We have designed and developed a number of unique experimental facilities to investigate both fundamental and applied aspects of clathrate hydrate or gas hydrate. In this section, we will highlight a few apparatus. For further information, please contact Prof. Linga at praveen.linga@nus.edu.sg.
Fixed bed reactor
A 1.2L high pressure apparatus was established to demonstrate the hydrate based gas separation process in a fixed bed configuration with the objective of finding the porous media that can result in enhanced kinetics and higher separation efficiency for CO2 capture. This facility has state of the art capabilities to perform batch and semi-batch experiments with precise accuracy for both hydrate formation and dissociation. It consists of a crystallizer, reservoir, PID controller, control valve, two pressure transmitters, two analog pressure gauges, chiller and NI DAQ system coupled with Labview software on a computer. For more details: click here
Application: CO2 capture, seawater desalination.
Methane Hydrate Energy Exploration Rig 1
A 2L high pressure hydrate rig was designed to mimic methane hydrate formation in natural environment, to study the dissociation behaviour of hydrate samples and the effect of salt in hydrate formation and dissociation. To meet these objectives, this facility is equipped with capability to perform batch and semi-batch experiments. It consists of a crystallizer and a reservoir, both welded with cooling jacket, PID controller, control valve, two pressure transmitters, two analog pressure gauges, chiller and NI DAQ system coupled with LabView software on a computer. Application: Methane/CO2 Hydrate Formation and Dissociation in porous media.
Methane Hydrate Energy Exploration Rig 2
A 1L capacity high pressure reactor designed with top and bottom injection ports has been newly devolved to form methane hydrate under an excess water environment similar to naturally occurring NGH in marine locations. Another salient feature is the ability to inject dissociation promoter or CO2 from different parts of the sediment. This facility is capable of capturing time-dependent water production profiles along with the gas production profiles. Application: methane/water production from hydrates, CH4–CO2 exchange process
Methane hydrate Energy Exploration Large Rig 3
A 5.9L high pressure hydrate rig was designed to mimic methane hydrate formation in natural environment and to study the radial dissociation behavior of hydrate samples. This rig was set up by a collaboration project with civil and mechanical engineering. The setup is equipped with thermal management system, back pressure valve to dissociate at constant pressure and electrical heating system. For more details: click here
A 150 ml capacity high pressure crystallizer fitted with 30 cm marine type quartz windows rated for 100 bar pressure was established for the conduction of kinetic study on gas hydrates. The crystallizer is kept immersed in a water bath and mounted on submersible stirrer for mixing the reactor contents. Can be operated in batch and semi-batch manner. A PID controller aids in the precise control of the crystallizer pressure during semi-batch study. The setup also comprises of a control valve, two pressure transmitters, two analog pressure gauges, chiller and NI DAQ system coupled with LabView software on a computer. For more details: click here
Application: Fundamental study and intrinsic kineticsof gas hydrates
Morphology apparatus 1
A crystallizer column with two lids on both sides is employed to understand and elucidate the morphology of hydrate crystal formation. This reactor can operate up to 100 bars. A microscope coupled with video camera is connected to observe the size and shape of hydrate crystals formed. The apparatus also consists of a chiller, pressure transmitter, analog pressure gauge, NI DAQ system coupled with LabVIEW software and iSolution software to record images on a computer. For more details: click here
Application: Crystal size, shape and growth
High pressure morphology apparatus 2
We have desinged a unique high pressure morphology reactor with cooling arrangement that will enable us to observe crystal morphology at high pressures. A microscope coupled with video camera is connected to observe the size and shape of hydrate crystals formed. The apparatus also consists of a chiller, pressure transmitter, analog pressure gauge, NI DAQ system coupled with LabVIEW software and iSolution software to record images on a computer.
Application: Crystal size, shape and growth
Phase equilibria apparatus
A high pressure apparatus to determine the hydrate phase equilibrium. The setup has a crystallizer with two quartz window to observe the hydrate crystals. Pressure search method, temperature search method and P-T cycle method can be employed to determine the hydrate equilibrium pressure and temperature. The set up is equipped with pressure transmitter and an analog pressure gauge to measure pressure and thermocouple for temperature measurement. This set up is also equiped with DAQ system with Labview interface on a computer.
Featuring the exclusive calvet three-dimensional sensor, the μDSC7 evo microcalorimeter (HP-μDSC, VII Evo, Setaram Inc., France) can be used for highly sensitive and precise calorimetric measurements. It is able to study samples in liquid, gel, powder and solid forms in both isothermal and temperature scanning mode, with the operating temperature from -45 to 120 ℃. It has a resolution of 0.02 μW and a temperature uncertainty of ±0.2 K. Gas tight high pressure cells and gas panel are specialized for gas hydrate application, which enable measurements with pressure up to 400 bar.
Application: thermal properties of petroleum fluids, hydrate thermal properties
In-situ Raman spectroscopy
Our lab has a Raman spectrometer (SRaman-532) that operates with a laser wavelength of 532 nm in the range of 150-4490 cm-1 spectral coverage. In-situ Raman spectrometer employs two optical fibre cables that are connected to a compact, Raman probe tip that focuses the laser onto the sample which also collects the Raman signal to be processed by the detector.
Application: Phase transition behaviour, guest occupancy in hydrate cages
HyDesal prototype (patented)
To overcome the challenge of scalability, we have designed and validated a cylindrical annular bed reactor for HyDesal. Through this patented design, we are able to demonstrate a water recovery of more than 35% in a 30 min operation with a salt rejection of 85-90% in one throughput. Our scale-out design is first of the kind and highly efficient.
Application: Seawater desalination, process water treatment, brackish water treatment
SNG prototype (patented)
In general terms, this patented apparatus provides a SNG (solidified natural gas) forming system that is able to integrate typical steps such as hydrate formation, excess water removal and pelletization in a single system. The present invention also provides a method which only requires moderate operating pressures and higher temperatures as compared to conventional methods, while still achieving high hydrate conversion, making the system and method a lower cost method as well as more suited for large-scale natural gas hydrate production and storage.
Application: SNG technology, Hydrate pellets of any structure
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