US: California-based Heliogen has developed concentrated solar-thermal plants (CSPs) with the ability to focus sunlight to generate temperatures over 1000°C by micro-adjusting mirrors using computer technology. It has now engaged Parsons Corporation to build arrays of its CSPs for installation in cement pre-calciners. Requiring 900°C heat, these represent the largest part of the industry’s CO2 output. The technology will firstly reduce this by replacing fossil fuels with a clean heat source, which moreover entirely bypasses the electrical grid. Heliogen CEO Bill Gross says that the installations will make carbon capture and storage (CCS) of the remaining CO2 emissions from the conversion of limestone to lime easier by removing other pollutants. Heliogen is now targeting 1500°C from its CSPs, which would enable them to supersede cement fuels in kilns.
