Process water recirculation during hydrothermal carbonization as a promising process step towards the production of nitrogen-doped carbonaceous materials

Dominik, Wüst ; Arauzo, Pablo ; Habicht, Sonja ; Cazaña, Fernando (Universidad de Zaragoza) ; Fiori, Luca ; Kruse, Andrea

Resumen: Hydrothermal Carbonization (HTC) refers to the conversion of biogenic wastes into char-like solids with promising perspectives for application, but a process water (PW) results which is difficult to dispose untreated. Thus, a biorefinery approach including one or two recirculation steps with the additional objective of improving the physico-chemical characteristics of the solid was performed in this study. During HTC, constitutive molecules such as saccharides, proteins and lignin of Brewer''s Spent Grains decompose into hundreds of organic compounds, following complex reactions. To get deeper insights a combination of proximate, ultimate and structural analysis for solid products as well as liquid chromatography for liquid products were the choice. The main reactions could be identified by key compounds of low and high molecular weight resulting from hydrolysis, dehydration, decarboxylation, deamination as well as amide formation and condensation reactions. Their intensity was influenced by the feedwater pH and reaction temperature. Via reactions of Maillard character up to around 90% of the dissolved nitrogen of the recirculated process water at 200, 220 and 240 degrees C result in the formation of nitrogen containing heterocycles or rather Quartnernary nitrogen incorporated into the hydrochar (HC). Thus, already one recirculation step during HTC at 240 degrees C promises the fabrication of high added-value materials, i.e. nitrogen doped carbonaceous materials.

Idioma: Inglés

DOI: 10.1007/s12649-021-01603-x

Año: 2022

Publicado en: WASTE AND BIOMASS VALORIZATION 13 (2022), 2349–2373
ISSN: 1877-2641

Factor impacto JCR: 3.2 (2022)

Categ. JCR: ENVIRONMENTAL SCIENCES rank: 146 / 275 = 0.531 (2022) - Q3 - T2

Factor impacto CITESCORE: 6.9 - Energy (Q2) - Environmental Science (Q1)

Factor impacto SCIMAGO: 0.599 - Environmental Engineering (Q2) - Waste Management and Disposal (Q2) - Renewable Energy, Sustainability and the Environment (Q2)

Tipo y forma: Article (Published version)

Área (Departamento): Área Ingeniería Química (Dpto. Ing.Quím.Tecnol.Med.Amb.)