The research in Plant Design focuses on process development, design, simulation, integration and optimization, as well as process safety, inherent safety, occupational health and sustainability. The key theme is the development of systematic methodologies that enable chemical engineers to identify optimal, sustainable and creative strategies that lead to process enhancement, safety and energy efficiency. Fundamental chemical engineering principles are coupled with systems engineering approaches to develop methods and computer-aided tools that are generally applicable to variety of existing and new processing facilities such in chemical, petroleum and biorefining industries.


On going projects:


Optimization of biorefining routes

Biofuels from biomass have raised much interest because of their potential to replace especially fossil liquid fuels. The process route optimisation is however a complex task because of many types of biomaterials available as feedstocks and the several process options existing for refining these materials. Typical processed involved are fractionation processes (such as cellulose or hemicellulose separation from biomass) and chemical or biochemical conversion processes (e.g. conversion of carbohydrates to ethanol).

The decisions made in biorefinery route selection are: 1) which raw materials to use, 2) how to fractionate the raw material in an optimal way, 3) how to process these fractions further by chemical and biochemical processes, and finally 4) how to integrate the production into existing production processes and sites. The preliminary selection of routes has many criteria but in general the sustainable utilization of biomass should find routes that retain the maximum amount of material and energy content of feedstocks in the products. A tool for making process efficiency and feasibility evaluations is therefore needed to aid in this work.

The efficiency of processes can be evaluated from several points of view. In preliminary design simplified criteria are often used such as: 1) material efficiency (how much of the weight of the raw material is converted into products, 2) raw material energy conversion efficiency (how the energy content of feedstocks and products compare) and 3) economic potential (what is the cost difference of raw materials and products when the yield is taken into account).

From product point of view also the product quality as fuel and the suitability for existing users and distribution systems is essential. From environmental point of view the efficiency of the fuel for CO2 emission reduction is essential. This is determined on lifecycle basis by considering the whole production and logistics chain of the product.

As a first criterion it would be attractive to find routes that retain the maximum amount of material and energy content of feedstocks in the products. This is important especially in fuel production. Therefore lignocellulosic biomass refining routes to various products were first studied from material & energy efficiency point of views. Second evaluation criterion is economy. We have made the cost studies for most conventional biorefining routes  in the last years.

The sustainability point of view has a major effect on the process sustainability. Here sustainability is defined as the amount of resources used. The value of sustainability can therefore be expressed as the amount of the limiting unit; i.e. the renewable energy needed for creating the resources needed for the production. Several biofuel production routes were evaluated from this point of view too.

Researchers: Kristian Melin, Sha Sha


Chemical process safety enhancement by exploiting accident knowledge


In last decades, considerable recourses have been used for creating accident reporting system in the chemical process industry (CPI). The aim has been to collect accident information that provide a better understanding on the causes of accidents and to create lesson learnt as well as recommendations for accident prevention. However, major accidents still occur in the CPI. Obviously, there has been something missing or left unrecognized in spite of the safety promotion efforts. It seem to point out that the current practice in loss prevention i.e. mainly human-organizational oriented, are still insufficient and its implementation is ineffective to prevent accidents.

As the number of accidents in the CPI is not decreasing, the aim of this project is to understand the technical and design reasons of accidents. Several earlier studies show that the contribution of technical and design to accidents is significant. However, due to lack of studies, little is known about them. In this project the accident cases are explore to identify the equipment types frequently involved in accidents and the technical reasons of accidents. The typical design errors made and their timing during design were identified.

Focus is given to disseminate the accident knowledge in to design system by promoting accident prevention through design changes and utilization of the inner layers of layer of protection. Process safety considerations in plant design are enhanced by developing a design oriented safety method that can be applied throughout process lifecycle. This method will contribute to a safer chemical plant design by early detection and elimination of errors during design project. This would help in detecting the root causes of accidents at their source and not only try to manage the risks by safety management systems afterwards.

Based on the accident information gathered in this study, accident contributor rankings and a accident contributor identification method for design were proposed. The new safety method was tested with the Bhopal accident case study. It could identify 85% of the accident contributors and design & operation errors involved. 

Co-operation project with Universiti Teknologi Malaysia

Researcher: Kamarizan Kidam



Chemicals from black liquor

 Depleting resources have shifted the focus onto biofuels. Pulp and Paper industries are considered as a potential source for the production of biofuels.  Black liquor obtained during pulping contains more than 50% of organic matter present in the wood used for pulping. The rich organic content of black liquor makes it an attractive option for the production of bio-based fuels. The purpose of this research is to study the possible ways of converting black liquor into fuel products.  

The thesis explores a number of options available in the literature to accomplish the goals of producing fuels. Experimental work is conducted on enhancing the concentration of dissolved solids and finally decomposing them under varied conditions. The experimental results have been supported by Aspen simulation results. The major products formed after thermal decomposition experiment was analyzed to be methane and synthesis gas. The experimental work has been further used to predict an industrial design for thermal decomposition of wheat straw black liquor. A feasibility study for the predicted industrial process is studied to estimate the production cost and understand the profitability of the process on an industrial scale foe various products such as synthetic natural.

Searchers: Raja Hassan, Kristian Melin



Abatement of greenhouse gas emissions

The world’s population growth and the improvement in standards of living inevitably increase consumption and natural resource stock use. One of the greatest challenges for sustainable development is to change the existing production and consumption patterns. Today’s “business as usual (BAU)” scenario would drive the global economy in an unsustainable, conflict prone situation where the demand on energy, pure drinking water and food for the growing population would surpass the worldwide supply of these commodities.

Sustainable use of all natural resources, reduction of the emissions of greenhouse gases (GHG) and protection of human habitat from severe pollution are all issues that can, at least partially, be solved with technological innovations and accompanying economic resources, provided, that global policy incentives in form of international and national agreements are in place. In future, a paradigm change from fossil fuel resource base towards a more green economy would be a long term solution.

General computational equilibrium (GCE) models are widely used to predict the economic, social and climatic impacts of increasing amount of anthropogenic greenhouse emissions. These models usually treat the manufacturing sector as a whole or are based on estimates showing a wide range of deviations. Linking process/product based chemical engineering analyzing tools and models with the economic GCE models would improve the understanding of the dynamics of industrial greenhouse gas emissions, and therefore would help to identify abatement possibilities for different manufacturing sectors.


The objective of this study is to generate new chemical engineering analyzing tools and models to identify and to quantify detailed GHG abatement options for processes and products in manufacturing sectors. The magnitude of greenhouse gas emissions and their abatement cost thus derived could be then linked to the existing economic GCE models on climate change. The analyzing tools and models are based on actual physical emissions of greenhouse gases expressed in CO2 equivalents. The key issues include enhanced resource efficiency, reduction of greenhouse gas emissions both from the process side and from the energy use in industrial sectors. Fuel switching from coal and heavy fuel oil to natural gas or to recycled/renewable fuels or raw materials is among the options considered.

 Results of study

 The research produces analyzing tools and models to identify and to quantify detailed GHG abatement options for processes and products in manufacturing sectors. The initially screened sectors include iron & steel; aluminium & non-ferrous metals; machinery; pulp & paper & printing; food & tobacco; chemicals & petrochemicals; cement; and other industry. In addition, new analytical data is produced on actual GHG abatement costs for different sectors using a uniform capital recovery factor. The results of this study will contribute to integrating the environmental dimension of industrial GHG emissions into the economic dimension of climate change impacts and to improve the methodological framework for modeling industrial carbon contribution.

Researcher: raili.kajaste [at] aalto [dot] fi


Wet air oxidation processes

Wet Air Oxidation (WAO) is a well established technology and has been primarily applied for the treatment of e.g. industrial waste with high content of organic matter. The process oxidizes the organic or inorganic matter present in the waste stream in a liquid phase at high temperatures and high pressure.

WAO is an aqueous process in which soluble and suspended organic matter constituents are oxidized by dissolved oxygen. The reaction takes place in liquid phase where water plays an important role. Water not only provides a medium for dissolved oxygen to react with organics, but can also react in part with organics. The reaction is exothermic; hence water also acts as a moderant by providing a medium for heat transfer and excess heat removal. The oxidization is theorized to be a free radical reaction and can be catalyzed using homogeneous or heterogeneous catalysts. The WAO process is carried out in the liquid phase at elevated temperatures (150-3500C) and pressure (0.5-20MPa) using oxygen or oxygen enriched air.

Enhanced solubility of oxygen in the aqueous phase drives the reaction to completion. This state of enhanced solubility is achieved by maintaining the liquid phase at elevated temperatures and pressures. Reaction takes place in the aqueous phase; therefore elevated pressures are applied. The greater the temperature, greater is the extent of oxidation attained, converting the pollutants to low molecular weight oxygenated compounds. The degree of oxidation is predominantly controlled by temperature, partial pressure of oxygen, residence time in the reactor and the oxidizability of the material under consideration.

Reseacher: Raja Hassan, Kristian Melin



Sustainable economy in process industry - the renewable energy footprint


Requirements for renewable energy utilization will change the energy intensive industry. The future prospect is a sustainable economy. The implementation of the sustainable economy requires however large changes in raw materials and industry, especially the industry producing energy intensive products such as fuels, plastics and chemicals. Making the renewable based evaluations requires applicable energy focused environmental accounting methods.

A potential accounting methodology available is based on the embedded energy evaluation (i.e. the renewable energy footprint). The method measures all resources (e.g. raw materials, energy, services and investments) by a single unit; solar energy. This allows evaluation and optimization of different manufacturing routes to be made on a single basis, which reflects the renewable energy and raw material usage.


This study aims to utilize an energy focused environmental accounting method for evaluating fully sustainable manufacturing processes. The method is based on the embodied energy (emergy) principle, which expresses all resources on a single basis; solar energy. The method makes it possible to evaluate energy and manufacturing processes on sustainability and CO2 reduction basis. In this research existing energy, basic raw materials and fuels manufacturing industry is restructurized to minimize the energy & raw material demand. These represent fully renewable manufacturing concepts for the basic raw materials such as heat & power, steel, transportation fuels and plastics in future. The result also represents a minimum of renewable raw material usage. Even a fully sustainable economy represents a futuristic view; it serves as a goal to which the current industrial economy can be compared in reducing CO2 emissions the emissions at the moment.

 Results of study

The research allows energy intensive processes to be optimized based on renewable energy & raw material demands. The method allows also the structurization of manufacturing chains. In this work optimal renewable energy based manufacturing routes are searched for liquid biofuels and chemicals. First the embedded energy in electricity and steam produced in biomass fired CHP power plants and in biofuel production (ethanol and FT liquids from biomass) l manufacturing were evaluated.

Researcher:  Sha Sha


Entrepreneurship in chemical technology

The aim of research is to study entrepreneurship in chemical technology. This means the introduction of new ideas and businesses into action. First was studied how the education of chemical technology is, or should be, changing with the changing world:

The traditional chemical engineering paradigms have been the unit operations approach and later transport phenomena. Most of the education of chemical engineering has been based on these two basic approaches. The question raised is what is the next paradigm and further, how it should be taken into account in the education on chemical engineering? There have been several proposals for the next paradigm, such as process systems engineering, integrated multidisciplinary and multi-scale process engineering, chemical product design and sustainable chemical engineering.

As the World, with new global connections and dependencies, is changing, the industry is evolving and perceptions of these changing, the knowledge and information needed in succeeding should meet new ways of segmenting education. The skills sought after can be identified as basic engineering skills, ability to life-long learning and skills to adapt and create.

Our claim is that not only the industry is differentiated but also the education should  differentiate to comply with the changes of industry and society taking place. For example, the chemical engineering curriculum should be different in industrializing countries than in the traditional industrial countries, since also the industries and work tasks are different. The chemical engineer curriculum in Europe should be focusing on science skills, new product development and creativity whereas Asian chemical engineering education should focus to high-quality engineering and design. 

Researchers: Victor Heinänen, Timo Seuranen


Inherent Occupational Health

Occupational health is concerned with the two-way relationship between work and health. Health differs from safety in terms of the probability for the event to occur and the time for the effect to appear. The impact of occupational health on industries is significant since each year, more people die from diseases caused by work than are killed in industrial accidents.

Various methods and tools are developed for assessing health hazards in workplaces. However, they are applicable only to existing and operating plants. The concept of inherent safety professes that hazards, which might arise in the possible routes to a product, should be identified early; that is when the plant is still ‘on paper’. The fundamental decisions made in the conceptual design stage have major effects on the process safety, health, and environmental (SHE) performance. The choice of route fixes the chemicals present in the plant, and hence the actual and potential exposure of the workers. As the project proceeds through the life cycle stages, the opportunities for and the cost of implementing inherently healthier design features are progressively worsening.

Inherent occupational health assessment is an approach to reduce hazards by choosing healthier chemicals and process concepts. I.e. inherent occupational health relies on the healthier and safer properties of chemical substances, process conditions, operations, and work procedures in a process. This research presents new systematic approaches for evaluating inherent occupational health of chemical processes in process development and design.

In the R&D stage, the Inherent Occupational Health Index (IOHI) is proposed based on healthier and safer reaction chemistries, properties of compounds present, and process conditions such as pressure, volatility, exposure limits, and temperature etc.

In the preliminary design stage, chronic health risk is calculated due to exposure to fugitive airborne emissions based on flow sheet data and precalculated process modules’ emission, estimated process plot areas, and wind velocities. Health Quotient Index (HQI) is used as a health indicator to compare estimated chemical concentrations to their exposure limits. 

In the basic engineering stage, the Occupational Health Index (OHI) utilizes detailed fugitive emission calculations based on piping and instrumentation diagrams. The method evaluates quantitatively chronic inhalation risks to noncarcinogens and carcinogens, acute inhalation risk, and qualitatively dermal/eye risk.

For fugitive exposure estimation new methods were developed. Three approaches for estimating chemical concentration due to fugitive emissions are proposed based on simple PFD, detailed PFD, and PID, which were tested on the actual Borealis Polymers plant in Porvoo. A more realistic approach was developed for estimating health risks of fugitive occupational exposure by using statistical meteorological data.

Finally the integration of the inherent occupational assessment methods with the existing computer aided design tools was studied. Also the correlation between index-based SHE assessment techniques was analyzed to find out, if any interdependency exists between SHE characteristics at the inherent level.

The research is continuing with evaluation of VOC emissions from utility systems.

Co-operation project with Universiti Teknologi Malaysia

Reseacher: Dr. Mimi Hassim (Universiti Teknologi Malaysia)

Mimi Haryani Hassim, Inherent Occupational Health Assessment in Chemical Process Development and Design, Plant Design Report Series, No. 96, 2010.


Ended projects


Concepts for second generation biorefinery

This was Academy of Finland and UPM Kymmene financed  project with research groups of Chemical Engineering, Clean Technology, and Plant Design. The objective of this project was to create new generation lignocellulosic bio-refinery process concepts connected to an industrial e.g. pulp plant site. The development is done by using latest methods of process modeling, process development and wood chemistry.

The project emphasizes the concept of sustainability in the development of bio-refinery technology by aiming at efficiency in material, energy and environmental aspects. First level balance models are developed for subprocesses to screen raw material / process concepts. These models are used for optimizing the process alternatives for input (biomass), and outputs streams (e.g. fuels, heat, power and chemicals) and for creating new innovative process concepts. Optimization is done under varying technical and environmental boundary conditions.

Phenomena-based models will be developed to study selected subprocesses in more detail. These models and experiments will be utilized for enhancing and intensifying the selected process steps and concepts.

Emphasis is given on the following process routes integrated to existing pulping plants:  biomass hydrolysis and prehydrolysis processes, carbohydrate utilization and fractionation by chromatography, ethanol production, micro-, nanocellulose and special pulp products, possibilities to use non-wood raw materials such as annual plants.

Feasibilities and material and energy efficiencies for new routes of biorefining are being calculated and compared with existing routes such as the Fischer-Tropsch route.

Several dissertations, licentiate and master theses were produced.

Contact: Markku Hurme


Microsphere Manufacturing Process Development

The research aimed to the development of microsphere manufacturing process based on emulsification techniques. The important characteristic of particles is the shape and particle size distribution. The aim was to develop a novel hydrocarbon-in-fluorocarbon emulsion solvent extraction based microsphere preparation process. In the first step of the process an emulsion was produced. The dispersed phase of the emulsion contained the matrix material of the microspheres. In the second step of the process, the hydrocarbon from the dispersed phase was extracted into the continuous phase by mixing the emulsion with the excess of the perfluorocarbon. Two different solidification strategies were used: I) the emulsion formed in a vessel was transferred into another vessel containing an excess of the perfluorocarbon, and II) the excess of the perfluorocarbon was added to the emulsion. The critical emulsification and solidification parameters affecting the size, the size distribution, and the morphology of the microspheres were investigated.

A good agreement between the size of the microspheres and the Weber number (emulsification step) was found. With the preparation method I, the mixing conditions in the solidification step also affected the size of the microspheres, partly because the stability of the hydrocarbon-in-perfluorocarbon emulsion was poor.

The size of the microspheres was affected not only by the surfactant concentration but also by the volume ratio of the dispersed phase to the continuous phase. At a low volume ratio of the phases, the surfactant concentration was the dominating factor, whereas the volume ratio of the phases was the dominating factor at a high volume ratio.

The viscosity of the phases affected the size of the microspheres. The viscosity of the dispersed phase decreased with a decreasing matrix material concentration and as a result, the size of the microspheres decreased. The size of the microspheres decreased as the continuous phase viscosity increased.

The morphology of the microspheres could be controlled by changing the solidification rate. The solidification rate was adjusted by changing the temperature of the perfluorocarbon used in the solidification step and the hydrocarbon concentration of the perfluorocarbon used in the solidification step. The compactness of the microspheres increased with a decreasing solidification rate.

Reseacher: harri.heiskanen [at] aalto [dot] fi



Industrial scale chromatographic separation of compounds from biomass hydrolysates

Carbohydrates are composed of a number of various monosaccharides, glucose being the most abundant. Some of the monosaccharides are valuable compounds used in the food and pharmaceutical industries. They can be separated from biomass hydrolysates e.g. by chromatographic methods.

In this thesis, chromatographic separation of valuable compounds using ion exchange resins was studied on an industrial scale. A novel chromatographic separation process was developed for fucose, starting from pre-processed spent sulfite liquor. Chromatographic separation of galactose was tested with three biomass hydrolysates; lactose, gum arabic and hemicellulose hydrolysates. A recovery process for arabinose from citrus pectin liquid residual and for mannose from wood pulp hydrolysate were also developed and experimentally verified.

In addition to monosaccharides, chromatographic separation of glycinebetaine from vinasse was examined with a hydrogen form weak acid cation exchange resin. The separation involves untypical peak formation depending, for example, on the pH and the cation composition. The retention mechanism was studied in more detail using closely related molecules under different separation conditions. The mechanism was found to be hydrogen bonding between glycinebetaine and the resin. 

In the experimental work of this thesis, all four resin types – strong acid cation, strong base anion, weak acid cation and weak base anion exchange resins – were used. In addition, adsorption equilibrium data of six monosaccharides and sucrose were measured with the resins in sodium and sulfate forms under industrial conditions because such data have been lacking.

A systematic method for conceptual process design and sequencing of chromatographic separation steps was developed. Heuristics were drawn from the current industrial practices also for the selection of a suitable ion exchange resin for the separation of a sugar from a biomass hydrolysate.

Researcher: Pia Saari




Production processes for recombinant proteins and monoclonal antibodies; techno-economical evaluation  

Recombinant proteins and antibodies for therapeutic or diagnostic use can be produced in many host organisms (microbial, insect and mammalian cells), in different bioreactors (stirred-tank bioreactor, hollow fiber bioreactor and disposable bag bioreactors) and using various feeding strategies (batch, fed-batch or perfusion). The manufacturing cost (€/g) of the product depends on the characteristics of the production host (growth rate, productivity) and on the production method (cell density in the bioreactor phase and the overall yield). Most critical variables are the fermentation titer (g/l) and the total yield (%).

The manufacturing costs of production of recombinant proteins and monoclonal antibodies were analyzed for two applications. In the recombinant protein application the focus was on the effect of production host and in the monoclonal antibody application in different bioreactor setups. The E. coli was found to be the lowest cost system in HIV-1 Nef-protein production. In Mab production, the hollow fiber bioreactor was found to have slightly lower manufacturing costs than the perfusion stirred-tank bioreactor. Also a crystallization method for recombinant HIV-1 Nef protein was developed.

Licentiate thesis:

Raisa Vermasvuori:  Production of Recombinant Proteins and Monoclonal Antibodies –

Techno-Economical Evaluation of the Production Methods, 2009



Decision making and case-based reasoning in design

Conceptual process design phase is of prime importance to the performance and the profitability of  processes. It is also a highly complex task with a large number of process alternatives and a large variety of requirement specifications. Therefore, it is essential to continuously improve design methods. The research should not only be focused on modeling unit operations  but also to develop a framework to support design tasks during the lifecycle of the chemical process.

The research presents new methods and application examples to answer the challenges. Case-based reasoning (CBR) provides a method for fast process and equipment design by utilizing earlier knowledge systematically. In new designs feedback from earlier experiences is taken into account, and a creative aspect can be included by the use of analogies. The thesis presents new method for CBR-based separation process synthesis by selection of single separations, selection of separation sequences and selection of combined (hybrid) separations. Selection of single separation also includes selection of azeotropic separations. Also a CBR-based method for combinatorial mixer equipment design from parts. The applicability of CBR in separation process selection and design was studied by building few prototype CBR systems. Object database techniques in chemical process engineering have been illustrated by building applications for an inherently safer process design and for a heat exchanger selection.

The research also presents new methods and approaches to respond to the new challenges in process development and design, which attempt to amalgamate process design with design process management and the important extension of process integration towards the consideration of process sustainability; extending the horizon to process life-cycle and offering a systematic aid to decision making at the conceptual design stage aiming at multicriteria optimality. The methods presented include: 1) Extended problem solving based method for process design, 2) analytic hierarchy process based multicriteria decision making approach for process concept evaluations, 3) genetic algorithm based process synthesis method using multicriteria approach under uncertainty, 4) evaluative approach to process development, 5) enhanced modeling approach for different life-cycle phases and model library, 6) approach for multicriteria based assessment with life-cycle perspective and 7) decision based project management tool for product and process development projects.  The combined approach presented includes these methods together with scope of evaluation definition, life-cycle indicators and a tool pack of general methods.

A web-service based approach in conceptual process design, parameterized constructors, which are able to construct process and initial data for control system configuration is also introduced in the thesis. The preliminary process design task can be first defined in a more general level and as the design process proceeds; more accurate models (e.g. PI and control system diagrams, simulation models) are composed and used.

Researchers: Timo Seuranen, Elina Pajula, Krisztina Cziner


Seuranen, Timo, Studies on Computer-Aided Conceptual Process Design. Chemical Technology. August 2006.

Pajula Elina, Studies on Computer Aided Process And Equipment Design In Process Industry, 2006

Cziner, Krisztina, Multicriteria Process Development and Design, Plant Design Report series No. 93, 2006, HUT.



Process Integration Efficiency

Various types of models and methods are used to design and analyze industrial processes. Mostly their use deals with partial system efficiencies like utility system efficiency. A model for treating the entire system has been missing. An integrated industrial process consists of interconnected production processes of the process industry (e.g. pulp and paper, metallurgical, chemical and energy production industries).
The project study the conceptual approach to the evaluation of integrated industrial processes. According to research results, efficiency can be categorized into material efficiency, energy efficiency and operational efficiency. These dimensions are described using criteria and case-specific indicators. The criteria and indicators sometimes represent certain perspectives of design, such as economy or environment.
The concept of efficiency can be attached to systems of varying physical scales. In its narrowest context the scale covers equipment and unit processes. In its largest context the scale covers complete production sites. The scale determines which criteria and indicators are emphasized in the evaluation: technical ones are emphasized on the equipment and unit process scale and strategic ones are emphasized on the site scale.
An important part of the proposed concept is the way in which the potential for improvement is dealt with. The potential for improvement is dependent on the life span phase of the mill, the physical scale of the problem and the number of priority criteria (potential in respect of one criterion versus potential in respect of several simultaneous criteria). The potentials are categorized into three groups: 1) structural (theoretical) potentials, 2) technical potentials and 3) economic potentials. The research also indicates that efficiency improvement activities have to be done in close cooperation with company's operational management. The connection is required to prioritize actions and to implement corrective actions.
The developed concept is qualitative and it is applied on case-by-case basis. The concept does not contain a quantitative analysis; it is used to formulate the problem and to select the correct and detailed tools for the work. The results of evaluation can be utilized e.g. to compare unit processes and process concepts against each other.

Mari Tuomaala, Conceptual Approach to Process Integration Efficiency, TKK Dissertations 73, 2007, HUT.

Krisztina Cziner, Multicriteria Process Development and Design, Plant Design Report series No. 93, 2006, HUT.


Nanoparticle processing

The aim of this research was to explore possible methods for the production of silica (silicon dioxide, SiO2) nanoparticles. In the literature review part, the polymerization behavior of silica and state-of-the art ion exchange methods for silica nanoparticle production are described. Further, silica nanoparticle aggregation, disaggregation, and production of precipitated and fumed silicas are briefly covered. Judging from the literature survey, ion exchange methods that are currently being used seem unpractical for producing large quantities of silica nanoparticles, and therefore the development of a novel process is required.

In the experiments, three different methods, namely acid neutralization, precipitation, and coagulant processes were tested experimentally. All these methods are based on neutralization of water glass (sodium silicate) with acid. It was found that the Acid Neutralization method, which is characterized by low silica concentration, could only produce small particles in the range of 10 nm in dilute suspensions. Further, the stability of the products was poor. Using the precipitation technique, primary particle sizes of 10-50 nm could be achieved. Silica concentration was the parameter that had the greatest influence on primary particle size. These particles, however, formed always aggregates with sizes up to the millimeter scale. It was not possible to disperse these aggregates using existing equipment. Using the coagulant method, discrete particles up to 100 nm could be produced, but the large amount of coagulant needed in the process proved to be a severe problem. Of these three processes, the precipitation process was chosen as the basis for pilot and industrial process design in the process design part of the thesis. Based on the experiments, a pilot process was designed. The aim was to design a process that can be built using already available equipment. The process consists mainly of a batch stirred tank reactor, where the precipitation reaction is performed, and a possibly a bead mill for dispersion of the aggregates. The capital investment cost of the pilot process and the production cost in the industrial process were estimated.

Researcher: Younghun Kim



Nomadic Use of a Plant Model

Nose project studies methods and tools for ubiquitous plant model usage. Location aware services, augmented and virtual reality techniques are studied in process industry surroundings in order to provide plant model services to a mobile device. The main result of the project will be an open framework specification and implementation for a nomadic plant model usage. The framework is tested by building pilot cases to the environment. This way the pilots will be tested in actual industrial surroundings. Test cases are selected by participating companies. Company headed development projects are started during and after the Nose project in order to package the technology into company specific products. The project is coordinated by VTT and financed by Tekes, VTT and companies.

Researcher: Timo Seuranen

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