Issue 24, 2021

Liquid fuel production via supercritical water gasification of algae: a role for solar heat integration?

Abstract

Algal biomass is an attractive feedstock for carbon-neutral fuel production due to high growth rates and its potential to be farmed in artificial ponds on non-arable land. Supercritical water gasification (SCWG) of algae is appealing because it eliminates a drying step and offers fast kinetics, low char/tar rates, high carbon efficiency and good scale-up potential. Limited understanding of the algae breakdown mechanisms in SCWG, including kinetics and char formation, together with high pressures and temperatures, challenging for containment materials, make reactor design difficult. Dewatering and pumping of algae at high concentration in a cost-effective manner is also challenging. Integration of concentrated solar-thermal (CST) heat into SCWG of algae offers the potential for lower-cost fuel production, since CST is a cheaper energy source than unprocessed algae. However, CST heat integration is challenging due to the additional impact of sunlight variability. Integration of intermittent solar synthesis gas flows with downstream liquid-fuel processing such as the Fischer–Tropsch or methanol synthesis raises other challenges. Off-sun SCWG reactors downstream of a high-temperature salt storage offer future potential. The falling cost of green hydrogen input offers new opportunities to achieve lower-cost solar-SCWG system configurations. This review provides a general overview of algae-fed SCWG technology and challenges, then discusses CST-integrated SCWG of algae and its prospects for lower-cost liquid fuel production.

Graphical abstract: Liquid fuel production via supercritical water gasification of algae: a role for solar heat integration?

Article information

Article type
Review Article
Submitted
11 Oct 2021
Accepted
14 Oct 2021
First published
19 Oct 2021

Sustainable Energy Fuels, 2021,5, 6269-6297

Liquid fuel production via supercritical water gasification of algae: a role for solar heat integration?

M. B. Venkataraman, A. Rahbari, P. van Eyk, A. W. Weimer, W. Lipiński and J. Pye, Sustainable Energy Fuels, 2021, 5, 6269 DOI: 10.1039/D1SE01615F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements