Extrudate catalysts

An example of the distribution of Ni and V profiles in a HDS catalyst extrudate after an initial period of operation was shown in Fig. 38. The... 

The final catalyst extrudates were prepared according to the procedure described elsewhere [5]. This catalyst is hereafter referred to as H-Y/TFA. 

The reaction of l-hexene on 1/16 1 Pt/ AlaOj (Engelhard E-302) reforming catalyst extrudates was chosen as the test reaction. Figure 1 shows a schematic of the reactor unit A Waters dual piston HPLC pump rated to provide flow rates between 6 and 600 ml/h with a pressure head up to 414 bar was used to feed 1-hexene (Ethyl Corporation CAS 592-41-6 Lot 851201). By closing the liquid shut-off valve (V3) and opening the gas shut-off valve (V2), either hydrogen or nitrogen gas may be admitted to the reactor unit. The feed gas was selected by a three-way, computer-controlled solenoid valve (VI). 

The catalyst performance tests were carried out in bench scale isothermal trickle-bed reactors. The reactor was loaded with 373 cm catalyst extrudates (0.13 cm diameter). The catalyst was diluted with 0.2-O.3 mm diameter (50-80 mesh) inert glass beads in order to improve the liquid distribution and contacting effidency witbin the reactor. 

Barothermal treatments were applied directly to catalyst extrudates. In the course of mechanochemical treatments, extrudates were physically milled, loaded into a planetary mill and extruded again after the treatment. 

The experimental rig consisted of a stainless tubular preheater and reactor in series, 17 mm ID and 250 mm long with 5.5 mm axial thermowell. Electric tapes controlled by Eurotherm heated the reactor and preheater. 1-4 g of catalyst (extrudates 1.5 mm in diameter and 2-3 mm length) diluted with 4-8 g of inert SiC pellets to keep the reactor isothermal, was located between two layers of SiC particles of 3-4 mm in diameter. The preheater, operated at 300°C was filled with SiC. 

Physical Parameters Catalyst size and shape PDIL Catalyst (CD-Ed-101) Extrudates 3 mm x 5 to 10 mm Imported Catalyst Extrudates 4 mm x 4 to 7 mm... 

From the preliminary results of the bench scale pilot plant of the U.S. Environmental Protection Agency, Tseng et al. reported that a commercial SCR catalyst, extruded V20sA i02 based with some W, gave reduced NO conversion when 95 ppm SO2 was introduced into their flue gas stream from natural gas combustion. They also stated that this catalyst was less active at 440 °C than at 353 °C when 95 ppm SO2 was present in the flue gas. No further comments regarding this SO2 poisoning were offered. 

Catalytic combustion of SO2, toluene and 1,2-dichloroethane were conducted at atmospheric pressure in a tubular flow reactor with an inner diameter of 18 mm. Catalyst extrudates or monoliths were packed into the reactor with glass wool plugs at each end. The reactor was placed in a furnace equipped with a temperature control to maintain a constant reactor temperature, and two thermocouples to measure the inlet and outlet reactor temperatures. Gas compositions and flow rates were set by mass flow controllers. The following reaction conditions were used to test the cataljTic activity of the 0.2 wt. % Pt supported samples ... 

Fixed-bed hydropyrolysis tests at 15 MPa were conducted using either ca. 0.5 or 1 g of sample for the low and high carbon deactivated catalysts selected for detailed investigation. For some tests, the deactivated catalysts (extrudates) were ground and diluted in sand. The procedure used has been described elsewhere a relatively slow heating rate of 5 C min... 

Hydrocracking tests were conducted in an isothermal gas phase / trickle-bed reactor of 20 mm internal diameter. The catalyst bed, containing 3 g of catalyst extrudate, was diluted with nominally 0.8 mm SiC granulate in the volume ratio 2 1 (diluent catalyst) and was both preceded by and supported on beds of pure SiC granulate which acted as preheat and post reaction temperature trim zones, respectively. 

Figure 1.3 Structure at different length scales of catalyst extrudate.

The set of kinetic experiments was conducted in a bench-scale HDT unit. The plant consisted of two FBRs in series (-500 cm of catalyst in each reactor) which were loaded with a triple layer of catalyst extrudates a front-end HDM catalyst, a mid-end catalyst with balanced HDM/HDS activity, and a tail-end highly active catalyst for HDS and HCR. Catalysts were activated in situ by sulfiding with spiked straight-run gas oil (1.46 wt% sulfur, also containing 1.0 wt% dimethyl disulfide). The feedstock was an AR (343°C-i-) from a Mexican heavy crude oil (13°API). 

The elemental profile distribution of both molybdenum and phosphorus, across the transversal section of the alumina extrudates. was obtained using the scanning electron microscopy technique (SEM). An ISI-60 apparatus equipped with an energy dispersive X-ray analyzer (Kevex S-7000) was used for these measurements. Catalyst extrudates were mounted on an epoxy slide and then polished before scanned under the electron beam. 

Figure 3 Light microscope pictures of a catalyst extrudate prepared with NH4FeEDTA a) pH - 5.3, b) pH = 7.1, C) pH = 8.5...

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