Run Parameters for a Continuous Hydrogenation Process Using ACMC-Pd To Replace Commercial Batch Reactor Processes

Abstract

Continuous hydrogenation using ACMC-Pd monolith catalysts was studied for four chemistries of industrial interest. The chemistry was run in a 30.5 cm catalyst bed with repeated passes to simulate a longer commercial catalyst bed in which >97% conversion would be completed in a single pass of the reactor with no recycle. The selected liquid flow rate (0.086 cm/s) enabled >97% conversion for the four chemistries using practical ranges of temperature (60–180 °C), pressure (0.348 to 3.48 MPa), and required bed lengths (4.3 to 6.1 m). The unsaturated bonds hydrogenated included nitro, carbonyl, olefin, and aromatic bond types. The most challenging reaction was the conversion of a neat olefinic/aromatic substrate (requiring 7 moles of hydrogen per mole of product) run with a low-temperature/high-temperature reactor configuration. The same catalyst was used for all of the chemistries, and the changeover from one chemistry to another involved simple solvent/substrate rinses of the reactor. The data can be used to estimate the number of commercial reactor tubes, temperature, pressure, and bed length needed for the production of commercial quantities of specialty and pharmaceutical chemicals.

Bi-Metal-Supported Activated Carbon Monolith Catalysts for Selective Hydrogenation of Furfural

“…It is possible that STYs could be increased by increasing the FUR feed rates and optimizing the H 2 gas and liquid flow rates to generate a Taylor flow in the carbon monoliths (our calculations in the past work under the conditions employed in this work indicate that we were in film flow) . The Taylor flow regime could increase the H 2 mass transfer and allow one to process higher FUR concentrations or feed rates. , …”

“…Each monolith structure has a diameter and length of 1 in, 529 cells/in 2 , a wall thickness of 0.01 in, a cell spacing of 0.0435 in, a geometric surface area of 70.84 in 2 /in 3 , and an open frontal area of 0.593 in 2 . Details on the ACM production procedure and pictures of ACM have been previously published. − Four cores of ACM were loaded into a Parr Packed Bed Reactor System (details have been previously described). − ACM catalysts were reduced for 4 h prior to the reaction in the 100 mL/min flow of pure hydrogen at 250 °C. Next, aqueous FUR hydrogenation reactions were conducted at liquid flow rates of 0.5 to 16 mL/min, temperatures of 120–180 °C, and pressures of atm to 300 psig using a feedstock of 44 g/L FUR (purchased from Sigma-Aldrich, 99%) dissolved in DI water.…”

“…25 The Taylor flow regime could increase the H 2 mass transfer and allow one to process higher FUR concentrations or feed rates. 25,26 Increased hydrogenation activity in bimetal systems is not unprecedented. As noted in the Dupont patent, the RuRe/C 52 Iron-promoted Pd on carbon silica supports increased the TOF (s −1 ) for propanal (0.17 s −1 ), acetone (0.45 s −1 ), and 5hexene-2-one (0.35 s −1 ) hydrogenation by a factor of 5, 4, and 2, respectively, compared to the monometal.…”

Continuous Hydrogenation of Aqueous Furfural Using a Metal-Supported Activated Carbon Monolith

“…Ammonia-TPD analysis was performed to determine the quantity and strength of acid sites as previously described. 49 It should be noted that, to obtain strong acid site density for Pd/ACM (Table 1), the peak area of a Pd/GAC desorption curve (same GAC used to make the ACM) from 300 to 500 °C was subtracted from the Pd/ACM peak area over the same range. TPR analysis was performed to determine the reducibility of the catalyst, and CO pulse titration was performed to determine the dispersion and particle size of the metal on the fresh catalysts.…”

Continuous Hydrogenation: Triphasic System Optimization at Kilo Lab Scale Using a Slurry Solution

“…A very common practice is the use of a trickle bed reactor (Saroha and Nigam, 1996;Al-Dahhan et al, 1997;Deutschmann et al, 2009) containing a packed bed of catalyst, which the reactants flow through (Gulotty et al, 2018). This is widely used in industry (Perry and Green 2008;Johnson et al, 2012;Rinaldi 2014;Carangio et al, 2020;Fernandez-Puertas et al, 2020), as it allows good control of reaction conditions and simplified scale-up (Jiménez-González et al, 2011;Hickman et al, 2013;Gutmann et al, 2015;Russell et al, 2017;Duan et al, 2020).…”