No one here is denying that it's possible to take CO2 and (while inputting energy) manufacture ethylene.
Rather, the point is that the energy required to do that - unless obtained from, e.g., nuclear power - probably involves the creation of CO2 somewhere up the line.
At present, tree (and other plants) are the most-efficient converters of CO2 into other valuable outputs (incl. O2 and wood).
Regards,
Right I was just separating green fantasy from chemical engineering and economics. This process could be useful if it takes a waste product such as CO2 from oil well tank battery vents or natural gas separation plants or ethanol bioreactors or anaerobic sewage sludge reactors or landfill gas capture/ methane recovery or coal gasification plant exhaust or... You get the point CO2 is a cheap abundantly available commodity having a process that can take it and with cheap energy such as natural gas at 90 cents a therm or lignite at $3 a ton or base bar nuclear power off peak at $1 mill/Mwh and turn it into ethylene which can then be via polymerization turned into high value plastics PETE LDPETE HDPETE or via oligomerization into a whole range of alkenes, alkanes, or PAOs all of which are worth thousands of dollars per ton. Ethylene can be turned into PAOs such as Mobil one Motor oil which sells for $9 a quart. Breaking the double carbon bond of CO2 is a massive advance in catalyst technology with wide reaching outcome. All the greenwashing aside the raw tech is a huge advance for petrochemical industry.