The use of repurposed steel pipes can support a circular economy by reducing the need for new materials and produce CO2e savings as high as 97%, says Sean Conway, Managing Director, Decom Engineering Ltd, UK.


Interest is growing in the use of repurposed steel pipes in infrastructure projects as an alternative to ‘virgin’ new steel pipes, primarily due to the significant carbon benefits associated with their use. Perhaps this is no coincidence, given that reducing the emission of greenhouse gases (GHG) is front of mind for many responsible industrial sector players – and those who are seen to be more reticent in playing a meaningful role in addressing global warming are coming under increasing scrutiny from shareholders, investors and government and regulatory bodies.

Environmental benefits

One of the most significant environmental benefits of using repurposed steel pipes is the reduction in GHG emissions, when comparing the process of stripping coatings on used pipe in preparation for reuse with the manufacturing process of new steel pipes, and as a study conducted by Decom Engineering shows, in some cases the CO2e savings can be as high as 97%.

Another benefit of using repurposed steel pipes is that it reduces the amount of waste sent to landfill. Steel pipes are one of the most commonly recycled materials in the world, and using repurposed steel pipes can pre-vent them from being discarded and polluting the environment. Recycling steel pipes also reduces the demand for new steel, which in turn reduces the environmental impact associated with the mining and processing of raw materials.

In addition to the environmental benefits, using repurposed steel pipes can also be cost-effective. Repurposed steel pipes can often be obtained at a lower cost than new steel pipes, which can save money on building and infrastructure projects. The use of repurposed steel pipes also reduces the need for additional materials, such as concrete and plastic, which can further reduce costs and environmental impacts.

With this in mind, Decom commissioned a study which examined the carbon footprint of the various stages required to remove the coatings from steel pipes using its coating removal machine (CRM) – an industrial lathe used for stripping back coatings from steel pipes. The findings were compared with the estimated carbon emissions generated if a similar quantity of virgin steel pipe was produced for use in infrastructure projects.

Typically, Decom’s CRM handles pipes decommissioned from the oil and gas industry, prime pipeline (surplus or unused pipeline) and subprime pipeline. The CRM is able to remove all coatings (FBE, PE, PP, tar, bitumen, etc.) and the pipe remains certified – which is essential for carrying on into new industries and uses such as piling, civil and construction.

Around 80% of pipes put through the CRM are 3-layer coated steel pipes with a coating of each fusion bonded epoxy (FBE), adhesive and polyethylene (PE). The CRM allows for coatings to be removed to a standard that allows for the pipe to be repurposed as opposed to recycled – a safer and more cost-effective handling of decommissioned or surplus pipelines, with the structural steel reused in form, as opposed to smelted and reformed. Additionally, the CRM’s ability to completely remove FBE from pipe provides a much-needed antidote to the environmental impact of subprime pipe storage, which can cause a rise in toxicity levels in water supplies and cause leaks, explosions and spills.

The study, carried out by respected environmental consultants Carbon Zero, revealed that businesses can improve their ESG credentials and make massive CO2 emissions savings by opting to repurpose steel pipes instead of commissioning new pipe.

Case studies

In addition to its CRM capabilities, Decom has invested heavily in developing a range of C-1 Chop Saws which are recognised as a safe and effective pipeline cutting solution for the decommissioning and maintenance of oil and gas pipelines and installations. Cleanly cutting through 2 – 46 in. materials, these cold cutting saws can be deployed and operated within the harshest working conditions and are versatile, industry approved, single-blade pipe cutters, with the ability to clamp and cut a wide range of sizes with the same saw.

To establish the carbon savings of the CRM process, Carbon Zero looked at four case studies, two scenario-based and two evidence-based, involving recent projects completed by Decom. The first was an evidence-based case study concerning a consignment of just under 7000 pipes which were transported from Bilbao in Spain to Decom’s Northern Ireland base for processing through an in-situ CRM, with the pipes returned to the client on completion.

In the second scenario-based case study, Decom deployed a CRM to a client’s site in Perth, Australia, to process 130 km of pipe recovery for a client. No pipe transport was required in this case and the CRM was partly manufactured in Northern Ireland and shipped to Australia where fabrication was completed.

In evidence-based case study 3, Decom provided a CRM for a Dutch pipe stockist, with the machine shipped to Zeeland in the Netherlands, where all the pipe was received and processed before being returned to the client.

The fourth scenario-based case study was similar to the second with a CRM part manufactured in Northern Ireland, and transported for completion in Port Arthur, Texas, USA, where the pipe consignment was received, processed and returned to the end client.


The aim of this assessment was to provide an accurate comparison of car-bon emissions between Decom’s coating removal process for recovering decommissioned and prime surplus pipes, and the embedded carbon associated with sourcing new/virgin steel pipes. The scope of this assessment extended to all the associated carbon emissions related to the CRM, including fuel use, waste disposal, and general transport requirements of the pipes and CRM unit, with emissions related to the movement of staff excluded.

Case study 1

Case study 1 showed that the total carbon emissions generated by 1741 t of virgin steel (equivalent to the 7000 pipe consignment) would be 5260 t CO2e, compared to just 1869 t CO2e from the CRM process. This represents a potential carbon saving of 3391 t or 64% less CO2e.

Case study 2

Case study 2 involved the deployment of a CRM to Australia to process 130 km of pipe (10 833 pipes) recovery for a client. The study assessed emissions involved in the transportation of the CRM by sea to Perth from Belfast (via Normandy, France), road transport in both countries, the manufacture of 40.3 t of CRM components in Australia, as well as the transport, operation, maintenance and waste handling of the CRM in Australia.

The study estimated this would generate 3076.3 t CO2e. By comparison, the study estimated that if the same 130 km of pipes (37 341 t) of steel had been manufactured from scratch, the embedded carbon would be in the order of 112 770 t CO2e – a potential saving of 109 693 t, reducing carbon emissions by 97%.

Case study 3

Case study 3 looked at the processing of five consignments of pipe in the Netherlands totalling 5750 t. The CRM was shipped to the client site in Zeeland and the pipe consignments were transported from within the Netherlands, Cyprus and Germany, by road, sea and barge.

It was estimated that each 4 – 12 in. pipe took in the order of 30 min. to pass through the CRM. Each 16 – 24 in. pipe took in the order of 60 min. to pass through the CRM, and 700 operational hours were needed to process the 16 – 24 in. pipes.

Total emissions using the CRM process was estimated to be 446.1 t CO2e, compared to using virgin steel at 16 995 t CO2e, which represented a 97% carbon saving of 16 549 t CO2e.

Case study 4

Case study 4 involved the processing of four consignments of pipe at a client site in Port Arthur, Texas, with the CRM shipping from Belfast and 65% of the components later manufactured in the US.

The consignments, totalling 10 722 t of pipe, were transported to Port Arthur from Oklahoma, Missouri, and within Texas, and post-process were re-turned to clients. The pipe diameters ranged from 6 – 36 in. and it was estimated that operational hours totalled 4761.

Total emissions from transporting the CRM to Texas, part manufacturing of the CRM in the US, CRM operation, waste handling, pipe transportation and maintenance, totalled 2041.1 t CO2e. This compared to an estimated 31 456 t CO2e if virgin steel had been used – a carbon emission saving of 94% or 29 415 t CO2e.


This report shines a bright light on the advantages of repurposing steel tubulars for wider industrial use and draws some remarkable comparisons when contrasting the relatively low levels of CO2e produced in the coating removal process with much higher levels of carbon emissions when virgin steel is the favoured option.

Decommissioned or surplus pipelines would usually be sold for scrap with the coatings removed through labour intensive processes such as water jets, or smelted and reformed as new steel products of a lower quality (due to contamination from the coatings). Our CRM, however, offers an alternative approach for businesses which are serious about combatting global warming. The use of repurposed steel pipes can also support a circular economy; by reducing the need for new materials and extending the lifecycle of existing materials, we can create a more sustainable and resilient economy.

Decom’s report, which looked at scenarios in the UK, mainland Europe, Australia and the US, clearly shows that repurposing steel pipes can reduce GHG emissions, reduce waste, and can help to mitigate the impacts of climate change and promote sustainable development.

Decom’s CRM technology is an agile and flexible option for businesses which are focused on ESG issues and who are committed to playing a fuller part in reducing harmful CO2 emissions. Transporting redundant piping infrastructure for disposal – often thousands of miles away – should be a last resort and we will continue to invest in our CRM capabilities to provide a more economically and environmentally sound option to the onshore and offshore decommissioning industry.