3 rd International Conference on Chemical Looping, September 9-11, 2014, Göteborg, Sweden 1 Sour and acid gas combustion in a 500 W th CLC unit Arturo CABELLO 1# *, Francisco GARCÍA-LABIANO 1 , Luis F. DE DIEGO 1 , Pilar GAYÁN 1 , Alberto ABAD 1 , Juan ADÁNEZ 1 , Gerald SPRACHMANN 2 1 Instituto de Carboquímica (ICB-CSIC), Miguel Luesma Castán,4, Zaragoza, Spain 2 Shell Global Solutions International BV. Amsterdam, The Netherlands *Corresponding author, acabello@icb.csic.es, # Presenting author Abstract – Chemical Looping Combustion technology can join the exploitation of the energy potential of sour and acid gases and the CO 2 capture process in a single step. The resistance of oxygen carriers to sulfur becomes crucial when acid or sour gases are subjected to a CLC process since the H 2 S content can be very high. In this work, two highly reactive oxygen carriers based on copper (Cu14γAl) and iron (Fe20γAl) were used for acid and sour gas combustion in a continuous 500 W th CLC unit. 101 hours of continuous operation were conducted (60 hours with sour gas and 41 hours with acid gas) with H 2 S concentrations as high as 20 vol.%. This is the first time that fuels with so high H 2 S concentration are used in a CLC unit. The Cu-based oxygen carrier exhibited complete combustion of the fuel gases and no agglomeration. The sulfur was mainly released as SO 2 in the FR. However, formation of copper sulfides at all operating conditions prevents the use of this material for the combustion of these gaseous fuels. In contrast, excellent results were obtained with the Fe20γAl oxygen carrier. All the sulfur fed into the CLC system as H 2 S was burnt to SO 2 in the FR, without any SO 2 emission in the AR, and no iron sulfides formation. Based on these results, it was concluded that this material is very adequate for the combustion of acid and sour gas with high H 2 S contents. 1 Introduction Natural gas is usually considered as sour gas if the H 2 S content exceeds 5.7 milligrams of H 2 S per cubic meter of natural gas [1]. The waste gas stream from the sweetening process of a sour natural gas stream is commonly referred as acid gas. The exploiting of the energy potential of sour and acid gases entails the application of CO 2 Capture and Storage (CCS) technologies since the CO 2 content in these fuels can be very high. Within the options based on the energy exploitation of these fuels, Chemical-Looping Combustion (CLC) emerges as a possible technology. CLC has the advantage of an inherent CO 2 separation, avoiding additional separation units and energy penalties. Figure 1 shows the technology train to deal with sour and acid gases through CLC.