The power of computational thermochemistry in high-temperature process design and optimization: Part 1 - Unit operations

Industrial process modeling is increasingly accessible through computational chemistry packages. Computational Thermochemistry (CT) is particularly convenient for exploring the behavior of high-temperature processes (e.g., pyrometallurgical unit operations such as calciners, roasters, smelters, converters, and electric arc furnaces) since their operating conditions are mostly dictated by local/global thermodynamic phase equilibria. Under these high-temperature conditions, energy barriers are small and do not limit the kinetics of many chemical reactions. In this context, engineers-in-training must take full advantage of CT to explore and understand current unit operations in high-temperature manufacturing technologies. This work illustrates the strength of computational thermochemistry for high-temperature modeling through four case studies, i.e., 1. a carbo-reduction process, 2. a glass production/recycling furnace, 3. an aluminothermic reactor for the production of a ferro-niobium alloy, and 4. a titanium purification unit. Moreover, the relevance of key fundamental thermodynamic concepts is discussed through the modeling of these unit operations. All the thermodynamic simulations presented in this work were performed using FactSage, a metallurgy-specialized thermochemical package widely employed in both academia and industry. •The use of a thermochemical package (FactSage) and its extensive thermodynamic database for the simulation of high-temperature unit operations is presented.•The FactSage’s core module called Equilib is introduced through the carbo-reduction of roasted nickel sulfide ores (production of ferronickel alloy). Multi-phasic assemblage evolution, recovered metal composition, and slag phase composition illustrate the different reduction stages in this smelter.•Elemental partitioning and metal recovery were computed for an aluminothermic reactor to produce a niobium alloy. Results are in good agreement with the data reported by the CBMM mining company.•Thermochemical calculations are coupled with Life Cycle Assessment (LCA) data to quantify CO2 emissions related to the production of glass. The proposed model accounts for the greenhouse gas (GHS) emissions linked to the raw materials, mass/energy balances in a melting furnace, furnace efficiency, and amount of recycled cullets.•Thermodynamic simulations of a distillation unit for the purification for a Ti-sponge (obtained from carbo-chlorination) were performed. It is shown that MgCl2 (l) c