Powder Technology, Vol.316, 3-17, 2017
CLC, a promising concept with challenging development issues
Chemical Looping Combustion (CLC) is a promising technique to achieve fuel combustion in a nitrogen free atmosphere, therefore giving the possibility to separate and store or use CO2. Several potential applications are considered in the field of power generation with gas, liquid and mostly solid fuels. In the Carbon Capture, Storage and Utilization (CCSU) context, energy penalty is reduced with CLC compared to other routes. In addition, other applications of Chemical Looping Technology are considered in the field of H-2 production or gasification for instance. In the past years, a huge effort has been conducted worldwide to investigate CLC materials and process issues. In 2008, IFPEN and Total have started an ambitious collaboration to develop CLC applications. Nowadays, the CLC concept is well demonstrated on the pilot scale. The next step is to demonstrate the technology over time on a larger scale. For further developments, some challenges should be addressed, both on market and technical aspects: Short term market is limited. Uncertainties around CO2 emission market (i.e. carbon credits) and storage issues are hindering policy and public acceptance and still must evolve in the right direction, Financing of industrial Carbon Capture and Storage units in this context is challenging and other applications of CLC may require to be investigated such as utilization of captured CO2 for FOR purpose, The industrial use of synthetic metal oxides or natural ores at large scale generates a lot of issues related to availability, price, waste disposal, health and safety, additionally to chemical and mechanical aging, reactivity, and oxygen transfer capacity, Chemical looping reactor and process technology concepts have to be explored, developed, modeled and scaled up in order to ensure adequate power production together with good gas solid contact and reaction requirement, controlled circulation of mixtures of particle (oxygen carrier, ash, solid fuel for instance). All these points should be considered on very large scales for carbon capture and storage (CCS) applications in order to minimize energy penalty and cost in severe operating conditions (temperatures above 800 degrees C and intense solid circulation). Technical challenges remain to be solved and proven with large demonstration over long periods of time. In this context, research in the field of fluidization technology is essential and we will address some key points investigated at IFPEN as related to control of solid circulation, oxygen carrier attrition, conceptual design of CLC reactors and process performance. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Chemical Looping Combustion;CO2 capture and storage;CCS;CLC;CO2 use;Oxygen carrier;Fluidized bed;Power plant