A review of fractional distillation to improve hydrothermal liquefaction biocrude characteristics; future outlook and prospects. (November 2019)

• Record Type: Journal Article
• Authors: Taghipour, Alireza; Ramirez, Jerome A.; Brown, Richard J.; Rainey, Thomas J.
• Is Part Of: Renewable & sustainable energy reviews. Volume 115(2019)
• Publication Date: 2019-11
• Subjects: Biomass -- Hydrothermal liquefaction (HTL) -- Upgrading -- Biofuel -- Distillation -- Diesel engines; BSFC brake specific fuel consumption -- BTE brake thermal efficiency -- FTIR Fourier-Transform Infrared Spectroscopy -- GC-FID gas chromatography with Flame Ionization Detector -- GHG greenhouse gases -- HFO Heavy fuel oil -- HHV higher heating value -- HTL hydrothermal liquefaction -- LHV lower heating value -- MS mass spectrometry -- NMR nuclear magnetic resonance -- NOX nitrogen oxides -- PM particulate matter -- PN particle number -- SCWO supercritical water oxidation -- TAN total acid number -- TBP true boiling point -- TGA thermogravimetric analysis; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.rser.2019.109355
• Languages: English
• ISSNs: 1364-0321

Abstract

Abstract: Hydrothermal liquefaction (HTL) is an efficient thermochemical method for biomass conversion into biocrude which could be operated with a wide range of feedstock resources. However, HTL biocrude characteristics including viscosity, density, heating value, composition and stability are not comparable with conventional products. The current focus for upgrading mainly relates to catalytic and hydrogenation processes; however, physical processes are cheaper and more reliable. Fractional distillation has potential as a cost-efficient physical technique for biocrude upgrading or even co-processing with crude oil in a refinery. This review summarises and discusses changes in physical and chemical properties of biocrude using fractional distillation. Distillation reduces the oxygen content of biocrude for heavy fractions more than 53% on average. It also decreases the sulphur and nitrogen content of biocrude up to 5–44%. The potential role of distillation in preparing fuel suitable for diesel engines is investigated. The challenges and technical limitations in HTL biocrude application in industry are also discussed alongside with possible solutions and future research potential which addresses these challenges. Highlights: The Hydrothermal liquefaction impact on biomass was investigated. The distillation studies in both Hydrothermal liquefaction and pyrolysis were categorised and studied. Distillation could be helpful in more accurate biocure characterisation by separating the biocrude into simpler fractions. Distillation showed a possible impact on biocrude HHV, elemental content, viscosity and stability. Distillation may improve the current unacceptable biocrude diesel engine combustion both in emission and performance factors.