Dr Tom Croymans, Manager Innovation at Keppel Seghers, the environmental technology arm of global asset manager and operator Keppel Corporation, spoke to Victoria Hart about the company’s landmark Waste-to-Energy projects and his view of the future of the industry as a whole. 

Dr Tom Croymans’ route into the waste-to-energy sector was not a traditional one. A Chemistry graduate who switched to a PhD in Industrial Engineering, he admits that his current career path “was not planned, but the sustainability of the sector is something which interested me and matches with my values.” Nonetheless, as both Manager Innovation at Keppel Seghers, and as chairman of the ESWET CCUS working group, elected in 2021, his impact is clear.

Having begun as a solo Innovation Manager, responsible for R&D linked to Keppel’s core business – supplying waste to energy (WtE) technologies, such as the combustion grates and its control systems – Croymans now manages a team dedicated to innovation projects across carbon capture integration as well. 

As decarbonisation and the net-zero agenda rise rapidly up governments’ lists of priorities, evidenced by the UK’s recent announcement of £20bn funding for Carbon Capture, Utilisation and Storage (CCUS), the imperative of generating clean energy from waste is increasingly apparent. “A few years ago, people were talking about generating negative emissions and the role we have to play, but everybody was holding back,” Croymans recalls.

But now we are moving beyond the talking phase. There are a lot of projects being developed in the sector, and I believe everybody is convinced about the role we could and should play in contributing to the decarbonisation goals of governments.”

Keppel is leading two such WtE projects in Hong Kong and Singapore, where landmark integrated waste management facilities are under development. Indeed, the Hong Kong project realized by a Keppel-led consortium comprising Keppel Seghers and China Harbour Engineering Company Ltd, extends to the dredging of an artificial island on which the WtE facility is located.

“In Hong Kong, land is very scarce,” Croymans says, “so we are building the facility in large prefab modules in parallel with the construction of an artificial island which saves space and time. With the construction of the island being finished, we are moving the WtE facility modules via a barge to the island. One module weighs around 6,000 tonnes – a shipping that size in prefabricated parts over the sea has never happened before in our industry, so that is something very unique!”

In Singapore, a Keppel-led consortium comprising Keppel, China Harbour Engineering Company Ltd and ST Engineering Marine Ltd, are designing and building a WtE facility and a Materials Recovery Facility (MRF) as part of a new integrated waste management facility. This project, similar to the project in Hong Kong, prioritises efficient space management through co-locating the waste management facility with a water reclamation plant.

“The biogas that is produced at the reclamation plant will be fed into the incineration plant, where we will recover the heat and energy,” Croymans explains. “This will improve overall efficiency and also boost electricity generation, which in turn will be fed back into the water reclamation plant. The integrated facility is built around synergies to maximise the use of the land we have available.”

Although these individual projects are breaking new ground, the conversion of waste into clean energy in Asia as a whole still lags behind European efforts. According to the World Bank, due to Asia’s growing population and economic development, the amount of waste in the region is expected to double by 2050.

For Croymans, however, attitudes are moving in the right direction. “I think the fact that Asian countries are taking steps to treat their waste is a good sign. In Europe we also went through a process to be where we are now in terms of sustainable waste management. Pioneering countries like Belgium set the tone for Europe. Singapore and Hong Kong are good examples of how Asia is dealing with the waste management challenges. If we look back to Europe, first we incinerated the waste, then there was limited flue gas cleaning, sometimes even without heat recovery. Then heat recovery became the standard. Over time flue gas emissions became stricter, leading to expanded and more complex treatment. Now, what we see in Europe, as well as in Asia, is that the next step for the sector is to capture the CO₂.”

As technology and legislation evolve around the world, Croymans highlights the need to lead by example:

In Europe we have a lot of export products, and I always say that environmental legislation is also an export product – other countries are looking at how Europe is setting the tone.”

This trend-setting aspiration is reflected in the UK government’s recently announced funding for CCUS – the main focus of Croymans’ work at Keppel. 

Croymans recognises that carbon capture is in its infancy for many sectors, and that securing funding is still key, but he commends the system adopted by the UK: “I think how the UK have set it up is very interesting. Starting by decarbonising in clusters makes a lot of sense and is a very effective approach. It creates a lot of synergies and a focus point, which later on you can continue to expand. In terms of value for money, working in a cluster also improves effectiveness.”

Different strategies to support carbon capture are in play across Europe, with some governments, for example the Netherlands, imposing taxes on emissions released by waste-to-energy facilities. Croymans, however, believes that both taxation and government support are required to facilitate the full carbon capture process: “The critical question is always, when you have captured the CO₂, what are you going to do with it? And that is something that I believe governments need to play a role to support – to make sure the CO₂ can be transported and stored or utilized. We see a lot of players working on that, but there are still some legislative barriers that need to be crossed.”

In addition to his work at Keppel, Croymans chairs the CCUS working group for ESWET, the industry association for European Suppliers of Waste-to-Energy Technology, whose main goals he says are dissemination of information about legislative developments and feeding back the association’s stance to policy makers.

There is also an educational aim, as Croymans explains: “One example is lessons learned from member states where they have already put waste-to-energy on the ETS [Emissions Trading Scheme], like Sweden and Denmark. We also promote the role of waste-to-energy and CCUS to support the decarbonisation goals of governments. We have a role to play as a waste-to-energy sector which not everybody is aware of, because when people hear about waste incineration, they think it’s a bad thing.

In fact, when you add the CCUS layer, we are in effect one of the few solutions which can generate negative emissions or CO₂ removal at such a high scale.”

So, looking to the future, what are the main challenges for the sector?

“Managing complexity,” Croymans says. “Waste-to-energy, in the beginning, had simple heat recovery and limited flue gas cleaning. As a sector, we successfully incorporated more complex technologies over time, and now you can’t imagine we would build a facility without it. Looking at the future we see carbon capture is there as a new add-on, the utilisation part is coming along, we have sustainable aviation fuels, waste-to-hydrogen, we have stricter emissions, a higher level of metal recycling – so waste-to-energy is becoming more complex and all of these things are also linked to each other. At Keppel we believe that carbon capture will become the new normal, and so what was once seen as a challenge will become normal, and in turn something else more complex will come along.”

By Victoria Hart