After optimization using percolation theory, excellent absorbing properties (90% absorption) were achieved for Ni/C nanocomposites with advantages such as thin thickness (1.75 and 1.5 mm) and light weight (25 and 30 wt%).

A three-dimensional numerical investigation is presented on the coal combustion and NO x emission in a supercritical 600 MW wall fired utility boiler fed with lean coal. The distributions of velocity, temperature, and species were obtained using a finite volume method and some validated submodels. The influence of air staging condition, i.e., overfire air (OFA) ratio and OFA port position, on combustion and especially on NO x emission was studied. The temperature of the burner zone and the carbon content in fly ash increased with increasing OFA ratio, while the NO x emission decreased with increasing OFA ratio. An increase of the OFA port position resulted in a decrease of NO x emission and an increase of carbon content in fly ash. In addition, high burnout rate of pulverized coal and low NO x emission can be achieved in the present boiler, in which OFA was injected from Port 3 with a ratio of 34.2%. This study provides new insights into the physical and chemical processes in a wall fired utility boiler fed with lean coal and also illustrates a method to reduce NO x emission.

Epoxy composite coatings filled with fillers have been used extensively as anticorrosion materials. In this study, an alternating multilayer structure is designed to obtain multifunctional epoxy resin composite coating based on stepwise coating method via adding graphene and α‐alumina. Their mechanical properties, thermal conductivity, dielectric and anticorrosion properties are characterized. The toughness and the thermal conductivity clearly increase, while the dielectric properties decrease approximately to zero when the filler mass fraction increases from 0.00% to 0.15%. The whole corrosion process is controlled by electrochemical reaction, and the fillers effectively block the corrosive medium, thus improving the anticorrosion performance of the composite coating.

It is of great importance to clarify the effect of the combustion temperature in actual boilers on air-staging combustion of coals. In this work, a novel vertical tandem-type drop-tube furnace system was set up, in which a temperature of as high as 1600 °C can be achieved. Experimental investigations were performed thoroughly with particular attention to NO x formation and unburned carbon in ash. The results indicate that, to maximize NO x removal efficiency by air-staged combustion, the reducing zone should be under high temperature and strong reducing atmosphere (HT&SRA) conditions. A remarkably low NO x emission and high coal burnout can be attained concurrently by creating HT&SRA conditions in the fuel-rich zone. The NO x emission for high-volatile coals can be below 150 mg/m 3 . The special role of the temperature is discussed in detail in terms of the difference of NO x formation between the reducing zone exit and burnout zone exit. For comparison, the NO x emission in Ar/O 2 -and oxy-fuel-staged combustion was also studied. Staged combustion is as effective for NO x reduction in Ar/O 2 and oxyfuel as in air combustion. However, for oxy-fuel-staged combustion, the effect of HT&SRA conditions presents some differences, which are closely related with the oxygen proportion in the gas atmosphere. In addition, it is also found that the temperature in the burnout zone (800−1200 °C) has a weak effect on NO x generation, but CO emission would drastically increase when it is below 1100 °C.

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