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MechChem Africa talks to Rajend Govender, CEO of thyssenkrupp Uhde South Africa (tk Uhde SA), along with key team members, Neville Eve; Ranka Sofijanic and Nithesh Mohun, about the modularisation of chemical process plant and the company’s future-ready expertise in green hydrogen and organic carriers such as green ammonia.
Most of our work still comes from traditional brownfield sites, which are some of the toughest environments to work in, particularly in Africa,” begins Rajend Govender, CEO of thyssenkrupp Uhde SA. “This opens up the opportunity to adopt the modular plant approach, which is not new to us,” says the CEO, who is a chemical process technology specialist with 20 years’ experience with thyssenkrupp and Uhde.
“We have long been designing and building plants or sections of plant off-site under controlled conditions that are not subject to the congested and risky environment of a typical operational plant. Much of our current work involves installing purpose designed and manufactured modular replacement units,” he tells MechChem Africa.
Ranka Sofijanic, the company’s chief engineer for Piping and Mechanical, continues: “We are typically working on congested petrochemical plants that were originally stick-built, onsite. Upgrading such sites means work has to be done between the surrounding units, often while the plant is still live, which makes safety aspects critical. Work can only be done under hot work permits; the hours onsite are often limited by daily permitting requirements; and COVID throws additional limits on the number of workers allowed at any one time.
“By taking the modular approach, a whole plant upgrade can be built offsite on a skid, in an open and far safer environment. No hot work permits are required, there is no congestion, no live plant to work around and no additional man-hours need to be added to guarantee meeting deadlines,” she argues.
Describing a typical success, she says that tk Uhde successfully completed a modular plant upgrade for a coal tar filtration (CTFE) plant. “This project comprised 25 modules weighing up to 250 t. Modules included multidisciplinary pre-installation (piping, mechanical, instrumentation, electrical and structural) that were all built off-site, transported and installed in the live plant, and connected up,” she recalls.
Neville Eve, chief of strategy for tk Uhde SA, continues: “We have also just completed a 65 t module for Natref, which was built and tested off-site before being shifted into place by a self-propelled modular transporter (SPMT), while observing all COVID restrictions and without any delivery time delay.” he says.
“A modular plant is much more than a replica of a stick-build onsite construction that is built offsite, though. Modular plant has to be purpose designed with structural integrity so it can be safely and easily transported, placed and connected-up onsite in a ‘plug-and-play’ manner. Our design skills and experience in doing this routinely give us a competitive advantage,” Eve notes.
According to Govender, complementary skills sets such as laser scanning expertise are also important. “We have the modern resources and capability to scan an existing site in 3D before we start. This enables us to identify the exact space available and the exact positions for interconnection with the existing on-site plant. This allows us to design and build a perfectly customised module offsite that not only meets the upgrade requirements of the plant, but on installation, the unit will ‘plug’ into the existing plant like a block of Lego,” he explains.
Modularisation on a large scale enables plants to be built more cheaply. Logistics expertise allows the selection of the build location and vendor, including those offshore. “Our global parent has designed modules as large as 3 000 t, which can be built, for example, in the Far East and shipped to site in the Americas,” says Eve.
Sofijanic adds that while transportation of larger modules may seem expensive, it is actually very competitive when compared with the combined cost of shipping all of the individual materials and components required for a stick-build plant in a remote area. “While modular projects may attract small incremental design and structural steel costs, these are offset by the reduced cost of assembly, painting, insulation, inspections, testing and other work performed in the fabrication facility,” she says.
“Along with the densification advantage – modular design requires less plot space – structural design is critical and, owing to the increased quality required to ensure plug-and-play compatibility, the module’s reliability and life can be significantly improved,” continues Uhde’s Chief Piping Engineer. “Climatic conditions are also a factor. In some places, particularly in very cold or wet climates, there are several months of every year when construction work cannot be done. By building at a convenient off-plot site, the modular plant can be built in advance in a better environment, substantially reducing time required onsite. This saves construction time and costs – and this is also true in South Africa and Africa, where weather often plays a disruptive role,” Sofijanic informs MechChem Africa.
In addition, labour issues are more predictable in shop floor environments, where different disciplines such as insulation, painting, testing and shot blasting capabilities are more easily planned for and accessible. There is seldom a need to wait for a specialist to be mobilised onto an off-plot site, she adds.
Govender cites a local example where a plant had to be built in the heart of a gasification area with dangerous concentrations of phenolics in the surrounding atmosphere. “It was unsafe for any worker to be in that environment for more than 30% of a 12-hour shift. Everyone had to wear a full face mask at all times and nobody could be onsite for longer than four hours at a time.
“The solution was that we immediately adopted a modular approach, which massively improved the construction schedule and, of course, raised the end quality levels – because it is very hard to produce great quality construction work while sweating behind a full face mask,” he notes.
While modular plant design is far from novel – tk Uhde has long history in modular chlor-alkali plants, for example – the company now has the expertise to design and replace existing stick-built sections of plant with purpose built modules. “This is a much rarer skill that offers operators a more cost effective and reliable opportunity to upgrade and modify older plants,” Govender says.
In Africa, where the availability of contactors and expertise is scarce and the build often has to be done in remote areas with poor infrastructure, plant modularisation is the way to go,” he assures; adding that tk Uhde chlor-alkali plants, which electrolyse sodium chloride solutions to produce chlorine, sodium hydroxide (caustic) and sodium hypochlorite (bleach), are now being installed globally. These are all pre-assembled, tested, containerised, shipped to site and re-assembled.
Green hydrogen
According to Eve, the advent of Green Technology, including the world class manufacture of gH2 (green hydrogen) has leveraged Uhde’s state of the art electrolyser technology, originally developed for the manufacture of chlor-alkali products. The application of this technology in the green technology environment places it firmly at the heart of future business. “Our forward-looking focus is around green hydrogen and associated downstream technologies: green methanol, synthetic natural gas and green ammonia. We are now part of the Green Hydrogen Partnership (GHP) and working hard to transform the South African economy from being a fuel import dependent company to an exporting country – and the potential for South Africa is huge,” says Neville Eve.
Senior sales engineer for Green Hydrogen & Chemicals, Nithesh Mohun, explains: “In mitigation against climate change, countries are under increasing pressure to decarbonise. The production of green hydrogen using Uhde technology can be 100% CO2-free. All we need is a source of sea-, grey- or river-water. We first purify the water using reverse osmosis, before channelling the water to electrolysers, which ideally use renewable electrical power from a solar PV, wind or hydro powerplant to split the water molecule into close to medical grade oxygen (O2) and pure hydrogen (H2).
“Using the green hydrogen as feedstock, we can then produce green ammonia, which has use as a green fuel for marine vessels, fertilisers or explosives. In addition, we can harvest carbon from the CO2 emissions from traditional fossil-burning plants and, by combining it with green hydrogen, produce green methanol (CH3OH) or synthetic natural gas, which is very close to methane (CH4). Using green hydrogen as the starting point offers immense potential for the downstream green derivative products value chain,” Mohun tells MechChem Africa
With respect to costs of hydrogen production, Mohun estimates that, even with the cost of green-power factored in, the cost of hydrogen production will reach cost parity with traditional carbon-based steam reforming processes within the next few years. “Our hydrogen electrolyser technology using traditional power is already cost competitive with steam reforming processes in the cost range of US$1.8/kg to $2.4/kg. With the adoption of renewable power, we believe the total costs will fall into this range within the next four to five years,” adds Mohun.
“As well as being leaders in large scale green hydrogen production and derivatives, we are part of a large global organisation with local experience and capabilities that enable us to be very flexible with respect to the delivery of brownfield and greenfield projects, from small to very large,” says Govender. “We combine modern solutions with emerging and existing plant in a unique, flexible and locally appropriate way, as long-term partners to local owners and operators.
“thyssenkrupp Uhde has a role to play across the entire lifecycle of process plant in Africa. We have been around for a 100 years and in Southern Africa for more than 60 years, so we are not about to disappear,”
he concludes.
