CirTec step by step to a circular economy

Breakthrough in Cellulose Extraction

You could call them the King of the Sewer: CirTec, a member of the Water Alliance, is involved in just about everything done with the wastewater we produce —purification, thickening, screening, drying and reusing—sometimes using spectacular innovations. They have won multiple awards with it.

Their company Cellvation (a partnership with Recell Group), which has been producing 200 to 400 kilograms of Cellulose daily since 2017, also attracted a lot of attention. A striking feature of all CirTec’s activities is that they are bringing us closer to a circular economy, step by step. The company will be in the limelight once again in June 2021, this time with the CellCap machine. CirTec owner Coos Wessels calls it a global first; a breakthrough in extracting cellulose from sewage. His ambition is to sell a hundred units a year in the next five years.

COOS, LET’S START WITH THE QUESTION: WHAT DOES THE CELLCAP DO? The CellCap is a fine screening machine that consists of two parts. This is also what makes it unique—there are, roughly speaking, only two steps. In step 1, the cellulose washer removes the dirt (fats, hair, seeds, etc.) from the water and in step 2, the IntenSieve®—an improved, energy-efficient, rotating belt fine sieve—removes the cellulose. We are the only party in the world doing this.

Coos Wessels: 'the quality of cellulose in sewage water is exceptionally good'

WHAT ARE THE BENEFITS? By sieving suspended matter such as undissolved solids from sewage water, WWTPs can reduce their energy consumption and CO 2 footprint. The sieved material is referred toas screenings. Research shows that screenings contain an average ofaround 70% cellulose and that Dutch sewage contains 180,000 tonnes/yearof recoverable cellulose. In Western Europe, it amounts to nearly 4.5billion tonnes/year. The quality of cellulose in sewage water isexceptionally good, making it ideal for use as a high-quality, renewableraw material.

WE UNDERSTAND THAT THERE IS STILL SOMETHING TO BE DONE AFTER SIEVING? Correct. The cellulose still has to be purified. The challenge was figuring out how to strip cellulose of contaminants so that it can be reused and how to use those contaminants for biogas production. After years of development in various projects, we developed CellCap, a composite machine that purifies water and separates cellulose during the process (inline). This is the first time that this can be achieved in a single process.

WHAT DOES IT PRODUCE, EXACTLY? In addition to cellulose, the CellCap also yields a fermentable residue stream which can be used to produce biogas or methane. It all gets rather technical here, but a study conducted by an independent research agency concluded that the use of 1 tonne of recovered cellulose as a high-grade raw material across the entire chain would lead to savings of 2 to 2.5 tonnes of CO 2 eq in comparison to the reference situation. For a treatment plant with a scale of 300,000 pollution units, the above means that using CellCap technology can achieve an emission reduction of over 4,300 tons of CO 2 eq per year. To put that into perspective, it is equivalent to the CO 2 emissions of over 30,000 return flights from Amsterdam to Paris or the combustion of over 1.37 million litres of diesel!

WHO STANDS TO BENEFIT FROM THIS? Our planet, first and foremost. Humans have made a pretty big mess of things. That has to change. The sooner we achieve a fully circular economy, the better. But we also see enormous advantages for water treatment plants with the CellCap. They will make their processes cleaner, more energy-efficient

and in many cases they will also be able to make new products from residual materials. The rotating belt sieve (IntenSieve®) which is part of the CellCap technology also offers major benefits for industries. It can minimize water consumption at fish farms, reduce discharge costs or in-house purification costs at vegetable processing companies, and recover fibres in the paper industry.

THE WATER TECHNOLOGY SECTOR DOES NOT USUALLY EXCEL AT EXPRESSING MAJOR BUSINESS AMBITIONS, BUT YOU HAVE ALREADY STATED THAT YOU WANT TO SELL MORE THAN 100 MACHINES PER YEAR WITHIN THREE YEARS. Ambition is necessary; there is nothing wrong with that. We have more than ten years of experience in sieving sewage and industrial wastewater. The technology was developed very carefully and after years of research, and it works. Now we are rolling it out. We have already found partners in Italy, Austria, France and China, and we are talking with representatives in England and Russia. Things can always go wrong, of course, but I am optimistic.

WHERE WILL THE MACHINE BE MANUFACTURED? In the Netherlands, as far as I am concerned. There may come a time when you need to build machines locally, if only to reduce transport and thus CO 2 emissions. But first and foremost, I want to be loyal to the country that helped us develop this innovation through various grants.

Cellulose—the main component in paper—is a natural fiber found in plants and trees. It is an extremely useful raw material for humans. Among other things for paper, but also as a sustainable insulation material for the construction industry. One downside is that trees have to be felled for paper production. By recycling cellulose from wastewater, this is no longer necessary.