Black Liquor To Fuel Trucks?

Trucks that impose hardly any load on the environment from their emissions … Is this a dream, a future scenario, or is it possible now?

It’s closer to the latter, says Volvo Trucks, which is already running successful field tests with vehicles powered by bio-DME, a fuel that can be produced from biomass both cost and energy efficiently. For the transport industry, this could reduce dependence on oil and thereby reduce the environmental impact.

Since last autumn, ten specially adapted Volvo trucks have been operating on Swedish roads. They do not stand out in the traffic, they do not travel more slowly and they do not look any different, but they are a step toward that dream.

The reason is that they are powered by bio-DME. Because it is produced from biomass, it is renewable and can be made from totally natural raw materials. It also reduces carbon emissions by 95 percent compared with conventional diesel. The promising field tests have now reached the halfway point and the results so far have both met - and exceeded - expectations.

“We have, for example, demonstrated both that the technology works in practice, when it comes to both the production of fuel and trucks in traffic, and that the infrastructure with filling stations in different parts of Sweden works effectively. The test results bode well for the future,” says Lars Mårtensson, environmental director at Volvo Trucks.

The field tests, which are being conducted in collaboration with companies including Preem, the biggest oil company in Sweden, and Chemrec, the Swedish company which is responsible for fuel production, has aroused interested worldwide – an unexpected bonus, according to Mårtensson.

“We have shown that it’s possible to take an idea from the laboratory to full-scale operation and we have also successfully spread this knowledge all over the world. There is now a clear-cut interest from countries including China, Russia and the USA and they are markets with huge potential,” he says.

Bio-DME, dimethyl ether produced from biomass, is a liquid, so-called second-generation biofuel that can be made from wood or by-products and waste from agricultural production.

“According to the calculations, bio-DME could replace up to 50 percent of the diesel that is currently being consumed by commercial vehicles in Europe within the next 20 years. We have a chance to make a fantastic contribution to help the environment,” he adds.

The bio-DME that is being used in the Volvo Trucks field tests is made from black liquor (pictured), a by-product from the production of pulp. The black liquor is actually used in the flow of energy that powers the pulp mill. Chemrec’s process takes part of the black liquor, gasifies it and turns it into usable fuel which can currently, during the on-going field tests, be obtained at four filling stations in different parts of Sweden.

To date, the drivers who are operating the trucks in the field tests have reported that everything is as expected, which is a major success for the project – filling up with biofuel and driving should not be more complicated in any way or constitute a disadvantage in terms of performance.

Yngve Holm (pictured) is transporting pulpwood in northern Sweden in a DME-adapted Volvo FH-440. He is one of the test drivers and he has also reported a number of advantages, such as lower noise levels and, first and foremost, environmental aspects.

“I can drive about 650 kilometres on one tank and the truck runs just as well as it does on any other fuel. It is actually much quieter, both internally and externally,” says Yngve.

He has been participating in the field tests since last September and so far he has driven 40,000 kilometers. He has also been asked many questions about the new fuel and he says “Many people are curious and want to know how it works. I usually say that it works really well. The most important thing is that we are doing something for the environment and the future and that’s good for the soul, as I see it.”

The bio-DME he is using is produced just a stone’s throw from the filling station he uses, at the Chemrec plant in Piteå in northern Sweden, next to the Smurfit-Kappa Kraftliner paper mill. This plant is the first of its kind in the world. The process takes place in a high structure with no walls, consisting entirely of stainless pipes, stairs and tanks that make up a complicated system. Chemrec has quite simply connected itself to the existing mill infrastructure and set up another production line at the mill. It is then able to demonstrate on a small scale a highly cost- and environmentally-effective method for producing bio-DME. The capacity is approximately four tonnes of bio-DME a day.

“Bio-DME is produced in three stages. After collecting the black liquor from the pulp mill, we convert it into gas using pure oxygen and thereby produce syngas, a gas that can be synthesized. We wash the gas and then convert it to bio-DME. After that, the quality is checked and the fuel is transferred to a large tank near the mill for storage. The mill is then compensated with biomass known as forest slash, which is branches and the tops of trees that are left over when forests are cut down – a highly effective form of energy exchange,” explains Ingvar Landälv, technical director at Chemrec.

Bio-DME production is still in its infancy, but the potential is enormous.

“At the present time, we are only using one percent of the black liquor produced at the mill. If we can use our technology to convert all the black liquor to bio-DME, it would be able to power around 2,500 trucks, so we envisage incredible potential,” says Ingvar Landälv. “The black liquor capacity in Sweden alone corresponds to about 20 mills like this one.”

“We are focusing on industrializing our product together with the pulp industry both in Sweden and abroad,” says Max Jönsson, managing director of Chemrec.

A full-scale investment in bio-DME, using Chemrec’s production technology, Volvo Trucks’ automotive engineering and a fully developed filling station network, requires substantial funding.

“To realize their true potential and help to create the conditions for a climate-neutral transport system, the rules for the second generation of biofuels need to be set. We have shown that the technology works. The ball is now in the decision-makers’ court. It is up to them to create the conditions for this kind of production,” concludes Jönsson.

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