Smiths Seals a Reduction in Methane Emissions from Legacy Compressors


The Vision

A sealing solution to reduce methane emissions and cost-justify a step-change in environmental responsibility for the natural gas industry.

The Mission

By virtue of the polluting nature of the products they process, transmit or store, when certain industrial equipment leaks it can not only spell disaster for production targets and the bottom-line, but impact the environment, too. Problems escalate as equipment ages. Encouraging timely interventions isn’t easy, however, with environmental arguments often countered by commercial needs.

Take the example of legacy centrifugal compressors in the natural gas sector. 

There are still some 2,000 of these operating globally, all with ageing oil seals. These are widely acknowledged as a leading source of methane emissions today, responsible for 24 billion cubic feet annually. Methane is 30 times more potent a greenhouse gas than CO2, so this has triggered a global call to arms to tackle the issue.

However, the emission-reduction options to date have failed to convince in economic terms that matter to the decision-makers:

  • Oil seals that route emissions to a flare have offered small environmental gains but can still have a total lifecycle cost of nearly $20m per compressor over 15 years. In other words, there is no economic advantage in investing in this alternative technology
  • Oil seals that re-route emissions to alternative use as a fuel are significantly more preferable environmentally, but can still cost $13m per compressor over 15 years

To incentivise the industry to address the problem on the scale required to combat global warming, new alternatives were needed that would deliver operational savings along with environmental advantages.

The Innovation 

Previous innovations from the John Crane team at Smiths have set the shaft seal standard for all new centrifugal compressors in the natural gas industry. Building on this success, John Crane has now turned its creative engineering team to the issue of cost-effectively addressing the methane emissions issue in this industry. 

The result is a cost-justifiable, turnkey upgrade service for centrifugal compressor shaft seals that involves retrofitting a specially adapted version of John Crane’s sector-leading Aura gas seal system onto legacy compressors.

The Smiths Effect

Gas seals on centrifugal compressors have consistently delivered enormous environmental and safety improvements in the natural gas sector, exceeding the performance of oil seals. Critically, though, they also provide improved performance and operational savings. Over 25 years, this can deliver a cost-of-ownership of around $2m.

By rethinking the problem and applying an innovative solution, Smiths has achieved the one thing no predecessor has been able to: it has given operators the economic justification they needed choose the greener option, and to stimulate emission-reduction action across the sector worldwide.