Kombi-Max
Development of a combined device for the targeted chemo-physical modification of ingredients in suspensions using ultrasound and cold plasma
Duration from 01.08.2018 - 31.01.2021, supported by the European Regional Development Fund (ERDF) under the funding code (FKZ) TBI-V-247-VBW-86.
Farm manure and biomass from prunings or organic waste are processed in biogas plants. In 2014, the contribution to total electricity generation in MV amounted to 15 percent. A total of 540 biogas plants with an electrical output of around 300 megawatts were connected to the grid in the state. In Mecklenburg-Vorpommern, 11.3 million tons of untreated cattle manure and 2.2 million tons of untreated pig manure are produced each year and, in addition, millions of tons of solid manure are emitted each year from livestock farming, which is becoming increasingly intensive. There is an enormous need for treatment and emission avoidance here. According to the current state of the art, only 65%-90% of the organic content (depending on the substrate) is digested in most biogas plants, the rest remains unused. The aim of the project was to develop a completely new combination of ultrasound and cold plasma technology for the treatment of suspensions containing substances of biological origin or biomass.
For the combination with ultrasonic sources for biomass treatment, two different plasma sources such as spark discharge and alternatively microwave discharge were developed and tested. With both arrangements, discharges could be generated in liquid media or biomass. In investigations into the treatment of biomass and sodium carbomethoxicellulose on a laboratory scale, viscosity measurements with both the spark discharge and the microwave discharge showed that degradation reactions take place. In the second phase of the project, the project partner PRE Power, Recycling, Energyservice GmbH constructed a demonstrator with a capacity of 40 liters, which contains two industrial ultrasonic sources. A microwave source was used on this demonstrator. The tests showed that the plasma treatment significantly increased the COD values of slurry fermentation residues. This was particularly evident in batch tests.
The feasibility of treating biomass on an application-relevant scale and coupling it with ultrasonic sources was successfully demonstrated. Further work should focus on increasing the power of the microwave source.
