title: Recent process improvements for the ammonia fiber expansion (AFEX) process and resulting reductions in minimum ethanol selling price.
abstract: The ammonia fiber expansion (AFEX) process has been shown to be an effective pretreatment for lignocellulosic biomass. Technological advances in AFEX have been made since previous cost estimates were developed for this process. Recent research has enabled lower overall ammonia requirements, reduced ammonia concentrations, and reduced enzyme loadings while still maintaining high conversions of glucan and xylan to monomeric sugars. A new ammonia recovery approach has also been developed. Capital and operating costs for the AFEX process, as part of an overall biorefining system producing fuel ethanol from biomass have been developed based on these new research results. These new cost estimates are presented and compared to previous estimates. Two biological processing options within the overall biorefinery are also compared, namely consolidated bioprocessing (CBP) and enzymatic hydrolysis followed by fermentation. Using updated parameters and ammonia recovery configurations, the cost of ethanol production utilizing AFEX is calculated. These calculations indicate that the minimum ethanol selling price (MESP) has been reduced from $1.41/gal to $0.81/gal.
authors.affiliation: Michigan State University College of Engineering, 2527 Engineering Building, East Lansing, MI 48854, United States. newtone3@msu.edu
authors.forename: Elizabeth Newton
authors.initials: EN
authors.lastname: Sendich
authors.forename: Mark
authors.initials: M
authors.lastname: Laser
authors.forename: Seungdo
authors.initials: S
authors.lastname: Kim
authors.forename: Hasan
authors.initials: H
authors.lastname: Alizadeh
authors.forename: Lizbeth
authors.initials: L
authors.lastname: Laureano-Perez
authors.forename: Bruce
authors.initials: B
authors.lastname: Dale
authors.forename: Lee
authors.initials: L
authors.lastname: Lynd
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D001709:Biotechnology / Q000379:methods*; D003198:Computer Simulation; D000431:Ethanol / Q000191:economics*; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D007753:Laboratories; D008956:Models, Chemical; D014867:Water; D014994:Xylose / Q000378:metabolism
chemical_list: D014867:Water; D000431:Ethanol; D000641:Ammonia; D014994:Xylose; D005947:Glucose