Energy Technologies and CO2 Management: Session II
Sponsored by: TMS Extraction and Processing Division, TMS Light Metals Division, TMS: Energy Committee
Program Organizers: Alafara Baba, University of Ilorin; Lei Zhang, University of Alaska Fairbanks; Donna Guillen, Idaho National Laboratory; Xiaobo Chen, RMIT University; John Howarter, Purdue University; Neale Neelameggham, IND LLC; Cong Wang, Northeastern University; Ziqi Sun, Queensland University of Technology; Hong (Marco) Peng, University of Queensland; Yu Lin Zhong, Griffith University
Monday 2:00 PM
March 15, 2021
Room: RM 26
Location: TMS2021 Virtual
Session Chair: Donna Guillen, Idaho National Laboratory; Neale Neelameggham, IND LLC
2:00 PM
Low Energy Mesoporous Silica Recovery from a Nigerian Kaolinite Ore for Industrial Value Additions: Alafara Baba1; Abdullah Ibrahim1; Dele Fapojuwo2; Kuranga Ayinla1; Daud Olaoluwa1; Sadisu Girigisu3; Mustapha Raji1; Fausat Akanji4; Abdul Alabi5; 1University of Ilorin; 2University of Johannesburg; 3University of Ilorin; Federal Polytechnic Offa; 4SHEDA, Abuja; 5Kwara State University
The increasing industrial demands for mesoporous silica warrant the continuous development of less energy intensive, cheaper and eco-friendly technologies. Mesoporous silica from an indigenous kaolinite ore was synthesized by hydrochloric acid dissolution. Experimental reaction parameters were optimized to maximize silica recovery and the solid product was characterized using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Brunauer–Emmett–Teller (BET) Nitrogen adsorption–desorption measurements. The dissolution data shows the rate of reaction increase with increasing concentration, temperature but with decreasing solid-to-liquid ratio. The Avrami model proved most suitable model for describing the leaching process with Avrami parameter n value of 0.8 and calculated apparent activation energy of 7.22 kJ/mol suggested a diffusion controlling rate mechanism. The mesoporous product as characterized gave a pore size of 3.67 nm at the maximum probability and possessed suitable morphological applications as additive in polymers and catalysis.
2:20 PM
Prediction Model of Converter Oxygen Consumption Based on Recursive Classification and Feature Selection: Liu Zhang1; Zhong Zheng1; Kaitian Zhang1; Xinyue Shen1; Yongzhou Wang1; 1Chongqing University
To improve the prediction accuracy of oxygen consumption in the steelmaking converter, a prediction model of converter oxygen consumption based on long short-term memory (LSTM) network ensemble learning was proposed. The converter production data were clustered to construct multiple training subsets. And the prediction model of converter oxygen consumption was constructed by using the LSTM network for each subset. For the test sample, the weight of the prediction results can be determined by the mode matching degree between the test sample and different types of multiple models, and the oxygen consumption of the sample was estimated by the weighted sum from the prediction of the multiple models. The converter production data from a steel enterprise were used for testing. The results showed that the prediction accuracy of the ensemble learning model was higher than that of the single prediction model.
2:40 PM
Reduction Behaviors of Hematite to Metallic Iron by Hydrogen at Low Temperatures: Kun He1; Zhong Zheng1; Hongsheng Chen1; Weiping Hao1; 1Chongqing University
The efficiency use of hydrogen in iron and steel manufacturing is essential for reducing energy use and CO2 emissions. The reduction behavious of Brazilian hematite in 20%H2 (rest is Ar) at 400–570℃ were investigated in a micro fluidized bed. The crystalline phases, morphological, and internal structure of reduction products were examined. The results indicate that the reaction of hematite to metallic iron can be divided into two stages based on the conversion X, the first stage is the processes of Fe2O3→Fe3O4 at X<1/9, and the reaction of Fe3O4→Fe constituted the second stage. The rate constants of all individual reactions were increased with increasing temperatures. The number of pores and fissures were observed, as magnetite formed gradually, on the surface of ore and peripheral part of unreacted core of hematite. The reaction rate of the overall reduction was determined by phase boundary reaction.
3:00 PM
Simulation and Optimization of Defluorination and Desulfurization Processes of Aluminum Electrolysis Flue Gas: Xueke Li1; Yan Liu1; Xiaolong Li1; Ting-an Zhang1; 1Northeastern University
Aiming at the harmful gas pollutants of low concentration sulfur dioxide and fluoride in electrolytic aluminum flue gas, the process of fluorine and sulfur removal was simulated by NaOH-CO2 gas-liquid absorption system, and the influence of operation and structure parameters such as gas flow rate, liquid flow rate, size and type of filler on gas-liquid mass transfer process was explored. The results show that the gas flow rate is 1.5~2.0 m3/h, the liquid flow rate is 10~12 m3/h, and the filler is a Bauer ring with the nominal diameter (DN) of 16 mm, the gas-liquid mass transfer effect is the best and the maximum CO2 utilization rate is about 46%. According to the simulation results, when ammonia system is used to absorb sulfur dioxide and hydrogen fluoride, the concentration of sulfur dioxide and hydrogen fluoride can be reduced to 42 mg/m3 and 0.8 mg/ m3 respectively.
3:20 PM
The Influence of Hydrogen Injection on the Reduction Process in the Lower Part of Blast Furnace: A Thermodynamic Study: Zeji Tang1; Zhong Zheng1; Hongsheng Chen1; Kun He1; 1Chongqing University
H2 was used to instead carbon in the blast furnace, which can reduce CO2 emissions, has been focused in iron and steel manufacturing. For the operation conditions of the reduction of Wustite by carbon in the bottom of the blast furnace, the effect of different H2 injection concentrations to the reduction process was investigated by the minimum Gibbs free energy principle. The results indicate that the equilibrium of the reaction system and the reduction of Wustite were changed due to H2 addition. Wustite was reduced completely at different operating pressures and H2 concentration as H2 concentration was smaller; oppositely, Wustite cannot be reduced completely, and the reduction rate of Wustite and the mole fraction of CO were decreased with increasing H2 concentration. The carbon content in the equilibrium state first decreases and then increases as increasing H2 concentration, and the mole fraction of CO2 was the opposite.
3:40 PM
A Study of Numerical Modeling of Jet Heating Phenomenon in a Porous Media: Qingxuan Luo1; Yuchao Chen1; Armin Silaen1; Chenn Zhou1; 1Purdue University Northwest
Electric arc furnace (EAF) is a furnace that utilizes electric energy and chemical energy to melt scraps. Coherent jet is used in EAF to help stir, melt and oxidizes the scraps. This study is focused on the numerical modeling of the jet heating phenomenon through computational fluid dynamics (CFD) method. The approach of this study is to inject mixture gas of fuel and oxygen into a scrap zone. The fuel will be combusted to provide heat and the scrap phase will be simulated as porous media in Eulerian multi-phase model. A CFD code has been developed to simulate the momentum and energy interaction between the gas phase and scrap phase. This model will be able to simulate the heat transfer phenomenon within gas and solid phases.