as raw material. The effect of the impregnation ratio, activation temperature and the time needed for maximum removal of the phenolic compounds was assayed. The conditions for maximum adsorption were as follows: 799.18 °C, IR 4.88 and 101.38 min of activation, removing 55%, 64% and 41% of total phenolic compounds, HMF and furfural, respectively. The activated carbon obtained under optimum conditions (Aop) was submitted to adsorption kinetics and equilibrium assays. Experimental kinetic data were well represented by a pseudo-first order kinetic and intraparticle diffusion model, which helped explain the adsorption mechanism. Experimental isotherms were analysed with Langmuir, Freundlich and Temkin models, and Langmuir best fitted the experimental data. Hydrolysate from olive tree pruning residues, detoxified with the optimum activated carbon, was fermented with a commercial Saccharomyces cerevisiae yeast, obtaining a 100% theoretical maximum ethanol yield and a 56% bioconversion of fermentable sugars. [Display omitted] •Integral use of a residue for production of 2G bioethanol and adsorbent was performed.•A regional waste was used both as raw material and as detoxifier to obtain bioethanol.•Two experimental routes were carried out to obtain optimal conditions in the process.•An efficient detoxification method was developed to enhance bioethanol production.•Activated carbon eliminated more than 50% of toxic compounds for the fermentation.