Production of Mg(OH)2 from Mg-silicate rock for CO2 mineral sequestration

Sequestration of carbon dioxide in mineral rocks, also known as CO2 Capture and Mineralization (CCM), is considered to have a huge potential in stabilizing anthropogenic CO2 emissions. One of the CCM routes is the ex situ indirect gas/sold carbonation of reactive materials, such as Mg(OH)2, produced from abundantly available Mg-silicate rocks. The gas/solid carbonation method is intensively researched at Åbo Akademi University (ÅAU ), Finland because it is energetically attractive and utilizes the exothermic chemistry of Mg(OH)2 carbonation. In this thesis, a method for producing Mg(OH)2 from Mg-silicate rocks for CCM was investigated, and the process efficiency, energy and environmental impact assessed. The Mg(OH)2 process studied here was first proposed in 2008 in a Master’s Thesis by the author. At that time the process was applied to only one Mg-silicate rock (Finnish serpentinite from the Hitura nickel mine site of Finn Nickel) and the optimum process conversions, energy and environmental performance were not known. Producing Mg(OH)2 from Mg-silicate rocks involves a two-staged process of Mg extraction and Mg(OH)2 precipitation. The first stage extracts Mg and other cations by reacting pulverized serpentinite or olivine rocks with ammonium sulfate (AS) salt at 400 - 550 oC (preferably < 450 oC). In the second stage, ammonia solution reacts with the cations (extracted from the first stage after they are leached in water) to form mainly FeOOH, high purity Mg(OH)2 and aqueous (dissolved) AS. The Mg(OH)2 process described here is closed loop in nature; gaseous ammonia and water vapour are produced from the extraction stage, recovered and used as reagent for the precipitation stage. The AS reagent is thereafter recovered after the precipitation stage. The Mg extraction stage, being the conversion-determining and the most energy-intensive step of the entire CCM process chain, received a prominent attention in this study. The extraction behavior and reactivity of different rocks types (serpentinite and olivine rocks) from different locations worldwide (Australia, Finland, Lithuania, Norway and Portugal) was tested. Also, parametric evaluation was carried out to determine the optimal reaction temperature, time and chemical reagent (AS). Effects of reactor types and configuration, mixing and scale-up possibilities were also studied. The Mg(OH)2 produced can be used to convert CO2 to thermodynamically stable and environmentally benign magnesium carbonate. Therefore, the process energy and life cycle environmental performance of the ÅAU CCM technique that first produces Mg(OH)2 and the carbonates in a pressurized fluidized bed (FB) were assessed. The life cycle energy and environmental assessment approach applied in this thesis is motivated by the fact that the CCM technology should in itself offer a solution to what is both an energy and environmental problem. Results obtained in this study show that different Mg-silicate rocks react differently; olivine rocks being far less reactive than serpentinite rocks. In summary, the reactivity of Mg-silicate rocks is a function of both the chemical and physical properties of rocks. Reaction temperature and time remain important parameters to consider in process design and operation. Heat transfer properties of the reactor determine the temperature at which maximum Mg extraction is obtained. Also, an increase in reaction temperature leads to an increase in the extent of extraction, reaching a maximum yield at different temperatures depending on the reaction time. Process energy requirement for producing Mg(OH)2 from a hypothetical case of an iron-free serpentine rock is 3.62 GJ/t-CO2. This value can increase by 16 - 68% depending on the type of iron compound (FeO, Fe2O3 or Fe3O4) in the mineral. This suggests that the benefit from the potential use of FeOOH as an iron ore feedstock in iron and steelmaking should be determined by considering the energy, cost and emissions associated with the FeOOH by-product. AS recovery through crystallization is the second most energy intensive unit operation after the extraction reaction. However, the choice of mechanical vapor recompression (MVR) over the “simple evaporation” crystallization method has a potential energy savings of 15.2 GJ/t-CO2 (84 % savings). Integrating the Mg(OH)2 production method and the gas/solid carbonation process could provide up to an 25% energy offset to the CCM process energy requirements. Life cycle inventory assessment (LCIA) results show that for every ton of CO2 mineralized, the ÅAU CCM process avoids 430 - 480 kg CO2. The Mg(OH)2 process studied in this thesis has many promising features. Even at the current high energy and environmental burden, producing Mg(OH)2 from Mg-silicates can play a significant role in advancing CCM processes. However, dedicated future research and development (R&D) have potential to significantly improve the Mg(OH)2 process performance.

Utilization of non ferrous metals in boiler combustion environment

The made research is focused on possibility of application of non ferrous metals in boiler pressure parts as a substitute of currently used ferrous-base alloys. The main issue was to define resistive ability of some perspective non ferrous metals to chlorine induced corrosion. Experimental study was performed using simultaneous thermal analysis (STA) in the temperature range of 400-700 °C. The chloride induced corrosion was simulated by mixtures of metal samples with potassium chloride treated by synthetic air. The advantage of synergetic effect of non ferrous alloys compare to single metals is shown due to the obtained data from conducted thermal balance tests.

Waste-to-Energy Scenarios in the China Context

Waste incineration plants are increasingly established in China. A low heating value and high moisture content, due to a large proportion of biowaste in the municipal solid waste (MSW), can be regarded as typical characteristics of Chinese MSW. Two incineration technologies have been mainly established in China: stoker grate and circular fluidized bed (CFB). Both of them are designed to incinerate mixed MSW. However, there have been difficulties to reach the sufficient temperature in the combustion process due to the low heating value of the MSW. That is contributed to the usage of an auxiliary fossil fuel, which is often used during the whole incineration process. The objective of this study was to design alternative Waste-to-energy (WTE) scenarios for existing WTE plants with the aim to improve the material and energy efficiency as well as the feasibility of the plants. Moreover, the aim of this thesis was to find the key factors that affect to the feasibility of the scenarios. Five different WTE plants were selected as study targets. The necessary data for calculation was gained from literature as well as received from the operators of the target WTE plants. The created scenarios were based on mechanical-biological treatment (MBT) technologies, in which the produced solid recovered fuel (SRF) was fed as an auxiliary fuel into a WTE plant replacing the fossil fuel. The mechanically separated biowaste was treated either in an anaerobic digestion (AD) plant, a biodrying plant, a thermal drying plant, or a combined AD plant + thermal drying plant. An interactive excel spreadsheet based computation tool was designed to estimate the viability of the scenarios in different WTE cases. The key figures of the improved material and energy efficiency, such as additional electricity generated and avoided waste for landfill, were got as results. Furthermore, economic indicators such as annual profits (or costs), payback period, and internal rate of return (IRR) were gained as results. The results show that the AD scenario was the most profitable in most of the cases. The current heating value of MSW and the tipping fee for the received MSW appeared as the most important factor in terms of feasibility.

Improving the competitiveness of electrolytic Zinc process by chemical reaction engineering approach

This doctoral thesis describes the development work performed on the leachand purification sections in the electrolytic zinc plant in Kokkola to increase the efficiency in these two stages, and thus the competitiveness of the plant. Since metallic zinc is a typical bulk product, the improvement of the competitiveness of a plant was mostly an issue of decreasing unit costs. The problems in the leaching were low recovery of valuable metals from raw materials, and that the available technology offered complicated and expensive processes to overcome this problem. In the purification, the main problem was consumption of zinc powder - up to four to six times the stoichiometric demand. This reduced the capacity of the plant as this zinc is re-circulated through the electrolysis, which is the absolute bottleneck in a zinc plant. Low selectivity gave low-grade and low-value precipitates for further processing to metallic copper, cadmium, cobalt and nickel. Knowledge of the underlying chemistry was poor and process interruptions causing losses of zinc production were frequent. Studies on leaching comprised the kinetics of ferrite leaching and jarosite precipitation, as well as the stability of jarosite in acidic plant solutions. A breakthrough came with the finding that jarosite could precipitate under conditions where ferrite would leach satisfactorily. Based on this discovery, a one-step process for the treatment of ferrite was developed. In the plant, the new process almost doubled the recovery of zinc from ferrite in the same equipment as the two-step jarosite process was operated in at that time. In a later expansion of the plant, investment savings were substantial compared to other technologies available. In the solution purification, the key finding was that Co, Ni, and Cu formed specific arsenides in the “hot arsenic zinc dust” step. This was utilized for the development of a three-step purification stage based on fluidized bed technology in all three steps, i.e. removal of Cu, Co and Cd. Both precipitation rates and selectivity increased, which strongly decreased the zinc powder consumption through a substantially suppressed hydrogen gas evolution. Better selectivity improved the value of the precipitates: cadmium, which caused environmental problems in the copper smelter, was reduced from 1-3% reported normally down to 0.05 %, and a cobalt cake with 15 % Co was easily produced in laboratory experiments in the cobalt removal. The zinc powder consumption in the plant for a solution containing Cu, Co, Ni and Cd (1000, 25, 30 and 350 mg/l, respectively), was around 1.8 g/l; i.e. only 1.4 times the stoichiometric demand – or, about 60% saving in powder consumption. Two processes for direct leaching of the concentrate under atmospheric conditions were developed, one of which was implemented in the Kokkola zinc plant. Compared to the existing pressure leach technology, savings were obtained mostly in investment. The scientific basis for the most important processes and process improvements is given in the doctoral thesis. This includes mathematical modeling and thermodynamic evaluation of experimental results and hypotheses developed. Five of the processes developed in this research and development program were implemented in the plant and are still operated. Even though these processes were developed with the focus on the plant in Kokkola, they can also be implemented at low cost in most of the zinc plants globally, and have thus a great significance in the development of the electrolytic zinc process in general.

Promoting Cleantech in Emerging Markets: Business Model for Waste Pre-treatment Equipment in China

Waste incineration is becoming increasingly widespread method of waste disposal in China. Incineration plants mostly use grate and circular fluidized bed (CFB) technology. Waste combustion in cement production is also beginning to gradually increase. However, Chinese waste composition is causing problems for the energy utilization. Mechanical waste pre-treatment optimizes the combustion process and facilitates the energy recovery. The objective of this study is to identify how Western waste pre-treatment manufacturer could operate in Chinese markets. Chinese waste management industry is reviewed via PESTEL analysis. The current state and future predictions of grate and CFB incineration as well as cement manufacturing are monitored. Grate combustion, which requires lesser waste pre-treatment, is becoming more common at the expense of CFB incineration in China. The most promising future for waste treatment is in cement production industry. Waste treatment equipment manufacturer should try to create pilot projects with biggest cement producers with a view of growing co-operation in the future.

Biomass Utilization in PFC Co-firing System with the Slagging and Fouling Analysis

Master’s thesis Biomass Utilization in PFC Co-firing System with the Slagging and Fouling Analysis is the study of the modern technologies of different coal-firing systems: PFC system, FB system and GF system. The biomass co-fired with coal is represented by the research of the company Alstom Power Plant. Based on the back ground of the air pollution, greenhouse effect problems and the national fuel security today, the bioenergy utilization is more and more popular. However, the biomass is promoted to burn to decrease the emission amount of carbon dioxide and other air pollutions, new problems form like slagging and fouling, hot corrosion in the firing systems. Thesis represent the brief overview of different coal-firing systems utilized in the world, and focus on the biomass-coal co-firing in the PFC system. The biomass supply and how the PFC system is running are represented in the thesis. Additionally, the new problems of hot corrosion, slagging and fouling are mentioned. The slagging and fouling problem is simulated by using the software HSC Chemistry 6.1, and the emissions comparison between coal-firing and co-firing are simulated as well.

Kattilatekniikat biopolttoaineille alle 5 MW teholuokassa

Tässä kandidaatintyössä on tarkoituksena kertoa mahdollisista eri biopolttoaineista ja niiden polttamiseen kehitetyistä kattilatekniikoista alle 5MW:n kokoluokassa. Eri kattilatyyppejä esitellään ja vertaillaan niiden toiminta-arvojen ja investointihintojen perusteella. Lisäksi työssä esitellään näiden kattilatyyppien kotimaisia polttokattilavalmistajia ja -myyjiä tarkastellun tehoalueen rajoissa. Työssä käsitellään vain pienitehoisia biopolttoainekattiloita, jolloin kattilaratkaisut rajoittuvat lähinnä arina- ja leijukerroskattiloihin. Kaasutuskattilat rajattiin työn ulkopuolelle työn rajatun laajuuden takia. Kaasutuskattiloilla on myös Suomessa vähän ja niiden tarjonta on pientä. Kattiloista on pyritty selvittämään niiden paineluokat ja tuotetun veden tai höyryn lämpötila. Kattilavalmistajilta kerättiin tietoa kyselyillä ja internetsivujen avulla. Valmistajien ja toimittajien halukkuus kertoa omista tuotteistaan vaihteli jonkin verran. Tämän takia myös tiedon määrä tuotteista vaihtelee yrityksien välillä.

Leijukattilan savukaasujen loppulämpötilan hallinta

Nykyaikaista leijukattilaa voidaan ohjata ja säätää erilaisten säätöpiirien ja sekvenssien kautta erittäin tarkasti. Toiminnot on optimoitu parhaan hyötysuhteen saavuttamiseksi ja kunnossapitokustannusten minimoimiseksi. Tehokkaasta automaatiosta ja nykyaikaisista laitevalinnoista huolimatta leijukattiloissa on usein yksi osa-alue, jota ei pystytä hallitsemaan tehokkaasti. Useilla voimalaitoksilla savukaasu poistuu liian korkeassa lämpötilassa viimeiseltä lämpöpinnalta. Kun kattilahyötysuhdetta tarkastellaan epäsuoralla menetelmällä, savukaasuhäviö on merkittävin tekijä kaikista häviöstä. Tässä diplomityössä on etsitty mahdollisuuksia savukaasun loppulämpötilan hallintaan kattilan ajoarvojen muutoksella sekä lämpöpintoja muuttamalla. Tutkimus keskittyy Järvi-Suomen Voima Oy:n Ristiinan voimalaitokselle. Tutkimus on tehty yhteistyössä laitoksen omistajien Pohjolan Voima Oy:n, UPM-Kymmene Oyj:n sekä laitetoimittaja Valmet Oyj:n kanssa.

Leijukerroslämmönsiirtimien tukkeutuminen biovoimalaitoksessa

Leijukerroslämmönsiirtimien, eli hiekanpalautuspolvessa sijaitsevien tulistimien tukkeutuminen on ollut Kaukaan Voima Oy:n biovoimalaitoksen suunnittelemattomien seisokkien suurin syy vuodesta 2012 lähtien. Tulistimet tukkeutuvat kahdella tavalla. Nopeassa tukkeutumisessa tulistinkammion seinien kuonakerrostumat romahtavat yhtäkkiä tulistimen päälle tukkien sen. Tämä johtaa aina koko laitoksen alasajoon. Hitaassa tukkeutumisessa tulistinputkien pinnalle muodostuu vähitellen kerrostuma sekä tulistinputkien väliin jää suurempia kappaleita, jotka tukkivat tulistinta. Nopea tukkeutuminen johtuu tuhkassa olevien alkali-, eli kalium- ja natriumyhdisteiden synnyttämistä kerrostumista lämmönsiirrinkammion seinille. Hidas tukkeutuminen johtuu osittain myös alkaliyhdisteistä, mutta merkittävämpi aine tulistinputkien pinnalla olevassa kerrostumissa näyttää olevan kalsiumsulfaatti, joka tukkii tulistinta. Palavan aineen pääsy tulistinkammioon ilmanjakoasetuksista ja tulistinkammion rakenteesta johtuen aiheuttaa kerrostumien syntymisen. Kerrostumien syntymiseen johtavat syyt johtuvat monesta tekijästä ja yksiselitteistä aiheuttajaa on vaikea määritellä. Selvin yhteys on lietteen epätasaisessa poltossa ja turpeen käytössä. Nykyisillä lietteenkäsittelylaitteilla lietteen tasainen syöttö on vaikeaa ja se aiheuttaa ongelmia. Turpeen poltto biopolttoaineiden rinnalla pitää tulistimet puhtaampina. Muita todennäköisiä kerrostumia lisääviä syitä ovat puhtaan hiekan vähäinen syöttömäärä ja usean huonomman polttoaineen yhtäaikainen poltto.

Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

The sorption behavior of dry products is generally affected by the drying method. The sorption isotherms are useful to determine and compare thermodynamic properties of passion fruit pulp powder processed by different drying methods. The objective of this study is to analyze the effects of different drying methods on the sorption properties of passion fruit pulp powder. Passion fruit pulp powder was dehydrated using different dryers: vacuum, spray dryer, vibro-fluidized, and freeze dryer. The moisture equilibrium data of Passion Fruit Pulp (PFP) powders with 55% of maltodextrin (MD) were determined at 20, 30, 40 and 50 ºC. The behavior of the curves was type III, according to Brunauer's classification, and the GAB model was fitted to the experimental equilibrium data. The equilibrium moisture contents of the samples were little affected by temperature variation. The spray dryer provides a dry product with higher adsorption capacity than that of the other methods. The vibro-fluidized bed drying showed higher adsorption capacity than that of vacuum and freeze drying. The vacuum and freeze drying presented the same adsorption capacity. The isosteric heats of sorption were found to decrease with increasing moisture content. Considering the effect of drying methods, the highest isosteric heat of sorption was observed for powders produced by spray drying, whereas powders obtained by vacuum and freeze drying showed the lowest isosteric heats of sorption.

Production of magnesium carbonates from serpentinites for CO2 mineral sequestration : optimisation towards industrial application

Global warming is one of the most alarming problems of this century. Initial scepticism concerning its validity is currently dwarfed by the intensification of extreme weather events whilst the gradual arising level of anthropogenic CO2 is pointed out as its main driver. Most of the greenhouse gas (GHG) emissions come from large point sources (heat and power production and industrial processes) and the continued use of fossil fuels requires quick and effective measures to meet the world’s energy demand whilst (at least) stabilizing CO2 atmospheric levels. The framework known as Carbon Capture and Storage (CCS) – or Carbon Capture Utilization and Storage (CCUS) – comprises a portfolio of technologies applicable to large‐scale GHG sources for preventing CO2 from entering the atmosphere. Amongst them, CO2 capture and mineralisation (CCM) presents the highest potential for CO2 sequestration as the predicted carbon storage capacity (as mineral carbonates) far exceeds the estimated levels of the worldwide identified fossil fuel reserves. The work presented in this thesis aims at taking a step forward to the deployment of an energy/cost effective process for simultaneous capture and storage of CO2 in the form of thermodynamically stable and environmentally friendly solid carbonates. R&D work on the process considered here began in 2007 at Åbo Akademi University in Finland. It involves the processing of magnesium silicate minerals with recyclable ammonium salts for extraction of magnesium at ambient pressure and 400‐440⁰C, followed by aqueous precipitation of magnesium in the form of hydroxide, Mg(OH)2, and finally Mg(OH)2 carbonation in a pressurised fluidized bed reactor at ~510⁰C and ~20 bar PCO2 to produce high purity MgCO3. Rock material taken from the Hitura nickel mine, Finland, and serpentinite collected from Bragança, Portugal, were tested for magnesium extraction with both ammonium sulphate and bisulphate (AS and ABS) for determination of optimal operation parameters, primarily: reaction time, reactor type and presence of moisture. Typical efficiencies range from 50 to 80% of magnesium extraction at 350‐450⁰C. In general ABS performs better than AS showing comparable efficiencies at lower temperature and reaction times. The best experimental results so far obtained include 80% magnesium extraction with ABS at 450⁰C in a laboratory scale rotary kiln and 70% Mg(OH)2 carbonation in the PFB at 500⁰C, 20 bar CO2 pressure for 15 minutes. The extraction reaction with ammonium salts is not at all selective towards magnesium. Other elements like iron, nickel, chromium, copper, etc., are also co‐extracted. Their separation, recovery and valorisation are addressed as well and found to be of great importance. The assessment of the exergetic performance of the process was carried out using Aspen Plus® software and pinch analysis technology. The choice of fluxing agent and its recovery method have a decisive sway in the performance of the process: AS is recovered by crystallisation and in general the whole process requires more exergy (2.48–5.09 GJ/tCO2sequestered) than ABS (2.48–4.47 GJ/tCO2sequestered) when ABS is recovered by thermal decomposition. However, the corrosive nature of molten ABS and operational problems inherent to thermal regeneration of ABS prohibit this route. Regeneration of ABS through addition of H2SO4 to AS (followed by crystallisation) results in an overall negative exergy balance (mainly at the expense of low grade heat) but will flood the system with sulphates. Although the ÅA route is still energy intensive, its performance is comparable to conventional CO2 capture methods using alkanolamine solvents. An energy‐neutral process is dependent on the availability and quality of nearby waste heat and economic viability might be achieved with: magnesium extraction and carbonation levels ≥ 90%, the processing of CO2‐containing flue gases (eliminating the expensive capture step) and production of marketable products.

Puu- ja turvetuhkan hyötykäyttökelpoisuuteen vaikuttavat tekijät pienillä polttolaitoksilla

Energiantuotannossa syntyvä tuhka voi olla laadultaan hyvin vaihtelevaa ja laadunvaihtelulle on haastavaa löytää yksiselitteistä syy-seuraussuhdetta. Ympäristönsuojelulainsäädäntö ja taloudelliset intressit ohjaavat tuhkantuottajia etsimään tuhkalle sopivia hyötykäyttökohteita, ja sen vuoksi tuhkan laatuun ja hyötykäyttökelpoisuuteen vaikuttavia tekijöitä on tarpeen selvittää. Tässä diplomityössä on tutkittu pienissä, alle 50 MW:n polttolaitoksissa syntyvää tuhkaa. Tavoitteena oli selvittää, kuinka tuhkan hyötykäyttökelpoisuuteen voidaan vaikuttaa. Tutkimuksen kohteena oli polttoainekoostumuksen, poltto-olosuhteiden ja tuhkan jälkikäsittelyn vaikutus tuhkassa olevien haitta-aineiden pitoisuuksiin ja liukoisuuksin. Työhön sisältyi myös aiemmin tehtyjen tuhka-analyysien tarkastelu sekä tuhkakokeet kahdella kohderyhmään kuuluvalla laitoksella. Työssä todettiin lentotuhkan haitta-ainepitoisuuksien ja -liukoisuuksien olevan keskimäärin korkeampia kuin pohjatuhkan vastaavien, ja että tyypillisesti arinakattilan tuhkien haitta-aineet ylittävät useammin hyötykäyttökelpoisuuden raja-arvoja kuin kuplaleijupetikattilan tuhkien. Lisäksi havaittiin metsätähdehaketuhkan kelpaavan useammin hyötykäyttöön kuin rankahaketuhkan.

Effect of Material Recycling on the Feasibility of Solid Recovered Fuel Fired Power Plant

This master’s thesis examines the effects of increased material recycling on different waste-to-energy concepts. With background study and a developed techno-economic computational method the feasibility of chosen scenarios with different combinations of mechanical treatment and waste firing technologies can be evaluated. The background study covers the waste scene of Finland, and potential market areas Poland and France. Calculated cases concentrate on municipal solid waste treatment in the Finnish operational environment. The chosen methodology to approach the objectives is techno-economic feasibility assessment. It combines calculation methods of literature and practical engineering to define the material and energy balances in chosen scenarios. The calculation results together with other operational and financial data can be concluded to net present values compared between the scenarios. For the comparison, four scenarios, most vital and alternative between each other, are established. The baseline scenario is grate firing of source separated mixed municipal solid waste. Second scenario is fluidized bed combustion of solid recovered fuel produced in mechanical treatment process with metal separation. Third scenario combines a biomaterial separation process to the solid recovered fuels preparation and in the last scenario plastics are separated in addition to the previous operations. The results indicated that the mechanical treatment scenarios still need to overcome some problems to become feasible. Problems are related to profitability, residue disposal and technical reliability. Many uncertainties are also related to the data gathered over waste characteristics, technical performance and markets. With legislative support and development of further processing technologies and markets of the recycled materials the scenarios with biomaterial and plastic separation may operate feasibly in the future.

Tutkimuskattilan taselaskenta

Diplomityön tavoitteena oli luoda Varkauden energiatutkimuskeskuksen tutkimuskäyttöön tarkoitetun kuplapetikattilan tase- ja säätölaskenta. Työssä on esitelty yleisesti kuplapetikattiloiden teoriaa ja tarkasteltu lyhyesti kuplapetikattilan muodostamaa kokonaisuutta energiantuotannossa. Työssä käsitelty tutkimuskattila ei ehtinyt valmistua ennen tätä diplomityötä, joten mittauksia käytön ajalta ei voitu suorittaa ja sisällyttää tähän työhön. Lisäksi mahdolliset käytössä havaittavat korjaukset ja parannukset taselaskentaan jäivät tämän työn tarkastelun ulkopuolelle. Taselaskennan muodostamisessa hyödynnettiin kattilan suunnitteluvaiheessa luotuja säätö- ja PI-kaavioita. Säätömekaniikkaa luodessa huomioitiin mahdollisimman tarkasti automaatiojärjestelmän vaatimukset ja suorituskyky. Työssä on esitetty suuri määrä kattilalaskennan kannalta keskeisiä yhtälöitä. Prosessia ja säätömekaniikkaa mallinnettiin laskentaperusteisesti, työssä on esitetty yhtälöistä saatavat tulokset kattilaa ajettaessa tyypillisillä arvoilla 100 %:n teholla. Työn tuloksena tutkimuskattilalle saatiin säätömekaniikka, jolla pystytään arvioimaan viipymäaikaa kattilassa. Lasketun viipymäajan avulla polttoprosessi kattilassa voidaan suunnitella ja suorittaa tutkimuskäyttöön vaaditulla tarkkuudella ja laissa säädettyjen määräyksien mukaan, mikäli kierrätyspolttoainetta käytetään yli 50 tonnia vuodessa.