Compressor Q&A: Cook Compression

Explain why compressor technology is so crucial to downstream operations?

Compressors are fundamental to the operation of downstream facilities. Similar to the crucial role that pumps serve in moving liquids, compressors generate the necessary pressure rise to move gases – of varied type and purpose – throughout a downstream facility. From the crucial yet relatively low pressure (150 psi) plant utility air systems serving instruments, pneumatic tools, rotating devices, and plant control devices, to the 50 000 psi hyper compressors essential for low density polyethylene (LDPE) production, compressors serve a wide breadth of applications.

Whether reciprocating, centrifugal, or screw type, compressors are typically a large energy consumer, are essential to continuous production, and must reliably and safely transport high pressure and often hazardous gases throughout numerous plant processes. Accordingly, compression technology – encompassing the electrical systems that control and monitor compressors, to the mechanical parts and engineered materials of their componentry – is crucial for minimising energy consumption, downtime, and risk to plant personnel and the environment we all share.

What steps do you take to improve equipment reliability and safety?

Cook Compression closely equates reliability with safety. The reliability of compressor components is foundational to ensuring overall safe compressor operation. It is too easy to surmise that some compressor component failures may only have a small consequence. Even where a failure results in considerable production or capital loss, those negative outcomes remain small and inconsequential relative to the ever-present likelihood that a compressor component failure could lead to a systemic failure – causing personal injury or the release of an explosive or environmental hazard. This is especially true for the high stresses that compressor valves, packings and sealing components endure. The solution for reliability is in two parts: in the component design and in proper maintenance.

For downstream applications, Cook Compression designs components to the particular circumstances of each application, including but not limited to the range of expected gas composition, speed range, pressures, gas loads, lubrication and temperature range. Engineers then optimise the component designs by drawing from a breadth of common and specialty materials to ensure reliability and safety, as well as to maximise efficiency and longevity. Once installed and run for a period of time, component reliability depends on the aforementioned application-specific design as well as adherence to recommended maintenance activities.

Long-term best practices for maintenance include evaluating changing operating conditions, such as those that might arise from feedstock property changes. Given the decades-long lifespan of most reciprocating compressors, they are likely to operate with different gas compositions, pressures and output requirements at various points in their life. When such changes occur, the cycle of reliability must begin again, including a re-evaluation of the components’ suitability for safe and reliable operation under the new conditions and, where necessary, a new optimised design.

How can compressor technology assist plants operating in extreme environments or with demanding applications?

For compressors in extreme environments and demanding applications, highly engineered products are paired with specially formulated materials to achieve efficiency and reliability targets. Thermoplastic materials can be optimised with custom fillers to maximise the function of the component (e.g. oil wiping) and to address specific process needs (e.g. non-lubricated, dry gas, high temperature). Experience has shown that specially formulated materials, paired with a fit-for-purpose design, can extend seal component life while improving sealing effectiveness and compressor throughput.

Plants operating with demanding conditions must balance longevity of components with cost-effectiveness. Exclusive specialty materials such as Vespel or Torlon can provide high performance in difficult applications, but at excessive cost and lead time relative to uniquely blended PTFE and PEEK formulations. Component manufacturers who possess the in-house knowledge for creating and proving out such blends provide a balance of performance, cost and timely delivery for plants.

How can compressor technology help to reduce emissions in downstream operations?

Minimising compressor emissions is closely linked with proper configuration and maintenance. For instance, reciprocating compressors operating with valves that do not maximise process flow require greater input power to overcome the valves’ inefficient operation. For an engine-driven compressor, or a motor-driven compressor supplied by a fossil fuel-driven electrical generator, that inefficient valve ultimately leads to excess CO₂ emissions from excess fuel burn. Likewise, poorly maintained valves and valve designs that are more prone to fouling will effectuate the same indirect contribution of excess CO₂ emissions in driving the compressor.

The packing case of the reciprocating compressor is the primary source of emissions of the process gas itself. While most downstream compressors utilise vapour recovery and purge systems to prevent direct leakage to the atmosphere, those systems have limited capacity and under certain conditions may be taken to flare. Ultimately, minimising emissions in both direct and indirect form requires proper component selection and best practice maintenance for the specific operating conditions and overall compressor design.

How have advancements in digitalisation changed the compressor sector?

Digitalisation has arguably provided, and will continue providing, the greatest opportunity for improving overall equipment effectiveness (OEE) for compressors. Hydrocarbon processing facilities began adopting digital technologies in asset management decades before the current wave of Cloud/Industrial Internet of Things (IIoT) technologies, analytic-based data science tools, and digital connectivity solutions. While the initial generation of digital technology matured and served reliability professionals exceptionally well, today’s digital solutions are contributing dramatic advances.

Reliability-centered maintenance (RCM) and condition-based maintenance (CBM) stand out as areas that are increasingly governed by modern data availability and analytics. With today’s leading technologies, compressor operators are connecting individual component sensors and integrating existing legacy data systems with maintenance management systems and digital twin technologies, which have been demonstrably effective in improving predictability of equipment health and revealing ways to optimise uptime and efficiency. The key to these systems’ efficacy is less about the technology, however, and more rooted in how they can embed operational and subject matter expert (SME) knowledge within RCM/CBM. For all that digital hardware and software adds to the compressor sector, it is digitisation’s ability to enhance SME productivity that drives improved OEE outcomes. Success is premised on the fact that digitisation facilitates collaboration among SMEs representing the compressor operators, maintenance teams, OEMs, and component manufacturers.

What does the future hold for compressor technology?

Given their fundamental role in transporting gases, compressors will continue to be vital to the energy industry’s future. Accordingly, in the face of global challenges to reduce greenhouse gas emissions and conserve natural resources, compressor technology will continually evolve to operate with greater efficiency and lower energy consumption. Since compressors are often driven by electrical motors, they fit well within the progression toward renewable-generated electrical power. Moreover, as alternative fuels such as hydrogen come into the carbon-neutral mix of energy sources, compressors will adapt to move that gas too. The challenge of compressing hydrogen fuel gas is maintaining gas purity (which requires non-lubricated components) and achieving high compression ratios. The stress and demands on sealing materials under such conditions exceed those in typical industrial hydrogen compression applications. As technology evolves to meet the challenges facing hydrogen fuel gas compressors, the resulting material technology is expected to feed back into many traditional downstream compression applications for further reliability, safety and efficiency advances.

All questions answered by Ben Berwick, Product Manager, Cook Compression.

Ben Berwick joined Cook Compression in 2020, bringing 25 years’ experience creating technology solutions for increased reliability and efficiency of industrial rotating machinery and compression systems. Ben previously served in design engineering, strategic marketing, and leadership roles for Bently Nevada Corp., Dresser-Rand, Rolls-Royce Power Systems, and Honeywell Process Solutions.

This was a preview of the 'Compressor Q&A', which featured in the August issue of Hydrocarbon Engineering. To read the full Q&A, which includes answers from a number of leading experts in compressor technology, sign in here or register for a free trial subscription.

Read the article online at: https://www.hydrocarbonengineering.com/special-reports/25082021/compressor-qa-cook-compression/