Heliogen looks to heat cement pre-calciners straight from solar

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.