Compressor Q&A: Howden

Explain why compressor technology is so crucial to downstream operations?

Compression technology is crucial to many processes as it is frequently the heart of the process that either maintains flow or compacts and pressurises the gaseous medium for reactors, storage and transportation. Gas compressors together with liquid pumps are often the highest energy consumption components of process systems and the correct selection of compression technology is crucial for continuous operation, safety, efficiency and reliability of plants, especially downstream operations.

How can compressor technology help to improve efficiency in downstream operations?

Efficiency improvements in downstream operations is often a factor of utilisation and hence compressor reliability is a key factor. The basics of compressor technology have all been long established, and as a whole, the industry and its key players - mature. Continuous developments in materials, lubricants, seal and valve design together with computer aided analysis and design, all combine to provide marginal improvements in efficiency, reliability and extended mean time between maintenance (MTBM). For efficient operation, it is imperative that the correct compressor technology is selected based upon:

1. Volumetric flow, pressure rise, static pressure range, temperature range.
2. Continuous or intermittent operation.
3. Flow and pressure regulation requirement.

It is this third criteria of flow and pressure regulation that is too often overlooked in helping to improve efficiency in downstream operation. Plants rarely operate at design and hence the ability of the selected compression technology, together with its capacity control technology to maintain high efficiency away from design flow or pressure, can significantly influence plant operation. Additionally, today’s process requirements often operate on shorter timescales as customers are producing more on demand.

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

Safety is at the core of what we do throughout our business. Our commitment to safety is embedded throughout all departments and locations in Howden. Our people and processes foster this culture across product lifecycle including design, manufacturing and testing, to transport, installation and operation as well as maintenance.

Safety and awareness training is carried out frequently within Howden, where performance is monitored and challenged monthly at board level in pursuit of achieving zero accidents. Additional experience from even minor incidents is circulated both internally and externally via safety alert notifications. With over 160 years of engineering excellence, Howden is recognised as a trusted supplier of reliable compressors that meet the demands and specifications of continuous critical service applications, often operating in harsh environments. For Howden, continuous improvement of equipment reliability and safety is carried out through design. It is also important to recognise that reliability directly affects safety, not only the consequences of a catastrophic failure, but more that lack of reliability usually demands human intervention – and working on site is an increased risk for safety.

Howden Uptime, the company’s performance analytics tool, supports the implementation of new processes in the digital refinery. It delivers actionable insights into how equipment is operating under specific conditions. This insight can predict when equipment needs maintenance, which can then be used to prevent any cases of unexpected downtime resulting in cost savings, increased reliability and increased safety.

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

For plants operating in extreme environments or with demanding applications, selection of compressor technology based on reliability and safety should be the priority. This inherently results in a compressor that is robust and provides ease of maintenance, another important consideration for often remote, extreme environments.

Ultimate efficiencies are usually the product of fine tolerances, demanding relatively clean process gases and operating environments to allow these tolerances to be maintained.

Circumstances where compressor operation will be in an extreme environment or has a demanding application favour compressor selection based upon reliability, aiming to achieve improved plant efficiency by ensuring maximum availability and utilisation. Outages in remote and extreme environments can often be lengthy and costly.

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

Compressors are one of the main energy consumers in downstream operations. This energy requirement is in the form of motive power to drive rotation of the compressors. Improvements for efficient operation (especially at part load) reduce power absorbed, which in turn reduces carbon emissions. Many of the gases handled in downstream operations have a significant greenhouse effect and hence improvements to reduce seal leakage and any subsequent containment are vital.

Although reduced emissions applied to compressor technology is mainly related to efficiency (drive power/carbon footprint) and process gas leakage, the use of mechanical vapour recompression (MVR) applied to evaporators, concentrators, crystallizers and distillation can significantly reduce thermal demand and subsequent emissions by effectively recycling the latent component of heat. MVR has the potential to be applied far more widely across downstream operations and create a step change toward electrification of wider process plants.

What has been your company’s biggest recent achievement or innovation in compressor technology?

This depends on how “biggest recent achievement or innovation” is defined. In terms of downstream operations, it would have to be Free Floating Piston^™ technology for Howden’s Thomassen oil-free reciprocating compressor and especially its application for hydrogen compression. The extended continuous running of oil-free reciprocating compressors on hydrogen at up to 100 bar and 20 MW rating is now well proven with blue chip producers, some having in excess of 100 000 hr operation without the need for piston ring or bearer band change and with no noticeable reduction in performance.

We are experiencing a significant increase in activity and business in this area, which is linked to the expanding market for biofuels and the inevitable hydrogen economy.

Howden has served the grey hydrogen market in a large number of applications for many years. For the rapidly evolving green and blue hydrogen markets, Howden solutions already serve a wide variety of clean energy/hydrogen applications such as eFuel, green steel and hydrogen refuelling stations, as well as power-to-gas worldwide.

How have advancements in digitalisation changed the compressor sector?

Historically, Howden has contracted to supply both bare shaft machines and skid mounted compressor packages. The skid mounted compressor packages for the oil and gas market in particular are always provided with extensive instrumentation for control, monitoring and protection. The split between local control panel with a programmable logic controller (PLC) and interface for customer connection to their distributed control system (DCS) has gone in favour of the latter, especially for downstream operations. In many cases, this information had always been available but from a security perspective, contained by customer concerns.

Improvements in communications technology and its security, coupled with an increase of remote operation/control and reduced experience at site, has created a need and opportunity for the Internet of Things (IoT).

We have developed Howden Uptime to bring real time communication options for customer support. Benefits include: compressor performance optimisation using digital twin technology, early warning of potential issues, extended maintenance intervals, avoidance of unplanned downtime, and expert advice close at hand (online assessment).

Describe a challenging project that you have encountered recently.

Renewable energy and the need for energy storage is a constant source of new challenges for Howden where compression is often a component. One recent project success in Denmark basically took electrical energy provided by wind power and via electrolysis to deliver up to 8 tpd of green hydrogen. The challenges themselves are not the actual compression of hydrogen where machines are rated 2000 Nm³/hr to 200 bar, and for which our technology is well proven, but the flexibility for integration with new partners evolving new systems and practices to:

• Manage the green hydrogen produced from wind parks and deliver to refineries.
• Flexibility in operation to accept variances of green hydrogen production rates and distribution networks.
• Partner with vehicle manufacturers to connect to the entire hydrogen value chain.
• Deliver factory tested modular packages, reducing site installation time and costs.
• Breadth of experience and scale up to 20 MW rating.
• Regional Howden service support and Howden Uptime real-time online communication options.

How has the COVID-19 pandemic affected the downstream compressor market?

The COVID-19 pandemic has had a negative impact on the petrochemical, oil and gas (PCOG) compressor market. Fortunately, Howden has endured the period extremely well overall, benefiting from having a global manufacturing footprint, a broad range of compressor products (reciprocating, rotary [screw and lobe], turbo centrifugal, diaphragm, etc.), coupled with flexibility across applications, industries, and a wide customer base.

What does the future hold for compressor technology?

Our mission is to provide products and services to enable our customers’ vital processes to advance a more sustainable world. To do this, we have an increased focus on the hydrogen economy, energy storage, biofuel production and energy recovery.

The United Nations Framework Convention on Climate Change (UNFCCC) has been active since 1992 bringing the world’s best scientists together with political leaders to recognise climate change, provide evidence of the causes and predict the consequences. To date, through various revisions of the UNFCCC Report on Climate Change, each update has provided evidence that exceeded prior predictions – all being worse. The need for change is finally being accepted. Practical revolutionary compressor technology is not currently visible, and increased activity with biofuels and hydrogen will create a direction of evolution within compressor technologies. Gains for increased efficiency of compressor technology may only be achievable for short initial periods. The development of compressor capacity and pressure control features using instrumentation, data acquisition and analysis to drive advanced actuators are likely to bring the largest gains in performance and efficiency at ‘off peak’ design (variable clearance pockets, variable valve timing, and variable speed).

All questions answered by Richard Smith, Director of Product Strategy, Howden.

Richard has approximately 40 years of experience in providing practical customer solutions for process applications combining thermodynamics and rotating machinery. Initially orientated toward heat transfer and change of state involving heavy slow rotation machinery, an early career change toward gas compression developed a broad experience across the power generation, mineral refining, petrochemical, and general heavy industries. High power applications involving fans, rotary, reciprocating compressors coupled with the high speeds of turbo technologies, have created solid foundations to recognise and provide optimum and reliable 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/02082021/compressor-qa-howden/