New Animation: Combustion Test

We have added a new animation to our Learning Resources section. New animation illustrates combustion tests using various fuels and different mixture rates. Check out the animation here.

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EcoHousing Market Survey Report

Ecohousing is European project which goal is to increase the use of energy saving heating systems, biofuels and energy efficiency home appliances. The partners of the project are Finland, Estonia and Latvia and the survey was conducted in these countries. The target of the survey was to collect information about energy efficiency in households in Estonia, Finland and Latvia. The survey dealt with the following issues

  • People’s common attitudes towards energy issues like eco efficient housing, energy saving and existing guidance
  • People’s eagerness to save energy and reduce energy consumption at home
  • What kind of heating systems are used and what kind of heating and lightning habits are prevalent
  • How the household appliances are purchased, installed, used and maintained at home

It is necessary to reduce the energy consumption in households and to increase the overall energy efficiency. The energy use of heating and lightning are significant. The market of home appliances is becoming more and more common across the Europe, but conditions differ from country to country due to climatic, geological, cultural, legislative and behavioral differences. It is clear that the effects of installation, location and use of home appliances on energy consumption in household are significant. Consumers’ preferences to adopt knowledge and information are different. This survey gets an indication about the state of knowledge and awareness on energy efficiency and the behavior of consumers with respect to consuming energy of consumers. The purpose of this survey was also to gather background information which is needed when creating new advising material.

Results and full report are available here.

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New video: Tips for using dishwasher

Check out our latest video that gives some tips what to keep in mind while using dishwasher.

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How to maintain the pellet heating system

TTS has published a video (in Finnish) on how to maintain the pellet heating system!

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New Animation: Save Water

We actually all know that when washing dishes in the sink, we should use the plug. Washing under running water will spend far more water than washing in the sink. Check out this animation to find out how much water you can save when using the plug in the sink. You can also pay visit to our Learning Resources section to see all the previous materials.

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Summary of the thesis: Peculiarities of pretreatment and fuels refining of biomass

Summary of the thesis: Peculiarities of pretreatment and fuels refining of biomass
Andres Menind PhD
Full thesis can be found here:

In accordance with Directive 2009/28/EC on the promotion of the use of energy from renewable sources, Estonia is obliged to increase the share of renewable energy sources in the whole of energy consumption as compared to the reference year of 2005 to 25% by 2020. At the moment, the use of biofuels in Estonia is still low, but interest in the use of biofuels is constantly increasing.

About 283,000 ha of agricultural land were abandoned and 123,000 ha are no longer in agricultural registers (Roostalu et al., 2008). There is around 200 000 hectares of permanent grasslands (grassland occupation over 5 years) in agricultural production and production of green fodder in tons was from 1.5 to 1.9 Mt in a year (Agriculture in figures 2009). Kukk and Sammul investigated meadows that are under environmental protection and estimated that semi-natural meadows cover 130,000 ha in Estonia (Kukk and Sammul, 2006). Biomass production in meadows ranges from 1.7 to 5.7 t/ha yr. Total production from semi natural meadows is approximately 182,000 t /yr of dry matter (Melts et al., 2008).

Even if there are sufficient residues for briquetting to be considered feasible, there are other factors that must be considered, and problems that need to be overcome before the widespread adoption of these wastes as a fuel substitute becomes possible (K. Mason, 2007). Residues vary widely in their form and characteristics, which determines how well they can be used as fuel. One of the technologies for energy conversion of hay is anaerobic digestion with manure in an agro-energetic chain. Another possibility for producing briquettes is complex technologies such as an integrated generation of solid fuel and biogas from biomass (IFBB) separating materials into liquid and solid fractions (press liquids and press cake).

Scheme of IFBB technology

The thesis is based on the above mentioned facts, directives, resources and problems with materials and wastes come from agriculture and industry (pulp and paper industry), which may be considered as a potential source for fuels.

The aim of this thesis is to define the effects of pretreatment and technological peculiarities on using biomaterials on refined ways for fuel production. These can be grouped into sub-categories: briquetting, materials pretreatment and fractionation, bio-gasification and additionally some necessary indicators of cost components and efficiency. This was achieved by completing the following objectives:

1. Manufacture of briquettes in a controlled reproducible way, from a different particular material, wastes and silage press cake. Investigation of material properties, which includes briquette density, moisture content, particle size, physical- mechanical indicators during the briquetting process, mechanical properties and chemical composition of briquettes.
2. Pretreatment and fractionation of materials for IFBB. Investigation of the effect of dewatering silo for composition change analysis. Determination of ash quantity and behavior changes during combustion. Chemical composition and fiber analyzes for different materials (hey, press cake, pulp and paper industry residues) Evaluation of the distribution of chemical elements between fractions during the dewatering process.
3. Bio-gasification potential and process activity tests and a comparison of effects arising from the pretreatment and implementation of IFBB technology. Chemical composition and fiber analyzes for different materials (hey, press cake, pulp and paper industry residues)
4. Analysis of some process cost components and efficiency which are important to evaluate economic aspects of the product or technology.

The novelty of this research consists firstly in tests with materials which due to a lack of knowledge or research data is not available with reference to Estonian local materials. Such materials are biomass (hay, silage) grown on nature preserves with requirements to make one late harvest once a year in July and pulp and paper industry residues without subsequent purpose of use. Pulp and paper industry residues are PR and PRPF which currently are mainly stored at landfills or other agreed places. The assumption is that these materials may be a feasible resource for fuels refining and applying appropriate pretreatment and technologies.

Scheme of dewatering press Vincent CP4

Secondly the novel aspect of the research consists of the determination of differences and the effect of using the Vincent press for the dewatering of biomass. All available data about dewatering to date was about conic or common cylinder presses. Vincent CP4 press has a divided screw with added fingers in the press chamber, which provided the basis for a hypothesis that divided the screw with added fingers in the press chamber, which as a result may give better DM and elemental mass flow into press fluid and dryer press cake.

Thirdly in research there is speculation that in mixes of different species there may be differences in ash melting characteristics resulting in a higher ash softening point than appears in pure species samples. In experiments sunflower and hemp were used.

General conclusions

1. Fiber hemp and energy sunflower both have potential as raw material for biomass briquetting. Calorific values (16.6–17.4 MJ/ kg) of briquettes pressed from different materials did not differ significantly and compared well with each other. The compactness of hemp briquettes was dependent on lignin content. The average content of lignin in dioecious hemp was higher than of monoecious hemp. Mixes of briquettes of fiber hemp and sunflower in some cases have better ash behavior characteristics than pure species. Further research is needed.

2. Lignin content and particle size both have an effect on biogas yield. If different hay samples are analyzed separately then the correlation between biogas yield and the particle size mean is strong with R2 value from 0.52 to 0.97. The correlation between the biogas yield and lignin content has R2 value 0.52 (r= -28.774, p=0.002). The results are showing that there is a negative correlation between the biogas yield and particle size. The biomass of low quality hay that is mainly unused could be converted to energy in a biogas plant.

3. Volume weight of loose hay is low (about 20–50 kg/m3) but as a result of the briquetting technology application, the density of material increases up to 40 times. The best quality herbaceous briquettes can be produced from silage press cake which has a high volume weight (938 kg/m3) and lower mineral content.

4. There is no big difference in calorific value (5.24 MWh/DMt) when comparing herbaceous briquettes with firewood or wood briquettes. The cost price of herbaceous biomass briquettes obtained by methods described in this study is about two times lower than the price of wood briquette in the market. Bulk weight of briquettes (0.48 t/m3) is higher than the bulk weight of firewood but lower than the bulk weight of wood briquettes.

5. When applying the separation process to silage, on average about 65% of elements: P, K, Mg and Ca are pressed out to PF and can possibly return back to fields. AST for average cake was 1171 oC. The calculated temperature of AST for PC approaches the level of the corresponding value of common firewood. Integrated generation of solid fuel and biogas from biomass enables usage of CHP heat for pre-treatment and thermal drying year around. IFBB has about 60% higher energy production. A more complicated technological chain using IFBB is partly reduced by simplified biogas plant requirements and a decreasing need for capacity (required volume of digester decreases about 4 times).

Vincent CP4

6. Vincent CP4 press has a divided screw with added fingers in the press chamber gives better DM and elemental mass flow into PF for elements K, Ca, P and dryer press cake (DM of PC up to 53%) when comparing the reference source. Mass flow of Ca (56.3%) to PF is undesirable, lowering AST. Proportionately up to 0.32 of the DM contained in the silage was transferred into the press fluid during mechanical dehydration which is up to 28% higher than was described by Richter. That confirms the hypothesis that Vincent type of presses gives better DM and elemental mass flow into press fluid as a result.

7. The results of the briquetting test proved that briquette density is not only depending on the compacting pressure, but the material parameters and pressing temperature used are also important.

8. Based on ethanol potential tests results we can conclude that PR could effectively be used for bioethanol production, but bark is a very poor feedstock for bioethanol production. Briquettes from bark and PR are stable and have good shape. Briquettes from bark have higher ash content (4.49%) than briquettes normally from wooden residues. PFS and PRPF have similar BMP, 333 and 351 LCH4/ KgTS, respectively. 80% of methane potential is achieved during 7 to 8 days. SAD has lower (216 LCH4/KgTS) biomethane potential than PFS and PRPF, and 80% of methane potential is achieved during approximately 20 days.

9. There is no great difference between the calorific value of various biomass samples (5.06…5.42 MWh/DMt). Cost per energy unit of hay samples and rye straw is at the same cost level (18.60–21.15 €/MWh). The cost price of herbaceous biomass briquettes obtained by methods described in this study is about 1.5-2 times lower than the price of wood briquettes in the market.

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Andres Menind defended his doctoral thesis

We are proud to announce that Andres Menind from Estonian University of Life Sciences, who is also participating in Ecohousing Project, has successfully defended his doctoral thesis “Peculiarities of pretreatment and fuels refining of biomass”. Thesis was supervised by professor Jüri Olt and the opponent was professor Dagnija Blumberga (Riga Technical University). Thesis is available in Estonian University of Life Sciences library and University of Tartu library.

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Research of Environmental and Climate Technologies

“Energy Efficient and Ecological Housing” (ECOHOUSING) project
Riga Technical University 53rd International Scientific Conference dedicated to the 150th anniversary
“Research of Environmental and Climate Technologies”
11.-12. October, Riga

On 11th and 12th of October representatives of all the “ECOHOUSING” project partners were invited to “Riga Technical University 53rd  International Scientific Conference dedicated to the 150th  anniversary”, specifically to the section “Environmental and Climate Technologies” in regard to the theme of “Research of Environmental and Climate Technologies”. Different themes related to renewable recourses and sustainable development were discussed during this conference.

One of the main research areas was innovations and new directions in the field of renewable energy resource use. Professor Dagnija Blumberga was opening the conference on 11th of October with the keynote speech “Innovative Technologies for Green Energy in Latvia” which highlighted the potential use of fuelwood, agricultural waste, biomass from waters and organic waste by 2030 in Latvia. Potential of renewable energy assessments were also presented within the study of Prof. Gatis Bažbauers “Environmental and Economic Aspects of Using Wind Power in Heat Pumps of District Heating Systems” and within the presentation related to the paper “Energy Saving and GHG Emission Reduction in a Micro-CCHP System by use of Solar Energy “ presented by professor Ion V. Ion from Romania.

In the first day of conference more than 40 different researches were presented in the poster session when each author gave a short presentation about the main goals and results of his research. Within this section the achieved targets and main focus areas of “ECOHOUSING” project was presented in the posters “Combustion Tests in ECOHOUSING Project” by Anna Beloborodko and “Energy Efficient and Ecological Housing: Overview of ECOHOUSING Project” by Francesco Romagnoli. All the participants and listeners (also from other sections) were able to get acquainted with the contents of those posters on both days of the conference.

“Energy Efficient and Ecological Housing: Overview of ECOHOUSING Project” by Francesco Romagnoli

Around 10 posters were related to the properties of boiler houses and other combustion installations, for example, posters “The Regulation Possibilities of Biomass Combustion” by V.Suzdalenko, “A Review on Suspended Wood Dust Combustion. Efficiency and Fuel Quality” by K.Silins, “District Heating Return Temperature Influence on the Flue Gas Condenser Capacity” by I.Veidenbergs etc. Other posters covered different research fields, among the others: Life Cycle Assessment and Impact Assessment, Ecodesign, Clean Technologies, Biofuels, Energy Efficiency, Wind Energy etc.

The second day of the conference (12th of October) was dedicated to the “Environmental Assessment, Evaluation and Management”. The presentations were mostly about the waste treatment possibilities. Although session also included two more specific papers about the combustion and methanization processes: “The Quality of Pellets Available on the Market in Latvia: Classification according EN 14961 Requirements” by V. Kirsanovs, L. Timma, A. Zandeckis, F.Romagnoli and “Influence of Temperature and Pressure Change on Adiabatic and Isothermal Methanization Processes” by J.Rusanova.

Together 15 scientific papers and 41 posters were presented in this conference; 50 researches were conducted in Latvia, including 43 carried out at Riga Technical University, three at University of Latvia, two at Latvian University of Agriculture, one at Rezekne Higher Education Institution and one at Daugavpils University. In total six papers were presented by international guests from ”Dunarea de Jos” University of Galati (Romania), Technische Universität Berlin (Germany), Gazi University (Turkey), K. Alanne Aalto University (Finland), Cyprus University of Technology (Cyprus) and Utrecht University (Netherland).

The conference has provided a good opportunity for the understanding of the last developments and trends within the use of biomass and other renewable sources in the heating sector. Moreover within the conference has been given visibility to the “ECOHOUSING” project and achieved targets.

Francesco Romagnoli
Riga Technical University
Institute of Energy Systems and Environment
Kronvalda bulv. 1, LV-1010, Rīga
Tel.: +371 67089908

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Baltic Environmental Forum organised an international workshop “Rural-Urban energy co-operations for energy efficient and ecological housing”,

Workshop participants:  experts from Latvia, Germany and Norway

The goal of the workshop:

  • to get acquainted with experiences on utilisation of renewable energy sources for heat production at dwelling houses  and improving energy performance of buildings
  • to discuss possibilities for cooperation between stakeholders at rural and urban areas for energy production from renewable energy sources to satisfy local and regional energy demand.

 Discussion topics:

  • Good practice examples of regional renewable energy concepts and experiences  of energy-efficient cities in Germany;
  • Practical experience of using biomass and solar energy in combi-systems for heat supply of multi–apartment building in Latvia;
  • Implementation of complex solutions for energy efficiency and use of renewable energy sources in Latvia;
    • Experience of using biomass in energy production at local level in Latvia;
    • Sustainable land management from an urban-rural perspective;
    • Chances and challenges of rural-urban energy co-operation.

 The program of the workshop is available here.

 Presentations are available here and report from the workshop (in English) is available here.

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Francesco Romagnoli and Aivars Žandeckis have successfully defended their doctoral thesis

We are proud to announce that two Riga Technical University researchers Francesco Romagnoli and Aivars Žandeckis who are also participating in Ecohousing Project have successfully defended their doctoral thesis and have become Doctors of Science! Both theses are related to topics also discussed within Ecohousing Project. On 27th August Francesco Romagnoli defended his thesis „Model for sustainable bioenergy production and use” and on 6th September Aivars Žandeckis defended his thesis „Modular Solar and Pellet Combisystem for Apartment Buildings. Experimental Research and Optimization”.

The general objective of Francesco Romagnoli’s doctoral thesis is the development of an integrated analytical tool for the environmental performance evaluation of different bioenergy routes within several possible “green” policy alternatives. Within his thesis Francesco analyzed the environmental performance and sustainability of different types of bioenergy and different types of technologies using the Life Cycle Assessment (LCA). The schemes proposed within the model can be further exploited at the European scale involving other types of policy instruments and bio-energy routes not investigated at in this step of research.

The theme of Aivars Žandeckis dissertation is closely related to main research field of Ecohousing, because he particularly investigated the combined solar and pellet system for the heating of multi-family apartment building. His work involved development, installation and optimization of this system, which is based entirely on local and renewable energy resources and suitable for Latvian climatic conditions. His study has a number of target groups, among them apartment building residents, equipment installers and distributors, manufacturers of pellet based heating equipment and modular boilerhouses, municipalities, parliamentary representatives, and investors.

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