The process as used today needs expensive enzymes, and large companies dominate this market, researchers said.
Now Danish and Iraqi researchers have developed a new technique that avoids the expensive enzymes.
Researchers said the production of second generation biofuels thus becomes cheaper, probably attracting many more producers and competition, and this may finally bring the price down.
Bioethanol, which is made from the remains of plants after other parts have been used as food or other agricultural products, and therefore termed "second generation," is seen as a strong potential substitute candidate.
A big challenge is therefore to become able to produce bioethanol from plant parts, which cannot be used for food.
The goal is to produce bioethanol from cellulose. Cellulose is very difficult to break down, and therefore cannot directly be used as a food source, researchers said.
"But the patented enzymes are expensive to buy. We are proud to now introduce a completely enzyme-free technique that is not patented and not expensive. The technique can be used by everybody," said Per Morgen from University of Southern Denmark.
The acid is called RHSO3H, and it is made on the basis of rice husks.
The ashes from burnt rice husks have a high content of silicate, and this is the important compound in the production of the new acid.
The scientists paired silicate particles with chlorosulfonic acid and this made the acid molecules attach themselves to the silicate compounds.
"The result was an entirely new molecule - the acid RHSO3H - which can replace the enzymes in the work of breaking down cellulose to sugar," said Morgen.