Experiments of dense-phase pneumatic conveying of two fuel powders (Jinling petroleum coke and Huaibei anthracite coal) using nitrogen were carried out in an experimental facility including top-discharge and bottom-discharge blow tanks with design pressure up to 6.4 MPa. Petroleum coke and anthracite coal, which are widely used as attractive feed stocks for gasification, were chosen as conveying materials. The effect of blow tank type and powder properties on conveying characteristics at high pressure were investigated. Meanwhile, comparisons of conveying capacity, conveying stability and power consumption between these two kinds of blow tanks and the two fuel powders were made. The results indicate that the top-discharge blow tank has higher conveying capacity and better conveying stability, while the bottom-discharge blow tank has higher solid-gas ratio and lower power consumption. The anthracite coal has higher material mass flow rate and better conveying stability than petroleum coke due to its better flowability.