Abstract

The treatment and disposal of grape marc, a residue from grape processing, represents a significant economic and environmental challenge for the winemaking industry. Hydrothermal treatment of grape marc could be an efficient way for producing solid fuels on-site at the wineries. In this work the effects of treatment temperature and liquid pH on grape marc char and liquid properties were determined based on laboratory experiments and the combustion characteristics of char were assessed through thermogravimetric analysis and fuel ash classification. The results showed that hydrothermal treatment increased the energy and carbon contents and decreased the ash content of grape marc. The effect of liquid pH was statistically significant (p < 0.05) only for the determined carbon yield of liquid samples. The energy yield from grape marc was maximized at lower treatment temperatures, which also decreased the content of less thermally stable compounds in the attained char. Higher treatment temperatures decreased grape marc solid, carbon and energy yields and led to an increase in thermally labile compounds compared to lower temperatures likely due to the condensation of liquid compounds or volatiles trapped in the pores of char particles. The alkali metal contents of char ash were reduced coupled with an increase in respective phosphorus. Overall the results support the use of hydrothermally treated grape marc in solid fuel applications, if elevated levels of ash phosphorus can be tolerated. (C) 2017 Elsevier Ltd. All rights reserved.

Keywords

Combustion behavior; Grape pomace; Hydrothermal carbonization; Response surface methodology; Thermogravimetric analysis; Wet torrefaction

Published in

Energy Conversion and Management
2017, Volume: 145, pages: 371-377
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Mäkelä, Mikko

  • Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences
    
  • Tokyo Institute of Technology

Sustainable Development Goals

Ensure access to affordable, reliable, sustainable and modern energy for all


UKÄ Subject classification

Renewable Bioenergy Research


Publication identifier

DOI: https://doi.org/10.1016/j.enconman.2017.05.015

Permanent link to this page (URI)

https://res.slu.se/id/publ/91431