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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Bioproducts Research » Research » Publications at this Location » Publication #343735

Title: Hydrothermal carbonization of autoclaved municipal solid waste pulp and anaerobically treated pulp digestate

Author
item REZA, M. TOUFIQ - Ohio University
item CORONELLA, CHARLES - University Of Nevada
item Holtman, Kevin
item Franquivillanueva, Diana
item POULSON, SIMON - University Of Nevada

Submitted to: ACS Sustainable Chemistry & Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2016
Publication Date: 6/24/2016
Citation: Reza, M., Coronella, C., Holtman, K.M., Franqui-Villanueva, D.M., Poulson, S.R. 2016. Hydrothermal carbonization of autoclaved municipal solid waste pulp and anaerobically treated pulp digestate. ACS Sustainable Chemistry & Engineering. 4(7):3649-3658. doi: 10.1021/acssuschemeng.6b00160.

Interpretive Summary: This study is part of a larger program in which solid wastes, including municipal solid waste (MSW) is converted to bioenergy by application of autoclaving (steam-cooking) as pretreatment protocol. In this study, two streams were isolated from the MSW-treatment protocols; (1) the autoclaved organic fraction of municipal solid waste (OFMSW) and the digestate from OFMSW pulp after it has been treated by anaerobic digestion (AD). Hydrothermal carbonization (HTC) of these streams at 200, 250, and 300 °C for 30 min and 2 h was applied to create an energy-dense solid hydrochar from these two streams, so that these could further be used as biofuels; i.e. as alternatives to coal in a utility plant, for example. The fate of inorganics, especially the heavy metals in hydrochar, is critically important and highlighted in this report. In addition, other (aqueous) products were analyzed to identify the chemicals produced and the chemical changes during HTC. From an array of measurement protocols, it was concluded that the hydrochar becomes increasingly richer energy with an increase HTC temperature over the range studied.

Technical Abstract: In this study, the autoclaved organic fraction of municipal solid waste pulp (OFMSW) and the digestate from OFMSW pulp after anaerobic digestion (AD) were processed by hydrothermal carbonization (HTC) at 200, 250, and 300 °C for 30 min and 2 h. The focus of this work was to evaluate the potential for producing an energy-dense solid hydrochar from either OFMSW or digestate by HTC. The fate of inorganics, especially the heavy metals in hydrochar is discussed. In addition, the aqueous products were analyzed to identify the chemicals produced and the chemical changes during HTC. A carbon balance was performed from the solid and liquid phase analyses. Moreover, two conceptual MSW treatments consisting of autoclaving with or without AD, but including HTC, were proposed and mass and energy balances were performed. From the proximate, ultimate, FTIR, and fiber analyses, the hydrochar becomes increasingly energy and inorganic dense with the increase of HTC temperature.