Modifications and Improvements to the Collector Metal Method Using an mhd Pump for Recovering Platinum from Used Car Catalysts

Today recovery of platinum from used auto catalysts has become a necessity due to great demand for this catalytic metal. There are many methods of recovering platinum from used catalysts on the market, one of them is the original collector metal method using the magneto-hydrodynamic (mhd) pump. This method is based on the continuous flow of the collector metal (lead) in the channel of the device, which can be obtained by using the mhd pump at the device operating temperature of 673 K. Proper selection of process parameters such as power frequency (25–100 Hz), inductor current density (20 A, 40 A, 60 A), gaps between the inductor and the liquid metal channel (2,4,8), flow velocity, secondary voltage (19 V, 40 V, 60 V) ensures proper efficiency of the device. Some parameters were selected on the basis of numerical simulations, others were experimentally verified—the tests were carried out for different washing out times (600 s to 3600 s), and different secondary voltage and inductor supply frequency (25 Hz to 45 Hz). Platinum washing out efficiency of up to 98% was obtained with a relatively short washing out time and low values of secondary voltage and inductor frequency. To improve the efficiency of the process, the thermal efficiency of the device was increased by 8% by insulating the cover of the device. Further modifications to the process include changing the collector metal—preliminary studies show that the addition of lithium increases the extraction of platinum from thin catalytic layers as a result of reduced surface tension of the extraction liquid. The preliminary results of the PbLi alloy spread on platinum coated surface seem to be very promising.

Modeling, Evaluating and Scaling up a Commercial Multilayer Claus Converter Based on Bench Scale Experiments

Industrial scale reactors work adiabatically and measuring their performance in an isothermal bench scale reactor is faced with uncertainties. In this research, based on kinetic models previously developed for alumina and titania commercial Claus catalysts, a multilayer bench scale model is constructed, and it is applied to simulate the behavior of an industrial scale Claus converter. It is shown that performing the bench scale isothermal experiments at the temperature of 307 ºC can reliably exhibit the activity of catalytic layers of an industrial Claus converter operating at the weighted average bed temperature (WABT) of 289 ºC. Additionally, an adiabatic model is developed for a target industrial scale Claus reactor, and it is confirmed that this model can accurately predict the temperature, and molar percentages of H2S and CS2. Based on simulation results, 20% of excess amount of Claus catalysts should be loaded to compensate their deactivation during the process cycle life. Copyright © 2020 BCREC Group. All rights reserved

Surface structure-dependent electrocatalytic reduction of CO2 to C1 products on SnO2 catalysts

Surface structure-dependent electrocatalytic reduction of CO2 to C1 products on SnO2 catalysts was attributed to the in situ formation of different Sn/SnO2 catalytic layers on their surfaces.