Cargando…

Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks

BACKGROUND: In this study, a two-step processing method (hydrothermal liquefaction followed by catalytic upgrading) was used to produce upgraded bio-oil. A comprehensive screening analysis of algal species, including four microalgae and four macroalgae, was conducted to bridge the gap between previo...

Descripción completa

Detalles Bibliográficos
Autores principales: Xu, Yu-Ping, Duan, Pei-Gao, Wang, Feng, Guan, Qing-Qing
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879921/
https://www.ncbi.nlm.nih.gov/pubmed/29619079
http://dx.doi.org/10.1186/s13068-018-1083-2
_version_ 1783311081895100416
author Xu, Yu-Ping
Duan, Pei-Gao
Wang, Feng
Guan, Qing-Qing
author_facet Xu, Yu-Ping
Duan, Pei-Gao
Wang, Feng
Guan, Qing-Qing
author_sort Xu, Yu-Ping
collection PubMed
description BACKGROUND: In this study, a two-step processing method (hydrothermal liquefaction followed by catalytic upgrading) was used to produce upgraded bio-oil. A comprehensive screening analysis of algal species, including four microalgae and four macroalgae, was conducted to bridge the gap between previous accounts of microalgae and macroalgae hydrothermal liquefaction and the upgrading process of the resulting crude bio-oils. RESULTS: Hydrothermal liquefaction using eight algal biomasses was performed at 350 °C for 1 h. The microalgae always produced a higher crude bio-oil yield than the macroalgae due to their high lipid content, among which Schizochytrium limacinum provided the maximum crude bio-oil yield of 54.42 wt%. For microalgae, higher amounts of N in the biomass resulted in higher amounts of N in the crude bio-oil; however, contrary results were observed for the macroalgae. The crude bio-oils generated from both the microalgae and macroalgae were characterized as having a high viscosity, total acid number, and heteroatom content, and they were influenced by the biochemical compositions of the feedstocks. Next, all eight-crude bio-oils were treated at 400 °C for 2 h with 10 wt% Ru/C using tetralin as the hydrogen donor. The hydrogen source was provided after tetralin was transformed to naphthalene. All the upgraded bio-oils had higher energy densities and significantly lower N, O, and S contents and viscosities than their corresponding crude bio-oils. However, the H/C molar ratio of the upgraded bio-oils decreased due to the absence of external hydrogen relative to the crude bio-oils. The S content of the upgraded bio-oil produced from upgrading the Schizochytrium limacinum crude bio-oil was even close to the 50 ppm requirement of China IV diesel. CONCLUSIONS: Microalgae are better feedstocks than macroalgae for liquid fuel production. Biochemical components have a significant impact on the yield and composition of crude bio-oil. Tetralin does not perform as well as external hydrogen for controlling coke formation. The S content of the upgraded bio-oil can be reduced to 76 ppm for the crude bio-oil produced from Schizochytrium limacinum. Upgraded bio-oils have similar properties to those of naphtha and jet fuel. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13068-018-1083-2) contains supplementary material, which is available to authorized users.
format Online
Article
Text
id pubmed-5879921
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-58799212018-04-04 Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks Xu, Yu-Ping Duan, Pei-Gao Wang, Feng Guan, Qing-Qing Biotechnol Biofuels Research BACKGROUND: In this study, a two-step processing method (hydrothermal liquefaction followed by catalytic upgrading) was used to produce upgraded bio-oil. A comprehensive screening analysis of algal species, including four microalgae and four macroalgae, was conducted to bridge the gap between previous accounts of microalgae and macroalgae hydrothermal liquefaction and the upgrading process of the resulting crude bio-oils. RESULTS: Hydrothermal liquefaction using eight algal biomasses was performed at 350 °C for 1 h. The microalgae always produced a higher crude bio-oil yield than the macroalgae due to their high lipid content, among which Schizochytrium limacinum provided the maximum crude bio-oil yield of 54.42 wt%. For microalgae, higher amounts of N in the biomass resulted in higher amounts of N in the crude bio-oil; however, contrary results were observed for the macroalgae. The crude bio-oils generated from both the microalgae and macroalgae were characterized as having a high viscosity, total acid number, and heteroatom content, and they were influenced by the biochemical compositions of the feedstocks. Next, all eight-crude bio-oils were treated at 400 °C for 2 h with 10 wt% Ru/C using tetralin as the hydrogen donor. The hydrogen source was provided after tetralin was transformed to naphthalene. All the upgraded bio-oils had higher energy densities and significantly lower N, O, and S contents and viscosities than their corresponding crude bio-oils. However, the H/C molar ratio of the upgraded bio-oils decreased due to the absence of external hydrogen relative to the crude bio-oils. The S content of the upgraded bio-oil produced from upgrading the Schizochytrium limacinum crude bio-oil was even close to the 50 ppm requirement of China IV diesel. CONCLUSIONS: Microalgae are better feedstocks than macroalgae for liquid fuel production. Biochemical components have a significant impact on the yield and composition of crude bio-oil. Tetralin does not perform as well as external hydrogen for controlling coke formation. The S content of the upgraded bio-oil can be reduced to 76 ppm for the crude bio-oil produced from Schizochytrium limacinum. Upgraded bio-oils have similar properties to those of naphtha and jet fuel. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13068-018-1083-2) contains supplementary material, which is available to authorized users. BioMed Central 2018-04-02 /pmc/articles/PMC5879921/ /pubmed/29619079 http://dx.doi.org/10.1186/s13068-018-1083-2 Text en © The Author(s) 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Xu, Yu-Ping
Duan, Pei-Gao
Wang, Feng
Guan, Qing-Qing
Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
title Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
title_full Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
title_fullStr Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
title_full_unstemmed Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
title_short Liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
title_sort liquid fuel generation from algal biomass via a two-step process: effect of feedstocks
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879921/
https://www.ncbi.nlm.nih.gov/pubmed/29619079
http://dx.doi.org/10.1186/s13068-018-1083-2
work_keys_str_mv AT xuyuping liquidfuelgenerationfromalgalbiomassviaatwostepprocesseffectoffeedstocks
AT duanpeigao liquidfuelgenerationfromalgalbiomassviaatwostepprocesseffectoffeedstocks
AT wangfeng liquidfuelgenerationfromalgalbiomassviaatwostepprocesseffectoffeedstocks
AT guanqingqing liquidfuelgenerationfromalgalbiomassviaatwostepprocesseffectoffeedstocks