In collaboration with Linköping-based waste energy producer Tekniska verken, Scania Engines is currently testing one of its engines using raw gas, biogas that is “untreated”. That means it is not cleaned or upgraded to remove wastewater, carbon dioxide and other particles, as happens with the production of bio-CNG for vehicle fuels. Instead, it is taken directly from the digestion chambers, which break down the organic waste to be used in its raw state as fuel for the Scania engine, to see how it performs over 600 hours of tests.
Scania’s hope is that if the engine can work with this raw gas, it will be an even quicker and cheaper process of producing biogas for power generation, and another valuable source of alternative energy from recycled material. The engine used is a Scania 16-liter V8, made for low-pressure CNG for power generation.
The idea is still at the experimental stage, as Holger Mattsson, Project Coordinator at Scania Engines, explains. “We have been working with Tekniska verken for the past two years, initially with CNG, and we started testing raw gas in early 2017,” he said. “In September 2017 we carried out the latest round of testing and have been reviewing the results during the following months.”
Tekniska verken excels at producing CNG to be used as vehicle fuel. Indeed, the city of Linköping, which owns the company, runs its bus system exclusively on CNG. But while Tekniska verken’s focus is not necessarily on raw gas, it will be taking a close interest in the results of the tests, according to Erik Nordell, Development Engineer at Tekniska verken, who has been coordinating the work with Mattsson and his Scania team.
Even closer to home, Scania is also set to work with Telge Återvinning in Tveta, Södertälje, a waste-recycling entity owned by Södertälje council. At Scania’s instigation, the pair run tests to see how Scania’s engines can run on simple gas – in other words, gas that is extracted directly from landfill sites. This will mean taking the gas directly from source without refining or upgrading it by drilling holes directly into Telge’s landfilled waste.