Oil refineries collectively account for about 4-6 % of global CO2 emissions and Fluid Catalytic Cracking (FCC) units are responsible for roughly 25 % of these. Although post-combustion and oxycombustion have been suggested to capture CO2 released from the regenerator of FCC units, Chemical Looping Combustion (CLC) is also a potential approach. In this study, the applicability of CLC for FCC units has been explored. A refinery FCC catalyst (equilibrium catalyst-ECat) was mixed mechanically with reduced oxygen carriers; Cu, Cu2O, CoO, and Mn3O4. To identify any detrimental effects of the reduced oxygen carriers on cracking, the catalyst formulations were tested for nhexadecane cracking using ASTM D3907-13, the standard FCC microactivity test (MAT). To investigate the combustion reactivity of coke with physically mixed oxidised oxygen carriers, CuO, Co3O4 and Mn2O3, TGA tests were conducted on a low volatile semi-anthracite Welsh coal, which has a similar elemental composition to actual FCC coke, with various oxygen carrier to coke ratios over the temperature range 750-900 °C.The results demonstrated that, whereas Cu was detrimental for cracking n-hexadecane with the ECat, Cu2O, CoO, and Mn3O4 have no significant effects on gas, liquid and coke yields, and product selectivity. Complete combustion of the model coke was achieved with CuO, Co3O4 and Mn2O3, once the stoichiometric ratio of oxygen carrier/coke was higher than 1.0 and sufficient time had been provided. These results indciate that the proposed CLC-FCC concept has promise as a new approach to CO2 capture in FCC.

2,6-Dimethylnaphthalene (2,6-DMN) is a commercially important chemical for the production of polyethylenenaphthalate and polybutylene naphthalate. However, its complex synthesis procedure and high production cost significantly reduce the use of 2,6-DMN. In this study, the synthesis of 2,6-DMN was investigated with methylation of 2-methylnaphthalene (2-MN) over metal-loaded beta zeolite catalysts including beta zeolite, Cu-impregnated beta zeolite and Zr-impregnated beta zeolite. The experiments were performed in a fixed-bed reactor at atmospheric pressure under a nitrogen atmosphere. The reactor was operated at a temperature range of 400-500°C and varying weight hourly space velocity between 1 and 3 h -1 . The results demonstrated that 2,6-DMN can be synthesized by methylation of 2-MN over beta type zeolite catalysts. Besides 2,6-DMN, the product stream also contained other DMN isomers such as 2,7-DMN, 1,3-DMN, 1,2-DMN and 2,3-DMN. The activity and selectivity of beta zeolite catalyst were remarkably enhanced by Zr impregnation, whereas Cu modification of beta zeolite catalyst had an insignificant effect on its selectivity. The highest conversion of 2-MN reached 81%, the highest ratio of 2,6-DMN/2,7-DMN reached 2.6 and the highest selectivity of 2,6-DMN was found to be 20% by using Zr-modified beta zeolite catalyst.

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Chemical looping combustion (CLC) of n-hexadecane and n-heptane with copper and manganese oxides (CuO and Mn 2 O 3 ) has been investigated in a fixed bed reactor to reveal the extent to which low temperature CLC can potentially be applicable to hydrocarbons. The effects of fuel to oxygen carrier ratio, fuel feed flow rate, and fuel residence time on the extent of combustion are reported.Methane did not combust, while near complete conversion was achieved for both n-hexadecane and n-heptane with excess oxygen carrier for CuO. For Mn 2 O 3 , complete reduction to Mn 3 O 4 occurred, but the extent of combustion was controlled by the much slower reduction to MnO. Although the extent of cracking is relatively small in the absence of cracking catalysts, for the mechanism to be selective for higher hydrocarbons suggests that the reaction with oxygen involves radicals or carbocations arising from bond scission. Sintering of pure CuO occurred after repeated cycles, but this can easily be avoided using a support, such as alumina. The fact that higher hydrocarbons can be combusted selectively at 500 °C and below, offers the possibility of using CLC to remove these hydrocarbons and potentially other organics from hot gas streams.

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Heavy industries including cement, iron and steel, oil refining, and petrochemicals are collectively responsible for about 22% of global CO 2 emissions. Among these industries, oil refineries account for 4-6%, of which typically 25-35% arise from the regenerators in Fluid Catalytic Cracking (FCC) units. This article reviews the progress in applying CO 2 capture technologies to FCC units. Post combustion and oxyfuel combustion have been investigated to mitigate CO 2 emissions in FCC and, more recently, Chemical Looping Combustion (CLC) has received attention. Post combustion capture can readily be deployed to the flue gas in FCC units and oxyfuel combustion, which requires air separation has been investigated in a pilot-scale unit by Petrobras (Brazil). However, in comparison, CLC offers considerably lower energy penalties. The applicability of CLC for FCC has also been experimentally investigated at a lab-scale. As a result, the studies demonstrated highly promising CO 2 capture capacities for FCC with the application of post combustion (85-90%), oxyfuel combustion (90-100%) and CLC (90-96%). Therefore, the method having lowest energy penalty and CO 2 avoided cost is highly important for the next generation of FCC units to optimize CO 2 capture. The energy penalty was calculated as 3.1-4.2 GJ/t CO 2 with an avoiding cost of 75-110 e/t CO 2 for the application of post combustion capture to FCC. However, the application of oxyfuel combustion provided lower energy penalty of 1.8-2.5 GJ/t CO 2 , and lower CO 2 avoided cost of 55-85 e/t CO 2 . More recently, lab-scale experiments demonstrated that the application of CLC to FCC demonstrate significant progress with an indicative much lower energy penalty of ca. 0.2 GJ/t CO 2 .