Abstract

The aim of this project is to develop an integrated biotechnical process for the production of the bulk-chemical l,3-propanediol (PD) from glycerol waters by using directly the biological waste from biodiesel plants. To increase PD yield, the use of wastes from food industries as co-substrate will also be investigated. To enable the use of these cheap impure substrates the necessary desalting will be done by electrodialysis. A new, highly product-tolerant strain will be used in immobilised form for enhanced productivity and process stability. To gain high PD concentrations, a (fed)-batch system will be set-up. For process control an online -sensor will be developed to monitor the concentration of the substrates. To prevent bacteria inhibition and facilitate PD-recovery, organic acids as by-products will be removed by electrodialysis. All work will be accompanied by economic analysis of the individual steps.

Objectives

The objectives of the project are as follows:

• To have the microorganism IK123 producing propandiol derived from glycerol water from biodiesel production with a molar yield of >90% when using co-substrates.
• To reach a final PD concentration of >110g/L.
• To provide an electrodialysis unit suitable for desalination of crude (co-) substrates.
• To have a sensitive biosensor for reliable online-analysis available.
• To develop an optimal fermentation procedure including feeding of substrates and using cheap media.
• To use a continuous removal of inhibiting by-products like organic acids by electrodialysis. To increase the activity of the bioprocess by using a suitable immobilisation procedure.
• To have a complete economic validation of the integrated process.
• To organise the "1st European Symposium on Biotechnical Valorisation of Industrial Effluents and Wastes - BioVIEW".

Description of the work

Cheap, low concentrated glycerol waters from biodiesel production and carbohydrate containing wastes from industry will be evaluated for their suitability for microbial PD production. Electrodialysis units for desalination of the crude (co) substrates will be developed and built. The fed-batch-fermentation step itself will be optimised regarding its productivity by determination the optimum feeding regime, costs for the cultivation medium will be minimised by replacing yeast extract. Controlling the feeding possibly in real-time will be able by employing biosensors that will be developed and that are specific for the different substrates, e.g. glycerol. Bacteria either immobilised by adsorption or by gel-entrapment will be compared among each other and with suspended cells regarding their PD formation activity and the consequences for the process stability and the necessary equipment. To reach a higher PD concentration during the fermentation, inhibitory by-products (organic acids) should be removed simultaneously to PD formation. This will be done using electrodialysis modules. The fermentation broth with possibly no organic acids will be further processed to gain the PD by distillation. The sampling of (co-) substrate will economically be accompanied, as will be the final rating of what was achieved in the project. The project management will control the progress of the project and coordinate the work. In addition, the internet presentation of the project, meetings, and the "1st European Symposium on Biotechnical Valorisation of Industrial Effluents and Wastes - BioVIEW" will be organised.

Milestones and expected results

• M1 : Decision about the (co-) substrate sources to use in the following course of the project
• M2: Essential choices regarding the use of co-fermentation and immobilisation method
• M3: An Integrated process for the biotechnical production of PD from organic wastes
• End result: Having a competitive, cost-efficient biotechnical process for producing a value-added compound for the chemical industry from renewable resources

Contacts

Co-ordinator

• Horst GOTTFRIED / Federal Agricultural Research Centre GERMANY

Participant

• Ulrich JAHNZ / GeniaLab Biotechnologie GmbH GERMANY
• Lubos NOVAK / MEGA A.S. Department of Final Technologies / CZECH REPUBLIC
• Jan HIRSCH / Slovak Academy of Sciences Institute of Chemistry / SLOVAKIA
• Markwart KUNZ / Sudzucker AG Mannheim/Ochsenfurt GERMANY