In situ hydrothermal synthesis of MnO2 nanowires/wood derived activated carbon hollow fibers composite and its application in supercapacitor

Composite electrode material composed of MnO2 nanowires and wood-derived activated carbon hollow fibres (Mn@ACHFs) was successfully fabricated by in situ hydrothermal method. In this work, MnO2 nanowires were developed by adjusting the mass ratio of potassium permanganate and wood activated carbon hollow fibres (ACHF). The ACHF with hierarchical porous structure served not only as the support for the growth of MnO2 particles, but also as the electric double layer capacitance for the composite electrode. The Mn@ACHFs exhibited an outstanding specific capacitance of 420 F.g-1 at 1 A.g-1 and cycle stability with 99.7% capacitance retention after 5000 cycles at 5 A.g-1. Electrochemical characteristics of the prepared composites are attributed to the synergetic effect of the double layer capacitance of the hierarchical porous ACHF and the layered structure of MnO2, which can efficiently enhance the conductivity and stability of the electrodes.

Analysis of the formation and primary minimization of nitrogen oxides during the combustion of nitrogen-rich post-consumer wood waste

The article presents research on mechanism of formation of nitric oxide during combustion of wood derivative wastes in grid furnace boilers including waste incineration plants. Considering their elemental composition (large amount of nitrogen) they require supervision in thermal processes for their treatment. Concentrations of the formed nitric oxides, depending on the parameters of the combustion process and the size of the combusted grains, were subject to evaluation. The source of nitrogen in tested wastes is urea-formaldehyde resin used as a joint. The tests proved that the dominant mechanism is fueling mechanism for formation of nitrogen oxides. It is possible to limit this mechanism with original methods that interfere directly into the combustion process in the chamber (following temperature regime, granulation and humidity of the waste, intensity of mixing waste on the grill, stream of original air in the amount adjusted to the combustion phase in the grill). The article specifies main recommendations for the conduction of thermal transformation of wastes minimizing fuel nitric oxides.