Future Combustion Technology for Synthetic and Renewable Fuels in Compression Ignition Engines (REFUEL) - Final report

This domestic project, Future Combustion Technology for Synthetic and Renewable Fuels in Compression Ignition Engines (ReFuel), was part of a Collaborative Task "Future Combustion Technology for Synthetic and Renewable Fuels in Transport" of International Energy Agency (IEA) Combustion Agreement. This international Collaborative Task is coordinated by Finland. The three-year (2009-2011) project was a joint research project with Aalto University (Aalto), Tampere University of Technology (TUT), Technical Research Centre of Finland (VTT) and Åbo Akademi University (ÅAU). The project was funded by TEKES, Wärtsilä Oyj, Neste Oil Oyj, Agco Sisu Power, Aker Arctic Technology Oy and the research partners listed above. Modern renewable diesel fuels have excellent physical and chemical properties, in comparison to traditional crude oil based fuels. Purely paraffinic fuels do not contain aromatic compounds and they are totally sulphur free. Hydrotreated Vegetable Oil (HVO) was studied as an example of paraffinic high cetane number (CN) diesel fuels. HVO has no storage and low temperature problems like the fatty acid methyl esters (FAMEs) have. The combustion properties are better than those of crude oil based fuels and FAME, because they have very high cetane numbers and contain no polyaromatic hydrocarbons (PAH). With low HVO density, viscosity and distillation temperatures, these advantageous properties allow far more advanced combustion strategies, such as very high exhaust gas recirculation (EGR) rates or extreme Miller timings, than has been possible with current fossil fuels. The implementation of these advanced combustion technologies, together with the novel renewable diesel fuel, brought significant nitrogen oxides (NOx), particulate matter (PM) emission reductions with no efficiency losses. The objective of ReFuel project was to develop new extremely low emission combustion technologies for new renewable fuels in compression ignition engines. The target was to decrease emissions at least by 70%. The scope was to utilize the physical and chemical properties of the renewable fuels that differ from properties of the traditional crude oil based fuels and to develop optimum combustion technologies for them. The project focused firstly, on paraffinic high cetane number fuels i.e. hydrotreated vegetable oil fuel as a typical representative of this kind of fuel and secondly, on fuels with high content of oxygenates. This was implemented by blending oxygenate to HVO fuel.

Tutkimuksia typenoksidien vähentämisestä keskinopeaan laivamoottoriin

This experimental research studied different technologies for reducing nitrogen oxides (NOx) in the exhaust gases, running with a large-bore medium-speed diesel research engine. NOx mainly form during combustion in local high temperature zones. This study considered primary methods, avoiding high combustion temperatures. In particular, the Miller cycle, which is a proven concept for NOx reduction, was deeply studied. This technology was applied by closing early the intake valves to create a first gas expansion before the compression stroke, thus reducing the effective compression ratio. At high load, a detailed analysis of the mixing-controlled combustion, which constitutes the most influent part of the combustion process, was carried out, reaching in-cylinder pressure of 300 bar. Same NOx level and no soot were achieved increasing the output power, while keeping the same fuel injection pressure.At partial load, a more extensive study of different Miller rates was performed. An advanced Miller rate resulted in NOx reduction up to 55%. Since the Miller cycle presented some limitations, other techniques were implemented together with the Miller cycle. First, a split injection strategy was tested with low fuel injection pressure. Then, a paraffinic fuel, hydrotreated vegetable oil (HVO), was tested, while keeping lower oxygen content in the combustion chamber, obtained by retaining a part of the exhaust gases. The results of the experiments with split injection showed that it was difficult to decrease further NOx emissions compared to the values obtained with the Miller cycle alone, but specific fuel consumption decreased when a small pilot injection was used. However, a later injection timing could be used to obtain lower NOx values with a small drawback in fuel consumption. HVO's ignitability allowed running with very advanced Miller cycle and low oxygen content. It was possible to obtain low NOx figures, but a certain increase of specific fuel consumption took place.This thesis showed that a unique tool for obtaining a significant NOx reduction without drawbacks in the whole engine load spectrum could not be found. Due to lower combustion temperatures, a higher specific fuel consumption was a common downside. Optimization of injection strategy, use of alternative fuels and dilution with inert mass are valuable tools to implement for achieving low engine-out NOx in large-bore engines. However, the investment costs the possible drawbacks must be accurately evaluated in each case.  Tämän väitöstutkimuksen tavoitteena oli vertailla erilaisia tekniikkoja typen oksidien (NOx) vähentämiseksi isossa keskinopeassa tutkimusmoottorissa. Pääsääntöisesti NOx-päästö muodostuu paikallisen korkean lämpötilan alueilla ja tässä tutkimuksessa hyödynnettiin menetelmiä korkeiden palamislämpötilojen välttämiseksi. Erityisesti tutkittiin eri sovelluksien niin kutsuttu Miller-työkiertoa, joka on tunnettu tekniikka NOx-päästön vähentämiseksi. Tämä toteutettiin aikaisella imuventtiilien sulkemisella tehollisen puristussuhteen pienemiseksi. Täydellä kuormalla saavutettiin erittäin korkea sylinteripaine (300bar) ja palamisprosessi oli näissä olosuhteissa lähes täysin sekoituksen. Moottorin tehoa pystytiin nostamaan merkittävästi korkeamman sylinteripaineen ansiosta ja Miller ajoitusta käyttämällä NOx päästöt eivät nousseet normaali tehoon nähden. Korkean kuorman testeissä hiukkaspäästöt olivat erittäin alhaiset. Osakuormalla tehtiin laajempi Miller-työkierto parametritutkimus. Aikaisella Miller-ajoituksella NOx:n vähentäminen oli jopa 55%. Miller-ajoitus asetti joitakin käyttörajoituksia alhaisilla kuormilla, ja siksi Miller-ajoituksen rinnalla hyödynnettiin myös muita tekniikoita. Jaksotettua polttoaineen ruiskutusta tutkittiin alhaisella polttoaineen ruiskutuspaineella, koska sen on todettu alentavan paineen nousun jyrkkyyttä nopeakäyntisissä moottoreissa. Miller-työkiertoa tutkittiin myös käyttämällä parafiinistä uusiutuvaa korkean setaaniluvun dieselpolttoainetta (vetykäsitelty kasviöljy, HVO) ja alentamalla moottorin täytöksen ilmakerrointa. Jaksotettu ruiskutus ei laskenut NOx–päästöjä merkittävästi käytettäessä Miller-ajoitusta alhaisella kuormalla, mutta moottorin polttoaineen kulutus laski jaksotetulla ruiskutuksella. HVO:n parempi syttyvyys (korkea setaaniluku) mahdollisti voimakkaamman Miller-ajoituksen ja alhaisella happipitoisuuden palotilassa. HVO:lla oli mahdollista saada alhaisia NOx arvoja, mutta samalla polttoaineen ominaiskulutus nousi. Tämä väitöstutkimus osoitti se, että yksi menetelmä ei tarjoa ratkaisua NOx päästöjen vähentämiseen kaikilla kuormitusalueilla, mutta hyödyntämällä useita eri tekniikoita voidaan saavuttaa merkittäviä NOx päästöjen alenemisia. Huomattavaa oli kuitenkin se, että monissa kuormapisteissä moottorin polttoaineen kulutus kasvoi samalla. Miller-työkierto, ruiskutuksen strategian optimointi, vaihtoehtoisten polttoaineiden käyttö ja pakokaasujen takaisin kierrätys ovat hyviä välineitä alhaisten NOx:n päästöjen saavuttamiseksi laivamoottoreissa

Quantum Spin Coherence and Electron Spin Distribution Channels in Vanadyl-containing Lantern Complexes

We herein investigate the heterobimetallic lantern complexes [PtVO(SOCR)4] as electrically neutral electronic qubits based on vanadyl complexes (S = 1/2) with nuclear spin-free donor atoms. The derivatives with R = Me (1) and Ph (2) give highly resolved X-band EPR spectra in frozen CH2Cl2/toluene solution, which evidence the usual hyperfine coupling to the 51V nucleus (I = 7/2) and an additional superhyperfine interaction with the I = 1/2 nucleus of the 195Pt isotope (natural abundance ca. 34%). DFT calculations ascribe the spin-density delocalization on the Pt2+ ion to a combination of π and δ pathways, with the former representing the predominant channel. Spin relaxation measurements in frozen CD2Cl2/toluene-d8 solution between 90 and 10 K yield Tm values (1-6 μs in 1 and 2-11 μs in 2) which match or even outperform those of known vanadyl-based qubits in similar matrices. Coherent spin manipulations indeed prove possible at 70 K, as shown by the observation of Rabi oscillations in nutation experiments. The results indicate that the heavy Group 10 metal is not detrimental to the coherence properties of the vanadyl moiety and that Pt-VO lanterns can be used as robust spin-coherent building blocks in materials science and quantum technologies

Quantum Spin Coherence and Electron Spin Distribution Channels in Vanadyl-containing Lantern Complexes

We herein investigate the heterobimetallic lantern complexes [PtVO(SOCR)4] as electrically neutral electronic qubits based on vanadyl complexes (S = 1/2) with nuclear spin-free donor atoms. The derivatives with R = Me (1) and Ph (2) give highly resolved X-band EPR spectra in frozen CH2Cl2/toluene solution, which evidence the usual hyperfine coupling to the 51V nucleus (I = 7/2) and an additional superhyperfine interaction with the I = 1/2 nucleus of the 195Pt isotope (natural abundance ca. 34%). DFT calculations ascribe the spin-density delocalization on the Pt2+ ion to a combination of π and δ pathways, with the former representing the predominant channel. Spin relaxation measurements in frozen CD2Cl2/toluene-d8 solution between 90 and 10 K yield Tm values (1-6 μs in 1 and 2-11 μs in 2) which match or even outperform those of known vanadyl-based qubits in similar matrices. Coherent spin manipulations indeed prove possible at 70 K, as shown by the observation of Rabi oscillations in nutation experiments. The results indicate that the heavy Group 10 metal is not detrimental to the coherence properties of the vanadyl moiety and that Pt-VO lanterns can be used as robust spin-coherent building blocks in materials science and quantum technologies

Dual Structure of a Vanadyl-Based Molecular Qubit Containing a Bis(β-diketonato) Ligand

We designed [VO(bdhb)] (1′) as a new electronic qubit containing an oxovanadium(IV) ion (S = 1/2) embraced by a single bis(β-diketonato) ligand [H2bdhb = 1,3-bis(3,5-dioxo-1-hexyl)benzene]. The synthesis afforded three different crystal phases, all of which unexpectedly contain dimers with formula [(VO)2(bdhb)2] (1). A trigonal form (1h) with a honeycomb structure and 46% of solvent-accessible voids quantitatively transforms over time into a monoclinic solvatomorph 1m and minor amounts of a triclinic solventless phase (1a). In a static magnetic field, 1h and 1m have detectably slow magnetic relaxation at low temperatures through quantum tunneling and Raman mechanisms. Angle-resolved electron paramagnetic resonance (EPR) spectra on single crystals revealed signatures of low-dimensional magnetic behavior, which is solvatomorph-dependent, being the closest interdimer V···V separations (6.7−7.5 Å) much shorter than intramolecular V···V distances (11.9−12.1 Å). According to 1H diffusion ordered spectroscopy (DOSY) and EPR experiments, the complex adopts the desired monomeric structure in organic solution and its geometry was inferred from density functional theory (DFT) calculations. Spin relaxation measurements in a frozen toluene-d8/CD2Cl2 matrix yielded Tm values reaching 13 μs at 10 K, and coherent spin manipulations were demonstrated by Rabi nutation experiments at 70 K. The neutral quasi-macrocyclic structure, featuring nuclear spin-free donors and additional possibilities for chemical functionalization, makes 1′ a new convenient spin-coherent building block in quantum technologies

Italy nd the Middle East. Geopolitics, Dialogue and Power during the Cold War, edited by Luciano Monzali and Paolo Soave

Italy played a vital role in the Cold War dynamics that shaped the Middle East in the latter part of the 20th century. It was a junior partner in the strategic plans of NATO and warmly appreciated by some Arab countries for its regional approach. But Italian foreign policy towards the Middle East balanced between promoting dialogue, stability and cooperation on one hand, and colluding with global superpower manoeuvres to exploit existing tensions and achieve local influence on the other. Italy and the Middle East brings together a range of experts on Italian international relations to analyse, for the first time in English, the country\u2019s Cold War relationship with the Middle East. Chapters covering a wide range of defining twentieth century events \u2013 from the Arab-Israeli conflict and the Lebanese Civil War, to the Iranian Revolution and the Soviet invasion of Afghanistan \u2013 demonstrate the nuances of Italian foreign policy in dealing with the complexity of Middle Eastern relations. The collection demonstrates the interaction of local and global issues in shaping Italy\u2019s international relations with the Middle East, making it essential reading to students of the Cold War, regional interactions, and the international relations of Italy and the Middle East