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The application-attractive form of TiO₂, CeO₂ and CuO-based open-cell foam supported catalysts was designed to investigate their catalytic performance in oxidation of two model volatile organic compounds—methanol and dichloromethane. TiO₂-CeO₂, TiO₂-CuO and TiO₂-CeO₂-CuO catalysts as thin films were deposited on VUKOPOR®A ceramic foam using a reverse micelles-controlled sol-gel method, dip-coating and calcination. Three prepared catalytic foams were investigated via light-off tests in methanol and dichloromethane oxidation in the temperature range of 45–400 °C and 100–500 °C, respectively, at GHSV of 11, 600 h⁻¹, which fits to semi-pilot/industrial conditions. TiO₂-CuO@VUKOPOR®A foam showed the best catalytic activity and CO₂ yield in methanol oxidation due to its low weak Lewis acidity, high weak basicity and easily reducible CuO species and proved good catalytic stability within 20 h test. TiO₂-CeO₂-CuO@VUKOPOR®A foam was the best in dichloromethane oxidation. Despite of its lower catalytic activity compared to TiO₂-CeO₂@VUKOPOR®A foam, its highly-reducible -O-Cu-Ce-O- active surface sites led to the highest CO₂2 yield and the highest weak Lewis acidity contributed to the highest HCl yield. This foam also showed the lowest amount of chlorine deposits.

In this paper, a novel application of industrial waste, namely red mud (RM), in the abatement of two malodorous and harmful sulfur compounds, dimethyl disulfide (DMDS) and methyl mercaptan (MM), is presented. The effects of calcination and activations with hydrochloric acid or a mixture of hydrochloric and orthophosphoric acid on the properties and performance of RM are compared using laboratory-scale experiments. The RM-based materials were characterized by XRF, XRD, FE-SEM, N₂-physisorption, TGA/DTA, and FTIR analyses. RM exhibits very promising catalytic properties in the abatement of both DMDS and MM. The hydrochloric acid-activated RM was the most active in both cases, which was explained by its rather high specific surface area (144 m² g⁻¹), higher contents of Fe₂O₃ and TiO₂, as well as lower content of phosphorus. For both DMDS and MM, the main oxidation products were sulfur dioxide, carbon monoxide, and carbon dioxide. DMDS was observed as a reaction intermediate in MM oxidation. While the final conversions of DMDS and MM were high, the oxidation was not complete, indicated by the formation of carbon monoxide. Nevertheless, the modified RM appears as a very interesting alternative to the existing DMDS and MM abatement catalysts.

This study proposes a product sustainability assessment tool (PSAT) that addresses the environmental, health and safety, social, and economic sustainability aspects from a life cycle perspective. The proposed PSAT uses the principles of Green Chemistry, Industrial Ecology, and Green Engineering as guidelines in the development of its assessment criteria. The developed assessment criteria are expressed as easy-to-answer questions covering the environmental, social, health and safety and economic aspects of sustainability. PSAT also incorporates life cycle assessment impact categories and the Circular Economy approach. PSAT comprises an Excel checklist of a questionnaire with a drop-down list of answers to select from describing the sustainability impact of the assessed product. PSAT serves to highlight the sustainability hotspots in a product’s life cycle. The questionnaire consists of qualitative and quantitative assessment criteria and contains a total of 97 questions, out of which there are 11 design questions, 22 materials selection questions, 31 manufacturing questions, 24 use questions, and 9 end-of-life questions. The PSAT scoring system enables users to compare the sustainability performance of their products. PSAT aims to aid users in making informed decisions before purchasing a product based on the information on how the product is designed and what materials it contains, how it was manufactured, how it will perform during its use, and what will happen at the end of its useful life. It also aims to aid product manufacturers and designers in incorporating sustainability into all stages of the product life cycle. The PSAT methodology promotes a holistic view of a product life cycle, including the design, materials selection, manufacturing, use, and end-of-life stage. As a case study, PSAT was used to perform a comparative sustainability assessment of two types of 3 MW rated power wind turbines: a direct-drive permanent magnet synchronous generator (

This thesis work aims to develop sustainability assessment tools for chemical processes, unit operations, catalysts, and products and to test the tools on products containing critical rare earth elements (REEs). This thesis is a part of the study where a Green Chemistry-based Sustainability Assessment Tool (SAT) was developed for the early design phase of chemical production processes. The SAT tool is comprised of indicators selected using the twelve principles of Green Chemistry as guidelines. It was tested on conventional and carbon dioxide-based formic acid production routes. Similarly, a sustainability assessment tool was developed based on the integration of Green Engineering principles and the multi-criteria decision analysis (MCDA) analytical hierarchy method (AHP). The developed tool is suitable for the assessment of catalysts in chemical processes. It was tested in ethanol steam reforming using four nickel (Ni)-catalysts (REEs and non-REEs). The Ni-catalysts were assessed and compared against each other to determine the substitution potential of REEs in catalysts. Thirdly, a Product Sustainability Assessment Tool (PSAT) was developed for assessing the sustainability of products. Here the principles of Green Chemistry, Industrial Ecology, and Green Engineering were used as guidelines in developing the assessment criteria. The developed PSAT tool also incoorporates life cycle impact categories and Circular Economy approach. It takes into account five life cycle stages of a product: design, materials selection, manufacturing, use, and end-of-life. The developed PSAT tool was tested on two 3 MW wind turbine generators; a) a doubly fed inductor generator (DFIG) without an REEs containing permanent magnet and b) a direct-drive Permanent Magnet Synchronous Generator (PMSG) containing REEs. The results obtained from the assessment of ethanol steam reforming catalysts demonstrated that cerium and lanthanum oxide supported catalysts can be successfully subst, Tiivistelmä Tämän väitöskirjatyön tavoitteena on kehittää kestävyyden arviointimenetelmiä kemiallisten prosessien, yksikköoperaatioiden, katalyyttien ja erilaisten tuotteiden arviointiin sekä testata menetelmiä kriittisiä harvinaisia maametalleja (REEs) sisältävien tuotteiden arviointiin. Väitöskirjatyö on osa tutkimusta, jossa kehitettiin Vihreän kemian periaatteisiin perustuva (Green Chemistry -based) kestävyyden arviointityökalu (SAT), joka soveltuu kemiallisten tuotantoprosessien varhaisen suunnittelun aikaiseen arviointiin. SAT-työkalu koostuu indikaattoreista, jotka valitaan Vihreän kemian kahdentoista periaatteen avulla. SAT-työkalua hyödyntämällä arvioidaan muurahaishapon kahden tuotantoreitin, teollisessa käytössä olevan ja hiilidioksidipohjaisen valmistusreitin, kestävyyttä. Tässä työssä kehitettiin myös Vihreän tekniikan periaatteisiin perustuva (Green Enggineering principles -based) ja katalyyttien kestävyyden arviointiin soveltuva arviointityökalu, joka pohjautuu Aspen Plus -prosessisimulaation, analyyttisen hierarkiamenetelmän (Analytical Hierarchy Method - AHP), min-max-normalisointitekniikan ja Likert-asteikon samanaikaiseen käyttöön. Kehitettyä työkalua testattiin vertailemalla etanolin höyryreformointia neljällä nikkelikatalyytillä, joista kaksi sisälsi ja kaksi ei sisältänyt REE-metalleja. Nikkelikatalyyttien vertailu tehtiin REE-katalyyttien korvausmahdollisuuden määrittämiseksi. Väitöskirjatyössä kehitettiin myös tuotteen kestävyyden arviointimenetelmä (PSAT). Tässä menetelmässä hyödynnetään indikaattoreiden valinnassa vihreän kemian, teollisen ekologian ja vihreän tekniikan periaatteita. PSAT-menetelmään integroitiin myös elinkaariarvioinnin (LCA) avulla saatavat vaikutukset. PSAT-menetelmässä arvioidaan viisi tuotteen elinkaaren vaihetta, jotka ovat tuotteen suunnittelu, materiaalien valinta, valmistus, käyttö ja käytöstä poistuminen. PSAT soveltuu tuotteiden kestävyysarviointiin ja toimii ohjeena vertailtaessa tuotevaihtoehtoja. PSAT-menetelm

Volatile organic compounds (VOCs) are regulated by stringent legislation that sets high requirements for treatment systems. Catalytic total oxidation is a feasible technology to treat VOC emissions both cost-effectively and in a destructive way. Catalysts used in VOC oxidation need to be highly active and selective yet additionally resist catalyst deactivation. In this work, 33 catalysts supported on γ-Al2O3, CeO2, Al2O3-CeO2 and Al2O3-TiO2 were investigated in dichloromethane (DCM, 23 catalysts) and dimethyl disulphide (DMDS, 18 catalysts) oxidation. Pt, Au, Pd, Rh, Cu or V2O5 alone or as combinations were used as the active phases. The catalysts were extensively characterised using various methods. The main aim of the thesis was to study the applicability of Au catalysts in the oxidation of chlorinated and sulphur-containing VOCs. The obtained results can be used to develop better commercial catalysts for VOC incinerators intended for industry. In DCM oxidation, the deposition of an active metal on the supports enhanced selectivity, while the effect was insignificant in DCM conversion, with the exception of Au/Al2O3 and Pt-Au/Al2O3 catalysts. Amongst the studied catalysts, Pt/Al2O3, Au/Al2O3 and Pt-Au/Al2O3 were the most active and selective in DCM oxidation. The performance of Pt/Al2O3 was explained by high acidity and reducibility, whereas with Au/Al2O3 and Pt-Au/Al2O3, it was a result of high acidity, small particle size and uniform distribution of Au. Stability experiments showed that the Pt/Al2O3 and Pt-Au/Al2O3 catalysts were durable. In DMDS oxidation, in most cases the active phases improved the activity and selectivity of the supports. The presence of Cu and CeO2 resulted in significant formation of formaldehyde instead of CO2. The H2-TPR experiments suggested that improved reducibility plays a key role in DMDS oxidation. In addition, oxygen activation showed correlation with the formation of oxidation products. The most active catalysts wer, Tiivistelmä Haihtuvien orgaanisten yhdisteiden (VOC) päästöjä rajoitetaan tiukalla lainsäädännöllä haitallisten vaikutuksien vuoksi, ja siksi päästöjä käsittelevien teknologioiden täytyy olla tehokkaita. Katalyyttinen kokonaishapetus on toimiva menetelmä, jolla VOC-ilmapäästöjä voidaan käsitellä ympäristöystävällisesti ja taloudellisesti. Katalyyttimateriaalien täytyy olla aktiivisia, selektiivisiä sekä erittäin kestäviä. Tutkimuksessa arvioitiin 33 erilaista γ-Al2O3-, CeO2-, Al2O3-CeO2-, Al2O3-TiO2 -tuettua katalyyttiä dikloorimetaanin (DCM, 23 katalyyttiä) ja dimetyylidisulfidin (DMDS, 18 katalyyttiä) hapetuksessa. Aktiivisina aineina käytettiin platinaa, kultaa, palladiumia, rodiumia, kuparia tai vanadiinia yksin tai seoksina. Katalyyttejä karakterisoitiin kattavasti eri menetelmillä. Tavoitteena oli tutkia kultakatalyyttien soveltuvuutta klooria ja rikkiä sisältävien VOC-yhdisteiden kokonaishapetuksessa. Koetuloksia voidaan hyödyntää VOC-polttolaitteistojen kaupallisten katalyyttien kehitystyössä. Dikloorimetaanin hapetuksessa aktiivisen metallin lisäys paransi selektiivisyyttä useimmilla katalyyteillä, kun taas vaikutus dikloorimetaanin konversioon oli merkityksetön paitsi Au/Al2O3 ja Pt-Au/Al2O3 katalyyttien tapauksissa. Tutkituista katalyyteista Pt/Al2O3-, Au/Al2O3- ja Pt-Au/Al2O3 -katalyytit olivat aktiivisimmat ja selektiivisimmät. Korkea happamuus ja hyvä pelkistyvyys selittivät Pt/Al2O3 -katalyytin suorituskykyä, kun taas Au/Al2O3- ja Pt-Au/Al2O3 -katalyyttien tapauksissa korkea happamuus, kultapartikkelin pieni koko ja hyvä dispersio selittivät suorituskykyä. Pt/Al2O3- ja Pt-Au/Al2O3 -katalyytit olivat kokeiden perusteella stabiileja. Dimetyylidisulfidin hapetuksessa aktiivisten metallien lisääminen paransi katalyyttien aktiivisuutta ja selektiivisyyttä useimmissa tapauksissa. Cu ja CeO2 aiheuttivat formaldehydin muodostumista hiilidioksidin sijaan. H2-TPR kokeiden perusteella katalyyttien pelkistyvyydellä on tärkeä rooli dimetyylidisulfidin hapetuk

Exhaust after treatment systems are becoming more complicated with the ever-stricter emission regulations. To meet the regulation limits, a tightly packed high-performance system is required. In selective catalytic reduction (SCR) systems, ammonia (NH³) uniformity is a key performance indicator. In this work, a low flow intrusion automated device was designed to measure NOₜ reduction from the SCR catalyst outlet. A topological surface was reconstructed from the measurement data to obtain the shape of the distribution. Before the actual measurements, the method was theoretically tested with distribution extracted from computational fluid dynamics (CFD) simulations. The results show that in stable engine load conditions, uncertainty of the measurement was low, approximately 1.1% from the measured value. In the case of high uniformity, a satisfactory result can be obtained with 10 to 20 measurement positions, whereas in the case of low uniformity, the number of positions should be increased. The distribution shape between the measurements was consistent throughout the measurements.

Geopolymers have not been extensively employed as catalytic materials despite of their zeolite-resembling Si–Al structure. Geopolymerization offers a novel way for preparation of catalysts and possibility to use waste or industrial side-stream derived raw material as a resource for catalyst manufacturing. This work concentrates on metakaolin-based geopolymer materials that were prepared, characterized and tested as alternative environmentally benign catalyst supports for the oxidation of dichloromethane. The geopolymers with the Si/Al ratio of 1.5 were modified with HCl to increase their specific surface area, which is important in catalytic applications. Significant increase in specific surface areas was achieved via leaching of Na and Al from the geopolymer structure. Highest specific surface areas achieved for calcined geopolymers were over 500 m²g⁻¹. Use of acid concentrations higher than 1 M led to the dehydroxylation of the geopolymer. Dehydroxylation decreased the total acidity of geopolymer through the loss of the Brønsted acid sites, which are responsible for the adsorption of dichloromethane in the beginning of the catalytic reaction. Absence of Brønsted acid sites was observed by the formation of CH₂O as the only reaction intermediate. The best result in the dichloromethane oxidation was found with the geopolymer treated with 1 M HCl. Without using any additional active sites, the maximum dichloromethane conversion of 90% was reached at 525 °C with the maximum HCl yield of 83%. This result indicates the good potential of modified geopolymers to be used as catalyst supports in environmental applications.

Dichloromethane (DCM) is a noxious chemical that is widely used in industry. The current work focuses on the catalytic abatement of DCM from industrial effluents to minimize its harmful effects to the environment and human wellbeing. Three transition metal oxide catalysts (V, Cu and Mn) supported on γ-Al₂O₃ were synthetized for total oxidation of DCM in presence of steam. Thermodynamic modelling was used to reveal information related to the stability of the used transition metal oxides in the abatement conditions. The results showed that with 10 wt-% CuO and 10 wt-% V₂O₅ containing catalysts 100% conversion of DCM together with 90% HCl yield and insignificant by-product formation can be achieved at temperature around 500 °C. According to modelling, V₂O₅ should be stable at the conditions of DCM oxidation, while CuO would be more stable at higher temperature level (decomposition of CuCl₂ starts at 300 °C). MnCl₂ remains stable until 800 °C, which leads to deactivation of MnO₂ catalyst. Presence of steam inhibits the poisoning of the materials by chlorine based on thermodynamic calculation. XRF analysis supports the results of thermodynamic modelling — used MnO₂ and CuO catalysts contain chlorine, which was not detected in case of V₂O₅/Al₂O₃. CuO/γ-Al₂O₃ seems to be a good alternative to noble metal catalysts for the total oxidation of dichloromethane when used in the presence of steam and the temperatures above 300 °C to minimize Cl-poisoning. The outcomes of this study showed that the prepared metal oxides are promising catalysts to minimize pollution caused by chlorinated volatile organic compounds.

The light rare earth elements (LREEs) lanthanum, cerium, neodymium and praseodymium are increasingly used in renewable energy technology and are applicable in portable electronic devices, such as phosphors in lightning applications and in catalysis. The extraction of REEs from virgin ores causes environmental degradation. LREEs are considered as critical metals. To overcome the environmental and criticality challenges of LREEs, recycling presents means by which they can be obtained from secondary sources. Presently, the recycling rate of LREEs is still very low. Substitutes of LREEs in most cases are either inferior or still undiscovered. This study investigates the criticality challenges and environmental impacts of producing LREEs from virgin ores. It focuses on LREEs obtainable in selected end-of-life products considered to have significant recycling potential; these include NdFeB magnets, Ni-MH batteries, phosphors in lighting and catalysts. Current recycling technologies, including representative methods and current recycling challenges are also reviewed. Although current recycling technologies have recorded growth, there is still a need for further improvements. The article highlights current LREEs substitution advances and the faced challenges in finding suitable LREEs substitutes. Furthermore, future ways to promote sustainability of LREEs recycling, to improve substitution, and to tackle the criticality challenges of LREEs are proposed.

Silica modified alumina was used in this study for coating of a cordierite monolith substrate with two different channel densities. The performance of the prepared monolith catalysts was evaluated in catalytic total oxidation of dichloromethane before and after Pt impregnation. The characteristics similar to the powder form catalysts were kept rather successfully after washcoating the monolith as evidenced by electron microscopy (FESEM) and N2 physisorption. A dichloromethane (DCM) conversion of higher than 80% at 500 °C was reached over all the catalysts with 200 cpsi. The maximum conversion was obtained with the catalyst containing 10 mol % of silica. The total amount of major byproducts (CO, CH3Cl and CH2O) were slightly decreased by increasing the silica loading, and remarkably after Pt impregnation. After impregnation of Pt, the HCl yields were increased for two samples with the higher loading of silica (10 and 15 mol %) and reached the maximum when silica loading was 10%. Even though Pt impregnation did not significantly affect the DCM conversion, it improved the selectivity. Comparison between the two substrates (200 and 600 cpsi) evidenced that the key parameters of the monolith influencing the DCM oxidation are low value of open fraction area, hydraulic diameter, thermal integrity factor and high value of mechanical integrity factor and geometric surface area.

The aim of this work was to study the influence of the support oxide properties on the total oxidation of dichloromethane in moist conditions. The support materials γ-Al2O3, TiO2, CeO2 and MgO were synthesized by a sol-gel method followed by wet impregnation of Pt and characterized by different physico-chemical techniques. The conversion of DCM was higher than 90% at 500 °C over impregnated and non-impregnated Al2O3, TiO2 and CeO2, even at high GHSV. CO, CH3Cl and CH2O were the major by-products observed and their amounts decreased after Pt impregnation. The CH3Cl formation was higher when Lewis acid sites were present while the existence of Brønsted sites promoted the CH2O formation. The complete conversion of DCM was achieved at around 450 °C over the Al2O3 and Pt/Al2O3 and at 500 °C for Pt/TiO2. These two catalysts exhibited the highest total acidities among the materials tested. The activity of Pt/Al2O3 remained the same also after 55 h of testing, however, increase in Pt particle size and decrease in acidity were observed. Pt/CeO2 while being less active showed smallest amount of by-product formation during the whole temperature range used in light-off tests. This is most probably due to its easy reduction ability. The textural parameters of the supports did not appear to be the key parameters when considering the activity and selectivity of the catalysts.

The releases of chlorinated volatile organic compounds (CVOCs) are controlled by strict regulations setting high demands for the abatement systems. Low temperature catalytic oxidation is a viable technology to economically destroy these often refractory emissions. Catalysts applied in the oxidation of CVOCs should be highly active and selective but also maintain a high resistance towards deactivation. In this study, a total of 33 different γ-Al2O3 containing metallic monoliths were studied in dichloromethane (DCM) and 25 of them in perchloroethylene (PCE) oxidation. The active compounds used were Pt, Pd, Rh or V2O5 alone or as mixtures. The catalysts were divided into three different testing sets: industrial, CVOC and research catalysts. ICP-OES, physisorption, chemisorption, XRD, UV-vis DRS, isotopic oxygen exchange, IC, NH3-TPD, H2-TPR and FESEM-EDS were used to characterise the catalysts. Screening of the industrial catalysts revealed that the addition of V2O5 improved the performance of the catalyst. DCM abatement was easily affected by the addition of VOC or water, but the effect on the PCE oxidation was only minor. Based on these screening tests, a set of CVOC catalysts were developed and installed into an industrial incinerator. The comparison between the laboratory and industrial scale studies showed that DCM oxidation in an industrial incinerator could be predicted relatively well. Instead, PCE was always seen to be oxidised far better in an industrial unit indicating that the transient oxidation conditions are beneficial for the PCE oxidation. Before starting the experiments with research catalysts, the water feed was optimised to 1.5 wt.%. Besides enhancing the HCl yields, water improved the DCM and PCE conversions. In the absence of oxygen, i.e. during destructive adsorption, the presence of water was seen to have an even more pronounced effect on the HCl formation and on the catalysts’ stability. In the DCM oxidation, the addition of the active, Tiivistelmä Klooratuille orgaanisille hiilivedyille (CVOC) on asetettu tiukat päästörajoitukset niiden haitallisten vaikutusten takia. Tästä johtuen myös puhdistusmenetelmien tulee olla tehokkaita. Katalyyttinen puhdistus on teknologia, jolla nämä usein vaikeasti käsiteltävät yhdisteet voidaan taloudellisesti tuhota. Käytettävien katalyyttien tulee olla aktiivisia ja selektiivisiä sekä hyvin kestäviä. Tässä työssä tutkittiin yhteensä 33 erilaista γ-Al2O3-pohjaista hapetuskatalyyttiä metyleenikloridin (DCM) käsittelyssä, niistä 25 testattiin myös perkloorietyleenin (PCE) hapetuksessa. Aktiivisina metalleina katalyyteissä käytettiin platinaa, palladiumia, rhodiumia ja vanadiinia yksin tai seoksina. Katalyytit jaettiin kolmeen ryhmään: teolliset-, CVOC- ja tutkimuskatalyytit. Aktiivisuuskokeiden lisäksi katalyyttejä karakterisoitiin ICP-OES-, fysiorptio-, kemisorptio-, XRD-, UV-vis DRS-, isotooppivaihto-, IC-, NH3-TPD-, H2-TPR- ja FESEM-EDS-pintatutkimusmenetelmillä. Koetulokset osoittivat, että vanadiini paransi teollisuuskatalyyttien aktiivisuutta ja selektiivisyyttä. VOC-yhdisteen tai veden lisäys paransi DCM:n hapettumista, mutta PCE:n hapettumiseen niillä ei ollut vaikutusta. Testien perusteella kehitettiin CVOC-katalyytit, jotka asennettiin teolliseen polttolaitokseen. Laboratoriossa ja teollisuudessa tehdyissä testeissä havaittiin, että DCM:n hapettuminen oli laboratoriokokeiden perusteella ennustettavissa. Sen sijaan PCE hapettui teollisuudessa aina paljon paremmin kuin laboratorio-olosuhteissa. Tämä osoittaa, että muuttuvat hapettumisolosuhteet vaikuttivat positiivisesti PCE:n hapettumiseen. Veden määrä syöttövirrassa optimoitiin 1,5 %:iin ennen tutkimuskatalyyttien testausta. Selektiivisyyden lisäksi vesi paransi DCM:n ja PCE:n konversiota. Hapettomissa olosuhteissa, ts. tuhoavien adsorptiokokeiden aikana, vesi paransi reaktion selektiivisyyttä HCl:ksi ja CO2:ksi vielä entisestään. Tämän lisäksi vesi lisäsi katalyytin stabiilisuutta. DCM:n hapetuksessa a