Imperial College London


Faculty of EngineeringDepartment of Chemical Engineering

Professor of Energy Engineering



+44 (0)20 7594 1830g.maitland Website




Mrs Sarah Payne +44 (0)20 7594 5567




401ACE ExtensionSouth Kensington Campus





My current research centres on finding answers to the question ‘How can we continue to use fossil fuels for most of this century (as I believe we must) without causing catastrophic climate change?’.   The work aims to provide solutions for managing the transition from oil, gas and coal to more sustainable, renewable energy sources and vectors. A common thread running through all my research interests is making the links between interactions at the molecular/colloidal level and the bulk properties of materials and then to exploit this to give accurate data for fluid properties which provide solutions for industrial problems – Fluids Engineering.   The research forms part of the Physical Properties and Analytics Laboratory, with links to several of the Department’s research themes: Energy/Sustainability, Molecular/Materials and Multiscale Driven Chemical Engineering.

The research is built around three main themes:

(a)    Carbon Capture and Storage
My research within the Qatar Carbonates and Carbon Storage Research Centre, QCCSRC, of which I am the founding Director, focuses on making accurate experimental measurements for CO2-brine-hydrocarbon fluids under HPHT reservoir conditions of the thermophysical properties which determine how CO2, and its mixtures with other co-injected gases, behaves when it is injected into an underground storage site, mixes with the in situ reservoir fluids then flows and reacts over long periods of time within the porous/fractured carbonate rock minerals that constitute the reservoir.  The philosophy is to make measurements at selected temperatures, pressures and fluid-rock compositions relevant to carbon storage processes and then to use these data to calibrate, validate and use predictive models to enable the required properties of fluid mixtures of arbitrary composition to be predicted as a function of temperature and pressure as they move through a reservoir.  The research is done in close collaboration with Professor J P Martin Trusler. The most powerful predictive models are based on simplified molecular models incorporated within the framework of statistical mechanics (for equations of state and phase behaviour) and advanced kinetic theory (for transport properties).  These models are developed by Professor George Jackson, Professor Amparo Galindo and Professor Velisa Vesovic and we work with them on applying them to both model fluid mixtures and complex, real reservoir crude oils and brines.

The main properties of interest are:
-    Vapour-liquid phase behaviour
-    Interfacial tension and fluid-mineral contact angles
-    Transport properties: viscosity and diffusion
-    Mineral-CO2 reaction kinetics
The equipment is custom-designed and built within the Department and produces data of high precision.  The skills of the Departmental Mechanical Workshop are critical to achieving the research goals.  More details of the Thermophysics Lab are given here.  We work with other groups within QCCSRC on how the data and predictive models for these properties may be incorporated into pore-scale models and reservoir simulators for CO2 storage design.

Current research projects (jointly with Professor Martin Trusler) include:
-    Phase behaviour, solubilities and densities of impure CO2 mixed with model and reservoir brines at high temperatures and pressures (Rayane Hoballah)
-    Interfacial tension and contact angle measurements for CO2 and impure CO2 mixtures with water, brines and hydrocarbons at high temperatures and pressures (Florence Chow)
-    Diffusion of CO2 in water and hydrocarbons at high temperatures and pressures (Shane Cadogan)
-    The pH of CO2 dissolved in water and brines and the reaction of CO2 with carbonate minerals at elevated temperatures and pressures (Cheng Peng)
-    The viscosity of CO2 and its mixtures with impurities in model and reservoir brines at high temperatures and pressures (Claudio Calabrese)
-    The reaction of CO2 with carbonate minerals and rocks in the presence of gaseous and mineral surface impurities (Benaiah Anabaraonye)

Recent completed projects include:
-    Interfacial Tension of Aqueous and Hydrocarbon Systems in the Presence of Carbon Dioxide at Elevated Pressures and Temperatures (Apostolos Georgiadis, 2011)
-    Measurement and Prediction of the Viscosity of Hydrocarbon Mixtures and Crude Oils (Faheem Ijaz, 2011)
-    Interfacial Properties of Reservoir Fluids and Rocks (Xuesong Li, 2012)
-    Phase Behaviour and Physical Properties of Reservoir Fluids Under Addition of Carbon Dioxide (Saif Al Ghafri, 2013)
-    Viscosity and Density of Aqueous Fluids with Dissolved CO2(g) (Mark McBride-Wright, 2013)

In the carbon capture area, I collaborate with Dr Paul Fennell on developing more efficient and cost-effective carbon capture processes.  Current projects include:
-    Use of calcium looping systems in pyrolysis and combustion of biomass (Joseph Yao)

A recently completed project on carbon capture is:
-    Development of Advanced Amine Systems with Accurate Vapour-liquid Equilibrium Measurement (Danlu Tong 2012)

(b)    Exploitation of non-conventional sources of hydrocarbons
Unconventional oil and gas represent an even greater resource than conventional sources; however compared to conventional oil and gas production methods, current processes are generally more energy intensive and have a higher carbon footprint.  My research is seeking ways to recover and utilise these valuable non-conventional resources in ways that minimise both the energy input required and the CO2 emissions resulting from the processes.  The areas covered are:
-   Subsurface processing of heavy oil, tar sands and oil shales, combined with in situ carbon capture and storage
-    The production of non-conventional gas (gas hydrates, shale gas) using CO2  to enhance production before being sequestered in the producing formation

A long-term aim of this research is novel integrated processes for clean, sustainable production of non-conventional fossil fuels, especially gas hydrates and heavier crudes.  I am exploring with Dr Klaus Hellgardt, Professor Sandro Macchietto and others the possibilities of exploiting the inherent thermal and pressure energy of in situ reservoir fluids and of using the long high temperature, high pressure underground well network for sub-surface separation and chemical conversion processes, alongside downhole removal and sequestration of low value and polluting materials.  The overall aim is to transform the routes by which we extract and process fossil fuels so that power, clean fuels and chemical feedstocks, in appropriate combination, are the dominant process outputs.
Current and recent projects include:
-    Production, Stabilisation and Carbon Capture for Gas Hydrates (Hao Bian) (with Dr Klaus Hellgardt and Dr Jerry Heng)
-    Properties and Production of Natural Gas Hydrates (Udennaka Paul Igboanusi 2009)

(c)    Renewable production of hydrogen using green algae and cyanobacteria
The most likely long-term source of global energy will be solar, where capturing but a small fraction of the energy reaching the earth’s surface will meet all our energy needs on a continuing basis.  As well as converting solar radiation to electrons for electricity supply, it may also be directly converted to fuels and chemicals.  My research is this area, carried out in collaboration with Dr Klaus Hellgardt, has been investigating processes for the direct production of hydrogen (as a zero-carbon fuel or energy vector) from water using sunlight and the enzymatic conversion pathways embedded in natural micro-organisms such as green algae and cyanobacteria.  The work investigates the effect of parameters such as light intensity, illumination patterns, the type and control of nutrients (such as sulphate or nitrate deprivation to achieve anaerobic conditions) as a means of understanding better the underlying mechanisms and enabling the design of photo-bioreactors at different scales to explore the possibility of large-scale commercial hydrogen production processes based on this approach. A major challenge has been to control nutrient addition in such a way that hydrogen is produced continuously rather than peaking and decaying as the micro-organisms die or fail to maintain their anaerobic condition. A novel two-stage chemostat approach has been developed by which we achieve continuous co-production of H2 and biomass in the laboratory. This may provide a route to producing continuous hydrogen in significant quantities at the pilot and larger scales.  The research has been funded by a £4m EPSRC Solar Hydrogen grant (2007-2012) of which we were both co-investigators (see solar routes to hydrogen).

The initial project investigating green algae was:
-    A study of the growth and hydrogen production of Chlamydomonas reinhardtii  (Bojan Tamburic, 2012)
The current project investigating cyanobacteria is:
-    Biophotolytic H2 and 1,3-propanediol production by a unicellular N2-fixing cyanobacterium Cyanothece  sp. ATCC 51142 (Pongsathorn Dechatiwongse)

Research Student Supervision

Jones,C, Quantification and monitoring of fluid phase behaviour and trapping in geological carbon sequestration sites

Ansari,H, CO2 enhanced shale gas recovery