Varied factors, challenges and opportunities must be considered before plant owners and engineers can tackle the decommissioning of a chemical site. But with no guiding principles to refer to, dealing with redundant or outdated assets is often unchartered and difficult territory for these chemical professionals.
At a time when many chemical installations are being mothballed, rationalised or permanently closed down, decommissioning is evidently an area that the chemical industry needs to understand more clearly. This is perhaps one of the main reasons why leading journal The Chemical Engineer (TCE) sought an in-depth knowledge-based comment from RVA Group, for inclusion within their September magazine.
Regular industry speakers and commentators the RVA team penned a three page educative resource with case studies, which you can read in full below. For further information about the preparation, undertaking or project management of a chemical decommissioning project large or small, please contact RVA Group on 01473 256890.
Chemical Plant Decommissioning
A step into the unknown?
When it comes to commissioning a chemical plant, there is no shortage of advice and best-practice case studies to draw on. But when faced with decommissioning, it is a very different story. With no guiding principles to refer to, dealing with redundant or outdated assets is often unchartered territory for plant owners and chemical engineers.
Decommissioning is evidently an area that the chemical industry needs to understand more clearly. This is particularly true now at a time when many chemical installations are being mothballed, rationalised or permanently closed down. Although plants often cease to operate as a result of the economic downturn, it is not always doom and gloom. For many chemical producers, full or partial site closures simply represent a consolidation of activities, an opportunity to upgrade equipment, and/or a desire to work more efficiently.
Whatever the driver, the challenge for the chemical industry is how to manage the decommissioning of plants safely, cost-effectively, and with minimum environmental impact.
What makes the decommissioning discipline different?
Firstly, it must be acknowledged that this can be a complex process. Looking at the undertaking with the same mindset as a construction or routine activity will rarely deliver the safest or lowest-cost outcome. Decommissioning cannot be viewed as merely the opposite of commissioning or a subset of maintenance.
In the normal course of production, scheduled turnaround exercises require a great deal of plant-specific knowledge to efficiently shut down, upgrade, repair and service equipment. Typically managed like military operations to minimise the loss of revenue and mitigate inherent hazards associated with this process, these activities will be planned well in advance to ensure the safe completion of works, on programme.
Understandably plant engineers and managers operate with a production mindset, as they are used to preparing their facilities for them to be put back into service. But faced with decommissioning, there are numerous opportunities and task appropriate techniques available that site personnel will not have even thought about.
This is not to say their knowledge is not integral to the process. But rather than for example, a site operative having to enter a confined space to clean a vessel, demolition methodology could allow the item to be mechanically opened for scrap with hazardous materials being remotely removed as a simultaneous activity – a safer, faster and more cost-effective option. Similarly a high level structure or pipebridge can be brought down to ground level quickly using sophisticated long-reach technology, rather than personnel working at height to carefully disassemble the equipment in-situ.
Know your options
But what strategy and methodology should be adopted?
Perhaps the reason why there is no ‘teach yourself guide to decommissioning’ is because every situation is different – there is no ‘one size fits all’ solution. Time must therefore be invested to build up an effective redundant asset management plan, bespoke to the chemical site concerned, because there will be a number of critical factors to consider. The expertise of experienced isolation, decontamination, demolition and dismantling specialists will add great value at this stage in order that the plant is safely prepared and unnecessary spend avoided.
Difficulties lie in making well-founded decisions about the future, especially at a time when pressures are mounting or there are gaps in knowledge. Indeed operators often assume that there are limited options available to them when closing a facility. They may therefore simply ask a demolition contractor for a price to clear the asset, before deciding whether to proceed with the exercise or not.
Naturally owners want to minimise cost, yet delaying projects that are deemed unaffordable is not always the most appropriate solution. They will inevitably have to be tackled at a later date and in most cases the financial burden will have further increased due to continuing overheads and liabilities such as hazardous material containment, infrastructure deterioration, loss of utilities, security provisions, regulatory compliance fees, care and maintenance costs and local authority building rates.
Specialist tools such as feasibility studies therefore play a crucial role in the development of safe yet commercially sound redundant asset management plans. This investigative exercise generates reliable and unbiased site and plant-specific data, from which a number of options can be explored and an optimum strategy identified for the project.
Engineering experience, sector knowledge and commercial awareness is needed to determine a clear and realistic view of the chemical plant’s true liability or opportunity, from which site owners can make informed decisions. Achievable costs, potential hazards and risks, the status of the supply chain, the commodity value of scrap, technological trends and requirements in emerging markets, waste management obligations, required resources, relevant legislation and programming and scheduling constraints, will have all been impartially assessed.
Whilst certainly a complex exercise, the conduction of a feasibility study is not an onerous or cost prohibitive process. On the contrary the preparation of this management instrument can unveil new value-adding opportunities and identify potential revenue streams that might not previously have been considered.
One option may be to dismantle equipment for re-sale, re-erection and operation elsewhere. This was the strategy for a 4,500-tonne ammonia plant, carefully removed from GrowHow UK Limited’s former fertiliser production site in Severnside, near Bristol.
Alternatively, plant demolition may be deemed most appropriate, particularly where there is the possibility to generate an income stream to offset cost as a consequence of scrap value. Not only does this mitigate ongoing levels of liability, but in some cases the project can be self-funding or even cash-positive. For example when INEOS ChlorVinyls, Europe’s largest polyvinyl chloride manufacturer, ceased manufacturing in Barry, it planned to decommission and clean the site before handing it back to the landlord with the plant intact. However a feasibility study exposed the full financial implications of this proposed site exit strategy and as a result of the options recommended by specialist consultants, the company handed the site back as flat slab having secured an income from the sale of the process equipment.
In some situations, the best course of action is to clear the site completely. One company that made this decision was world-leading crop protection organisation Nufarm. The company undertook a major project to decommission and clear its 12-acre site in Belvedere, Kent following the relocation of its UK operation to West Yorkshire. Nufarm assessed its options to determine the most commercially-viable route and considered either selling the site with redundant equipment in-situ or expanding its marketability by clearing it. A full decommissioning and demolition exercise was determined as the best-value option. Of course these organisations could mothball their sites until market conditions become more favourable and the plant can be sold or restarted. However whilst this may appear to be a straightforward option, full consideration must be given to ongoing safety risks, the need to re-test equipment, the availability of experienced personnel, continued site security and advances in technology that quite often firmly close the door on outdated production methods.
The beauty of a feasibility study though is that by assessing every risk and exploring every opportunity, an element of the unknown is removed and the overall best-value strategy can be selected. It may be that this comprises a number of isolation, demolition, dismantling and resale approaches. It sounds complex but it is certainly achievable if meticulous planning, sequencing and programming exercises have been carried out. It will also clearly identify which types of contractors will be most appropriate to bid for and undertake the actual works.
Regardless of the strategic route pursued, every project has the potential to present difficulties, whether they are related to the age and make-up of a structure, the process nature of the plant during its operational life, or the location of other activities adjacent to a site. However where possible challenges are anticipated and planned for, it naturally follows that they can be addressed more efficiently and mitigation measures taken.
Chemical plants may contain corrosive, toxic or flammable materials for example, but that doesn’t mean that equipment cannot be safely brought to a known state and subsequently removed. GrowHow for instance were faced with the need to clear a range of facilities – including nitric acid, ammonia, carbon dioxide and ammonium nitrate production plants, utilities equipment, laboratories and office buildings – from nine separate locations within their site. However precise project management and teamwork ensured the successful completion of this mammoth task.
Elsewhere, during the aforementioned Nufarm project, utmost coordination and teamwork was required to not only ensure the safe execution of works on-site, but to also minimise the disruption caused to the numerous commercial properties bordering the installations. But intense planning and stringent management protected Nufarm’s commercial neighbours.
Whilst the closure of a chemical site is often a processing firm’s last resort, taking the decision to decommission and clear a plant can often give a much-needed boost to the local community. This was the case when a former chemical production facility in Knottingley was removed to give the site a new lease of life.
For 70 years the plant was used for the production of final and intermediate products for the chemical market. Its list of previous owners includes Midland-Yorkshire Tar, Croda, Shell, Inspec and Degussa.
But following the cessation of production, the site was acquired by a property developer who wished to transform it into a mixed-use location comprising offices, light industrial units, housing and associated amenities. Such regeneration projects can of course create a range of jobs therefore bringing significant benefits to the local area.