Hydrogen Production by Catalytic Supercritical Water Gasification of Black Liquor-Based Wastewater

Hary Demey (), Gilles Ratel, Bruno Lacaze, Olivier Delattre, Geert Haarlemmer and Anne Roubaud
Additional contact information
Hary Demey: CEA, LITEN, DTCH, Laboratoire Réacteurs et Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France
Gilles Ratel: CEA, LITEN, DTCH, Laboratoire Réacteurs et Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France
Bruno Lacaze: CEA, LITEN, DTCH, Laboratoire Réacteurs et Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France
Olivier Delattre: CEA, LITEN, DTCH, Laboratoire Réacteurs et Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France
Geert Haarlemmer: CEA, LITEN, DTCH, Laboratoire Réacteurs et Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France
Anne Roubaud: CEA, LITEN, DTCH, Laboratoire Réacteurs et Procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France

Energies, 2023, vol. 16, issue 8, 1-13

Abstract: In this work, the wastewater obtained from the hydrothermal liquefaction of black liquor was treated and valorized for hydrogen production by supercritical water gasification (SCWG). The influence of the main process parameters on the conversion yield was studied. The experiments were conducted at three different temperatures (below and above the critical point of water): 350 °C, 450 °C and 600 °C. The results showed that by increasing the temperature from 350 °C to 600 °C, the total gas yield was highly improved (from 1.9 mol gas/kg of dried feedstock to 13.1 mol gas/kg of dried feedstock). The H 2 composition was higher than that of CH 4 and CO 2 at 600 °C, and the HHV of the obtained gas was 61.2 MJ/kg. The total organic carbon (TOC) removal efficiency was also improved by increasing the temperature, indicating that the SCWG process could be used for both applications: (i) for wastewater treatment; (ii) for producing a high calorific gas. The experiments with the Raney-nickel catalyst were performed in order to study the catalyst’s influence on the conversion yield. The results indicated that the catalyst enhances carbon conversion and gas production from mild to higher temperatures. The maximum total gas yield obtained with this catalyst was 32.4 mol gas/kg of dried feedstock at 600 °C, which is 2.5 times higher than that obtained at the same operating conditions without a catalyst. The H 2 yield and the HHV of the obtained gas with the catalyst were 20.98 mol gas/kg dried feedstock and 80.2 MJ/kg, respectively. However, the major contribution of the catalytic SCWG process was the improvement of the total gas yield at mild operating temperatures (450 °C), and the obtained performance was even higher than that obtained at 600 °C without catalyst (17.81 mol gas/kg dried feedstock and 13.1 mol gas/kg dried feedstock, respectively). This is a sustainable approach for treating wastewater at mild temperatures by catalytic SCWG.

Keywords: black liquor; catalyst; supercritical water gasification (SCWG); wastewater treatment; hydrogen production (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.mdpi.com/1996-1073/16/8/3343/pdf (application/pdf)
https://www.mdpi.com/1996-1073/16/8/3343/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:16:y:2023:i:8:p:3343-:d:1119421

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().