Steam Injection Remediation UK

Enhancing Sustainability of Vapour Phase Activated Carbon

Increasing the Efficiency and Sustainability of Vapour Phase Activated Carbon

The performance of activated carbon is of course variable depending on the contaminant.  Some organic compounds adsorb to vapour phase activated carbon very efficiently indeed, sometimes in excess of 40% weight for weight, others conversely adsorb very poorly.  For vapour phase activated carbon the efficiency of adsorption is also greatly influenced by humidity and temperature.  The efficacy and indeed viability of the treatment approach therefore depends not just on the contaminant and it’s concentration but also on the condition of the vapour in which it is carried.  It also depends on the mass expected.

Activated carbon in vessels situated outside in ambient weather conditions will perform very badly in cold weather as the vapour cools.  Condensation will cause accumulation of water in the vessels and water vapour will preferentially adsorb to the carbon at the cost of the contaminant.  A worst case scenario could be an air stripper or multi-phase extraction system delivering wet warm air to a cold carbon vessel.

Likewise, consider the activated carbon isotherm for a given contaminant at different temperatures.  The higher the temperature, the less efficient the contaminant uptake.  A soil vapour extraction  system, and in particular a multi-phase extraction system will inherently heat up the extracted soil gas through the system.  The harder the blower or pump is working the hotter the discharged soil gas will be.  The temperature of soil gas discharged from an SVE system can quite typically be in the region of 40oC.  A hard working MPE system can heat the extracted soil gases to 80 oC.  Depending on the contaminant this can very significantly reduce the activated carbon performance.

Vapour Conditioning System Developed by Cornelsen

Cornelsen has developed a vapour conditioning system wherein extracted soil gases discharged from the SVE or MPE system (or air stripper) are cooled, moisture is condensed out and then the gases are reheated to ensure that the relative humidity is below 70%, thus preventing water vapour using up the activated carbon pore spaces.

A simple cost benefit analysis considering the additional process plant vs the consumption of activated carbon will quickly inform the project team of the relative value of vapour conditioning.

In 2013/2014 Cornelsen undertook two projects where the benefit of deploying vapour conditioning prior to the activated carbon could be measured in terms of several hundred thousand pounds.  Both projects involved dichloromethane which adsorbs relatively poorly to vapour phase activated carbon.  As one of those projects entail steam injection, two vapour conditioning systems were required.  One system was installed at the inlet of the SVE system to cool the gases to a safe temperature within the operational limit of the blower (Note normally this will be 40oC), then a second system at the discharge given the inevitable heat increase which occurs by energy transfer through the blower.

Contact Cornelsen for a Cost Benefit Analysis

The cost and benefits are easy to assess and the solution quite simple to deliver.  The choice between vapour conditioning vs increased activated carbon consumption can be as simple as straight maths.  The added sustainability associated with the use of less activated carbon and all the transport and works associated with changing the carbon are similarly persuasive.  Conversely, where the contaminant mass is low the poor performance may have little impact on the overall volume of activated carbon required and therefore the costs may exceed the benefit.  The same may be true for organic contaminants which inherently adsorb more efficiently.

In summary, we recommend a simple cost benefit analysis based on isotherms obtained from activated carbon suppliers at different temperatures.  Cornelsen will be pleased to assist in the cost benefit analysis and in the provision of the cooling/warming and heat exchange equipment. Use the Contact Form to send us a message today.

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Steam Injection Remediation

Steam Injection Remediation by Cornelsen

With UK project experience delivering both in-situ thermal desorption (ISTD) and steam injection remediation systems, developed over the course of the last 7 years, Cornelsen undertook its second major steam injection project in the UK in 2014.

Compressed Air and Steam

Unlike conventional steam injection, Cornelsen, together with our partner Reconsite GmbH delivers a steam/compressed air mix.

Advantages of this process include:

  • Increasing the efficiency of heat propagation through the formation by convection;
  • More efficient mass removal;
  • Reducing the risk of dispersing the contaminant plume by a condensing steam front as the water/contaminant mix evaporates quickly into injected air at temperatures well below 100 oC (the point of steam distillation).

Cornelsen personnel operated and optimise the remediation system continuously throughout the project and successfully met the performance parameters of our client and the operational up time requirements of 95%.  Another steam injection project is currently underway in Berlin, Germany.

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All steam injection systems and process plant is available ex stock for rapid mobilisation.  This includes all the necessary cooling and heat exchange plant as well as critical safety equipment.  No system installation will be completed without a detailed Hazard and Operability study (HAZOP) which we would expect to undertake together with our client.  Thereafter, all system infrastructure including pipework, electrical supply, control systems and safety systems are undertaken in house by Cornelsen engineers.

Cornelsen Expansion

Company News 2015 Cornelsen Expansion

2014 was Cornelsen’s busiest year.  This included the recruitment of two new engineers and our second apprentice engineer; our previous apprentice Ben now being a fully qualified Service Engineer and PLC programmer.

September 2014 also saw us break ground on a new office and workshop facility near Bristol.   This new development allows us to centralize all our UK process plant at a secure yard contained within our own new premises and provides excellent new workshop facilities for our mechanical and electrical engineers.  Together with our new office space, these new facilities will enable us to provide a higher level of service to our clients through greater efficiency in storage, maintenance and construction, whilst simultaneously providing us with a firm footing and the space for continued growth.

Purpose-built facility designed with a clear identity

Office Pic3

• Construction of a new building with a footprint of 476m².
• New office accommodation of 145m², with potential for an additional mezzanine floor to allow for further growth.
• Workshop provided for the repair and maintenance of plant and equipment.
• External storage area and service yard.