Physics of the urban production of algae in photo-bio reactors for the utilization in vertical farms

Die heutige Lebensmittelindustrie verlangt nach einer großen Menge nicht erneuerbarer Ressourcen wie Rohöl, Erdgas und Phosphatgestein. Um die Ernährungssicherheit der kommenden Generationen zu garantieren ist es notwendig diese Abhängigkeiten zu minimieren. Dabei stellen sich die Fragen, welche Technologien zur Gewinnung von erneuerbaren Energieträgern dafür genutzt werden könnten. Ist es zum Beispiel großtechnisch und ökonomisch möglich Algendünger in Photobioreaktoren zu produzieren und so N und P aus dem Abwasser zu recyceln? Ist es des Weiteren möglich diesen Prozess energieautark zu gestalten um so die Verwendung von nicht erneuerbaren Energieträgern zu vermeiden? Anhand von Beispielen aus der Literatur untersucht diese Arbeit das Potential von Mikroalgen, städtischem Abwasser Nährstoffe zu entziehen um diese wieder in den urbanen Lebensmittelkreislauf zurück zu führen. Eine biophysikalische Beschreibung der Algen- und Hitzeproduktion in Photobioreaktoren an Wiener Hausfassaden dient zur Berechnung des Masse- und Energieflusses. Die Verfaulung der produzierten Biomasse wird vorgeschlagen um deren Düngereffizienz zu steigern und um gleichzeitig CH4 als Energieträger zu gewinnen. Die Ergebnisse des Rechenmoddels werden zur Abschätzung der Kosten für eine Algendüngemittelproduktion in Wien verwendet. Der mögliche Einsatz des Biodüungers in vertikalen Farmen wird diskutiert. In Wien könnten an einer 100m*100m Hausfassade jedes Jahr 271t Mikroalgen wachsen. Die Verbrennung des produzierten Biogases könnte dabei den Heiz- und Strombedarf decken. Da die einzelnen Glieder dieser energieautarken Prozesskette bereits existieren ist diese Art der Biodüngerprodution mit Hilfe von Photobioreaktoren technisch realisierbar. Das Produkt wäre jedoch selbst nach optimistischer Abschätzung neun mal so teuer wie kommerzieller Dünger. Dieses Konzept einer Bioraffinerie birgt jedoch ein enormes Einsparungspotenzial für Rohöl, Erdgas und Phosphorgestein und ist damit der alleinigen Nutzung von Biomasse als Energieträger einen Schritt voraus. Bestätigt wird das durch die Berechnung des Wirkungsgrades für die Umwandlung von Sonneneinstrahlung zu Algenbiomasse für eine direkte Verbrennung: Mit knapp 4% liegt dieser weit unter dem moderner Photovoltaikanlagen für die Stromproduktion.Todays agricultural food production depends on the availability of non-renewable resources like crude oil, natural gas and phosphor rocks. Tomorrow`s food security can only be ensured by reducing this dependency. There are open questions concerning the methods that can be used for the production of renewable sources in order to achieve this goal. Is it technically and economically feasible, for instance, to produce micro-algal fertilizer in photo-bio reactors to recycle N and P from waste water streams? Is this furthermore possible by avoiding the combustion of non-renewable energies to become energy self-sufficient? Relevant examples from literature will be used to investigate the micro-algal potential to extract nutrients from urban waste water streams for the re-injection into the food chain of the population. The production algae and heat will be described in a bio-physical way to calculate the mass- and energy flux in photo-bio reactors, attached to walls of buildings in Vienna. It will be suggested to decompose the generated bio material through anaerobic digestion to increase the N- and P share on one hand and to produce methane as an energy carrier on the other hand. The calculation model will be used to estimate the costs of producing a micro-algal fertilizer in Vienna. Furthermore a possible utilization of the generated fertilizer in vertical farms will be discussed. About 271t micro algae per year could be produced on a 100m*100m wall in Vienna. The combustion of the produced biogas could meet the entire heat- and electrical energy demand of the production process. By demonstrating the technical feasibility of every single part of the energy self-sufficient production chain, the technical feasibility of the whole concept is ensured. The costs of this product, however, would be nine times higher than the costs of commercial fertilizer. The bio-refinery in question still has a great potential when it comes to saving a high amount of non-renewable resources, thus making it an attractive alternative to the exclusive use of biomaterial as an energy carrier. This can be further shown by comparing the sunlight irradiation on a photo-bio reactor with the calorific value of the produced micro algae: This calculation yields an energy conversion efficiency of about 4% which could be surpassed by the electricity production of every available photovoltaic system

Densification and conversion technologies for bioenergy and advanced biobased material supply chains - a European case study

Zusammenfassung in deutscher SpracheIn the upcoming decades, the European Union intends to shift its main input from fossil energy towards renewable sources and technologies. Today, over 60% of primary renewable energy in the EU28 is based on biomass produced by photosynthesis cultivated in forestry and agricultural systems. The current dominance of biomass within the renewable energy sector can be attributed to its cost-effectiveness and to its simplicity in providing renewable space and process heat and in providing a liquid fuel for transportation compared to other renewable alternatives. With this thesis I seek to explore the continuing substitution of fossil carbon-based economic activities with those based on biogenic carbon. I analyse the possible development of both the bioenergy sector and also of new branches of the bioeconomy, replacing those currently based on considerable amounts of fossil carbon. I discuss densification technologies and the way in which they could help to overcome limitations with regard to resource allocation of feedstock with relatively low carbon density, high water content and high heterogeneity, in comparison to current fossil feedstock. Lastly I examine the commoditisation process of resulting densified biomass products. To tackle these issues and related questions, I (1) construct scenarios for the demand of advanced biobased materials; (2) outline and apply a generic biomass-to-end-use chain tool capable of estimating densified bioenergy carrier deployment costs for a high variety of possible relevant supply chains; and (3) perform an econometric analysis to quantify the integration and efficiency of the European market for the currently most-traded densified bioenergy carrier. I find that, while primary biomass supply for bioenergy and advanced biobased materials could grow from about 7 EJ today to 11-17 EJ in 2050 in the EU28, the share of this supply for biobased chemicals - especially biobased plastics and bitumen - could reach 6-15%. Furthermore, I find that densification technologies such as pelletisation, torrefaction and pyrolysis could already reduce heating costs in Europe, and has the potential to cut the cost of lignocellulosic biomass-based electricity, transport fuel and chemical production in the future. If biomass is torrefied before pelletisation, savings of up to 3 €*GJ-1 could be achieved for woodchip-to-FT-synthesis supply chains. Costs saving effects of densification efforts are found to be higher for increased storage times than for increased transportation distances. It can, however, also be demonstrated that European markets for residential heating based on wood pellets are not efficiently integrated today, and that liquidity and competitiveness would have to be altered in order to support the commoditisation process of this product. Therefore, data availability and quality has to be improved to increase transparency and public perception with respect to fungibility of same-quality pellets independent of pellet colour or supply-chain affiliation, e.g. whether regionally or internationally traded.In den nächsten Jahrzehnten soll die Deckung des Energiebedarfs der Europäischen Union von fossilen Energieträgern auf erneuerbare Ressourcen verlagert werden. Zurzeit wird über 60% der erneuerbaren Primärenergie in der EU-28 aus Biomasse abgedeckt. Die relative Kosteneffizienz und auch Simplizität der Bioenergie zur Raumwärmeproduktion und zur Produktion von flüssigen Treibstoffen können als mögliche Gründe für die derzeitige Dominanz der Biomasse im Erneuerbarensektor genannt werden. Mit dieser Dissertation möchte ich die aktuellen Substitutionsbemühungen von fossilen- zu biogenen kohlenstoffbasierten ökonomischen Aktivitäten bis 2050 analysieren. Dafür untersuche ich mögliche Entwicklungen im Bioenergiesektor, aber auch von anderen Branchen der Wirtschaft die bis jetzt auf beträchtlichen fossilen Kohlenstoffmengen basieren. Außerdem diskutiere ich Verdichtungstechnologien zur Überwindung der Beschaffungslimitierungen in Bezug auf die relativ geringen Kohlenstoffdichten biogener Rohstoffe. Letzteres erforsche ich den Kommodifizierungsprozess der resultierenden verdichteten Biokohlenstoffträger. Um diese Themen und ihre Fragen zu behandeln (1) erstelle ich Entwicklungszenarien für fortschrittliche Biomaterialien; (2) entwerfe und verwende ich ein generisches Biomasseversorgungskettenmodel und; (3) nutze ich ökonometrische Methoden um die Integration und Effizienz der europäischen Markte für verdichtete biogene Kohlenstoffprodukte zu quantifizieren. Neben einem erwarteten Wachstum der Biomasseversorgung von derzeit 7 EJ auf 11-17 EJ in 2050 weisen die Szenarien zwischen 6-15 % des Biomasseeinsatzes für biobasierte Chemikalien auf. Untersuchte Verdichtungstechnologien können schon jetzt Kosten im Raumwärmesektor und in weiterer Folge auch zur Bereitstellung von Strom sowie flüssigen Biotreibstoffen und auch Chemikalien basierend auf Lignocellulose senken. Ein, der Pelletisierung vorgeschalteter Torrefizierungsprozess könnte Versorgungskettenkosten um bis zu 3 €*GJ-1 senken. Einsparungspotentiale sind bezogen auf Speicherkosten höher als für Transportkosten. Allerdings sind selbst die in den letzten Jahren etablierten europäischen Holzpelletsmärkte zur Raumwärmeproduktion noch nicht effizient integriert. Liquidität und Wettbewerbsfähigkeit müssten verstärkt werden um hier den Kommodifizierungsprozess zu unterstützen. Um die besprochenen Sektoren der Bioökonomie zu stärken ist außerdem eine erhöhte Markttransparenz zentral. Diese sollte von allen Marktteilnehmern unterstützt und auch eingefordert werden. Deutlicher Forschungs- und Handlungsbedarf besteht in Bezug auf Marktdatenverfügbarkeit und Marktdatenqualität. Die Markttransparenz sowie die öffentliche Meinung bezüglich der Vertauschbarkeit von Pellets gleicher Qualität soll dadurch verbessert werden.10

Strategies for the Mobilization and Deployment of Local Low-Value, Heterogeneous Biomass Resources for a Circular Bioeconomy

With the Bioeconomy Strategy, Europe aims to strengthen and boost biobased sectors. Therefore, investments in and markets of biobased value chains have to be unlocked and local bioeconomies across Europe have to be deployed. Compliance with environmental and social sustainability goals is on top of the agenda. The current biomass provision structures are unfit to take on the diversity of biomass residues and their respective supply chains and cannot ensure the sustainability of feedstock supply in an ecological, social and economical fashion. Therefore, we have to address the research question on feasible strategies for mobilizing and deploying local, low-value and heterogeneous biomass resources. We are building upon the work of the IEA Bioenergy Task40 scientists and their expertise on international bioenergy trade and the current provision of bioenergy and cluster mobilization measures into three assessment levels; the legislative framework, technological innovation and market creation. The challenges and opportunity of the three assessment levels point towards a common denominator: The quantification of the systemic value of strengthening the potentially last remaining primary economic sectors, forestry, agriculture and aquaculture, is missing. With the eroding importance of other primary economic sectors, including fossil fuel extraction and minerals mining, the time is now to assess and act upon the value of the supply-side of a circular bioeconomy. This value includes the support the Bioeconomy can provide to structurally vulnerable regions by creating meaningful jobs and activities in and strengthening the resource democratic significance of rural areas

Strategies for the Mobilization and Deployment of Local Low-Value, Heterogeneous Biomass Resources for a Circular Bioeconomy

With the Bioeconomy Strategy, Europe aims to strengthen and boost biobased sectors. Therefore, investments in and markets of biobased value chains have to be unlocked and local bioeconomies across Europe have to be deployed. Compliance with environmental and social sustainability goals is on top of the agenda. The current biomass provision structures are unfit to take on the diversity of biomass residues and their respective supply chains and cannot ensure the sustainability of feedstock supply in an ecological, social and economical fashion. Therefore, we have to address the research question on feasible strategies for mobilizing and deploying local, low-value and heterogeneous biomass resources. We are building upon the work of the IEA Bioenergy Task40 scientists and their expertise on international bioenergy trade and the current provision of bioenergy and cluster mobilization measures into three assessment levels; the legislative framework, technological innovation and market creation. The challenges and opportunity of the three assessment levels point towards a common denominator: The quantification of the systemic value of strengthening the potentially last remaining primary economic sectors, forestry, agriculture and aquaculture, is missing. With the eroding importance of other primary economic sectors, including fossil fuel extraction and minerals mining, the time is now to assess and act upon the value of the supply-side of a circular bioeconomy. This value includes the support the Bioeconomy can provide to structurally vulnerable regions by creating meaningful jobs and activities in and strengthening the resource democratic significance of rural areas

Strategies for the Mobilization and Deployment of Local Low-Value, Heterogeneous Biomass Resources for a Circular Bioeconomy

With the Bioeconomy Strategy, Europe aims to strengthen and boost biobased sectors. Therefore, investments in and markets of biobased value chains have to be unlocked and local bioeconomies across Europe have to be deployed. Compliance with environmental and social sustainability goals is on top of the agenda. The current biomass provision structures are unfit to take on the diversity of biomass residues and their respective supply chains and cannot ensure the sustainability of feedstock supply in an ecological, social and economical fashion. Therefore, we have to address the research question on feasible strategies for mobilizing and deploying local, low-value and heterogeneous biomass resources. We are building upon the work of the IEA Bioenergy Task40 scientists and their expertise on international bioenergy trade and the current provision of bioenergy and cluster mobilization measures into three assessment levels; the legislative framework, technological innovation and market creation. The challenges and opportunity of the three assessment levels point towards a common denominator: The quantification of the systemic value of strengthening the potentially last remaining primary economic sectors, forestry, agriculture and aquaculture, is missing. With the eroding importance of other primary economic sectors, including fossil fuel extraction and minerals mining, the time is now to assess and act upon the value of the supply-side of a circular bioeconomy. This value includes the support the Bioeconomy can provide to structurally vulnerable regions by creating meaningful jobs and activities in and strengthening the resource democratic significance of rural areas

The dynamics of the global wood pellet markets and trade – key regions, developments and impact factors

The global pellet market is growing but with different characteristics in different countries and regions. In this paper we trace developments between 2008 and 2016. For 2008, production was reported at 9.8 Tg, expanding globally to 14.3 Tg in 2010 and surpassing 26 Tg in 2015. Global hot spots are North America (production) and Europe (consumption). Sustainability certification was applied for about 9 Tg in 2016. Nevertheless, projections for future development are difficult as low pellet prices and uncertain sustainability obligations may hinder further expansion. In general, there is a strong dependency of the pellet market on the policy framework