Hydrothermal liquefaction of four brown macro-algae commonly found on the UK coasts: An energetic analysis of the process and comparison with bio-chemical conversion methods. (1st January 2015)

• Record Type: Journal Article
• Authors: Anastasakis, K.; Ross, A.B.
• Is Part Of: Fuel. Volume 139(2015)
• Page Start: 546
• Page End: 553
• Publication Date: 2015-01-01
• Subjects: Macro-algae -- Liquefaction -- Hydrothermal -- Energy balance -- Seaweed; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2014.09.006
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Bio-crudes and bio-chars were produced from hydrothermal liquefaction of four brown macro-algae. A new approach of studying the energy balance of the hydrothermal process was introduced. Reactor loading (biomass and water) and temperature have a big influence in energy balance. HTL of L. saccharina and A. esculenta exhibited the best energy balance. HTL has higher energy output than fermentation and similar with AD. Abstract: Hydrothermal liquefaction (HTL) of four brown macro-algae was used to produce bio-crude and bio-char in an energy favorable way. Bio-crude yields between 9.8 wt% and 17.8 wt% (daf) with HHVs between 32 and 34 MJ/kg and bio-char yields between 10.9 wt% and 18.6 wt% (db) with HHVs between 15.7 and 26.2 MJ/kg were produced. A modification of the energy consumption ratio (ECR) index was attempted in order to include in the formula the calculation of the specific heat capacity of the feedstock used, as well as the increase of the specific heat capacity of water with temperature. A comparison in terms of energy output was made between the products from HTL and products from bio-chemical conversion of macro-algae such as anaerobic digestion (AD) and fermentation. The results indicate that HTL has higher energy output than fermentation and analogue of that from anaerobic digestion (7.91 MJ/kgseaweed and 8.25 MJ/kgseaweed from HTL and AD respectively).