Succinic acid could well become an important raw material for the plastics industry if it is possible to produce the acid biotechnologically and cost-effectively. A research project focusing on the biotechnological production of succinic acid under the leadership of BASF SE, which is part of the Biopolymers/Biomaterials Cluster, has now been granted funding by the German Ministry of Education and Research. This is an important step towards the production of high-quality plastics based on biological materials that can also be biologically degraded.
Succinic acid is regarded as the great white hope among organic molecules. In 2004, the American Department of Energy identified succinic acid as one of twelve so-called platform chemicals that can be produced using biotechnological methods, thereby paving the way for industrial molecules. Among these twelve chemicals, succinic acid is believed to have the greatest potential for the future. The term platform chemical refers to compounds that can be used to produce a broad range of technologically relevant substances. For example, 1,4-butanediol (which has a similar chemical structure as succinic acid) can be manufactured on an industrial scale from the anhydrides of succinic acid. At present, succinic acid has its greatest potential as a new raw material in the plastics industry where it can be used to produce new, biologically degradable polyesters. Previously, succinic acid was exclusively produced from fossil materials and can be too expensive for such applications.
Succinic acid, an intermediate product in the metabolism of many organisms, could become an interesting alternative for the petrol-based production of 1,4-butanediol. New biotechnological methods could considerably increase the appeal of this biomolecule if they turn out to be more economical than traditional methods. Succinic acid can be synthesised in microorganisms like Escherichia coli or yeasts, but such methods are still quite expensive.
With the "Production of polyesters on the basis of succinic acid produced by fermentation" project, the Biopolymers/Biomaterials Cluster is aiming to produce marketable plastics in an economical way by biotechnologically and cost-effectively producing the raw material used in this process, namely succinic acid. This would open the door to plastics that are based on biotechnological processes and that can be biologically degraded.
BASF SE, which is coordinating the project, owns a very promising microbial production strain, which, in contrast to other organisms, produces very high quantities of succinic acid. The researchers hope to further increase the yield and secure the high purity of the product through the genetic modification of the strain and by optimising the bioprocess parameters. Downstream steps in the value creation chain, for example the chemical conversion of succinic acid to 1,4-butanediol or the production of marketable plastics, are also taken into account in the project. Due to their high mechanical durability and thermostability, which are often combined with the ability to biologically degrade, such plastics are particularly suitable for the manufacture of robust consumables. The researchers are looking for partner companies to take over the evaluation of these plastics.
In contrast to butanediol, the world market for succinic acid is currently negligibly small. Current estimates suggest that at present about 25,000 t of succinic acid are produced worldwide; the market is growing by about 10 percent per year. If succinic acid became an attractive raw material for butanediol production thanks to new biotechnological production methods, then this would result in a huge market potential: the chemical industry produces about 900,000 t petrol-based 1,4-butanediol per year, of which the majority is used for the production of 2.3 million t of plastics. The entire market volume of products produced from 1,4-butanediol is estimated at over 5 billion euros.