� TECHNOLOGY �
Fig . 1 : Reduction step Fig . 2 : Oxidation step input gases . In both the second and third options , the CO 2 is directly reduced into CO . No reverse water-gas shift reaction is required .
The oxidation reactions where hydrogen , CO , or syngas are produced are all mildly exothermic . Thus , the heat inputs required to keep the reaction in thermodynamically favorable conditions are mainly required in the reduction step . Heat to drive the reaction can come from just about any medium , but OMC is focused on commercializing the technology by using waste heat from other processes along with electric resistance heating as the heat source . Since the active materials are highly durable and continuously recycled in the process , the overall carbon intensity of the process will be determined by the percentage of heat obtained from renewable or waste sources .
Key differentiators
The interaction between the iron aluminate bed material and either the reducing or oxidizing environments is non-catalytic by nature . Thus , no catalyst of any type is consumed in this process and there is consequently no need for critical materials like noble metals , cobalt , yttrium , iridium , etc . The reactor is simply a refractory brick-lined ( i . e ., alumina-lined ) steel vessel , and the bed material is also a mixture of iron oxide and aluminum oxide . This , “ ironaluminum sandwich ,” leads to commercial configurations with low capital costs . Plant life is estimated to be 20 years or greater .
Scaling the reactor up is a straightforward process , as standard fluidized column reactor vessel dimensions and materials can be utilized . No new factories are required , and no new mass production techniques need to be created and implemented , saving both time and expense in scaling up . Furthermore , a single reactor system consisting of two columns where fluidized beds alternately oxidize and reduce to enable continuous production , could – at an industrially relevant scale – produce either 50,000 + kg of
H 2 per day or 500,000 + kg of syngas per day depending on C : H ratios desired .
Another material advantage is exceptional chemical stability . In an ongoing durability campaign , even after over a thousand cycles ( 500 + hours at process conditions ), we have yet to observe any indication of degradation
Green Steel World | Issue 9 | November 2023 25