title: Activated carbon from pyrolysis of brewer's spent grain: Production and adsorption properties.
abstract: Brewer's spent grain is a low cost residue generated by the brewing industry. Its chemical composition (high nitrogen content 4.35 wt.%, fibres, etc.) makes it very useful for the production of added value in situ nitrogenised activated carbon. The composition of brewer's spent grain revealed high amounts of cellulose (20.8 wt.%), hemicellulose (48.78 wt.%) and lignin (11.3 wt.%). The fat, ethanol extractives and ash accounted for 8.17 wt.%, 4.7 wt.% and 3.2 wt.%, respectively. Different activated carbons were produced in a lab-scale pyrolysis/activation reactor by applying several heat and steam activation profiles on brewer's spent grain. Activated carbon yields from 16.1 to 23.6 wt.% with high N-contents (> 2 wt.%) were obtained. The efficiency of the prepared activated carbons for phenol adsorption was studied as a function of different parameters: pH, contact time and carbon dosage relative to two commercial activated carbons. The equilibrium isotherms were described by the non-linear Langmuir and Freundlich models, and the kinetic results were fitted using the pseudo-first-order model and the pseudo-second-order model. The feasibility of an activated carbon production facility (onsite and offsite) that processes brewer's spent grain for different input feeds is evaluated based on a techno-economic model for estimating the net present value. Even though the model assumptions start from a rather pessimistic scenario, encouraging results for a profitable production of activated carbon using brewer's spent grain are obtained.
authors.affiliation: Research Group of Analytical and Applied Chemistry, Hasselt University, Diepenbeek, Belgium Research Group of Nuclear Technology, Hasselt University, Diepenbeek, Belgium kenny.vanreppelen@uhasselt.be.
authors.forename: Kenny
authors.initials: K
authors.lastname: Vanreppelen
authors.affiliation: Research Group of Analytical and Applied Chemistry, Hasselt University, Diepenbeek, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Vanderheyden
authors.affiliation: Research Group of Environmental Economics, Agoralaan Hasselt University, Diepenbeek, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Kuppens
authors.affiliation: Research Group of Nuclear Technology, Hasselt University, Diepenbeek, Belgium.
authors.forename: Sonja
authors.initials: S
authors.lastname: Schreurs
authors.affiliation: Research Group of Analytical and Applied Chemistry, Hasselt University, Diepenbeek, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Yperman
authors.affiliation: Research Group of Analytical and Applied Chemistry, Hasselt University, Diepenbeek, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Carleer
mesh_terms: D000327:Adsorption; D001515:Beer; D002606:Charcoal / Q000032:analysis / Q000737:chemistry*; D002523:Edible Grain / Q000737:chemistry*; D019649:Food Industry; D017745:Incineration; D007220:Industrial Waste / Q000032:analysis*; D010636:Phenols / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*
chemical_list: D007220:Industrial Waste; D010636:Phenols; D002606:Charcoal
keywords: Activated carbon; brewer’s spent grain; economic feasibility; phenol adsorption; pollution; pyrolysis; waste treatment