Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4768574 | Fuel | 2017 | 7 Pages |
Abstract
In this study, a novel two-stage hydrothermal liquefaction (HTL) process was employed to produce low-nitrogen bio-crude oils from microalgae, involving pre-treatment of the microalgae with a pre-cooled NaOH/urea solution or a dilute acid and HTL of the pre-treated algal feedstock at 250°C for 10-50 min. The results indicated that the pre-treatment with a pre-cooled NaOH/urea solution effectively removed carbohydrates and protein from the raw microalgae, leading to a decrease in carbohydrates and protein content by 12 wt% and 10 wt% (both absolute values), respectively, while retaining 70 wt% of the solid mass, corresponding to as high as 82% carbohydrates removal efficiency and 40% protein removal efficiency. The two-stage HTL process slightly increased the overall bio-crude oil yields relative to the conventional single-stage HTL process, and the bio-crude oils obtained from the two-stage HTL process have a better quality than those obtained from the single-stage HTL, in terms of lower nitrogen and oxygen levels and higher energy content.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Yulin Hu, Shanghuan Feng, Chunbao (Charles) Xu, Amarjeet Bassi,