Case Studies

Iodates Chlorine Scrubber

Background – A Chlorine Scrubbing column was installed on a system that extracted fumes from a reactor. The level of Chlorine in the discharge from the scrubber exceeded the prescribed limits so I was tasked with designing a new scrubber to operate in series with the existing scrubber.

This project involved

Site measurements (Chlorine discharges, extracted gas flowrate, pressure profile from the reactor to the column and its exit).
Process Investigation and Troubleshooting (the extraction rate was half the capacity of the fan and the pressure drop across the column was suspiciously low – it was found that the existing fan was operating in ‘stall’, and the cooling coil in the existing sump was incorrectly sized assuming steady state conditions).
Mass Transfer & Chemical Reaction (chlorine absorption and chemical reaction in the circulating scrubbing liquid and estimating of mass transfer coefficient from the existing column).
Heat Transfer (cooling coil sizing for the scrubbing liquid sump to maintain the liquid temperature during the heating cycle of the reactor – using unsteady state heat transfer).
Detailed Design (specification of the scrubbing column diameter, height of packing, support plate, top liquid distribution and redistributors, extraction fan rate and vacuum pressure, scrubbing liquid circulation pump rate).
Control and Safeguarding of factors affecting scrubbing efficiency (circulating scrubbing liquid flow / pressure, extraction suction pressure, scrubbing liquor temperature, cooling water pressure, scrubbing sump liquid level).

Pondering plant issues at William Blythe

Existing Chlorine Scrubber having its packing maintained.

This was the first job Euton saw through the whole project cycle from concept to operation, 4 to 5 years into his career. Subsequently he designed

an Oleum Scrubber for fume from a storage for Hickson and Welch,
a H2S Scrubber on a Waste Brine Treatment Plant for ICI,
a CO2 Absorber, CO2 Stripper, Purge Gas Scrubber, Purge Gas Stripper and Ammonia Scrubber for an Ammonia Plant to BASF aMDEA standards.

Euton has also been involved in troubleshooting

a Chlorine Scrubber at Hickson and Welch and
H2S Scrubbers at Point of Ayr Gas Terminal and Barrow Gas Terminal.

New Cl2 Scrubber to the left of the existing one

Douglas Produced Water Abatement

Background –In 2001 the OSPAR committee recommended a 15% reduction of oil discharged in produced water based on the producer’s calendar year 2000 produced water discharges. In addition, it was recommended that the monthly average oil in water (OIW) concentration limit be reduced from 40 mg/l to 30 mg/l. In the UK the DTI arranged for these changes to be implemented in 2006 so that the industry could adjust for the new requirements. For one asset Euton was involved in, produced water rates had doubled in the years post 2000 which meant that the required OIW discharge concentration to meet the new requirement was 5 mg/l – a big ask for any abatement system.

Euton was tasked with carrying out a trial of Epcon Compact Flotation units on the installation. He designed the trial and captured a comprehensive set of results to enable a thorough review of the technology to be made by the client. After receiving the report the client gave him responsibility for the installations Produced Water projects.

He next carried out a comprehensive review of the existing produced water equipment – reviewing the separator design, hydrocyclone operation and optimisation, degasser performance and gas flotation sparge system.

Finally, he was tasked with designing a Produced Water Reinjection trial using hired diesel driven pumpsets to inject produced water into one of the platform’s seawater injection wells. Despite some issues with the pumpsets transmitting vibrations to the platform pipework we were able to successfully prove the concept.

Produced Water Workshop details

After PWRI was selected as the preferred option Euton carried out the conceptual design of a full scale PWRI system. This involved converting a train of the existing seawater injection booster and injection pumps for produced water injection. This approach saved procurement and delivery time for new pumps enabling implementation of the project 12 months earlier and in time for the OSPAR implementation deadline. Following detailed design and installation he commissioned the new PWRI system that was capable of injecting 60kbwpd of produced water.

He was asked to write a paper summarising this work after delivering a presentation to the DTI Produced Water group. Euton has also carried out

PW debottlenecking for Eider Alpha (conversion of M to K hydrocyclone liners)
PW debottlenecking for Tern Alpha, (reinstatement of the flotation unit downstream of the hydrocyclones)

More recently he carried out a review of the produced water challenges of the Erskine production module on Lomond

Paper published at Produced Water Workshop 2007