PECT-F^® Pre-coalescer

PECT-F 3D

Overview

The " Performance Enhancing Coalescence Technology", the PECT range is a technology concept unique to Cyclotech. The first commercialised technology in this range is the PECT-F^®, denoting a Fibre based coalescer concept. Cyclotech developed the PECT-F^® technology to achieve a significant improvement in separation efficiency of Produced Water Deoiling Hydrocyclone systems.

The PECT-F^® technology is targeted at:

existing systems which do not meet current legal or stretch targets of performance, or require excessive chemical dosing to do so;
new-build systems where the application of Deoiling Hydrocyclones is potentially marginal due to difficult fluid characteristics.

Principle of Operation

Deoiling Hydrocyclones have steep droplet cut size curves. A typical performance curve for a Deoiling Hydrocyclone shows that a small increase in the inlet drop size significantly increases the separation performance – e.g. an increase in the drop size from 5 to 10 microns can increase the separation efficiency from 15% to over 90%. The effect of this small degree of droplet growth is the key target for the PECT-F^® technology.

The PECT-F^® is a media based coalescer which is installed as a cartridge assembly into either the inlet chamber of the Deoiling Hydrocyclone vessel or into a bespoke vessel located upstream of the PWT system. The inlet chamber of a typical conventional Deoiling Hydrocyclone is the largest chamber in the vessel and has a residence time of up to 20 seconds. The PECT-F^® uses this residence time constructively to achieve partial oil droplet coalescence to capture and grow droplets from a size that would not be separated by the Deoiling hydrocyclone to a size that can be separated. The following are the main parameters which must be optimized to maximize coalescence performance while maintaining a high insensitivity to solids blocking:

Orientation of coalescence media parallel to the bulk flow direction;
Media material selection;
Media density selection;
Media surface treatment selection;
Flow regime achieved by flow distribution devices within the PECT-F^® housing.

The Benefits

The benefits of the PECT-F^® technology include the following:

Improves the oil removal efficiency of existing Deoiling Hydrocyclones by up to 80%. It is particularly effective for condensate applications where traditionally Deoiling Hydrocyclones have had a history of poor performance often due to very small condensate droplet sizes;
Increases the turndown of Deoiling Hydrocyclones. Lower flowrates through the Deoiling hydrocyclone can cause a very significant tail off in separation performance (particularly in difficult applications where the emulsion stability is high) as the spin rate decays. With PECT-F^® installed, low flowrates actually result in increased contact time in the PECT-F^® Pre-coalescer, promoting further droplet growth and thus offsetting the impact of the loss of spin impact on Hydrocyclone performance;
Eliminates or reduces reliance on water clarifier chemicals;
Extends applicability of Deoiling Hydrocyclones to heavy oil, condensate and other marginal applications;
Easily retrofitted into most existing third party Deoiling Hydrocyclone systems without vessel or pipework modifications or hot work;
Low cost solution compared to others requiring additional equipment as the PECT-F^® utilises pre existing residence time;
Passive technology, it requires neither control nor external power.

System Design

The PECT-F^® coalescer can be integrated with the Cyclotech B20 Series Deoiling hydrocyclone systems to create an enhanced efficiency primary separation step in our Produced Water Treatment portfolio. PECT-F^® systems are available to suit Deoiling Hydrocyclone vessel diameters up to 50”NB. Materials of construction for the housing are typically 316L or Duplex Stainless Steels. The media material and surface treatment are specified for the specific applications.

Field Testing.

Cyclotech has a range of single B20 Series Deoiling Hydrocyclone test units (up to 900#) equipped with separate PECT-F^® field test units. Tests can be performed on live fluids to determine the possible separation performance of the B20 Deoiling Hydrocyclone with and without the PECT-F^® online. Effects of varying the PECT-F^® media parameters can be determined to optimise the media configuration. These test units are compact, require no utilities and come complete with all required valving, instrumentation and hosing. Cyclotech can also perform a full oil drop size characterisation of the existing Produced Water Treatment as part of these performance trials.

Please contact us if :

You have a poorly performing Deoiling Hydrocyclone (or other PWT technology) system;
You are proposing to install a Deoiling Hydrocyclone system for a difficult water treatment application;
You are trying to achieve stretched targets for produced water discharge;
You are trying to reduce deoiling chemical usage;
You require a fast track, low cost solution.

Available Resources