Lignocellulosic ethanol production at high-gravity: challenges and perspectives.

Lignocellulosic ethanol production at high-gravity: challenges and perspectives.

Trends in biotechnology (2013-11-16)

Rakesh Koppram, Elia Tomás-Pejó, Charilaos Xiros, Lisbeth Olsson

ABSTRACT

In brewing and ethanol-based biofuel industries, high-gravity fermentation produces 10-15% (v/v) ethanol, resulting in improved overall productivity, reduced capital cost, and reduced energy input compared to processing at normal gravity. High-gravity technology ensures a successful implementation of cellulose to ethanol conversion as a cost-competitive process. Implementation of such technologies is possible if all process steps can be performed at high biomass concentrations. This review focuses on challenges and technological efforts in processing at high-gravity conditions and how these conditions influence the physiology and metabolism of fermenting microorganisms, the action of enzymes, and other process-related factors. Lignocellulosic materials add challenges compared to implemented processes due to high inhibitors content and the physical properties of these materials at high gravity.

MATERIALS

Product Number

Brand

Product Description

48075

Supelco

Ethanol solution, certified reference material, 2000 μg/mL in methanol

277649

Sigma-Aldrich

Reagent Alcohol, anhydrous, ≤0.003% water

676829

Sigma-Aldrich

Reagent Alcohol, anhydrous, ≤0.005% water

PHR1070

Supelco

Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material

E-056

Supelco

Ethanol-20 (10 ampules/kit), 20 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E-053

Supelco

Ethanol-500, 500 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E-036

Supelco

Ethanol-400 (10 ampules/kit), 400 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

1012772

USP

Dehydrated Alcohol, United States Pharmacopeia (USP) Reference Standard

E-034

Supelco

Ethanol Calibration Kit, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

29221

Sigma-Aldrich

Ethanol, tested according to Ph. Eur.

493511

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, ACS spectrophotometric grade, 95.0%

02851

Sigma-Aldrich

Ethanol, for residue analysis

E-040

Supelco

Ethanol-10, 10 mg/dL in H₂O, pack of 10 × 1.2 mL ampules, certified reference material, Cerilliant^®

E-041

Supelco

Ethanol-150, 150 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E-029

Supelco

Ethanol-50, 50 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E7148

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, for molecular biology

51976

Sigma-Aldrich

Ethanol, BioUltra, for molecular biology, ≥99.8%, (absolute alcohol, without additive, A15 o¹)

02882

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 2% 2-butanone, A15 MEK¹, ≥99.8% (based on denaturant-free substance)

02857

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 4.8% methanol, F25 METHYL¹, ~96% (based on denaturant-free substance)

02856

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 4.8% isopropanol, A15 IPA¹, ≥99.8% (based on denaturant-free substance)

E-032

Supelco

Ethanol-200 (10 ampules/kit), 200 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E-030

Supelco

Ethanol-80, 80 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E-031

Supelco

Ethanol-100 (10 ampules/kit), 100 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E-033

Supelco

Ethanol-300, 300 mg/dL in H₂O, ampule of 10 × 1.2 mL, certified reference material, Cerilliant^®

E7023

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, for molecular biology

493546

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, meets USP testing specifications

459844

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, ACS reagent, ≥99.5%