Ari Jääskeläinen

Volatile fatty acids as an added value from biowaste

The aim of the present work was to provide proof of concept of employing a co-culture of K. mobilis and E. coli for producing short and medium chain volatile fatty acids (VFAs) from kitchen biowaste and potato peels. To this aim, experiments were carried out at pilot-scale installation with a bioreactor of 250L. Different feeding strategies were tested under microaerobic conditions, at pH 6.0-6.5 in order to enhance chain elongation. Acetic acid and ethanol were dominating products in the initial stages of the bioprocess, but in a relatively short time of approx. 20-22h from the process start accumulation of propionic acid took place followed by a chain elongation to butyric and valeric acids. The highest final products yield of 325mg/g TS was achieved for the substrate load of 99.1g TS/L (VS of 91.1g/L) and pH 6.5, with the productivity of 448mg/L/h. However, the highest average VFAs chain length (3.77C) was observed in the process run with the loading of 63.2g TS/L and pH 6.0. In this study, we demonstrated that the existing symbiosis of the co-culture of K. mobilis and E. coli favours formation and chain elongation of VFA, induced most likely by the enhanced ethanol formation. Our finding differs from the previous research which focus mostly on anaerobic conditions of VFAs production. The results provide good basis for further optimisation of VFAs production process.

Using slaughterhouse waste in a biochemical-based biorefinery – results from pilot scale tests

ABSTRACT A novel biorefinery concept was piloted using protein-rich slaughterhouse waste, chicken manure and straw as feedstocks. The basic idea was to provide a proof of concept for the production of platform chemicals and biofuels from organic waste materials at non-septic conditions. The desired biochemical routes were 2,3-butanediol and acetone–butanol fermentation. The results showed that hydrolysis resulted only in low amounts of easily degradable carbohydrates. However, amino acids released from the protein-rich slaughterhouse waste were utilized and fermented by the bacteria in the process. Product formation was directed towards acidogenic compounds rather than solventogenic products due to increasing pH-value affected by ammonia release during amino acid fermentation. Hence, the process was not effective for 2,3-butanediol production, whereas butyrate, propionate, γ-aminobutyrate and valerate were predominantly produced. This offered fast means for converting tedious protein-rich waste mixtures into utilizable chemical goods. Furthermore, the residual liquid from the bioreactor showed significantly higher biogas production potential than the corresponding substrates. The combination of the biorefinery approach to produce chemicals and biofuels with anaerobic digestion of the residues to recover energy in form of methane and nutrients that can be utilized for animal feed production could be a feasible concept for organic waste utilization.

Reuse and Circulation of Organic Resources and Mixed Residues

Organic side streams and biomass flows are treated daily in various industries as well as in cities and other communities. Agricultural residues often form more seasonal biomass sources. At many locations globally, combined processing of waste materials is a necessity in order to facilitate their safe disposal in high volumes. However, both as separate entities and mixed with each other, or with miscellaneous wastes, the biomass streams constitute important potential raw material resources. Their environmentally friendly, sustainable treatment and recirculation is encouraged by modern legislation and regulation. The ultimate purpose of the method development as well as the stipulation of rules should lie within the implementation of recycling technologies as they are continuously developed in all corners of the globe. A specific experimental project was carried out by six European Union Baltic Sea region countries. During the REMOWE project (Regional Mobilizing of Sustainable Waste-to-Energy Production) 12/2009–12/2012 and its continuation project ABOWE (Implementing Advanced Concepts for Biological Utilization of Waste) 12/2012–12/2014, various aerial resources were mapped in the participating countries, Germany, Poland, Lithuania, Estonia, Sweden and Finland. Practical experimentation on the utilization of the outlet mixtures were carried out using various microbiological means including techniques from dry digestion to bioengineering with mixed microbial strains. These kinds of holistic technology developments pave the way for a pattern of increasing recycling activities at the waste treatment sites. Then in the biorefinery field, the various processes could form a network of material flows which actually resemble the situation in Nature. Residues from any particular process could then be combined with other resource streams for novel solutions. Moreover, the leftovers from this network pattern could be repositioned into agricultural use as organic fertilizers, and returned to circulation. Also, the gaseous flows could be redirected to the process, most importantly with the assimilation and reuse of organic carbon. All these advancements could avert the climate effects of energy production by replacing incineration, and by combining waste combustion with modern incineration technologies, waste recycling and other processes. As an ultimate goal, there will be a complete circular economy.

Biorefinery Education as a Tool for Teaching Sustainable Development

Savonia University of Applied Sciences, Finland works closely with economic life and makes studies authentic by using Open Innovation Space learning. In this spirit, ABOWE biorefinery project and the related educational links served as a concrete tool for teaching sustainable development. Savonia invested in a mobile biorefinery pilot plant, which is based on the research of Finnoflag Oy, Finland. In this biorefinery plant solution, biodegradable wastes are valorized to platform chemical and energy products with the aid of microbes and their enzymes. The process is carried out in the same way as the circulation is taking place in the Nature. However, skilled personnel are required for conducting the process runs. Therefore, the engineering, construction and testing of the mobile biorefinery pilot plant served as an excellent opportunity for educating engineers to encounter the basics of biological industrial processes. The interdisciplinary project also provided means for learning from each other in a practical way. ABOWE has been positively evaluated for its multisector approach and for involving students and personnel from many educational organizations in the cooperation. Sustainable development was clearly a through-cutting principle during the project. This chapter aims to give an example of how a multidisciplinary development project can act as an educational tool for teaching sustainable development for the participant students as well as a part of continuing education for the personnel.

Comparative assessment of waste-to-energy potential in European regions

This paper presents the results of assessment of the current status of waste-to-energy utilisation in five selected regions, which was conducted within the REMOWE (Regional Mobilizing of Sustainable Waste-to-Energy Production) project. The REMOWE project is part of the Baltic Sea Region Programme 2007-2013 and has been partly-financed by the European Union. The objective of this paper is the evaluation of the current practice with focus on the best practices that can be transferred to other regions. The selected regions are Estonia; Lower Silesia (Poland), Western Lithuania and North Savo Region (Finland) and the County of Vastmanland (Sweden). The current situations in the project regions are presented with regard to the waste generation and treatment and the potential to use waste as RES. The waste types which were identified as relevant for energy recovery include municipal waste, sewage sludge, industrial waste (two streams: one suitable for biogas generation and the other one as alternative fuel for combustion) as well as animal manure. The greatest energy potential show residual municipal waste (68% of the total potential) and animal manure (24%). Energy recovery from these wastes should be a priority in waste management systems of individual regions. Current energy recovery from waste is very low in the considered regions, except for the County of Vastmanland, where app. 68% of the waste to energy potential is utilised. Keywords: waste, renewable energies, sustainability, residues.