Numerical Simulation Study on the Effects of Co-Injection of Pulverized Coal and Hydrochar into the Blast Furnace

To solve the energy crisis and slow down the greenhouse effect, it is urgent to find alternative energy sources for the iron and steel production process. Hydrochar is an auxiliary fuel and the only renewable carbon source that could reduce the injection of bituminous coal into the blast furnace. Numerical simulation is an effective method of understanding the combustion performance in the lower part of the blast furnace. A 3D blowpipe-tuyere-raceway model was established using the computational fluid dynamics (CFD) method to study the effects on combustion performance between pulverized coal and hydrochar. The results showed that co-injection of anthracite and hydrochar has a better combustion performance than co-injection of anthracite and bituminous coal, with a more appropriate distribution of temperature, velocity, and gas phase. With the co-injection of hydrochar, the total burnout rate and anthracite burnout rate increased, respectively, by 6% and 2.1%, which is caused by the interaction mechanism between anthracite and hydrochar. As a result, hydrochar as an auxiliary fuel for blast furnace injection not only can achieve low-carbon production and cut down carbon emission but also benefit the combustion process of anthracite coal.