CENTRE FOR PROCESS INTEGRATION AND MEMBRANE TECHNOLOGY
The Processing and Environmental Engineering Research Facility (PEERF) within the centre at Robert Gordon University is a well-established academic group. It also applies its core competency in catalysis and renewable energy technology. Recently the group has focussed on research and development in Membrane technology that have a good potential for environmental and economic benefits in commercial processing systems.
The mission of the PEERF Centre is in accordance with that of the University which in the current context is to:
- Conduct basic research and related developmental activities for the use of innovative technology for the benefit of the community
- Provide timely and effective technology transfer between the Center and industry/Sponsors
- Promote educational development
The pursuit of these objectives fosters increased university/industry interactions. These interactions produce industrially relevant research results that can be implemented in a timely fashion. In addition, students obtain valuable research training in the important technological area such as membrane technology. This results in students with the relevant skills who will have productive careers in either industry or academia.
The group has excellent experimental facilities, which include pilot-scale plants for effluent treatment, state-of-the-art analytical instruments, novel membrane reactors and scale-up of chemical processes. Activities within the PEERF include consultancy, academic activities and research.
The applications of the facility for industrial clients are for:
- Improving quality control in process systems
- Processing of alternative fuels and oils
- Developing novel membrane processes
- Simulating processes and optimising their configuration using computer modelling
- Determining process specifications to meet product quality standards
- Generating pilot plant data to serve on the basis for proposals to third parties
- Investigating novel process options for the chemical processing of natural gas
The centres international visibility has been demonstrated through an impressive portfolio of invited guest speaker presentations in key international conferences, participation in international networks and consistence in attracting outside funding for high quality research. Some of these include Universities (Calabria-Italy; Twente - the Netherlands; Lyon- France; Zaragoza- Spain; Georgia- U.S.A.), Research Institutes (IRC-France; Argonne- U.S.A.; and Sintef- Norway) and Government Organizations (United States Dept of Energy, and Bereau of the Interior- U.S.A.). Edward Gobina has made 23 international invited guest speaker presentations and 24 international conference presentations in over six
different countries world wide between 1993 to 2001. He has also participated in two international networks involving both the EPSRC and the European Science Foundation respectively.
Hybrid inorganic membrane technology shows promise in gas processing, Membrane Technology, Volume 2002, June 2002, Pages 6-11
Zeolitic Systems for Gas Separations and Integrated Membrane Reactors, Membrane Technology, Volume 1998, Issue 94, February 1998, Pages 7-12
Multifunctionality in chemical reactors incorporating high-temperature membrane technology, Membrane Technology, Volume 1997, Issue 86, June 1997, Pages 8-13
Reaction and separation synergy through membrane technology, Membrane Technology, Volume 1996, Issue 76, 1996, Pages 6-9
The teaching areas that benefit directly from the facility are as follows:
- Drilling engineering (postgraduate)
- Plant performance (mass transfer, membrane processes, fuel cells)
- Environmental engineering (waste management)
- Undergraduate and postgraduate projects
Courses are constantly updated to reflect scientific, technological and industrial developments. New courses at undergraduate and postgraduate level such as surface processing, integrated reactor technology, Hydrogen processing and gas-to-liquids technologies have recently developed. Students involved in the Centre projects obtain training that is directly relevat to Sponsor needs.
Research studies (Postgraduate, MPhil, PhD, and Postdoctoral) are mainly focussed on:
- Removal of NOx, SOx, H2S and particulate pollutants from mobile and stationary sources
- Purification of waste streams from chemical and allied sources
- Evaluation of alternative energy systems
- Conversion of remote gas to value-added liquid fuels, fuel components, petrochemicals and synthesis gas
PEERF has various experimental facilities for synthesis, characterisation and testing of membrane material.
The lab is well equipped with all facilities for preparation of inorganic hybrid membranes on large scale-up.
The Facility has eight membrane reactors including four tubular fixed bed reactors. The other four reactors are suitable for flat sheet membranes and enable to investigate both series and parallel flow patterns.
The lab has an experimental set up for the preparation of composite inorganic palladium and its alloy membranes using conventional electroless plating with osmosis.
Gas permeation system
The system includes mass flow controllers, valves and pressure transducers for the measurement of steady state or unsteady state gas permeation fluxes at various upstream and downstream pressures.
The Disk-Sandpack Permeameter is a modified HT-HP cell that can be packed with sand to simulate an unconsolidated formation. The sand can be packed firmly in the cell at water saturation and held in place using aloxite disks. It is also being modified to simulate flow of natural gas in coal beds and tight sands.
Gas chromatograph (Varian, 3380)
This equipment is useful in teaching, course development, routine sample analysis and research studies. It provides qualitative as well as quantitative information in environmental analyses, quality control and petrochemical processes.
Accelerated surface area and porosimetry analyser (Micromeritics, ASAP 2010)
This system automatically analyses samples, collects analysis data and performs calculations in order to determine porosity based on adsorption of gas at relative pressure (P/Po = 0.0 - 0.1). It is mainly applied in determination of surface area, pore volume and average pore size of porous material. It measures BET surface area in the range of 0.01- 1000 m2 g-1.
SediGraph 5010 automatic particle analyser
This particular instrument is under request. It enables fast, automatic analysis of particle size distribution in the range of 0.1 - 300 micrometers based on the principles of sedimentation and X-ray absorption.
Scanning electron microscopy
The University has two scanning electron microscopes, a Cambridge S90b used for undergraduate teaching and a Leo S430 used for teaching, analysis and postgraduate work. Although housed in the School of Applied Sciences, these instruments are accessible to all areas of science and engineering in the university.
The S430 is also fitted with backscattered electron and Energy Dispersive X-ray detectors. It provides significant information on particle size, external morphology, cracks and cavities) and elemental composition (EDX).
The research groupings at PEERF are mostly emphasised on chemical reaction pathway engineering; membrane-enhanced separation processes; integrated catalytic membrane reactor technology; gas conversion and hydrogen technologies and new energy systems.
Chemical reaction pathway engineering
Experimental as well as mathematical modelling is being conducted on partial oxidisation of paraffins using various types of reactor systems including fluidised beds, internal recirculation reactors and fixed beds. In addition, studies to determine the kinetics of catalytic dehydrogenation reactions with spontaneous product removal are currently being investigated. Reaction systems being studied include methane partial oxidation to syngas; ethane and n-butane dehydrogenation and n-butane partial oxidation to produce maleic anhydride.
Membrane-enhanced separation processes
An application of membranes in gas separations has always offered the chemical & process industry with an attractive alternative to conventional methods of separation. Due to their potential weight saving and modularity, they are usually preferred in applications where only minimum maintenance is required for example, offshore at remote locations. Research currently focuses on applications of novel polymeric and inorganic hybrid material to remove water vapour from gaseous streams; air separation; hydrogen recovery from waste gas streams and natural gas processing.
Integrated catalytic membrane reactor technology
The results obtained on the studies of catalytic reaction pathway engineering and membrane-enhanced separations have been correlated in the development of integrated membrane reactors. Therefore, the combination of chemical reaction and membrane-assisted separations within a single stage has resulted in the intensification of chemical processes.
In catalytic dehydrogenation, the reaction pathway is controlled by equilibrium. In this case, an application of a suitable inorganic membrane, which is selective to hydrogen, alters the reaction mechanism and consequently favours the formation of desired product. For example, in ethane and propane dehydrogenation using Pd- H2 selective membranes, reactor yields of up to 8 times the ‘equilibrium’ value have been achieved.
Gas conversion and hydrogen technologies
The conversions of natural gas into liquids including liquefied natural gas (LNG), methanol, ammonia and synthetic hydrocarbon liquids are being investigated. In the transportation market, particularly in Europe, diesel fuel is a preferred alternative for developing natural gas supplies rather than a synthetic hydrocarbon route, gasoline. Hydrogen can also be produced from natural gas as an energy source.
Research focuses on the process technologies currently available, the markets and the economic aspects of various commercial processes.
New energy systems
Research on new energy systems focuses on the development of Proton Exchange Membrane (PEM) fuel cells. Aspects being investigated include heat and water management, current collector design and fuel processing.
Research and Teaching Programmes
The PEERF has demonstrated an intense commitment to the development of interdisciplinary research programmes as a part of team accompanied by undergraduate, postgraduate students, chemists, chemical engineers and mechanical engineers. The various research programmes are as follows:
- Permeation of gases through porous and dense membranes
- Composite inorganic membrane application and comparison of silica and zeolite systems
- Gas separation using carbon as selective membranes
- Gas transportation through metallic and porous ceramic membrane systems at ambient temperatures
- Hydrogen recovery from waste gas streams using inorganic membranes
- Development of Membrane fuel cell
- Air separation and oxygen production using silver membranes
- Air separation and oxygen production using silver metal membranes
- An experimental investigation into hydrogen embrittlement of stainless steel fasteners
- Stress corrosion cracking monitoring in duplex stainless steel using acoustic emission technique
Development of hybrid inorganic membranes:
Research focuses on the development, characterisation and testing of hybrid inorganic membranes for upgrading low quality natural gas streams.
Dip-coating of metal salt or metal-organic/microporous precursors is the most frequently used technique for these membrane preparations. Other techniques such as RF-magnetron sputtering, osmosis-enhanced electroless plating, spray pyrolysis, metal-organic vapour deposition, pulsed laser deposition and electron beam are intended. Porosity characteristics of these materials are studied by surface area analyser, ASAP 2010. These membranes are being studied in collaboration with the School of Applied Sciences using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photo-electron spectroscopy (XPS) to establish optimal properties of novel membranes.
Applications of these novel membranes in gas separation processes are being investigated using specially designed permeation cell as well as fixed bed membrane reactor set-up. Experimental data is also being compared with numerical modelling.
This work is now being extended under the supervision of Dr. Edward Gobina through a research grant by Scottish Enterprise Proof of Concept.
The proof of concept involves the preparation and testing of novel hybrid inorganic membranes suitable for deployment in harsh environments.
Two different types of membrane structures viz., symmetric and asymmetric will be prepared and tested for their permeability in the selective separation of CO2 from natural gas. It involves surface modification of the membrane and thus taking an advantage of the chemical affinity between CO2 molecules and the micropore wall. Another approach is tailor-made microporous membrane using a molecular sieve or silica layer, which is capable of differentiating between molecules of different size (shape selective diffusion). These two methods of CO2 separation would undergo rigorous testing at the Robert Gordon University.
These tests are also proposed for CO2 separation from N2 that has a significant application in the recovery as well as possible re-use of CO2, released from stationary sources such as thermal power plants.
The competitive advantage through innovation depends on the ability of these hybrid materials to allow a selective passage of CO2 molecules through their network. It enables continuous production of a relatively pure methane retentate stream at high pressure.
The chemical and process industry is the likely route to commercialisation/ market for these membranes, especially industries involved in natural gas processing. It is projected that the time to market will range between 4-5 years after the proof of concept phase.
Other approaches of the PEERF's inter-disciplinary team include inventing economically substantial separation processes using novel membrane materials in order to meet defined performance criteria. It has been demonstrated for gas separations and integrated reactor technology.
A further approach is to direct research activities to meet crucial need of manufacturing industry. This is being demonstrated by the development of novel, synthetic routes to fine chemicals manufacture; research and development of compact deoxygenation systems for offshore water injection; and application of thermostable metallic membranes for hydrogen recovery from waste gas streams.