� TECHNOLOGY �
Refractory-lined , steel enclosed solar-electric receiver ( on the left ) containing a fully-integrated prototype fluidized bed reactor system ( on the right ).
A thermochemical pathway for making green hydrogen , syngas and CO
OMC Thermochemistry seeks to commercialize a thermochemical pathway that uses heat and globally abundant materials ( steel and aluminum ) in a readily scalable fluidized bed reactor to split water to make green hydrogen , reduce CO 2 to make CO , or co-feed water and CO 2 to make syngas . The technology is currently at an integrated benchtop scale ( Technology Readiness Level 5 ), and the company is looking for pilot opportunities with commercial collaborators .
By Britt Boughey and Kent Warren
Process overview
At its core , the process is best described as a chemical looping or two-step reduction-oxidation cycle . In the reduction step , the active material , an iron- and aluminum-based metal oxide , is fluidized in a fluidized bed reactor and reduced in an inert environment , releasing some of its oxygen in a nonstoichiometric , endothermic reaction .
For the oxidation step , there are three basic options that we have explored thus far . In the first , steam can be fed over the now oxygen-deficient ( or reduced ) active material , which strips the oxygen from the steam to produce green hydrogen gas as a product . In the second option , CO 2 can be used as the oxidant . Here , the reduced active material instead strips oxygen from the CO 2 to produce CO . Lastly , in the third option , one can simultaneously deliver both CO 2 and steam into the fluidized bed reactor . Here , the reduced metal oxide strips oxygen from both oxidant gases to make syngas , a combination of CO and H 2
. Importantly , the carbon-tohydrogen ratio ( or quality ) of the syngas can be controlled by varying the mixture of the
24 Green Steel World | Issue 9 | November 2023