Nicole Temple | MEL Candidate | Dec 16, 2022
Mentors: Daniel Brosig and Manuel Estandia, GCT
Abstract
The purpose of this project was to determine the technical and economic feasibility of the conversion of carbon dioxide (CO2) to methanol (MeOH) at Anglo American’s Barro Alto Nickel processing facility in Brazil. The metallurgical industry is notoriously both carbon intensive and difficult to decarbonize. Metallurgical coal is utilized as the reductant during calcination, while the combustion of coal is used to provide heat to the calcination step. The carbon-rich flue gas from the pre-reduction and calcination of nickel ore from the facility’s two rotary kilns can be polished and captured to be used as a feedstock for MeOH production. The three proven point-source carbon capture methods investigated within the scope of this project were:
• Standard Amine Liquid Solvent CO2 Capture (85-90% CO2 Recovery)
• Svante Temperature Swing Adsorbent CO2 Capture (85-90% CO2 Recovery)
• MTR Polaris Partial Pressure Membrane CO2 Capture (50-75% CO2 Recovery)
The pure CO2 stream can then be hydrogenized with green hydrogen (H2) to produce blue MeOH. Carbon Recycling International (CRI) has operational CO2-to-MeOH plants and was used as the design basis for this project. For every tonne of CO2 fed to the system, approximately 0.7 tonnes of MeOH can be produced. H2 is required to hydrogenate the CO2 at a rate of approximately 0.2 tonnes of H2 per tonne CO2. High and low CO2 recovery cases were investigated for each carbon capture method selected (six design cases total).
While the conversion of off gas CO2-to-MeOH aligns with Anglo American’s goal for carbon neutrality by 2040, the process is considered economically unfeasible in the current context for all six design cases. The three parameters that have the greatest impact on the economic feasibility of this project are the cost of hydrogen, the sales price of methanol, and the capital cost of the equipment, in order of magnitude. With the current base case assumptions, the operating costs outweigh the revenue, annually; therefore, the capital cost will have minimal effect on the project economics without additional changes. A sensitivity analysis was conducted, which indicated that at least two of the following changes are required for this project to become economically feasible:
1. Decrease H2 Purchase Price
2. Increase MeOH Sale Price
3. Reduce Capital Costs
4. Leverage Potential Future Policy Incentives (Carbon Credit)