Coal Direct Chemical Looping (CDCL) Process

The Coal Direct Chemical Looping (CDCL) process is a novel technology that produces hydrogen from coal with in-situ CO₂ separation. The CDCL process uses a composite iron oxide particle as an oxygen carrier to combust coal. These particles are reduced by coal to capture CO₂ in the reducer. These reduced particles are then used in the second reactor to produce hydrogen through oxidation using steam. Thye can also be used to react with air for heat and power generation. The indirect combustion of coal with composite iron particles significantly enhances the efficiency of the hydrogen production process. The demonstration results carried out in a bench scale unit show that more than 95% conversion of coal and >97% CO₂ are achieved under optimized reaction conditions.

In this paper, the CDCL process is first reviewed. The demonstration results are then presented. Effect of sulfur and ash on the performance of the composite iron oxide particle is also discussed.