The Cortus installation processes biomass such as wood chips, bark and fibre sludge from paper mills. These are “low-grade” fuels that cannot otherwise be used for energy recovery. The product is clean, tar-free gas comprising primarily carbon monoxide and hydrogen.
“This is quite simply an entirely new highly efficient technology. Cortus is unique on the world market. There is a wide range of applications; the gas can easily be burned directly in demanding high-temperature processes or converted to other energy forms such as electricity, renewable natural gas or liquid fuel,” says Pawel Donaj.
Cortus was formed in 2006, back when there were very few gasification plants around the world. The situation is similar today, but Cortus hopes to change that soon. In June, it will officially open its first commercial gasification plant is Höganäs, Sweden. There is a big market in Sweden, and also internationally.
Unique solution, but a lack of knowhow
Right away, Cortus identified major challenges that required finding methods to:
- Process low-grade or damp fuels that are not pretreated.
- Produce tar-free gas that can be used in different applications.
- Achieve a sufficiently high coefficient of efficiency to compete with fossil fuels.
The solution became what is today known as WoodRoll, which is the name of the installation that converts the fuel – biomass – to clean gas. In it the fuel is dried, pyrolysed and decomposed to create pure gas in the gasification process.
One of the installation’s major advantages is the great amount of energy and heat recovered by the system, which means a high-energy exchange. One of the major disadvantages, which is also Cortus’s strength, is the entirely unique solution.
“Its utter uniqueness meant we didn’t know how the material in the boilers would behave. There aren’t many people who can help us with our unusual technology – there’s a lack of research in the field.”
“The aim is to create greater understanding in the field of corrosion research.”
– Pawel Donaj, Project Engineer at Cortus Energy.
Research and industry in collaboration
Rikard Norling is project leader at RISE KIMAB, one of Europe’s leading corrosion and material research institutes and part of the research group at the High Temperature Corrosion Centre HTC centre of excellence. It is a seat of applied research with relevance to trade and industry.
It began its collaboration with Cortus in 2013 in an exchange that benefited the company on several levels through increased knowledge and an extensive network. Together, RISE KIMAB and Cortus are studying the material problems that can occur in the WoodRoll plant.
“The problems are different than with conventional combustion; there are different types of corrosion processes when there is a shortage or surplus of oxygen. In some cases it creates a more aggressive environment,” says Rikard Norling, Project Manager at RISE KIMAB.
This entails greater wear and affects efficiency. Different gases are produced depending on the fuel used. For example, coal has long been used for energy production and research on the corrosion processes here is more exhaustive.
“Research into the material problems that occur in this type of gasification – from biomass – is new.”
Field and laboratory tests
RISE KIMAB and HTC have extensive experience in corrosion research. To assist Cortus, Rikard and RISE KIMAB are using a laboratory environment to look into the material problems that can occur.
“We’ve tried to imitate different kinds of environment and conduct corrosion tests to understand the problems that occur. This has not only given Cortus a basic understanding of the field, but has also provided the same insight to other industries working with gasification, which can now take more informed decisions in their choice of materials from both an environmental and economic perspective.”
The research is tested in Cortus’s pilot plant in Kista.
“We’re building up fundamental knowledge that companies such as Cortus can then use in their decision processes.”
The aim is to create greater understanding in the field of corrosion research.
HTC’s network is global
In addition to knowledge, RISE KIMAB and HTC contribute an extensive network of industrial players, something Cortus draws great benefit from.
“Because ours is a small company, we have to find partners. HTC and RISE KIMAB’s collaboration with e.g. Sandvik and Kanthal also benefits us, as we use their technology in our processes. We all share an interest in creating more cost-effective, environmentally friendly materials,” says Pawel Donaj.
Advances make a breakthrough
Cortus recently succeeded in converting the gas from the plant into biomethane, i.e. renewable vehicle CNG. This provides their plant with additional fields of application.
“We will open our first commercial plant in June, and we’re very excited and looking forward to the results. There are great opportunities for growth and we can see robust markets all around the world, with possible collaborations in places like California, the USA in general, Japan and France.”
In other words, the green gas has great potential.
“The market will decide. The gas can be used for heating, electricity generation or vehicle fuel. This means great flexibility, and we’re looking forward to continued longterm collaboration with RISE KIMAB and HTC,” says Pawel Donaj, Project Engineer at Cortus Energy.
RISE KIMAB and the HTC centre of excellence
The HTC centre of excellence includes researchers from Chalmers University of Technology, KTH, RISE IVF and RISE KIMAB. RISE KIMAB is part of the RISE research institute and develops and improves total solutions within corrosion, materials and production technology.