Experimental Investigations of Physical and Chemical Properties for Microalgae HTL Bio-Crude Using a Large Batch Reactor

Energies

Richard J. Brown¹  Jana Kosinkova¹  Zoran Ristovski¹  Thomas J. Rainey¹  Farhad M. Hossain¹  Ben Hankamer²  Evan Stephens² 

[1] Biofuel Engine Research Facility, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia;The Institute for Molecular Bioscience, University of Queensland, 306 Carmody Road, St. Lucia, QLD 4072, Australia;

关键词: microalgae;    hydrothermal liquefaction (HTL);    bio-crude;    fatty acid methyl esters (FAME);    fuel properties;   

DOI  :  10.3390/en10040467

来源: DOAJ

【 摘 要 】

As a biofuel feedstock, microalgae has good scalability and potential to supply a significant proportion of world energy compared to most types of biofuel feedstock. Hydrothermal liquefaction (HTL) is well-suited to wet biomass (such as microalgae) as it greatly reduces the energy requirements associated with dewatering and drying. This article presents experimental analyses of chemical and physical properties of bio-crude oil produced via HTL using a high growth-rate microalga Scenedesmus sp. in a large batch reactor. The overarching goal was to investigate the suitability of microalgae HTL bio-crude produced in a large batch reactor for direct application in marine diesel engines. To this end we characterized the chemical and physical properties of the bio-crudes produced. HTL literature mostly reports work using very small batch reactors which are preferred by researchers, so there are few experimental and parametric measurements for bio-crude physical properties, such as viscosity and density. In the course of this study, a difference between traditionally calculated values and measured values was noted. In the parametric study, the bio-crude viscosity was significantly closer to regular diesel and biodiesel standards than transesterified (FAME) microalgae biodiesel. Under optimised conditions, HTL bio-crude’s high density (0.97–1.04 kg·L−1) and its high viscosity (70.77–73.89 mm2·s−1) had enough similarity to marine heavy fuels. although the measured higher heating value, HHV, was lower (29.8 MJ·kg−1). The reaction temperature was explored in the range 280–350 °C and bio-crude oil yield and HHV reached their maxima at the highest temperature. Slurry concentration was explored between 15% and 30% at this temperature and the best HHV, O:C, and N:C were found to occur at 25%. Two solvents (dichloromethane and n-hexane) were used to recover the bio-crude oil, affecting the yield and chemical composition of the bio-crude.

【 授权许可】

Unknown