Building a plant of any scale requires a great deal of planning and forethought and modularisation can offer a significant value solution to a construction project. The cornerstones of modularisation are high quality, accuracy, productivity, and safety as a result of off-site module fabrication in an enclosed, controlled workshop area, unhindered by adverse and hazardous environmental conditions.
Given the many advantages associated with modularisation, it is often considered as the go-to for all projects. However, Richard Kirk, Head of Project Management and Services at thyssenkrupp Uhde South Africa, cautions that modularisation is not necessarily always the right solution. “Each project is unique and a number of critical factors must first be considered before an informed decision can be made on what will present the most viable solution - complete or partial modularisation in combination with stick-build or even on-site stick-build only.”
To find the right solution requires the trifecta of experience, knowledge and expertise. thyssenkrupp Uhde’s decades of global and local experience in modularisation, with countless modular plants successfully executed world-wide, perfectly position the organisation as a specialist that is able to offer expert advice to customers on whether the modular option is the best value solution. “We refer to a value solution,” explains Kirk, “because it may not always be the most economical solution. First, value adding factors such as efficiencies and safety must be weighed in to determine economic viability.”
Plant location, logistics and the environment are three further key factors that must be considered before deciding on whether modularisation is the best option. Plants situated in remote areas with limited or no access to energy, water and labour resources are clear candidates for modularisation. Other conditions that can advocate a modular approach include difficult or hazardous onsite conditions where safety enhancements are a key decision factor.
Steven Hendry, Head of Construction at thyssenkrupp Uhde South Africa, draws a comparison between on-site and off-site construction. “There are a multitude of variables at play on-site that cannot be controlled and which potentially pose a risk to safety, affect work quality and impede productivity. For example, in the event of lightning, slippery conditions, gas leaks, power failures, water cuts, etc. work must stop.”
“Additionally, work permits, working hours, etc. can further restrict on-site work. Compare this to off-site module fabrication in a controlled environment where all the aforementioned risk factors and limitations are eliminated,leaving our skilled team free to work safely, unhindered and productively. In addition to improving schedules and speeding up manufacture and delivery times, work quality is also enhanced.”
The decision to go the modular route affects the entire project execution process - engineering, procurement, fabrication, logistics, delivery, installation, final hook-up and commissioning. It’s therefore essential that expert input is provided up front, right at the beginning of the project. Late decisions can turn into very expensive exercises due to all the necessary re-engineering and rework that are required.
Modularisation demands complicated end-to-end engineering right up to the smallest detail such as ensuring that all the links are a 100% correct for fast and seamless onsite connection. “This needs people who have a clear understanding of the entirety of the modularisation concept,” state Kirk and Hendry. “Our highly experienced and professional thyssenkrupp Uhde personnel at our local office collaborate with a global team, tapping into a vast knowledge pool and drawing on countless references from all our modular plants. We bring correct professional project management including contract, site and construction management specialists. We have all the right programmes, systems and technologies that have been tried, tested and proven!”
thyssenkrupp Uhde also harnesses the expertise of specialist suppliers, partnering with competent, like-minded modular fabricators in South Africa, Thailand and many other parts of the world. These partnerships extend thyssenkrupp Uhde’s flexibility, enabling the organisation to deliver modular solutions via land or sea to plants situated virtually anywhere in the world.
Kirk and Hendry point out that the transportation of the module is an important part of the preplanning process. “Route inspection is essential to ensure that obstacles such as low overhead power lines, poor roads and narrow bridges are factored in. This also enables us to predetermine the size and complexity of the modules. We may suggest some off-site module fabrication combined with stick building the rest of the project on site.”
thyssenkrupp Uhde’s modular builds range from small-scale packages right up to modules weighing in excess of 500t. “Our smaller solutions make up a substantial portion of our modular business and deliver a significant savings element for customers,” says Hendry. “Our recent fabrication of skid-mounted air compressors at the vendor’s premises for an ammonia plant refurbishment project, is a great example of our small-scale build capabilities. Our skid solutions are fully tested off-site before delivery to site.”
A large-scale build completed by thyssenkrupp Uhde involved the fabrication of some 20 to 30 modules weighing between 250t and 500t for a leading petrochemical customer. Kirk explains why this particular build is a classic example of a difficult work environment and late decision-making with associated cost implications.
“The customer realised late into the project that the wearing of full gas masks and protective gear at all times presented safety and productivity challenges, thus favouring an off-site modular fabrication over an on-site build.
We applied our modular expertise and capabilities to complete a great deal of necessary rework and delivered an optimum solution for our customer in partnership with a specialist modular fabricator.”
A four-year build of two modules required by another petrochemical customer for two separate projects was also recently completed by thyssenkrupp Uhde. Fabrication took place in the lay-down area from where the completed modules were transported to the operational area for hook-up.
Specialist builds are part and parcel of thyssenkrupp Uhde’s comprehensive modular capabilities. When a customer who operates in the chlorine industry in South and Sub Saharan Africa required a modular solution, the highly specialised and delicate nature of many of the plant’s processing units demanded a very different modular approach. thyssenkrupp Uhde competency and expertise once again ensured a masterclass in modular design; the modules were placed into these fragile process units with the balance of the plant completed by stick build. This project was executed together with thyssenkrupp nucera, who acted as technology provider for the chlor-alkali electrolysis. The world's leading supplier of chlor-alkali electrolysis technology has considerable experience with skid-mounted chlor-alkali plants, which are ideally suited to this modular design.