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16 results on '"Madsen, René B."'

7. Hydrothermal Liquefaction of Enzymatic Hydrolysis Lignin: Biomass Pretreatment Severity Affects Lignin Valorization

Author

Jensen, Mads M., primary, Djajadi, Demi T., additional, Torri, Cristian, additional, Rasmussen, Helene B., additional, Madsen, René B., additional, Venturini, Elisa, additional, Vassura, Ivano, additional, Becker, Jacob, additional, Iversen, Bo B., additional, Meyer, Anne S., additional, Jørgensen, Henning, additional, Fabbri, Daniele, additional, and Glasius, Marianne, additional

Published
2018
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15. Continuous Hydrothermal Liquefaction of Biomass in a Novel Pilot Plant with Heat Recovery and Hydraulic Oscillation.

Author

Anastasakis, Konstantinos, Biller, Patrick, Madsen, René B., Glasius, Marianne, and Johannsen, Ib

Subjects
BIOMASS liquefaction, BIOMASS energy, LIQUEFACTION (Physics), CONTINUOUS flow reactors, FLUIDIZED bed reactors
Abstract

Hydrothermal liquefaction (HTL) is regarded as a promising technology for the production of biofuels from biomass and wastes. As such, there is a drive towards continuous-flow processing systems to aid process scale-up and eventually commercialization. The current study presents results from a novel pilot-scale HTL reactor with a feed capacity of up to 100 L/h and a process volume of approximately 20 L. The pilot plant employs a heat exchanger for heat recovery and a novel hydraulic oscillation system to increase the turbulence in the tubular reactor. The energy grass Miscanthus and the microalgae Spirulina, both representing advanced dedicated energy crops, as well as sewage sludge as high-potential waste stream were selected to assess the reactor performance. Biomass slurries with up to 16 wt% dry matter content were successfully processed. The heat recovery of the heat exchanger is found to increase with reactor run time, reaching 80% within 5–6 h of operation. The hydraulic oscillation system is shown to improve mixing and enhance heat transfer. Bio-crudes with average yields of 26 wt%, 33 wt% and 25 wt% were produced from Miscanthus, Spirulina and sewage sludge, respectively. The yields also appeared to increase with reactor run time. Bio-crude from HTL of Spirulina was mainly composed of palmitic acid, glycerol, heptadecane and linolelaidic acid, while biocrude from sewage sludge contained mainly palmitic acid, oleic acid and stearic acid. In contrast, biocrude from HTL of Miscanthus consisted of a large number of different phenolics. An energetic comparison between the three feedstocks revealed a thermal efficiency of 47%, 47% and 33% and energy return on investment (EROI) of 2.8, 3.3 and 0.5 for HTL of Miscanthus, Spirulina and sewage sludge, respectively. [ABSTRACT FROM AUTHOR]

Published
2018
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16. Hydrothermal Liquefaction of Enzymatic Hydrolysis Lignin: Biomass Pretreatment Severity Affects Lignin Valorization

Author

Bo B. Iversen, Cristian Torri, Henning Jørgensen, Mads Møller Jensen, René B. Madsen, Demi T. Djajadi, Marianne Glasius, Jacob Becker, Elisa Venturini, Anne S. Meyer, Daniele Fabbri, Ivano Vassura, Helene B. Rasmussen, Jensen, Mads M., Djajadi, Demi T., Torri, Cristian, Rasmussen, Helene B., Madsen, René B., Venturini, Elisa, Vassura, Ivano, Becker, Jacob, Iversen, Bo B., Meyer, Anne S., Jørgensen, Henning, Fabbri, Daniele, and Glasius, Marianne

Subjects
Hydrothermal pretreatment, 020209 energy, General Chemical Engineering, Principal component analysis, GAS-CHROMATOGRAPHY, Biomass, Base-catalyzed depolymerization, Principal component analysi, BIO-OIL, 02 engineering and technology, CHEMICALS, KRAFT LIGNIN, chemistry.chemical_compound, Size exclusion chromatography, Enzymatic hydrolysis, PARAFAC2, 0202 electrical engineering, electronic engineering, information engineering, Lignin, Environmental Chemistry, Chemical Engineering (all), biology, Chemistry, Depolymerization, Renewable Energy, Sustainability and the Environment, Chemistry (all), food and beverages, MASS-SPECTROMETRY, General Chemistry, Miscanthus, Straw, 021001 nanoscience & nanotechnology, Biorefinery, biology.organism_classification, CONVERSION, Hydrothermal liquefaction, Thermogravimetry, GC-MS, ORGANOSOLV LIGNIN, 0210 nano-technology, SUPERCRITICAL WATER, Nuclear chemistry
Abstract

Alkaline hydrothermal liquefaction (HTL) of lignin rich enzymatic hydrolysis residues (EnzHR) from wheat straw and Miscanthus x giganteus was performed at 255, 300, and 345 degrees C to investigate valorization of this side-stream from second-generation bioethanol production. The EnzHR were from biomass hydro thermally pretreated at two different levels of severity (190 degrees C, 10 min or 195 degrees C, 15 min), and HTL at 300 degrees C of these EnzHR showed the most effective lignin depolymerization of the low severity EnzHR for both wheat straw and Miscanthus. The degree of depolymerization during HTL was temperature dependent and was not complete after 20 min at 255 degrees C, most distinctly for the Miscanthus EnzHR. The yields of 128 monomeric products quantified by gas chromatography mass spectrometry were up to 15.4 wt % of dry matter. Principal component analysis of the quantified compounds showed that nonlignin HTL products are main contributors to the variance of the HTL products from the two biomasses. The chemically modified lignin polymer was found to have increased thermal stability after HTL. Analytical pyrolysis was applied to investigate the chemical composition of a larger fraction of the products. Analytical pyrolysis contributed with additional chemical information as well as confirming trends seen from quantified monomers. This work is relevant for future lignin valorization in biorefineries based on current second-generation bioethanol production.

Published
2018
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