Ash fusibility is closely associated with ash slagging, which has great significance on efficiency and cleanliness of thermal conversion and coal utilization. Not being a dominant component of coal ash, Na2O is believed to be an inducement for slagging problems. In this study, for the realization of better understanding of the underlying mechanisms, the influence of Na2O on the ash fusibility was investigated from the perspectives of content variation and temperature rising. Experimental approaches, such as ash fusion temperature (AFT) test, X-ray diffraction (XRD), and scanning electronic microscope (SEM), were applied to quantify the ash fusibility and detect minerals’ transformation and surface morphology in ash melting. The ash melting process was simulated by a multicomponent system based on the FactSage database, which includes SiO2–Al2O3–Fe2O3–CaO–Na2O. This study also used Gibbs free energy theory to analyze the chemical reactions, mineral behaviors, and phase diagram and record the sodium migration in the melting process. In general, Na2O reduces the fusion temperatures of ash samples, which can be related to the performances of minerals albite, nepheline, and anorthite, as well as the eutectics they form.

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Excretion of 1,3-propanediol (1,3-PD) by K. pneumoniae was compared in ammonium- and phosphate-limited chemostat cultures running with an excess of glycerol. 59 and 43% catabolic flux were directed to 1,3-PD in ammonia-limited cultures and phosphate-limited cultures at dilution rate of 0.1 h(-1), respectively. Ammonia-limited fed-batch cultures produced 61 g 1,3-PD l(-1) and a total of 15 g l(-1) organic acid in 36 h. However, phosphate-limited fed-batch cultures excreted 61 g lactate l(-1) and 44 g 1,3-PD l(-1).

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Load frequency stability is an important power quality index in power system, any sudden load disturbance will cause the system load frequency deviation, and as the power system becomes more complex, the difficulty of control is also increasing, it is necessary to find a more appropriate control method. Considering that the load frequency control system model has the characteristics of multi-variable and strong coupling, combines the superior anti-interference and anti-coupling ability of the active disturbance rejection control, a novel scheme for power system load frequency control was presented based on the principle of active disturbance rejection control and effective open-loop transfer function. The simulation results show that the proposed method is simple tuning and strong decoupling ability, and provides a successful control of load frequency.