Utilization of CO-rich waste gases from the steel industry for production of renewable liquid fuels
- Production of fuels from CO-rich waste gases is economically viable.
- “Drop in” renewable fuels can be produced directly by a novel catalytic process.
- Proposed process improves the energy efficiency and economic value of the gases.
- CO2 emissions from the steel plant are reduced significantly.
Waste gases generated during steelmaking are an enormous source of CO2 emissions. Rather than supply heat and power to the plant by combustion, those gases can be utilized efficiently at a low cost to produce renewable liquid fuels. It upgrades the economic value of the gases and reduce CO2 emissions. CO-rich waste gases emitted from the blast furnace or basic oxygen furnace are of particular interest since they contain a valuable reactive compound that is simply combusted rather than converting it to green products. A novel Fe-based catalyst was used in this study to evaluate the performance of the projected syngas compositions as feed (H2/CO molar ratio of 0.7 and CO2 content above 30%v/v) for the CO hydrogenation process. The C5+ selectivity of the combined CO conversion and oligomerization processes was 81%, while the CO conversion was dependent on the WHSVCO and syngas partial pressure. Three cases were techno-economically evaluated based on the integrated steel plant with a production capacity of 12MM tonnes/year. The economics of the process depends mainly on the cost, composition and availability of the gases. Generally, the levelized cost of product is in the range of 0.38–0.78$/liter, which is significantly lower than the recent market price of renewable fuels. Sensitivity analysis suggests that the price can be further decreased. The energy efficiency is in the range of 41.7%-54.6% for all cases. Environmental benefits can be improved by integrating carbon-free H2 in the process, but its price should be reduced considerably to be economically feasible.
The full (paywalled) article appeared on the Science Direct website at https://www.sciencedirect.com/science/article/abs/pii/S019689042100409X]]>