Transalkylation of Methylamines:  Kinetics and Industrial Simulation

Abstract

A kinetic model for the transalkylation of methylamines over amorphous silica/alumina is presented. The experimental data obtained at temperatures ranging from 623 to 683 K and pressures ranging from 0.2 to 2 MPa were described adequately. Transalkylation reactions occur between ammonia/methylamine adsorbed on an acid site and ammonia/methylamine adsorbed on a neighboring base site. In all reaction paths, the surface reaction between adsorbed species was assumed to be rate determining. At all pressures, the fraction of free acid sites as calculated by the model is very low. The fraction of free base sites is low at high pressures only. Models derived from other mechanisms were rejected based on a statistical analysis, mechanistic considerations, and physicochemical interpretation of the parameters. An industrial transalkylation reactor was simulated. To enhance the rate of dimethylamine formation, a mixture with an excess of monomethylamine and a deficit of ammonia and trimethylamine is recommended as the inlet composition for a transalkylation reactor. Decreasing the inlet partial pressure of ammonia results in a reduced amount of catalyst required to obtain the equilibrium concentration of dimethylamine.

A two-dimensionally microporous thiostannate with superior Cs+ and Sr2+ ion-exchange property

“…Before the ion-exchange experiments, the phase purity was conrmed by PXRD on a selected polycrystalline sample (Fig. 49 Single-crystal X-ray crystallography reveals that FJSM-SnS belongs to the space group C2/c with cell parameters of a ¼ 22.5651 (10) (Fig. S2 †).…”

Layered metal sulfides with MaSbc− framework (M = Sb, In, Sn) as ion exchangers for the removal of Cs(Ⅰ) and Sr(Ⅱ) from radioactive effluents: a review

“…The interlayer spaces are occupied by highly disordered cations Me 2 NH 2 + and Me 3 NH + and lattice water molecules, with an estimated interlayer distance of 7.258 Å (Manos and Kanatzidis, 2012). The unexpected Me 3 NH + cations are believed to be generated in situ from the solvent Me 2 NH, according to the results of mass spectra (Staelens et al, 2004). FJSM-SnS was found to have excellent exchange properties for Cs + and Sr 2+ .…”

Electrochemical synthesis of trimethylamine by cathodic reduction of dimethylformamide using Cu and Pd cathodes

“…Methanol amination requires high temperature, high pressure, catalysis, high energy, and sophisticated equipment. This reaction is the main method of preparing TMA in industries [8][9][10]. The synthesis of TMA from CO 2 , H 2 and NH 3 has been investigated over various metal-alumina catalysts (Cu, Ag, Ni, Pt, Co, and Fe) prepared by coprecipitation.…”