Production of Customized Reactors by 3D Printing for Corrosive and Exothermic Reactions

This work presents a continuous reactor designed to be produced by 3D printing with the ultimate objective of performing fast, exothermic, and corrosive reactions. The dilution of sulfuric acid with water was used as a model for reactor design. A good mixing inside the reactor will promote the dilution and at the same time increase the heat transfer. Fast heat transfer is important to avoid vaporization of reactants/products and to control corrosion inside the reactor. The reactor was designed using a genetic algorithm to maximize the surface area of a prespecified reactor volume while ensuring a good mixing of the reactants. We have experimentally demonstrated that dilution of sulfuric acid can be done continuously in a Hartridge− Roughton mixer with lattices for enhanced heat transfer. Selected designs with internal and external lattices for enhanced heat exchange were manufactured by 3D printing using the Ti64 alloy. Different printing services were used to compare the quality of reactors that can be achieved by new industrial players that do not possess a 3D printer. One important item that should be considered when 3D printing is used for corrosive reactions is cross-contamination with other metals, since that can significantly affect the life and safety conditions of the reactors.publishedVersio

Shaping of metal-organic framework UiO-66 using alginates: Effect of operation variables

Shaping of metal-organic frameworks into macro-structured particles for reactors and separation processes is a fundamental step in their way towards commercialization. Extrusion techniques which are used for shaping many porous materials resulted in significant reduction of surface area in many MOF materials and thus alternative techniques are required. One alternative way to shape soft materials is to use a technique coming from molecular gastronomy and biology; the calcium alginate method. For this method, a slurry of the porous material and sodium alginate is prepared and then dropwise put in contact with calcium chloride solution forming spheres. Forming particles with both suitable diffusion and mechanical properties and without significant reductions in surface area, many operating variables must be tuned and optimized. This publication presents the results obtained showing the effects of varying several process variables of the alginate method for shaping UiO-66 MOF. Characterization in terms of surface area and other surface methods, force required to break particles (crushing strength) and measurement of isotherms of carbon dioxide. With this method we have produced MOF particles with crushing strength similar to alumina or silica) and with only 10% of reduction in surface area and adsorption capacity.acceptedVersio

How can Norwegian police crime prevention be strengthened through implementing "nærpolitireformen" – from a strategic perspective?

Erfaringsbasert master, 90 studiepoeng.I Norge er behovet for en reform av politiet begrunnet med at fremtidens politi må være i stand til å møte den kompliserte, alvorlige og grenseoverskridende kriminaliteten. Her er særlig NOU 2013:9 (Politianalysen) og Prp. 61 LS (2014-2015) sentrale dokumenter. Nærpolitireformen må også ses i lys av de reformtrender som har preget offentlig sektor de siste tiårene. Gjennom Prp. 61 LS (2014-2015) og Justis- og beredskapsdepartementets tildelingsbrev til Politidirektoratet for 2017 er det fastsatt at forebygging skal være politiets primærstrategi. Politiet skal også prioritere etterforskning og ha tilstrekkelig beredskap og krisehåndteringsevne ved ekstraordinære hendelser. På bakgrunn av dette krysspresset har vi formulert følgende problemstilling: Hvordan kan politiets forebyggende arbeid styrkes gjennom nærpolitireformen – sett i et strategisk perspektiv? Gjennom metodetriangulering har vi studert og vurdert styrende dokumenter, dybdeintervjuet halvparten av landets politimestre og rettet en spørreundersøkelse mot forebyggings- og radikaliseringskoordinatorene i politidistriktene. Til drøftingen har vi formulert fire forskningsspørsmål, og i drøftingen av disse har vi tatt i bruk perspektiver på organisasjoner og reform, den konseptuelle foretaksmodellen og strategisk ledelse. De viktigste funnene i avhandlingen er at begrepet forebyggende politiarbeid har et uklart innhold og at det er kulturelle utfordringer knyttet til innføring av forebygging som politiets primærstrategi. Styring og ledelse er essensielt for å balansere krysspresset mellom beredskap og forebyggende politiarbeid. Den strategiske ledelsen gir i større utstrekning enn fagkoordinatorene uttrykk for at de har tro på at det forebyggende arbeidet vil bli styrket gjennom nærpolitireformen. En styrking av faget forebyggende er nødvendig for å lykkes. Det forebyggende arbeidet må spres på flere problemeiere gjennom gjensidig forpliktende avtaler, og den nyopprettede funksjonen "politikontakt" vil spille en sentral rolle i dette. På bakgrunn av dette anbefales det at Politidirektoratet klart definerer hva som menes med forebyggende politiarbeid, at målstyringen tilpasses det forebyggende faget og at det legges betydelig innsats i å utvikle kultur, holdninger og ledelse på alle nivåer i politidistriktene.Engelsk sammendrag (abstract) The need for a reform within the Norwegian police is justified by the fact that future police must be capable of meeting complex, serious, and transboundary crime. Key documents supporting this are NOU 2013: 9 (Politianalysen) and Prp. 61 LS (2014-2015). ‘Nærpolitireformen’ must be also viewed in light of the reform trends that have characterized the public sector in the last decade. It has been established through Prp. 61 LS (2014-2015) and the ministry allotment letter from The Ministry of Justice and Public Security to The National Police Directorate, that crime prevention will be the main strategy for the Norwegian police in 2017. The police will simutaneaously prioritize the investigation of serious crime as well as maintain adequate preparedness and crisis management capability under extraordinary events. On that basis, we present the following issue: How can Norwegian police crime prevention be strengthened through implementing‘nærpolitireformen’ – from a strategic perspective? We have studied and analyzed the governing documents through data triangulation, interviewed half of the Chiefs of Police in Norway, and conducted a survey on the preventionand radicalization coordinators within the Norwegian police. We have proposed four research questions for discussion. To help answer our questions we applied several perspectives about organizations and reform, a model called ‘den konseptuelle foretaksmodell’, as well as strategic leadership. The most important discoveries in this thesis are that the concept of crime prevention has an unclear content, and that there are cultural challenges linked to implementing crime prevention as a main strategy. Management and leadership are essential for balancing the cross-pressures between police emergency and crime prevention. The survey revealed more insight on what the coordinators expressed about their beliefs on how crime prevention can be enhanced through police reform. Crime prevention needs strengthening to succeed. Preventitve efforts must be spread across several public institutions through mutually binding agreements. The recent new function ‘politikontakt’ will play an important part in this. Based on this, it is recommended that The National Police Directorate better define what constitutes crime prevention, that performance management is adjusted according to the characteristics of crime prevention, and that considerable effort is made in order to develop culture, attitudes and leadership at all levels within the Norwegian police

Effects of powder properties on the 3D printing of BaTiO3 ceramic resins by stereolithography

Stereolithography is a layer-by-layer building fabrication technique enabling production of advanced ceramic 3D shapes that are not achievable by other methods. Critical parameters of stereolithography are associated with the preparation of a ceramic resin exhibiting suitable rheological and optical properties, as well as tunable curing property to achieve the desired level of resolution of complex 3D parts. However, tailoring the cure depth for each layer is challenging for functional ceramics due to their high refractive index giving increased light scattering. Here, the stereolithography 3D printing of BaTiO3 ceramic resins is investigated by employing a desktop 3D printer (λ = 405 nm) and a commercial base resin. The effects of two BaTiO3 powders with different size distributions (one micro-sized powder with grains in the range 1–20 μm, and one agglomerated nano-sized powder in the range 60–100 nm), on the viscosity and curing characteristics of the ceramic resins were investigated. It is shown that the nano-sized powder resulted in increased viscosity, increased scattering, and reduced cure depth compared to the micro-sized BaTiO3 ceramic resin. In general, the cure depth decreased with increasing ceramic loading. Successful prints were obtained for an overcuring of at least 40% between layers to assure good adherence between the layers. The printing properties of the ceramic resins from both powders were suitable for printing green parts with 50 μm layer thickness.publishedVersio

Hvordan kan politiets forebyggende arbeid styrkes gjennom nærpolitireformen – sett i et strategisk perspektiv?

I Norge er behovet for en reform av politiet begrunnet med at fremtidens politi må være i stand til å møte den kompliserte, alvorlige og grenseoverskridende kriminaliteten. Her er særlig NOU 2013:9 (Politianalysen) og Prp. 61 LS (2014-2015) sentrale dokumenter. Nærpolitireformen må også ses i lys av de reformtrender som har preget offentlig sektor de siste tiårene. Gjennom Prp. 61 LS (2014-2015) og Justis- og beredskapsdepartementets tildelingsbrev til Politidirektoratet for 2017 er det fastsatt at forebygging skal være politiets primærstrategi. Politiet skal også prioritere etterforskning og ha tilstrekkelig beredskap og krisehåndteringsevne ved ekstraordinære hendelser. På bakgrunn av dette krysspresset har vi formulert følgende problemstilling: Hvordan kan politiets forebyggende arbeid styrkes gjennom nærpolitireformen – sett i et strategisk perspektiv? Gjennom metodetriangulering har vi studert og vurdert styrende dokumenter, dybdeintervjuet halvparten av landets politimestre og rettet en spørreundersøkelse mot forebyggings- og radikaliseringskoordinatorene i politidistriktene. Til drøftingen har vi formulert fire forskningsspørsmål, og i drøftingen av disse har vi tatt i bruk perspektiver på organisasjoner og reform, den konseptuelle foretaksmodellen og strategisk ledelse. De viktigste funnene i avhandlingen er at begrepet forebyggende politiarbeid har et uklart innhold og at det er kulturelle utfordringer knyttet til innføring av forebygging som politiets primærstrategi. Styring og ledelse er essensielt for å balansere krysspresset mellom beredskap og forebyggende politiarbeid. Den strategiske ledelsen gir i større utstrekning enn fagkoordinatorene uttrykk for at de har tro på at det forebyggende arbeidet vil bli styrket gjennom nærpolitireformen. En styrking av faget forebyggende er nødvendig for å lykkes. Det forebyggende arbeidet må spres på flere problemeiere gjennom gjensidig forpliktende avtaler, og den nyopprettede funksjonen "politikontakt" vil spille en sentral rolle i dette. På bakgrunn av dette anbefales det at Politidirektoratet klart definerer hva som menes med forebyggende politiarbeid, at målstyringen tilpasses det forebyggende faget og at det legges betydelig innsats i å utvikle kultur, holdninger og ledelse på alle nivåer i politidistriktene

NMR spectroscopic investigations into the mechanism of absorption and desorption of CO2 by (tris-pyridyl)amine Zn complexes

The Zn complex [(NN3)Zn(OH)]2(NO3)2 (1(NO3)2, NN3 = tris(2-pyridylmethyl)amine) reacts with atmospheric CO2 to form a zinc carbonate species {[(NN3)Zn]3CO3}(NO3)4 (2(NO3)4), isolable as a crystalline product from organic solvents. The aqueous chemistry of the CO2 absorption and desorption processes for 1(NO3)2 and the presumed end-point of the reaction, 2(NO3)4, was unknown and hence investigated by NMR spectroscopy. Carboxylation of aqueous solutions of both 1(NO3)2 and 2(NO3)4 form products that can best be described as mixtures of monomeric [(NN3)ZnCO3H]+ and dimeric {[(NN3) Zn]2CO3}2+, which are in a dynamic equilibrium on the NMR time-scale. No evidence for the involvement of 2(NO3)4 in the carboxylation-decarboxylation processes is observed. Rather, the data suggest that 2 (NO3)4 provides [(NN3)Zn(OH2)]2+ that does not participate in the CO2 chemistry upon warming. A mechanism that is supported by NMR experiments and that accounts for the formation of [(NN3) ZnCO3H]+ and {[(NN3)Zn]2CO3}2+ from both ends of the reaction manifold is proposed.acceptedVersio

Two-Phase Dibromocyclopropanation of Unsaturated Alcohols Using Flow Chemistry

Dibromocyclopropanations are conventionally done by addition of dibromocarbene to alkenes under phase-transfer conditions in batch reactions using a strong base (50% NaOH (aq)), vigorous stirring and long reaction times. We have shown that cyclopropanation of unsaturated alcohols can be done under ambient conditions using continuous flow chemistry with 40% (w/w) NaOH (aq) as the base. The reactions were generally rapid; the yields were comparable to yields reported in the literature for the conventional batch reactionpublishedVersio

Use of metal-organics based solvents for CO2 capture

There are a number of metal-organic compounds that can loosely be considered CA mimics and which are known to absorb CO2 directly from the atmosphere. The metal-organic complex, {Zn[N[CH2(2-py)]3](μ-OH)}2(NO3)2 (I), is one such complex. In the present study, the sorption of CO2 by water solutions of complex I have been studied by NMR (using D2O as solvent and absorbing 99.9% 13C enriched CO2) and vapor-liquid equilibria measurements to understand the mechanisms of sorption when using such complexes. The potential of I/water solvents for use in CO2 capture has been evaluated by comparison with mono- ethanolamine (MEA)/water solvents. The metal-organic solvent shows higher sorption capacity than MEA on a molar basis; also, three cycle tests indicate that I/water solvents can be regenerated efficiently at low temperatures giving a potential significant reduction in regeneration energy requirements as compared to MEA/water solvents. On the other hand, due to its more than 14 times lower molar mass, MEA solvents have higher CO2 sorption capacities on a kg solvent basis. The two solvents show similar sorption kinetics.publishedVersio

Shaping of metal-organic framework UiO-66 using alginates: Effect of operation variables

Shaping of metal-organic frameworks into macro-structured particles for reactors and separation processes is a fundamental step in their way towards commercialization. Extrusion techniques which are used for shaping many porous materials resulted in significant reduction of surface area in many MOF materials and thus alternative techniques are required. One alternative way to shape soft materials is to use a technique coming from molecular gastronomy and biology; the calcium alginate method. For this method, a slurry of the porous material and sodium alginate is prepared and then dropwise put in contact with calcium chloride solution forming spheres. Forming particles with both suitable diffusion and mechanical properties and without significant reductions in surface area, many operating variables must be tuned and optimized. This publication presents the results obtained showing the effects of varying several process variables of the alginate method for shaping UiO-66 MOF. Characterization in terms of surface area and other surface methods, force required to break particles (crushing strength) and measurement of isotherms of carbon dioxide. With this method we have produced MOF particles with crushing strength similar to alumina or silica) and with only 10% of reduction in surface area and adsorption capacity

Production of MOF Adsorbent Spheres and Comparison of Their Performance with Zeolite 13X in a Moving-Bed TSA Process for Postcombustion CO2 Capture

Well-shaped 300–700 μm spheres of aggregated metal–organic framework CPO-27-Ni crystallites have been produced using a spray-granulation method with cross-bonded alginate as the binder. The spheres are suitable for use in a moving-bed temperature-swing adsorption (MBTSA) process for postcombustion CO2 capture. The adsorption isotherm data of CO2, N2 ,and H2O have been measured in the temperature intervalof 30–120 °C, and adsorption kinetics have been estimated from breakthrough measurements. The adsorption data together with the physical characteristics of the spheres (pore-size distribution and porosity) have been used to simulate the performance of a MBTSA process utilizing the CPO-27-Ni/alginate spheres as adsorbent and compared to similar simulations using Zeolite 13X spheres. Simulations have been carried out in a natural gas-fired power plant (NGCC) context. The process simulations indicate that the net electric efficiency of the NGCC plant with a MBTSA process utilizing the CPO-27-Ni/alginate spheres is similar to that of a MBTSA process utilizing Zeolite 13X adsorbent, 56.1% and 55.9%, respectively, which are slightly higher than the net efficiency of the benchmark case NGCC with a MEA-based solvent process of 54.7%.publishedVersio