Hydrothermal carbonization of Biomass: New experimental procedures for improving the industrial Processes. (November 2017)

• Record Type: Journal Article
• Authors: Gallifuoco, Alberto; Taglieri, Luca; Scimia, Francesca; Papa, Alessandro Antonio; Di Giacomo, Gabriele
• Is Part Of: Bioresource technology. Volume 244:Part 1(2017)
• Page Start: 160
• Page End: 165
• Publication Date: 2017-11
• Subjects: Hydrothermal carbonization -- Silver fir -- Process optimization -- Liquid phase electrical conductivity -- Semi-empiric model equations; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2017.07.114
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: New experimental procedures for HTC industrial process optimization are presented. Liquid phase electrical conductivity is a key parameter for process monitoring. Simple, semi empirical equations with exceptionally good regressions are proposed. A process innovation is proposed introducing an additional flash expansion step. Abstract: This study aims to introduce new experimental methods, not yet described in the literature, to be adopted in hydrothermal carbonization processes. Silver fir was selected as model biomass in batch experiments in the range 200–300 °C, up to 120 min of reaction time, and at a 7:1 water to solid ratio. Simple equations were proposed for modeling the evolution of the process variables during the reaction, particularly the electrical conductivity of the liquid phase, correctly described by a simple two-step first order mechanism, regardless of the reaction temperature. At 200 °C, a perfect correspondence (R 2 = 0.9992) exists between liquid phase electrical conductivity and solid phase carbon content. The authors propose to monitor the industrial process withdrawing from the reactor the liquid and sampling its conductivity. The benefits of a flash expansion step between the reactor and the hydrochar drying units were discussed, and experiments demonstrated the usefulness of this process innovation.