Influence of torrefaction after densification on the fuel characteristics and the inherited gasification kinetics of Erianthus arundinaceus energy grass

Abstract

In this study, a mixture of breeding lines of Erianthus arundinaceus energy grass was pretreated prior to gasification. Although biomass torrefaction and subsequent pelletizing of torrefied biomass (TOP process) have been studied in details, the torrefaction of pellets (TAP process) still in its infancy. Therefore, samples prepared by TAP, torrefaction‐only and pelletizing‐only were compared in terms of fuel characteristics and gasification kinetics. Results showed that the mass yield decreased with increasing torrefaction temperature, whereas the higher heating value (HHV) continued to increase with temperature, which can be seen in the evolution of O/C and H/C atomic ratios. Tradeoff between mass yield and HHV points to 250°C as the optimum torrefaction temperature, as mass yield above 76% could be achieved. TAP process was superior not only in terms of producing fuel with higher energy density, but also the gasification reactivity was higher than that of torrefied‐only or densified‐only samples, suggesting TAP is promising to be employed within the gasification process. Yet, conducting TAP under higher torrefaction temperatures may weaken the reactivity due to the more release of potassium during pyrolysis. Lastly, gasification kinetics data revealed that the pretreated samples exhibited slightly higher activation energy.

Synergetic Co-Production of Beer Colouring Agent and Solid Fuel from Brewers’ Spent Grain in the Circular Economy Perspective

“…However, thr relatively low N content (Figure 5) suggests that the content of proteins was not significant. Similar trends, in terms of the location on Van Krevelen's diagram with increased severity of torrefaction, were observed for various lignocellulosic species of biomass, such as wood [113,114], beechwood [115], miscanthus [115], Sida hermafrodita [97], Erianthus arundinaceus [96], pepper pellets [114], perilla stem pellets [114], and Kenaf [116].…”

“…Torrefaction of the BSG, performed within this study's scope, leads to the loss of dry mass of the material, which is typical for the process [95][96][97][98][99]. Mass yield depended on both the temperature of the process as well as residence time (Figure 2).…”

Effectiveness of Torrefaction By-Products as Additive in Vacuum Blackwater under Anaerobic Digestion and Economic Significance

“…However, there are challenges associated with the use of torrefied biomass. One major challenge is the low bulk density of torrefied biomass compared to raw biomass, which can make transportation and handling economically challenging [114]. Integrating torrefaction with densification processes such as pelletizing can address this challenge by increasing the bulk density and thus enhancing the efficiency of storing and transporting biomass to mix with the BW.…”