Analyzing the methanation thermodynamic feasibility of steel plant byproduct gases.

To improve the utilization of byproduct gases in the steel plant, the coke oven gas (COG) methanation combined with blast furnace gas (BFG) and basic oxygen furnace gas (BOFG) was proposed in viewpoint of economy and environment. The optimization mathematics model based on Gibbs free energy minimization was established to predict the thermodynamic feasibility of the proposed methanation. To solve the proposed model, the convenient method was implemented by using the Gibbs module in Aspen Plus software. Effects of operation parameters on the methanation performance were revealed to identify the optimized conditions. To reduce the solid carbon concentration, it was found that the optimized conditions of temperature, pressure and stoichiometric number were 650 °C, 30 bar and 3.0, respectively. Moreover, it was discovered that 10 mol% of BFG or BOFG could be mixed into COG to obtain the maximum methane yield. In addition, it was testified that there were the good agreements between calculated results and industrial and published data, which indicated that the proposed methanation was thermodynamically feasible. Therefore, the simple and easy method was developed to evaluate the methanation operating conditions from the aspect of thermodynamic equilibrium, which provided the basic process conditions of byproduct gases methanation to enhance the steel plant efficiency and reduce carbon emissions.

Solvothermal Synthesis of Humic Acid-Supported CeO2 Nanosheets Composite as High Performance Adsorbent for Congo Red Removal.

Surface properties and structures of materials are essential for their adsorption of pollutants in water. Humic acids (HA)-supported CeO2 nanosheet composites are synthesised by solvothermal method. The size of CeO2 nanosheets are approximately 100-500 nm. The obtained composite exhibits superior adsorption ability for Congo Red (CR) in water, which can be attributed to its unique structure and highly dispersed CeO2 nanosheet. The composite's adsorption behaviour of CR follows a pseudo-second-order mode and Langmuir adsorption model well, and the maximum adsorptive capacity for CR achieves 260 mg g-1. The presence of CeO2 nanosheets enhances surface area and enriches the mesoporous structure of the composites, thereby promoting CR adsorption capacity.