IEG Vacuum Liquid Recovery™ System
- Patented design - proven engineering
- Quicker, Smaller, Smarter, Greener
IEG’s Vacuum-Enhanced Liquid Recovery™ (IEG
VLR™) process is an innovative technology underpinned by a detailed
knowledge of how hydrocarbons actually behave in the subsurface. Using
IEG VLR™ maximum recovery of free-phase product floating on top
of the groundwater can be achieved quickly and cost effectively using a
specially adapted well screened above the groundwater surface combined with one
of several possible hydrocarbon recovery systems.
By applying a low negative pressure to the well, the floating free product
moves horizontally, together with soil air containing hydrocarbon vapours, into
the well where they accumulate. Dependent on the properties of the soil,
the diameter of the sphere of influence of a VLR™ well can
extend for up to 20 metres. The application of negative pressure causes
up-welling of the air/water level inside the recovery well where the free
product layer mounds and forms a reservoir, into which an IEG
phase-separation device is lowered.
By then applying a low negative pressure, only the free phase hydrocarbon
product is extracted via the phase-separation system, where it is transported to
the surface and collected in a tank for onward disposal. Because
groundwater is not extracted, which would otherwise cause a cone of depression
and smearing of the unsaturated zone, hydrocarbon contamination is not
exacerbated.
The system offers many possibilities. For example, a significant
increase in the recovery rate may be achieved by the re-infiltration of treated
process air via infiltration wells which are normally installed radially around
the extraction well.
The IEG VLR™ system can be easily converted into a
bioventing system to further enhance remediation of residual hydrocarbons by
microbiological degradation. Depending on the extent of the contamination, it is
possible to install several VLR™-wells in a line to intercept
and recover hydrocarbons from a plume, without the usual disturbance and
inconvenience of installing a long trenched recovery system. Depending on
the properties of the soil, it is possible to design such a multi well system to
ensure that the spheres of influence overlap, providing an impassable
hydrocarbon recovery barrier.
Advantages
- No draw-down of the groundwater level.
- Capital costs are less compared with conventional systems, while at the same
time the efficiency is greatly increased.
- Reduced remediation time and treatment costs.
- System can be easily converted to a bioventing system.
- Low maintenance.
- System can be adapted to seasonal, diurnal or tidal groundwater
fluctuations.
- Control of negative pressure and extracted air with an adjustable tube.
- No expensive separation of oil and water mixed with air.
- Increase in free product recovery as compared to conventional systems.
- Simultaneous microbiological degradation.
The IEG VLR™ method is a process patented by
IEG.
