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Decommissioning: Preparing Plants for a Retrofit

By Richard Vann, RVA Group |

As technologies advance and market challenges continue to pose new pressures for operators, the decommissioning and retrofitting of facilities is inevitable. This article provides guidance on how to tackle projects of this nature safely and efficiently

As with many industrial sectors, the chemical process industries (CPI) have witnessed a marked upswing in the number of decommissioning projects being carried out worldwide. The drivers for such projects are multifaceted. The work required to pave the way for new or more efficient retrofitted or revamped plants is inherently hazardous, not to mention a step into the unknown for most chemical firms.

Some plants, particularly those constructed in the 1960s and 70s, have simply reached the end of their design life. They therefore pose too many inefficiencies — not to mention safety and reputational risks­— to warrant ongoing operation. Others have effectively reached their “sell-by-date” as a result of evolving environmental, health and safety (EHS) legislation and compliance standards, so they must be decommissioned and ring-fenced if operators are to remain on the right side of the law.

Elsewhere, changing economic trends mean that some markets are contracting, while others are in their comparative infancy and are expanding. We only have to look at India, for example, and the number of assets being transferred out to this emerging economy, to understand the potential that still exists for growth in this part of the world. This geographical shift is often the reason for some plants to be dismantled for re-erection elsewhere. And, in most cases, the closer the producer is to the end-use, the more cost-effective the process becomes. The market is certainly fragmented.


The drive for innovation

It can be said that many global chemical manufacturing companies are constantly looking to innovate — they are not standing still in terms of the processing methodologies that they implement. Instead, they are continually analyzing ways to produce more, for less. This continual drive to work smarter is often in itself the reason why some aged assets naturally reach the end of their useful life.

Of course, such inefficient processing equipment could remain in situ, albeit in a redundant state. But if a company is investing large sums of money in state-of-the-art technology, there is little logic in keeping older equipment. It hardly sets the right impression, and as the asset decays, the risks simply mount and the holding costs accelerate exponentially. Land is also extremely expensive, so if an asset is no longer fit for purpose or it distracts the brand from its lean manufacturing philosophy, its clearance will undoubtedly be deemed essential to pave the way for newer, cleaner and more intelligent equipment.

While such retrofit assignments may be necessary to help optimize a site’s footprint, they can also be incredibly complex in nature, especially if the wider facility remains operational throughout.

The challenge, therefore, is how to undertake such projects — after all, they require a very specific skillset and are often pressured by time and resource availability.


Understanding decommissioning

With very few guiding principles to refer to, dealing with redundant assets often represents uncharted territory for chemical engineers and plant owners. However, it is first essential to realize that decommissioning cannot be viewed as merely the opposite of commissioning or a subset of routine maintenance. It is drastically different. Nor is the clearance of an outdated asset simply a case of knocking the structure down. Decommissioning, decontamination, dismantling and demolition projects are undeniably scientific — they require a tremendous amount of technical knowledge, and the required preparatory work is extensive, with much attention paid to minute details.

Complete site clearance versus plant modernization. It may sound surprising, but the complete clearance of an entire site is often more straightforward than the removal of one single unit of a plant (Figure 1). This is because, from a technical perspective, a full clearance usually only requires a global isolation strategy. In simple terms, this is often a case of carrying out battery-limit isolations to render the plant “cold and dark.” When the site has been made safe, and residual hazards have been removed, all structures can then be dismantled and removed.

FIGURE 1. With careful planning, specific pieces of plant equipment can be removed from a chemical facility when preparing for a retrofit

FIGURE 1. With careful planning, specific pieces of plant equipment can be removed from a chemical facility when preparing for a retrofit

When working on a specific area of a plant, on a live site, the challenges are significantly different. Options are often limited, and certainly more intricate, due to the presence of live common services, adjacent hazardous processes, neighboring vehicular or pedestrian movements, more extensive stakeholder requirements, and the shared nature of facilities. Even the isolation strategy alone is far more complex. With potentially thousands of cables, pipes and services to consider, the impact of an under-planned localized isolation philosophy could be catastrophic. The best-case scenario may be business interruption, but in more extreme circumstances, the likelihood of a serious safety, environmental or commercial reputational incident, should not be underestimated.


Best-practice guidance

General advice for best practices is difficult to offer in granular detail, as every project has to be considered on its own merits — this is certainly not a discipline where “one size fits all” will suffice. However, there are a number of overarching recommendations that can be heeded in order to ensure the safe, cost-effective and environmentally robust completion of such a venture.

The guidance of an external decommissioning specialist is often the most responsible starting point. Of course, this expertise encounters a cost, and when all eyes are on the investment of the new replacement technologies, it is understandable to feel that financial resources may be better focused elsewhere. However, conflicting fiscal pressures do not mean that shortcuts are acceptable or that legislation can be flouted.

Armed with an experienced independent skillset, on the other hand, chemical engineers can instead make informed decisions about how to proceed with their project. It is also important to note that, if tackled properly from the outset, it is invariably possible to mitigate some of the anticipated expenditure and, in some cases, even generate a net revenue stream from the sale of scrap materials or the asset in its entirety. Knowledge is power, so this specialist insight is best sought at the earliest possible phase.


Feasibility and option studies

The first item that the external expert is likely to advise is the preparation of a feasibility and options study. Often commencing with a series of management workshops, this exploratory process helps to uncover the key issues associated with a plant, project and site, before providing a clear view as to the true opportunity or liability of the works. The findings documented in the resulting report will then usually highlight a number of technical and cost conclusions, as well as recommendations about the most appropriate route map for the assignment.

This project modelling exercise should also incorporate wider considerations, including the following: human-resources planning; market data that may influence the monetization of any redundant assets; and stakeholder relations to safeguard the integrity of the works through completion.

Defining project constraints

When decommissioning works are required to pave the way for a plant retrofit project, the risks are often heightened. This initial planning phase is therefore even more crucial, as it helps to identify the likely technical constraints that the team will encounter. These may include production requirements of the wider business or onsite neighbors, physical constraints posed by the geography of the site or the location of the asset concerned, and of course the safety challenges presented by working in an operational environment.

However, once the “big picture of risk” is created, the project team can then develop a strategy to properly manage each, in turn. This planning phase can take months, if not years, to complete. It all depends on the complexity of the work, as the lead time is commensurate with the number of hazards posed.


Working in a live operating site

It is possible — and safe — to decommission, decontaminate and then dismantle or demolish part of a plant while the rest of the site continues operating normally (Figure 2). In fact, it is quite commonplace.

FIGURE 2. Undertaking decommissioning works on an operational chemical site requires a great deal of early planning to ensure safety and efficiency

FIGURE 2. Undertaking decommissioning works on an operational chemical site requires a great deal of early planning to ensure safety and efficiency

For example, the sequential decommissioning and demolition of five redundant chemical-processing plants on a chemical manufacturing site in Northwest England was meticulously planned and coordinated to ensure the site could remain operational elsewhere with minimum disruption and utmost safety.

Priority was given to the complex dismantling of the plant’s four distillation columns, ranging from 40 to 60 m tall, which had to be dismantled to a low height during warmer-weather months, before the arrival of high winds. However, due to their proximity to high-hazard pipelines, and due to hot-cutting techniques being prohibited, an alternative dismantling process had to be devised. It was therefore required for the decommissioning team to oversee the more time-intensive, but less hazardous alternative, of using high-pressure abrasive water jets that ran around the circumference of the columns’ cut lines to eliminate the flammable risks, before the top sections could be removed by heavy crane machinery.

Such works could only commence on this site after the development of a detailed redundant-asset management review. This review assessed a number of units, the projected costs of removal, optimized sequencing and a potential rolling decommissioning program for several areas of the 125-hectare expanse.

Chemical firms do not always deal with every asset as soon as it shuts down, but the presence of a plan at least helps to inform what subsequent actions should be taken, and, ideally when these activities should occur. Scheduling is particularly important, because the costs and risks associated with redundant assets often continue and accelerate over time.


Required skillsets

It is important to note that the involvement of an external specialist with a defined demolition mindset should not be to the exclusion of people with plant-specific knowledge. Nobody will know an asset better than those who have worked on it during its operational life, so they will have an undeniably important role to play in the ensuing works.

Naturally, the plant owner may want most employees to focus on the revenue-generating production aspects of the site, but the inclusion of some of these personnel and resources will help to ensure a suitably skilled project team that will help pave the way for the retrofit to occur. The identification of the most appropriate people is therefore paramount, as is the selection of suitably skilled contractors to carry out the dismantling or demolition tasks themselves.


Shaping the exercise

Sometimes the preferable route is to completely demolish the unused asset. In preparing the asset for this process, methodologies must ensure environmental protection with respect to prevention of emissions or loss of containment, as well as waste management. Even so, such ecologically robust considerations do not just ensure compliance and the necessary fulfillment of duty-of-care responsibilities. If decontamination and dismantling strategies can be developed in line with the waste hierarchy, the level of materials that are salvaged and sent for recycling is maximized. Additionally, in some cases, this environmentally responsible route can also help the operator to realize meaningful income from the sale of scrap metals.

In other instances, the plant owner may even be able to carefully dismantle the entire asset so that it can be sold for reassembly elsewhere (Figure 3). This was what happened with a 4,500-ton ammonia production plant. Everything, down to the single vessels and associated pipework, was meticulously disassembled, coded and preserved before being packed into 120 containers, 60 enclosed crates and 80 open stillages, and shipped along with 30 outsized items of deck cargo, for reuse overseas.

FIGURE 3. Meticulous match-marking helps intricate equipment to be methodically dismantled for  re-erection at other sites

FIGURE 3. Meticulous match-marking helps intricate equipment to be methodically dismantled for
re-erection at other sites

Sometimes such disassembly projects simply facilitate the retention of an asset — not to mention the associated intellectual property — within the same company, as was the case when an operator in Singapore removed a number of pieces of equipment from a facility for consignment to sister plants worldwide.

Of course, there are scenarios where redundant chemical plants must in fact be cleared simply to unlock the value of the site for alternative use. This was the case when a 25-acre plant — which had seen many owners since it was first established in the early 20th century — was acquired by a commercial property specialist in the U.K. Extensive, innovative and pragmatic decommissioning of a range of process plant equipment and structures — many of which did not have any records of previous use or residual chemical status — helped take the land back to flat slab to make way for a new mixed-use site.

Concluding guidance

With projects seemingly able to unfold in such a diverse number of ways, it is understandable for chemical plant operators to feel a little overwhelmed as to how to move forward. Furthermore, the specifics of the assignment at hand certainly need to be extensively considered to provide any conclusive next-step guidance. However, there are three key points that will help to steer the safe, cost-effective and environmentally robust execution of any such undertaking:

  • Never ignore the value of the most important project resource — time. The planning phase will underpin the success of every ensuing stage of the retrofit, so it should not be rushed. This is the most crucial period in which to identify so-called “known

  • If the skillsets do not exist internally, bring the knowledge in. Papering over the gaps could be devastating. In selecting the right people to help, consider everything from competency, EHS records, availability and cost, but do not ever decide on the basis of fees alone

  • Do not underestimate the volume of the work involved, but it is also equally important to not overestimate it either. Often, procrastination can be the most costly and hazardous trait in any such project, so commit to a feasibility and options study, at the very least, to facilitate informed decision-making from that point forward   

Edited by Mary Page Bailey



Litmus_11cropRichard Vann is managing director of RVA Group (Kinetic Business Centre, Theobald Street, Borehamwood Hertfordshire, WD6 4PJ, U.K.; Phone: +44-208-387-1323; Website:, a specialist project-management and engineering consultancy that has provided decommissioning, decontamination, dismantling and demolition support on more than 700 projects worldwide. Vann is a past president of the Institute of Demolition Engineers (IDE) and the Institute of Explosives Engineers (IExpE). He also was recently chosen as this year’s keynote speaker for the World Demolition Summit (WDS) and selected for the judging panel of the Construction News Specialists Awards 2018.

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