Researchers at the University of Twente, the Netherlands (UT), aim to build a self-regulating, mobile pilot plant for the pyrolysis of paper sludge.

Paper sludge, the largest waste stream, is a nasty waste stream from paper factories made of organic molecules that are not useful and minerals.

Paper Sludge Party Dried. Click image for the largest view.

Paper Sludge Party Dried. Click image for the largest view.

Gerrit Brem, professor in Energy Technology at the University of Twente explains, “Paper sludge is half organic paper fibers and half minerals. When Alucha approached us with this question about paper sludge, we started experimenting out-of-the-box with our existing pyrolysis technology. We designed a new pyrolysis system that’s particularly suitable for paper sludge and similar waste streams. We have now applied for a patent for this new reactor.”

With pyrolysis, organic material is ‘cracked’ in a few seconds by heating it in the absence of oxygen. The UT is specialized in the pyrolysis of biomass such as wood, straw, grass and algae for fabricating fuels and products. The process has now been successfully applied on paper sludge. A new advanced reactor has been built and is now undergoing extensive testing in the Thermal Engineering lab.

The reactor can process both small and large particles and requires no external energy. After drying and pyrolysis, the fibers in the paper sludge are transformed into oil and flammable gas and the minerals can be used as a raw material for the paper industry. Moreover, the process keeps the paper industry from having to dump this waste stream for €70 per ton, as is now the case. The technology transforms the entire waste stream into something useful and that’s a huge step forward.

The big advantage of the mobile unit developed by the UT and Alucha is its direct contribution to the chain of production. No transport to large installations need to be done. Furthermore, the industry can use both the minerals and the pyrolysis oil in their own production processes.

After commissioning the pyrolysis installation at the Kleefse Waard industrial estate in Arnhem, that must be operational in mid-2016, Alucha ultimately wants to build more pyrolysis installations based on the knowledge from Twente. The Swedish paper company SCA will be the launching customer for the mobile centers, and many more installations are expected to follow at paper factories.

Gijs Jansen of Alucha said, “In 2010, we started testing at laboratory scale using a single kilogram of paper pulp. The reactor that has since been developed to separate paper sludge into bio-oils and minerals is a wonderful next step.”

As part of the Bioeconomy Innovation Cluster of Eastern Netherlands (Dutch: BIC-ON), Alucha has received €250,000 from the Province of Gelderland for the development of the mobile pyrolysis installation. In the current development phase, an Alucha engineer will work full-time at the UT for 6 months on the development of the pilot plant (proof of concept). A total of €3 million will be invested in the project in order to build a first industrial-scale unit. Kennispark Twente will continue to supply the required support for this for both the patent filing for the new pyrolysis concept and for the knowledge transfer.

Professor Brem expects more applications for the pyrolysis process to be found in the future. “This process of transforming biomass into fuel and minerals is incredibly promising. Lots more is sure to happen. Consider the processing of sewage sludge, for example . . . or of roadside grass, reeds, lignin, miscanthus or manure. I also expect potential applications in the valorization of waste streams using this so-called flash pyrolysis. Or consider refuse-derived fuel (RDF), used tires and packaging material. Other new routes are possible by using catalytic converters in the pyrolysis process, we were recently able to get high-quality oil and even chemicals from wood.”

These folks are on a roll. Lots of potential here. In Europe things are much closer together and people are further along in the recycling frame of mind than much of the rest of the world. A little more leadership at a steady pace should have a good closed loop system running by the time the inevitable third world pollution disaster makes the news.


2 Comments so far

  1. Matt Musson on June 19, 2015 9:55 AM

    Paper making has always been stinky and messy. Hopefully, this process will help reduce the environmental footprint.

    Re-using water and creating a chlorine free bleaching process have really been extraordinary environmental upgrades for that industry that we have seen already.

  2. Ramesh on July 28, 2015 10:39 AM

    Is it working or being tried out in a paper mill? If so can advise my friend, thanks in advance

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