Performance of silica-supported copper oxide sorbents for SOx/NOx-removal from flue gas I. Sulphur dioxide absorption and regeneration kinetics

Abstract

AbetractSulphur dioxide absorption and regsneratlon kmetlcs of several cohca-supported copper ox& (CuO) sorb&a were stud& 111 a mlcrobalance over a temperature range of 300 to 450°C The porous s&a support was prepared accordmg to a sol-gel technque, and CuO was dsposlted on thus support through an ion-exchange technque to achieve a uniform, highly duqersed CuO deposltlon Dunngup to 75 cycles of oxldatlon, sulphatlon, and reduction, the ion-exchanged sorbenta dd not show a algmficant loss m chemical a&&y except for some deactlvatlon m the first l-3 cycles The sulphatlon lnnetlcs of the preoxldti ion-exchanged so&tents were found to be III agreement with hterature data for unpregnated alumma-supported CuO sorbenta In case of dvect contact of reduced ion-exchanged sorbenta with smniated flue gas, the sum&.aneous and fast oxldatlon was determmed to have a large positwe effect on the sulphatlon rate up to approx~tely 60% convemlon to copper sulphate Thu was mamly attnbuted to structural effecta mslde the CuO deposita For the sulphated ion-exchanged sorbenta, the reduction by hydrogen was 1dentW as an autocatalyt~c reaction The autocatalytlc effect was also observed dunng the (much slower) reduction by methane, but there it was preceded by a penod m which a second autocatalytlc effect appsared The reaction kmetlcs of the ion-exchanged sorbenta developed were furthermore compared with expenmental resulta of other sdlca-supported CuO sorbs&a prepared by vacuum unpregnatlon and homogeneous deposition-pmpltatlon

Preparation of Aerogel-Supported Copper Oxide for the Methane Chemical Looping Combustion (CLC) Process

“…It is worth mentioning that the differences in redox reactivity of silica OC per unit copper oxide content were related to the OC preparation methods. Between the three different preparation techniques, ion-exchange, homogeneous deposition–precipitation, and impregnation, the impregnation method results in larger sizes of copper oxide deposits . The larger size of the CuO deposits of the OC reflects lower activity per unit of the copper oxide content.…”

“…Between the three different preparation techniques, ion-exchange, homogeneous deposition−precipitation, and impregnation, the impregnation method results in larger sizes of copper oxide deposits. 29 The larger size of the CuO deposits of the OC reflects lower activity per unit of the copper oxide content. Even if the copper oxide mass fraction is higher, the copper oxide size is probably larger causing more decrease in oxygen capacity, as can be seen in Table 2.…”

Investigation of combined S02/N0x Removal by Ceria Sorbents

“…for freshly prepared and used sorbent samples. X-ray diffraction shows neither crystalline CuO (see above discussion) or CuA120, in the fresh samples, nor crystalline CuSOj in the used samples [Centi, (1990; Friedman et al (1978); Kent et al (1977); Lo Jacono and Schiavello(l976); Pollack et al (1988); Waqif et ul. (1531), Yo0 et al (1994l.…”

Experimental research and characteristics analysis of alumina‐supported copper oxide sorbent for flue gas desulfurization

“…But they suffer from a common deficiency: they convert the air pollution problem into a solid or liquid pollution problem (Henzel et al ., 1982). Dry regenerative sorption processes based on chemical reaction of SO 2 with a metal oxide such as CuO (Yeh et al ., 1985;Centi et al ., 1990;Kiel et al ., 1992;Deng and Lin, 1995a) are considered as alternatives for flue gas desulfurization (FGD) because of their several advantages over the conventional wet-scrubbing, throwaway processes (Harriott and Markussen, 1992;Frey, 1993;Centi et al ., 1995).…”