
CPOTE2020
6th International Conference on
Contemporary Problems of Thermal Engineering
Online | 21-24 September 2020
6th International Conference on
Contemporary Problems of Thermal Engineering
Online | 21-24 September 2020
Abstract CPOTE2020-1092-A
Book of abstracts draft






A two-stage processing of cherry pomace via hydrothermal treatment followed by biochar gasification
Mariusz WĄDRZYK, AGH University of Science and Technology, PolandPrzemysław GRZYWACZ, AGH University of Science and Technology, Poland
Rafał JANUS, AGH University of Science and Technology, Poland
Marek MICHALIK, Jagiellonian University, Poland
The development of a new sustainable approach for the conversion of problematic waste residuals generated by agriculture as well as industry is among the global most challenging issues. Herein, we proposed a two-stage processing route for the conversion of cherry pomace being an exemplary high-moisture-containing material. Firstly, we transformed the feedstock into biochar via hydrothermal processing. The aim of this stage was to analyze the effect of processing temperature (200-350 °C) on the distribution of the yield of various groups of products. Among the gas-phase products, the dominant constituent was CO2. The residual solid called biochar was obtained with the highest yield (33-57 wt.%). The upgrading of the biochar was the subsequent step we aimed. For this purpose, we made an attempt to evaluate the feasibility of gasification of the biochar with CO2 using Rubotherm DynTHERM thermobalance (TG). The tests were carried out under elevated pressure (10 bar) with a constant flow rate of CO2 (100 ml/min) and constant heating rate (3 °C/min) from ambient temperature to 1000 °C. Herein, the main aim was to study the influence of the processing temperature at which biochar was produced on the gasification kinetics. We tested the composition of the biochars by means of ultimate analysis. The chemistry of the hydrochar surface was examined by infrared spectroscopy (FT- IR) within the spectral range of 600-4000 cm-1. It was found that the gasification process consists of two stages: pyrolysis (at ca. 300-600 °C) and main gasification reactions (at ca. 850-1000 °C). Based on TG analysis, the kinetic parameters i.e. activation energy and pre-exponential factor were calculated, which ranged between 501.8 kJ/mol to 543.6 kJ/mol and 9.8∙10^20 min-1 to 7.8∙10^22 min-1, respectively. It was found that the carbon content of resultant biochars increases with rising processing temperature from 56.5 wt.% to 74.4 wt.% for 200 °C and 300 °C, respectively. The biochars produced at different conditions exhibit various properties as a result of a gradual degradation of the original components of the raw material occurring with the increase in the processing temperature.
Keywords: Biomass conversion, Industrial waste valorisation, Hydrothermal treatment, Biomass gasification, Sustainability of biofuels production
Acknowledgment: This paper was prepared as a part of the research subsidy of the Faculty of Energy and Fuels at the AGH University of Science and Technology under project number 16.16.210.476. The research was carried out using the infrastructure of the AGH Centre of Energy, AGH University of Science and Technology.