Improved hydrolysis for higher digestion of organic material

In many cases hydrolysis has been the speed-determining step during anaerobic digestion of complex polymers and previous studies have shown that complex, less accessible organic structures usually only break down partially. In order to attain more efficient anaerobic digestion of complex substrates, the hydrolysis needs to be optimized.

Initially this project aims to enhance knowledge of hydrolytic reactions and define under-utilized substrate fractions during anaerobic digestion by characterizing complex organic structures which remain in different biodigestate. Thereafter results from the chemical characterization will be used for laboratory studies with the aim of optimizing the hydrolysis and digestion of defined organic structures which are difficult to break down from a microbial perspective for different processes.

Biogas in the paper and pulp industry

Producing biogas from the paper and pulp industry’s process waste water is technically a promising opportunity for increasing the production of biogas, and a potentially new business area for companies in the sector. However, in addition to the technical aspects, integrating biogas production in a part of an existing industrial process entails commercial and organizational challenges as well.

This project aims to analyze obstacles and driving forces for biogas production in the paper and pulp industry through case studies of the industry and potential partners. Questions which should be answered include which resources are required and how business models and strategies can develop in order to enable biogas production.

Biogas in the sustainable region – users and future visions

In order to attain greater understanding of the role of biogas for future sustainable development, a system perspective is required in which both supply and users are studied. While challenges on production and supply have had a large focus in such system analyses, the perspective on users and the role of users for the development of biogas has been missing. This project aims to investigate biogas development from a user perspective in a regional context. Obstacles and driving forces will be studied, as well as how biogas solutions are impacted by their specific socio-economic and political context and by institutional conditions.

Systems and technology for effective use of biofertilizers

An important area for the expanding biogas industry is how to ensure that the biodigestate, with its content of nutrients, can be retransferred as biofertilizer to agriculture. In most biogas reactors, it should be possible to pump the material which will undergo anaerobic digestion, which means that the biodigestate comprises a diluted nutrient solution. The consequence is that large volumes of water need to be transported when the biofertilizer will be retransferred to agricultural land. It may then be interesting to dewater the biofertilizer or to, for example, treat it in order to concentrate the nitrogen content. However, what is the best option taking into account costs of the process, different application areas, freight, storage, dissemination technology and environmental impact?
This development project within BRC aims to analyze different possibilities to develop the treatment and management of biofertilizers to strengthen the total commercial benefits of biogas solutions. The project is organized in four interacting activities:

  1. In a systems analysis, an assessment model will be developed to analyze and learn about critical factors that are affecting the economic and environmental results of different possible strategies to manage biofertilizers. Examples of such factors are digestate content, dewatering techniques and nitrogen concentration techniques, transport options and distance, techniques for spreading and storage capacities at different locations.
  2. An overview and evaluation of possibilities to maximize the value of different fractions of digestates will be conducted. In addition, trials will be conducted with combinations of different dewatering methods and different types of digestate. The most promising combination of techniques/processes (for example, treatment method, spreading technique or cultivation system) will be tried on a pilot/full scale during year 2.
  3. Through interviews with important actors, barriers and driving forces for use of biofertilizers in farming will be examined.
  4. A literature study will be conducted to identify and evaluate potential problems (plastic particles, spread of plant diseases and weed) of using biofertilizers in farming. Lab tests might be performed to investigate any specific issue.

Participants: Project leader Docent Karin Tonderski and Karin Johannesson från the division of Biologi, the Department of Physics, Chemistry and Biology, IFM. Professor Mats Eklund and PhD Students Carolina Ersson and Roozbeh Feiz from the Division of Environmental Technology and Management, Department of Management and Engineering, IEI.

Partners from Biototal AB, Kemira OYJ, Lantmännens Riksförbund LRF, Scandinavian Biogas Fuels AB, Svensk Biogas i Linköping AB and Tekniska verken i Linköping AB.

Enzymatic increase of sludge digestibility

A major substrate for biogas production in Sweden and worldwide is the sludge produced at various waste water treatment plants (WWTP). However, at plants that treat the sludge by anaerobic digestion to produce biogas, the degree of degradation is often found to be less than 50% and the material is thus strongly underutilized. It is well-known that the excess waste activated sludge (EWAS) consisting of microorganisms, is difficult to digest. Significant efforts have therefore been focused on making the bacterial flocs and bacterial content available for anaerobic digestion by various chemical, thermal and mechanical pre-treatment methods. However, since EWAS is so dilute, with a dry content of only approximately 0.5 – 3%, what is treated is mainly water and the use of these energy intensive pre-treatment methods are hard to justify. A more energy efficient way to disintegrate bacterial flocs and to break the bacterial cells would be to use enzymes, and a fair number of trials to use enzymes to accelerate the digestion have also been performed. However, the results from many of these trials are inconclusive in many respects and sometimes contradictory. Nevertheless, it can be concluded that the effect of enzyme addition to sludge has in some cases lead to an increase of the biogas production, however not to the degree where it is economically justifiable to add the large amount of enzymes that would be needed.

To find ways to increase the efficiency we therefore intend to perform a more thorough study to understand the mechanisms of various processes and thereby determine whether enzyme addition de facto is a feasible method to increase biogas production from anaerobic digestion of sludge. For this, it is necessary to monitor the fate of added enzymes by studying their activity, modification and lifetime at the conditions that would prevail in a real life process, rather than simply studying the effect in biogas production. This can then be used to correlate enzyme activity to, for example, metabolite turn-over and possible inactivation mechanisms of added enzymes. This will also give information about which of the many commercially available enzymes are most suitable for the intended process. By identifying possible inactivation processes we further hope to be able to enhance the efficiency and lifetime of the enzymes by adjusting the conditions or by modifying the enzymes with genetic engineering

Particpiants: Project leader Martin Karlsson, Rational Enzyme Mining AB and the Division of Biotechnology, Department of Physics, Chemistry and Biology, IFM. Professor Bengt-Harald ‘Nalle’ Jonsson and PhD Student Anna Hansson from athe Division of Biotechnology, IFM. Professor Bo Svensson from the Division Environmental Change, Department of Thematic Studies. Partners from Kemira OYJ, Scandinavian Biogas Fuels AB and Tekniska verken i Linköping AB.

Increased methane production and process stability in biogas reactors

Based on previous research, there is a good platform for simultaneously developing both microbial capacity in biogas reactors and strengthening process stability. Important components in this work comprise understanding and controlling the importance of trace element additions as well as rheology/viscosity in relation to substrate composition and process parameters.

The intention of this project is to further develop knowledge on the role of trace elements in the streamlining of biogas production as such and their role for the microorganisms’ production of organic substances, which in turn affect the rheology of reactor fluid.

In order to attain this, the project will conduct a series of lab-scale reactors with substrates relevant for the industry and optimize process conditions with regard to changes in substrate mixes, organic loading, trace element additions, stirring capacity, etc. These reactors will be operated in close collaboration with project partners and with the help of customary analyses like biogas and methane formation per added amount of organic material, fermentation efficiency, pH, alkalinity, degree of digestion, etc. Rheological characterization, determination of trace element availability, molecular biological characterization of microbiology society are determined in connection with changes in substrate mixer, loading and stirring variations, addition of trace element, etc.

The results will provide supporting material in which we integrate the opportunities for greater loading and replacement in tested processes as well as guidelines for further research studies within the area ahead of the next BRC phase. This means that the practical terms and conditions for, for example, dosage of trace elements, dimensioning of stirring, pumping and dewatering in the long run provide a safer base with lower risk of surprises in the form of process disruptions.

Participants: Project leader Associate Professor Annika Björn and Professor Bo Svensson, PhD Student Sepehr Shakeri Yekta and Research Assistant Pascal Ojong, from the Division Environmental Change, the Department of Thematic Studies. Researchers from the Division of Environmental Technology and Management, the Department of Management and Engineering, IEI, and the Division of Biotechnology, the Dapartment ocg Physics, Chemistry and Biology, IFM. Partners from Kemira OYJ, NSR AB, Scandinavian Biogas Fuels AB and Tekniska Verken i Linköping AB.

Municipalities as system builders in energy systems

In order to understand the development of technological systems, these systems must be analyzed as sociotechnical, i.e. based on an assumption where technology and its societal, economic and political factors interact and influence each other mutually. Technological development is shaped in a social context by networks where actors form these sociotechnical systems together. In this project, focus lies on municipalities’ driving roles as system builders in energy systems, in particular concerning biogas production. In several Swedish municipalities, biogas production is ongoing under municipal management, for example, through municipal energy and/or waste companies and sometimes in collaboration with private actors.

This project aims to analyze and explain municipalities as system builders, in order to increase knowledge of the obstacles, driving forces and learning concerning municipalities’ roles in the transition of the energy system.

  • How and why are sociotechnical energy system solutions concerning biogas initiated in a municipal context?
  • How do municipalities act as system builders alternatively to support technological development and commercialization of biogas?
  • Which obstacles and opportunities do actors face in these processes?

These are some of the questions that are of interest for the project. Besides literature and document studies, interviews as well as focus groups will be conducted with representatives from municipalities, academia, interest organizations, companies, citizens etc.

Participants: Project leader Assistant Professor Magdalena Fallde and Professor Jenny Palm, Professor Kajsa Ellegård and PhD Students Linnea Hjalmarsson from the Divion of Techology and Social Change, the Department of Thematic Studies. Professor Mats Eklund from the Division of Environmental Technology adn Management, the Department of Management and Engineering, IEI. Professor Bo Svensson from the Division Environmental Change, the Department of Thematic Studies. Helena Kock-Åström from Linköping Municipality and Mattias Philipsson and Stellan Jacobsson, Svensk Biogas i Linköping AB / Tekniska verken i Linköping AB.

Collaboration for improved economic and environmental performance

Existing biogas plants have a low level of profitability. Due to this, not many new production plants are being established. One of the most important areas for a well-functioning production system is to develop an efficient organization to handle material and energy flows which may provide increased profitability, reduced risk and improved environmental performance. The environmental performance of these systems is one of the most important driving forces for future developments not only to promote sustainable solutions, but also to comply with regulations which govern grants. Utilizing material and energy more efficiently will also allow cost savings to be made.

Application of the concept industrial symbiosis analyzes how different paths for collaboration on material and energy through, for example, use of waste and by-products or sharing of production plants between different companies, provides opportunities for improved economic and environmental performance. By using the results, opportunities for improved organization of biogas systems can then be provided. In addition to this, a tool for analyzing the economic and environmental performance of biogas systems will be developed. Different scenarios will be prepared in order to increase knowledge of how important parameters such as scale, localization close to cities or agriculture, different energy systems and proximity to biofertilizer markets affect the economy and environment.

Participants: Project leader Associate Professor Niclas Svensson. Researchers: PhD Michael Martin, Professor Mats Eklund and PhD Students Carolina Erson and Roozbeh Feiz, form the Division of Environmental Technology and Management, the Department of MAnagement and Engineering IEI. PArtners from Kemira Oy, Lantbrukarnas Riksförbund LRF, Linköpings kommun, Scandinavian Biogas Fuels AB and Svensk Biogas i Linköping AB.

Biogas in new industries

One way of increasing the production of biogas is to utilize material flows which are not currently being used, which at the same time can solve other environmental and energy-related problems. Several industrial sectors contain many energy and material flows, of which some could be used for biogas production. Potential flows may also be hidden in the production structures of industry. This project focuses on innovation, integration and implementation of biogas solutions from a system perspective.
Overall analyses of a number of industry sectors allow the identification of potential opportunities. Some industries and companies are studied in order to find process technology challenges, conduct overall energy system analyses as well as to study environmental performance and business opportunities. Possible production process changes are highlighted in discussions with companies and industries. Tools for analyzing energy systems at several different system levels are used: industrial systems, municipal systems and regional systems.

The work is intended to start with an operating environment and status description based on literature and other sources. The intention is, as a second step, to conduct a progress report at industry level and information is obtained from industry organizations, research institutes and collaboration partners, etc. Thereafter the aim is to study different concepts in these new industries in order to establish the process practicability of the concept. The next step is planned to analyze how the concept affects the ambient energy systems and environment, before the concept is also analyzed based on other aspects in the society. Furthermore, there are plans to test the concept in one or several case studies.

The aim is to find one or several new industries where biogas production is a resource-efficient way to utilize such material flows which are not currently used.

Participants: Project leader Associate Professor Magnus Karlsson, Associate Professor Mats Söderström, and PhD student Emma Lindkvist, from the Division of Energy Systems, Department of Management and Engineering, IEI. Researchers from the division of Environmental Technology and Management, IEI, and the divisions Technology and Social Change and Environmental Change, Department of Thematic Studies. Participants from the Federation of Swedish Farmers (LRF), Lantmännen, Scandinavian Biogas Fuels AB, and Tekniska verken i Linköping AB.

Systematic assessment of feedstock for an expanded biogas production

There are many different studies about feedstock for biogas production, clearly showing that there is large theoretical potential. However, in many cases this potential is far from being realized. There is a need for systematic assessment of feedstock which not only takes into account chemical or biological properties and available quantities, but which also covers technical, economic and environmental aspects.
The overall aim of this explorative project is to establish a method and apply it in order to structure relevant information about feedstock for biogas production, which should simplify substantiated decision-making and lead to resource-efficient biogas production. The method should include chemical, biological, technical, economic/commercial and environmental aspects for biogas, but also take into account other relevant products such as, for example, biofertilizer. This method shall make it possible to carry out both generic and case-specific assessments of feedstock and take temporal perspectives into account.
In the first hand the priority is to systematically assess promising, new feedstock categories which have the potential to contribute to a significant increase of biogas production, where valuable information is missing or incomplete. Examples could be aquatic biomass, lignocellulosic materials, etc.
In terms of the operations within BRC, an important aim is to highlight decisive challenges which should be the focus of research projects over the upcoming program periods.

Participants: Project leader Assistant Professor Jonas Ammenberg, Professor Mats Eklund and PhD Students Carolina Ersson and Roozbeh Feiz from the Division of Environmental Technology and Management, the Department of Management and Engineering, IEI. Professor Bo Svensson and Assistant Professor Annika Björn form the Division Environmental Change, the Department of Thematic Studies. Partners from Biototal AB, Lantbrukarnas Riksförbund LRF, Lantmännen, NSR AB, and Scandinavian Biogas Fuels AB.