Bernardo Castro-Dominguez

Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification.

Palladium-based catalytic membrane reactors (CMRs) effectively remove H2 to induce higher conversions in methane steam reforming (MSR) and water-gas-shift reactions (WGS). Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H2, CO and CO2. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H2O, CO2 and H2. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H2 and induce higher methane and CO conversions while yielding ultrapure H2 and compressed CO2 ready for dehydration. Experimental results involving (i) a conventional packed bed reactor packed (PBR) for MSR, (ii) a PBR with five layers of two catalysts in series and (iii) a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD) model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H2 permeance and purity, high CH4 conversion levels and reduced CO yields.

Economic performance evaluation of process system design flexibility options under uncertainty: The case of hydrogen production plants with integrated membrane technology and CO 2 capture

Abstract A hydrogen production plant with integrated catalytic membrane reactor modules (HP-CMR) represents a new technology option with potentially enhanced environmental performance characteristics. Therefore, HP-CMR techno-economic performance in the presence of irreducible sources of uncertainty (market, regulatory) ought to be comprehensively evaluated in order to accelerate the realization of future demonstration plants. The present study introduces a systematic methodological framework allowing the economic value assessment of various flexibility options in the design and operation of an HP-CMR plant under the above uncertainty sources. The primary objective is to demonstrate the potentially value-enhancing prospects of design flexibility options that capture the inherent optionality element in managerial decision-making to actively respond to uncertainties as they are progressively resolved. A detailed Net Present Value (NPV)-based assessment framework is first developed within which the above sources of uncertainty are integrated through Monte Carlo techniques. Various constructional and operational flexibility options are introduced pertaining to the installation decision and operating mode choice of the carbon capture and sequestration (CCS) unit, and HP-CMR economic performance is comparatively assessed. Finally, under certain scenarios of regulatory action on CO2 emissions, it is demonstrated that quite appealing economic performance outcomes could emerge for HP-CMR plants once design flexibility is introduced.

Electrospun API-loaded mixed matrix membranes for controlled release

The development of biocompatible membrane materials capable of delivering active pharmaceutical ingredients (APIs) over a fixed time period offers significant advantages to the pharmaceutical and biomedical industries alike. In addition the incorporation of APIs within polymeric materials potentially allows for the formation of amorphous solid dispersions (ASDs), which have shown enhanced bioavailability, increased dissolution profiles and enhanced adsorption into the blood stream. Mixed matrix membranes (MMMs) have been at the forefront of such developments, however manufacturing MMMs with consistent batch to batch physical characteristics has proved challenging thereby significantly impeding the use of such materials by the pharmaceutical sector. This article describes the development, for the first time, of API and molecular sieve loaded mixed matrix membranes (MMMs) via electrospinning techniques. The developed membranes displayed consistent and controllable physical properties and more efficient API release relative to membranes prepared using traditional casting techniques. Mathematical modelling disclosed that the membranes generated via electrospinning show excellent correlation between experimental and predicted API release kinetics thereby paving the way for the development of MMMs for both pharmaceutical and biomedical applications.