Janne Keränen

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Richard Tabor Greene

PUT

K.W. Chau

Hong Kong Polytechnic University

Martina Ulvrova

Swiss Federal Institute of Technology (ETH) & University of Zurich

Mara Reis

Pontificia Universidade Catolica de Minas Gerais

Apostolos Papanikolaou

National Technical University of Athens

Dario Pastrone

Politecnico di Torino

Ephraim Paul

Akwa Ibom State University

Carlos Lange

University of Alberta

Ian Forster

University of Zurich, Switzerland

Sohail Murad

Illinois Institute of Technology

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Papers by Janne Keränen

BIOCLUS - Developing research and innovation environment in five European regions in the field of sustainable use of biomass sources: WP2.1 c and d Biomass resources, production, use, processing and logistics in Central Finland in 2010 and future prospect for year 2020

VTT Technical Research Centre of Finland, 2012

Neo-Carbon Energy - final report

Report on the competition and price situation of wood biomass use in forest industry and energy sector: D7.1

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Development of a model of the world pulp and paper industry

This report introduces a bottom-up global pulp and paper model with a focus on energy consumption... more This report introduces a bottom-up global pulp and paper model with a focus on energy consumption and carbon emissions in the sector. It is a year by year recursive simulation behavioural model running till 2030, incorporating rich technological details and in depth market structures of the industry for 47 world regions. The long time horizon and the detailed modular structure enable the model users to assess the impacts of long term climatic scenarios. In addition to the Business as Usual developments of the sector, climate commitment scenarios are also presented, where the responses of the sector together with the main driving forces are identified. The scenarios reveal a significant carbon reduction potential in the pulp and paper making, and also point to a number of unique features of the sector in reacting to a carbon constraint. The mission of the JRC is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring ...

EUBIONET III—Solutions to biomass trade and market barriers

Renewable and Sustainable Energy Reviews, 2012

ABSTRACT The EUBIONET III project has boosted (i) sustainable, transparent international biomass ... more ABSTRACT The EUBIONET III project has boosted (i) sustainable, transparent international biomass fuel trade, (ii) investments in best practice technologies and (iii) new services on biomass heat sector. Furthermore, it identified cost-efficient and value-adding use of biomass for energy and industry. The aims of this article are to provide a synthesis of the key results of this project. Estimated annual solid biomass potential in the EU-27 is almost 6600 PJ (157 Mtoe), of which 48% is currently utilised. The greatest potential for increased use lies in forest residues and herbaceous biomass. Trade barriers have been evaluated and some solutions suggested such as CN codes for wood pellets and price indexes for industrial wood pellets and wood chips. The analysis of wood pellet and wood chip prices revealed large difference amongst EU countries, but also that on the short term prices of woody and fossil fuels are barely correlated. Sustainable production and use of solid biomass are also deemed important by most European stakeholders, and many support the introduction of harmonised sustainability criteria, albeit under a number of preconditions. The study identified also that a number of woody and agro-industrial residue streams remain un- or underutilised. The estimated European total potential of agro-industrial sources is more than 250 PJ (7.2 Mtoe), the amount of unutilised woody biomass (the annual increment of growing stock) even amounts to 3150 PJ (75 Mtoe). Finally 35 case studies of biomass heating substituting fossil fuels were carried out, showing that the potential to reduce GHG emissions ranges between 90 and 98%, while costs are very similar to fossil fuel heating systems. Overall, we conclude that solid biomass is growing strongly, and is likely to heavily contribute to the EU renewable energy targets in the coming decade.

Drying of thick foam formed mats comprising chemithermomechanical pulp fibers

BioResources

This paper focuses on the drying studies of foam-formed wood fibre based relatively thick materia... more This paper focuses on the drying studies of foam-formed wood fibre based relatively thick materials via infrared drying, impingement drying, and microwave drying. The drying experiments were carried out for materials with three initial moisture ratios and thickness levels. Material selection was guided by the possibility of using these kinds of materials in packaging and construction applications. The motivation for this study was the fact that in water-based manufacturing a lot of energy is consumed during the drying phase; therefore, the better understanding of drying kinetics is essential for improving the environmental friendliness and cost efficiency of material production. The results revealed differences in the results of drying methods and limitations for thick, porous wood fibre-based materials. The differences in these methods affected the drying rates and material quality, which both can arise as the limiting factor for material production. The highest drying rate was obs...

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Temperature Measurements and Simulations Inside a Paper in a Fuser Nip

In this paper temperature measurements and simulations were carried out to understand the mechani... more In this paper temperature measurements and simulations were carried out to understand the mechanisms of copying curl. Normal copy papers were studied, but special handsheets with built-in thermocouples were also used. A drying simulation program was used to show the temperature and moisture profiles inside paper in thickness direction. Results show, that during the nip the moisture moves towards the press roller side and then more moisture evaporates from the side which was in contact with the press roller, as it became more wet during the nip. At high speed, there is not enough time for even moisture distribution inside the paper sheet, as it happens at low speed. Curl phenomena in this case can be explained by difference in temperature and evaporation rate on two sides of paper sheet.

Some Insight on Paper Structure and Properties With Different Drying Conditions

Appita Journal: Journal of the …

Informit is an online service offering a wide range of database and full content publication prod... more

Anyone can simulate? The Q9 operations model to guide execution of simulation projects

VTT Tiedotteita - Research Notes 2537 In 2005, Tekes launched MASI, a five-year programme on mode... more VTT Tiedotteita - Research Notes 2537 In 2005, Tekes launched MASI, a five-year programme on modelling and simulation to develop the knowledge, methods and use of modelling and simulation in the Finnish industry and service sector. There are still relatively few simulation service providers on the market, and the benefits of applying modelling and simulation from the business point of view are not yet known. Due to this dilemma, we would like to start by discussing the role of simulation in the competitiveness of Finnish industry. What is the value of modelling and simulation competence? Are we on the right track if simulation methods developed in academia never enter the market or if simulation companies can only survive with public support? This report summarises the results of the SISU project, which was part of the MASI programme. The main goals of the project were to develop simulation methods suitable for small and medium-sized enterprises (SMEs); to make an implementation pla...

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Dewatering and structural analysis of foam-formed, lightweight fibrous materials

BioResources

This work studied the effect of the dewatering conditions on the behavior of fiber foams during d... more This work studied the effect of the dewatering conditions on the behavior of fiber foams during dewatering and on the final structure of the formed, thick, lightweight lignocellulosic materials. The vacuum level, fiber type, consistency, and basis weight of the fiber foam were all varied. During dewatering, the time evolution of the thickness of the fiber foam in the mold was studied, and the dryness of the fiber foam immediately after dewatering was measured. The density and pore size profiles of the final dry materials was measured using X-ray microtomography (µCT).

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Potential of Commercial Wood-Based Materials as PCB Substrate

Materials

In our research on sustainable solutions for printed electronics, we are moving towards renewable... more In our research on sustainable solutions for printed electronics, we are moving towards renewable materials in applications, which can be very challenging from the performance perspective, such as printed circuit boards (PCB). In this article, we examine the potential suitability of wood-based materials, such as cardboard and veneer, as substrate materials for biodegradable solutions instead of the commonly used glass-fiber reinforced epoxy. Our substrate materials were coated with fire retardant materials for improved fire resistance and screen printed with conductive silver ink. The print quality, electrical conductivity, fire performance and biodegradation were evaluated. It was concluded that if the PCB application allows manufacturing using screen printing instead of an etching process, there is the potential for these materials to act as substrates in, e.g., environmental analytics applications.

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Classification of used wood to biomass fuel or solid recycled fuel and cascading use in Finland

VTT has studied cascading use and energy use of used wood. The direct use of wood for energy is r... more VTT has studied cascading use and energy use of used wood. The direct use of wood for energy is relatively much lower, and the use of wood for pulp industry much higher in Finland than in the EU. As Finland ex- ports a significant part of its wood biomass (as pulp, paper and board, timber and plywood), the cascading cycles of wood products take place outside the Finnish borders, e.g. in other EU Member State. This limits the cascading cy- cles inside Finland. Guidelines has developed for the classification used wood (post-consumer wood) for energy use including implementation of the legislation and standards in Finland. It is necessary to define the impact of possible contaminants on the energy utilisation of used wood. This is helpful for categorisation, as well as for identification and characterisation of the contaminants. The guidelines also include an overall categorisation used wood. In this classification used wood is divided in 4 categories A, B, C and D. Categories A and B ...

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Esiselvitys: Pienoistehdas painetun älyn alustan valmistamiseen hiilidioksidi-kalsiumhydroksidi-mikrokuitukomposiittina

Stress oscillation in drying

Cascading use of wood in Finland: with comparison to selected EU countries

Cascading use of woody biomass is getting increasing attention in current European discussions to... more Cascading use of woody biomass is getting increasing attention in current European discussions to ensure the sustainable and resource-efficient use of wood in future bioeconomy. So far however, there is no exact agreement on what is meant by "cascading". This report shortly summarizes several definitions on cascading use of biomass and discusses their differences. In addition, the wood flows in Finland on the year 2013 are presented, as well as examples of wood flows in selected other EU countries. Based on the comparison, the differences between the countries are discussed. Finland exports most of the products processed from woody biomass. Thus, the cascading cycles often take place outside Finland. Therefore the role of a wood producing country (e.g. Finland), supplying virgin fibre, differs significantly from the consumer countries (e.g. Germany and Holland) with more recycling, which creates challenges for creation of common cascading concept. Cascading should be considered from the perspective of the whole wood using cycle, recognising the regional differences in wood flows, when discussing about the cascading principles. Furthermore, the overall efficiency of recycling needs to be taken into account. Confidentiality

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Analysis of the cylinder dryer with improved heat transfer rate

ABSTRACT In this paper, we analyse the improvements in heat transfer in drying cylinders designed... more ABSTRACT In this paper, we analyse the improvements in heat transfer in drying cylinders designed as multi-port cylinders with a considerably thinner cylinder shell. The basic motivation to study possibilities to increase rate of heat transfer is the decreased rate of heat transfer in multi-cylinder dryers, which are seen in modern, fast production machines. At a high rotational speed, a condensate layer on the inner cylinder surface is formed, which dramatically decreases the heat transfer rate from steam to the cylinder shell. Dryer shell made of cast iron with typical thickness of 30-45 mm is another barrier to heat transfer. Furthermore, considerable resistance to heat flow occurs at the contact interface between the cylinder and the paper surface. According to simulated results, it is possible to improve the heat transfer rate from steam to paper in average by 25% either by decreasing thickness of the cylinder shell from 35 mm to 10 mm or by increasing the condensate heat transfer coefficient from 2000 to 15000 W/m2oK. Combining both improvements increases the heat transfer rate by 50 %.

Simulated combined air-cylinder drying process

Effect of drying and fibre chemical composition on the creep strain of paper

Nous avons analyse l'effet de la methode de sechage sur le fluage de formettes de trois pâtes... more Nous avons analyse l'effet de la methode de sechage sur le fluage de formettes de trois pâtes differentes sechees pour l'essai. La methode de sechage simulait le sechage sur cylindres et le sechage sur plateau de contact. Des formettes standard ont aussi ete fabriquees. Nous avons trouve que la combinaison methode de sechage et pâte determinait le comportement de fluage. Aucune des methodes de sechage envisagees n'a presente la plus petite contrainte de fluage pour toutes les pâtes soumises a l'essai et tous les temps d'essai. Il a ete aussi impossible de classer les pâtes en fonction du fluage, peu importe la methode de sechage. Toutefois, pour toutes les methodes de sechage utilisees pour l'essai, la pâte a haut rendement a teneur en lignine offrait toujours la plus petite contrainte de fluage pendant que l'effet de l'hemicellulose etait associe a la methode de sechage.

Moisture and temperature measurement of paper in the thickness direction

In this work the z-directional moisture and temperature profile of fine paper was studied during ... more In this work the z-directional moisture and temperature profile of fine paper was studied during drying. The goal of this research was to determine moisture gradients in thickness direction during drying. This information is needed to improve existing drying models as well as to help deepen the understanding of the drying phenomena and its effects on paper structure. The gradient information can be directly used in the drying models and will assist in making more accurate estimations of the capacity and quality effects of drying on paper. For this study a new method for measuring the z-directional moisture profile of paper was developed. The results show that during paper drying there exist significant gradients in z-directional moisture with profiles showing differences in moisture content of up to 25-35% across the thickness of the sheet, depending on the drying conditions. Similar magnitude moisture content differentials are observed in both measurements and numerical simulations.

Cascading Use and Classification of Used Wood for Energy in Finland