Solar heat based cement kilns? - Decarbonizing cement industry In fact - CLIMAX
In 2020, Cemex and Synhelion, a startup, started an ambitious venture that would use concentrated solar thermal instead of fossil fuels to provide the heat for the clinker manufacturing ( https://bit.ly/3m2de0R ). And we are talking about a temperature of 1500 deg C. Currently, they are talking about a pilot effort.
Whew. Can this tech really work well, and work well on scale? Power tower technologies do deliver higher temperatures than parabolic trough but that;s still in the range of 600 deg C. A two and half fold increase in temperatures is quite a stunning fact.
Synhelion's technology is explained here - https://synhelion.com/technology . Interestingly, they mention that they use the greenhouse gas effect principle to reach these ultra-high temperatures.
Interestingly again, Synhelion is not focussed on the solar power market, and perhaps not too much even on industrial heating, but on using its high temperature solar systems to produce "solar fuels" - they use CO2 emissions from industrial processes and combine it with H2O at very high temperatures to produce syngas, which is then processed into liquid fuels using fairly established catalytic reactions.
The partnership with the cement major Cemex mentioned in the link above seems to be for using Synhelion technology for both replacing fossil fuels for heating in the clinker and use of CO2 from the clinker production for producing liquid fuels - making the entire cement production carbon neutral.
A super ambitious venture, a pilot project really worth watching over the next few months.