# Influence of Hydrothermal Carbonization on Catalytic Fast Pyrolysis of Agricultural Biomass
## 3 Results and Discussion  
Hydrothermal Carbonization--Process Performance and Effect of HTC Treatment on Valorized Miscantthus  
Mass yields (Figure 3) obtained during the experimental investigation performed within the scope of this work were higher in comparison to results reported by the literature for HTC of miscanthus. [PERSON] et al. [81] reported mass yields of 73%, 54%, and 51% for HTC of miscanthus at 180 \({}^{\circ}\)C, 200 \({}^{\circ}\)C, and 220 \({}^{\circ}\)C, respectively. The residence time of HTC was 60 min for the aforementioned study [81]. Similarly, [PERSON] et al. [55] obtained a mass yield of approximately 58% for HTC of miscanthus at 200 \({}^{\circ}\)C, with a residence time of one hour. The same study reported a mass yield of approximately 40% for HTC of miscanthus at 250 \({}^{\circ}\)C, also performed with a residence time of one hour [82]. [PERSON] and [PERSON] [82] reported a mass yield of 80% for HTC of miscanthus at 180 \({}^{\circ}\)C, with a residence time of 4 h. The same study reported mass yields ranging between 65% and 63% for HTC of miscanthus at 200 \({}^{\circ}\)C, with residence times ranging between 2 and 12 h [82]. This suggests that for HTC of miscanthus residence times longer than two hours do not have any significant influence on the mass yield, and are not justified since the process is finished before that time. On the other hand, mass yields obtained in this study were much higher. This is well explained by the residence time of 10 min used for this study. Similar mass yields have been reported for HTC of miscanthus by other studies, where shorter residence times were applied. For instance, [PERSON] and [PERSON] [83] reported mass yields for HTC of miscanthus at 190 \({}^{\circ}\)C ranging between 82.8% and 66.6% for residence times between 5 and 30 min. Similarly, [PERSON] et al. [84] reported a mass yield of 79% for HTC of miscanthus at 200 \({}^{\circ}\)C, with a residence time of 5 min. Small differences between \(Y_{m}\) reported by studies performed with short residence times and this study could be attributed mainly to heating rates and, as a consequence, heating-up time for the reactor, as well as cooling-down times. The study of [PERSON] et al. [84] did not report either the heating up time or heating rate and only reported that the cooling was obtained by immersing the reactor in an ice bath. On the other hand, the study of [PERSON] and [PERSON] [83] reported that it took 20 to 30 min for their reactor to achieve desired temperatures. The same study also reported cooling down in cold water, taking between 5 and 7 min [83]. Since both studies used similar reactors, produced by Parr and controlled by a PID controller, it seems plausible that also, in the case of experiments performed by [PERSON] et al. [84], similar time was needed to heat up the reactor to desired temperature. This is much higher than the heating up times in this study (3.5 to 9 min), suggesting lower average heating rates achieved by [PERSON] et al. [84]. In such circumstances, it seems plausible to use this as an explanation of achieving higher \(Y_{m}\) by this study, especially for HTC at 180 \({}^{\circ}\)C, for which it took only 3.5 min to reach the desired temperature by the reactor, in comparison to 20 min for Kambo and Dutta [83].