Sustainable management – car tires made from dandelions

Continental AG in Hanover produces 150 million tires per year. For this, the world’s fourth largest tire manufacturer needs a lot of natural rubber, which is obtained mainly in the tropical regions of Southeast Asia. In order to meet the growing demand for rubber – and therefore natural rubber – many hectares of rainforest must be cleared each year. Chemist Carla Recker wants to change that.

The scientist has been working in materials research for the tire maker for 26 years. Their goal is to replace natural rubber from jungle plantations with rubber obtained from Russian dandelions. “We can grow it right next to the factories that are in Europe or North America or anywhere in the world. This of course makes us much more efficient in terms of logistics, ”she explains.

A greenhouse at the University of Münster, about 300 square meters: an automatic irrigation system supplies the dandelion plants with water. Professor Dirk Prüfer and his team at the Fraunhofer Institute for Molecular Biology and Applied Ecology have been breeding here since 2010. It provides much more rubber milk than the domestic dandelion. “We started cultivating this plant around 2010,” explains the molecular biologist. “A good ten years or so until we have now achieved the goal of having a lucrative, ie economically reasonable, rubber content and also a plant that performs well in terms of performance. “

Rubber from dandelion root

The coveted raw material is found in white dandelion root. 30 centimeters long, thick as an index finger and weighing around 200 grams, Prüfer, who and his team grew the roots in stable, high-yielding rows, plucks a dandelion from the ground and breaks the root in half. “If you then separate these two parts of the fruit, they don’t come apart like a broken root, but there are tiny white threads hanging down inside. What you see there then is natural rubber. ”

The coveted rubber milk is obtained from dandelion root © imago images / Joerg Boethling

In the case of a native plant, this is “about one percent of the dry root mass.” In other words, when I dry a root, it contains about one percent natural rubber. For Russian dandelions, the base value is around three to five percent. “But we have now optimized it in terms of breeding, so that we have now reached about 15 to 20 percent.”

Serial production is planned

Making tires from dandelions was the idea that her colleagues have long ridiculed chemist Carla Recker. But the 56-year-old showed it to everyone. In 2012 it was able to win the first grams of brown dandelion rubber, in 2014 the first prototypes of a car tire were made in Aachen, and in 2016 the first truck tire with tread in dandelion rubber. The new tires have passed extensive driving tests. Dandelion rubber is of the same quality and can replace the old natural rubber from the tropics one by one. This convinced Continental bosses, but it will be some time before the dandelion tires go into mass production. “We assume that the end of this decade will come with the mass production of car tires.”

There are not enough Russian lion numbers yet. This is why Conti built a research center in Anklam, Mecklenburg, in 2018 as a nucleus of culture on an industrial scale. Russian dandelions are already cultivated there on 100 hectares. But Recker anticipates. “The objective is that we have reached a first state of equilibrium in 2035, and in this context we want to cover a significant part of our natural rubber needs. At least that’s the plan for now. ”

Rubber tree competition

Recker speaks of a market value of one billion euros. 1,500 to 2,000 jobs would be created in the processing of rubber plants alone. And in the subtropics, no additional rainforests would have to be cleared to obtain the rubber milk, Prüfer explains. “The yield per hectare of a rubber plantation is around one tonne. There are huge trees standing there. ”

On such a hectare, there are about 600 trees which are notched and from which the white milky sap, the latex, flows. “A tree like this produces only 1.5 kilograms of natural rubber per year, so not that much. You think it will be a few hundred kilograms, but it’s only 1.5 kilograms. And then you have a ton on a hectare with 600 trees. This is also what we are going to achieve with the dandelion. We are not there yet, we still have to do something, but that is the stated objective. “

From weeds to crops

As an agricultural crop, dandelions have the potential to become an alternative source of environmentally friendly raw materials, thereby reducing reliance on traditionally produced natural rubber. Dandelion is an undemanding plant and also thrives in areas that until now were not worth growing. The higher the demand and the more seeds there will be, the areas will certainly be extended and other areas in Germany will certainly be taken into account as well, ”Recker said. “These areas are an idea right now when there is a structural change, whether it is the Rhineland or Lusatia in central Germany, of course these could also be good areas for growth in the future.”

Farmers absolutely need to rethink. So far, dandelions have been a dreaded weed for them which they have had to fight intensively. In the future, its roots could represent a lucrative source of income for agriculture.

The idea of ​​extracting rubber from dandelions is one of the three proposals for the German Future Prize, endowed with 250,000 euros. Federal President Frank-Walter Steinmeier will announce the winner tomorrow in Berlin. Carla Recker is looking forward to it. “First of all, we are very proud to be among the nominees, it is a great honor and distinction for the scientific work that has been done – and also for the fact that Germany has built prospects for the future with her project “she emphasizes. “Whether we win the award or not, we leave that to the president and the jury, if that happens we will of course be even happier.”

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