Structured Catalysts and Reactors：结构化催化剂与反应器.ppt

Industrial Applications The Shell flue gas desulfurization The Shell flue gas desulfurization removes sulfur oxides from flue gas in a PPR using a regenerable solid adsorbent (acceptor) containing finely dispersed copper oxide. The essential elements in the development of the SFGD process are the development of a mechanically and chemically stable active acceptor that can withstand thousands of acceptance/regeneration cycles and the Parallel flow reactor as a dust-tolerant system. Flow scheme of the SFGD process as applied for sulfur oxides removal from refinery furnace off-gas. Groenendaal, W. et al.., AIChE Symp. Ser., 72, 12–22, 1976 The PPR and LFR are also applied in the process for NOx removal from off-gases. The Shell low- temperature NOx reduction process is based on the reaction of nitrogen oxides with ammonia catalyzed by a highly active and selective catalyst, consisting of vanadium and titania on a silica carrier. The low pressure drop and dust tolerance of the PPR and LFR are of potential interest in many end-of-pipe treatments of waste gases to reduce emissions that meet with increasing environmental concern. Structured Packings for reactive distillation The combination of chemical reaction with distillation of reactants in a single piece of process equipment is called reactive distillation. Since in a reactive distillation process the reaction products are continuously removed from the reaction mixture, chemical equilibrium limitations can be overcome and high reaction rates are maintained. Reactive distillation columns consist of three sections: a reactive section located between an upper enriching and a lower stripping section. The reactive distillation column can be regarded as a countercurrent gas–liquid catalytic trickle-bed reactor operating at the boiling point. The column internals need to fulfill various functions: Immobilize catalyst of particle sizes typically 0.2 to