Fig. 7. Profiles of local reaction rate of devolatilization within the particle at various overall conversions at Tr = 1173 K. (a) Wood log with the diameter of 14.5 mm, and (b) Sulfo-NHS-LC-Biotin pellets with the diameter of 8 mm.Figure optionsDownload full-size imageDownload as PowerPoint slide
4.3. Devolatilization temperature
Devolatilization temperature is characterized as the local temperature where the maximum rate of devolatilization appears throughout the particle at any given time (see Fig. 7). It is important information because we assume that the devolatilization temperature remains constant regardless the location of reaction front in the SCM. Fig. 8 shows the devolatilization temperature at various overall conversions obtained from the detailed particle simulation. It stayed almost constant temperature throughout the conversion, showing prothallus constant devolatilization temperature is a reasonable assumption. Therefore, method for the estimation of devolatilization temperature is necessary for the application of the SCM. Several methods were found in the literature  and . However, no method gave reasonable values compared with the devolatilization temperature of detailed particle simulation (Fig. 8).
In order to verify the existence of ineffective chlorine, humic tsa trichostatin solutions with different DOC concentrations were prepared to react with free chlorine. The DOC, TDN, NO3−, NO2− and NH4+ values of humic acid stock solution were determined as 22.7 mg-C/L, 1.1 mg-N/L, 0 mg-N/L, 0.03 mg-N/L and 0.05 mg-N/L, respectively, and the DON was calculated as 1.0 mg-N/L with DON/DOC mass ratio of 0.04. Based on the previous study, organic chloramines were formed fast during chlorination at the first hour . Because ineffective chlorine is one part of organic chloramines, the chlorination time in this study was set as 30 min at initial free chlorine dose of 5 mg/L as Cl2 and pH 7.0 controlled by 5 mM phosphate buffer. As Fig. 3 shows, the total residual chlorine decreased as DOC increased from to 15 mg-C/L, but the ineffective chlorine quantified after the proposed NaAsO2 quenching method increased from <0.02 to 0.08 mg/L as Cl2. The results indicated that ineffective chlorine existed at an unnegligible proportion in total chlorine, which increased with increasing DOC concentration during chlorination. From Fig. 3, with the increase of DOC, the free chlorine concentration decreased obviously while [NH2Cl] and [NHCl2] + [Organic chloramines] increased slightly (NHCl2 and organic chloramines were put together because they were indivisible). At DOC concentrations higher than 10 mg-C/L (corresponding to DON ? 0.4 mg-N/L), almost all free chlorine was consumed, but the concentration of ineffective chlorine kept increasing, which indicated that ineffective chlorine could be produced fast before free chorine was totally consumed, and spindle apparatus could exist stably during the whole chlorination process. Otherwise, ineffective chlorine concentration should decline due to the shortage of free chlorine and the competitive reactions between chlorine and other organic compounds.
The connection of liquid phase sonochemistry and non-spherical bubble dynamics has been highlighted also in other types of reactions. Sonoluminescence emissions of excited alkali metals from dissolved salts in water or acids are as well interpreted as a signature of liquid–gas mixture in the collapsing bubble, as the metal ions are non-volatile , , , ,  and . In some works a correlation of bubble translational motion and emission lines like Na∗ has been observed, which can as well be interpreted as a source of non-spherical dynamics. In particular a forward jetting collapse of a sufficiently fast moving bubble has been predicted  and  and observed , and the jetting seems to be an appropriate collapse modality of bubbles in sulphuric Nilotinib to emit the Na∗ line . The jetting mechanism as a source of liquid micro-drop injection into the hot gas phase has also been proposed by Troia et al. for the CCl4 decomposition in the Weissler type reaction , even though for a single levitated bubble. Recently, hints have been found recombinant DNA technology few-bubble cluster dynamics can boost emission of metal lines in aqueous solutions of the corresponding salts  and . Possible mechanisms of the liquid–gas mixture apart from jetting are surface shape (modal) oscillations , bubble splitting, and bubble coalescence. All these mechanisms might be contributing in the chemically active few-bubble clusters we observe, but discrimination between the different scenarios is not yet possible. Some subjective visual impressions from high-speed movies tend to the opinion that surface modes are a main agent, and that mainly or only the largest cluster bubble is really active.
The use of Ca(OH)2 pre-treatment increased the biomethane production from all the particle sizes tested in this study. Over the initial 5 days of agenerase the average rate of biomethane production resulting from 3, 2 and 1.25 mm straw was 40.45 NmL-CH4 g-VS−1 d−1. This rate was more than 4-fold the average rate of methane production over the same periods from the milled-only 10 mm straw. Although gas potential yields from the alkaline pre-treated 10 mm wheat straw were significantly lower than all the other particle sizes in the initial 5 days of digestion time, the larger particle size produced a similar amount of gas to the 1.25 mm cut at the 15-day time-point and was only significantly lower than the 2 mm milled particle sizes by day 30. The final biomethane potential yields achieved after Ca(OH)2 pre-treatment of wheat straw with 30 days of anaerobic digestion were 301 ± 4, 313 ± 2, 320 ± 10 and 305 ± 17 NmL-CH4 g-VS−1 from 10, 3, 2 and 1.25 mm milled straw sizes, respectively.