The prepared catalyst of tungstophosphoric acid supported on SiO2 has shown high activity, good selectivity of producing linear alkylbenzene (LAB) and 2-phenyl isomer and sufficient catalytic stability. Kinetics of benzene alkylation with 1-dodecene over this catalyst was investigated in a fixed-bed reactor after eliminating the influence of internal and external transport. Rate models of formation of different isomers of LAB were derived based on some simplifying assumptions. Kinetic parameters were determined.

The selective oxidatiou of n-butane to maleic allhydride (MA) oll a vanadium-phosphorus oxide (VPO) catalyst was studied using on-line gas-chronlatogr&phy combined with mass spectrometry (GH-MS) and transient response technique. The reaction intermediates, butene and furan were found ill the reaction elfluent under near industrial feed condition (3% butane+15% O2), while dihydrofuran was detected at high butane concentratiori (12 butane. 502). Some intermediates of MA decomposition were also identified. Detection of these intermediates shows that the vanadium phosphorus oxides are able to dehydrogenate butane to butene, and butene furl her to form MA. Based on these observations, a modified scheme of reaction network is proposed. The transient expetrinents show that butane in the gas phase may directly react with oxygen both on the surface and from the metal oxlde lattice, without a proceeding adsorption step. (Gas phase oxygen can be adsorbed and transformed to surface lattice oxygen but it can not participate in selective oxidation. Adsorbed oxygen leads to deep oxidation, while lattice oxygen leads to selective oxidation.

eration performance of n-butane selective oxidation to maleic anhydride over a VPO catalyst in fixed-bed reactors was investigated. A temperature-programmed oxidation experiment demonstrated that reoxidation sufficient to activate the catalyst could only be carried out at a temperature higher than that of butane oxidation step. A periodic operation scheme, simultaneous modulation of both composition and temperature, was proposed and examined in a fixed-bed microreactor filled with 0.6 g of crushed catalyst and in a tubular fixed-bed reactor packed with 30 g of catalyst. In both reactors, feed composition modulation enhanced selectivity to maleic anhydride, but the conversion of butane and the yield of maleic anhydride dropped. With a 1:0.4 cycle split and period of 4min, reoxidation of the catalyst at 530℃, and selective oxidation at 405℃, the yield of maleic anhydride by both composition and temperature modulation was improved by 11.4% over that obtained for operation under steady-state conditions with the same time-average flow of n-butane, which indicated that the higher reoxidation temperature was effective in improving reactor performance.

The reaction of the greenhouse gas, CO2, with Ca(OH)2 was explored using single-particle Raman spectroscopy to track the chemical reaction. Single particles were levitated in an electrodynamic balance (EDB) to maintain the particle in a laser beam. The levitation voltage provided gravimetric data. The humidity in the EDB chamber was varied to determine the effects of humidity on the reaction. It is demonstrated that no appreciable reaction occurs at low relative humidities (RH<70%). This is evidenced by no disappearance of the Raman peak associated with the [OH]-vibrational bond, but at high humidities (RH>70%) the Raman spectrum of CaCO3 developed as the reaction proceeded. The results are consistent with results from packed-bed studies of the reaction and are in agreement with similar findings for the SO2/Ca (OH) 2 reaction used for desulfurization, that is, the reaction does not proceed until multiple monolayers of water are adsorbed on the particle surface.

Linear alkylation (LAB) is an important intermediate in the detergent industry. This work deals with the suspension catalytic distillation (SCD) column used for synthesis of C12 alkylbenzene with benzene and 1-dodecene.Anovel solid catalyst, which is friendly to environment, was selected. The kinetic equations using this catalyst were measured in a fixed-bed reactor. The mathematical models of equilibrium (EQ) stage and nonequilibrium (NEQ) stage for alkylation of benzene and 1-dodecene were, respectively, established by incorporating the kinetic equations to simulate the SCD column. By comparison of the results from experiments, it was concluded that the NEQ stage model was more accurate than the EQ stage model for the simulation.