<p>Agglomeration (the sticking together of particles) is often the major growth mechanism in granulation processes. The population balance equation (PBE) is a mathematical framework that is often applied to systems to describe how the particle size distribution changes as a function of time. Different kinetic terms are included in the PBE to describe the different particle growth mechanisms. In this work, a new kinetic model framework is proposed for the growth mechanism binary agglomeration. Binary agglomeration means that only two particles are involved in an agglomeration event. The generality of the new model framework is an advantage over the previous coalescence kernel framework. It is shown that an existing coalescence kernel model can be expressed by means of the new framework.</p><p>The new model framework is then adapted to the special case of fluidized bed granulation (FBG) by proposing/choosing expressions for the three submodels in the model framework. An advantage of the new FBG model is that a maximum number of agglomeration events per unit time can be estimated. This means that the model is one step closer to being used predictively. At the moment, no population balance models can predict granulation processes where agglomeration is the dominant growth mechanism. It is shown that both the new FBG model and an existing model could fit experimental data well, however, the new model reflects the situation that the presence of surface liquid is rate limiting for the agglomeratio process.</p><p>Experiments in a laboratory batch fluidized bed granulator were carried out. Samples of the particle size distribution were taken at intervals during an experiment. These data were used to fit the model parameters of the FBG model. The dissertation includes a discussion of the effect of certain operating conditions such as bed temperature and liquid spray rate on a model parameter.</p>

Agglomeration (the sticking together of particles) is often the major growth mechanism in granulation processes. The population balance equation (PBE) is a mathematical framework that is often applied to systems to describe how the particle size distribution changes as a function of time. Different kinetic terms are included in the PBE to describe the different particle growth mechanisms. In this work, a new kinetic model framework is proposed for the growth mechanism binary agglomeration. Binary agglomeration means that only two particles are involved in an agglomeration event. The generality of the new model framework is an advantage over the previous coalescence kernel framework. It is shown that an existing coalescence kernel model can be expressed by means of the new framework. The new model framework is then adapted to the special case of fluidized bed granulation (FBG) by proposing/choosing expressions for the three submodels in the model framework. An advantage of the new FBG model is that a maximum number of agglomeration events per unit time can be estimated. This means that the model is one step closer to being used predictively. At the moment, no population balance models can predict granulation processes where agglomeration is the dominant growth mechanism. It is shown that both the new FBG model and an existing model could fit experimental data well, however, the new model reflects the situation that the presence of surface liquid is rate limiting for the agglomeratio process. Experiments in a laboratory batch fluidized bed granulator were carried out. Samples of the particle size distribution were taken at intervals during an experiment. These data were used to fit the model parameters of the FBG model. The dissertation includes a discussion of the effect of certain operating conditions such as bed temperature and liquid spray rate on a model parameter.

Äldre flerbostadshus i dagens Sverige använder sig av väldigt mycket energi i onödan. Uppvidingehus är ett fastighetsbolag som anser att deras flerbostadshus har en hög energianvändning. Tre områden i Åseda granskas under denna studie för att se ifall ett digitalt energistyrningssystem kan förminska energianvändningen på dessa områden. Resultatet redovisar vilka byggnader som skulle kunna uppnå en lägre energianvändning och ifall det är lönsamt för ett mindre bostadsföretag att investera i ett digitalt energistyrningssystem.

<p>This dissertation was undertaken to study two different subjects both related to molecular decomposition by applying a shock tube and non-thermal plasma to decompose selected hydrocarbons. The first approach to molecular decomposition concerned thermal decomposition and oxidation of highly diluted nitromethane (NM) in a shock tube. Reflected shock tube experiments on NM decomposition, using mixtures of 0.2 to 1.5 vol% NM in nitrogen or argon were performed over the temperature range 850-1550 K and pressure range 190-900 kPa, with 46 experiments diluted in nitrogen and 44 diluted in argon. By residual error analysis of the measured decomposition profiles it was found that NM decomposition (CH₃NO₂ + M -> CH₃ + NO₂ + M, where M = N₂ /Ar) corresponds well to a law of first order. Arrhenius expressions corresponding to NM diluted either in N₂ or in Ar were found as k_N2 = 1017.011×exp(-182.6 kJ/mole / R×T <cm³/mole×s> and k_Ar = 1017.574×exp(-207 kJ/mole / R×T )<cm3^/mole×s>, respectively. A new reaction mechanism was then proposed, based on new experimental data for NM decomposition both in Ar and N₂ and on three previously developed mechanisms. The new mechanism predicts well the decomposition of NM diluted in both N₂ and Ar within the pressure and temperature range covered by the experiments.</p><p>In parallel to, and following the decomposition experiments, oxidative experiments on the ignition delay times of NM/O₂/Ar mixtures were investigated over high temperature and low to high pressure ranges. These experiments were carried out with eight different mixtures of gaseous NM and oxygen diluted in argon, with pressures ranging between 44.3-600 kPa, and temperatures ranging between 842-1378 K.</p><p>The oxidation experiments were divided into different categories according to the type of decomposition signals achieved. For signals with and without emission, the apparent quasi-constant activation energy was found from the correlations, to be 64.574 kJ/mol and 113.544 kJ/mol, respectively. The correlations for the ignition delay for time signals with and without emission were deduced as τemission = 0.3669×10^-2×[NM]^-1.02[O₂]^-1.08×[Ar]^1.42×exp(7767/T) and τno emission = 0.3005×10^-2×[NM]^-0.28[O₂]^0.12×[Ar]^-0.59×exp(13657/T), respectively.</p><p>The second approach to molecular decomposition concerned the application of non-thermal plasma to initiate reactions and decompose/oxidize selected hydrocarbons, methane and propane, in air. Experiments with a gliding arc discharge device were performed at the university of Orléans on the decomposition/reforming of low-to stoichiometric concentration air/CH₄ mixtures. The presented results show that complete reduction of methane could be obtained if the residence time in the reactor was sufficiently long. The products of the methane decomposition were mainly CO₂, CO and H₂O. The CH₄ conversion rate showed to increase with increasing residence time, temperature of the operating gas, and initial concentration of methane. To achieve complete decomposition of CH₄in 1 m³ of a 2 vol% mixture, the energy cost was about 1.5 kWh. However, the formation of both CO and NOx in the present gliding discharge system was found to be significant. The produced amount of both CO (0.4-1 vol%) and NO_x (2000-3500 ppm) were in such high quantities that they would constitute an important pollution threat if this process as of today was to be used in large scale CH₄ decomposition. Further experimental investigations were performed on self-built laboratory scale, single- and double dielectric-barrier discharge devices as a means of removing CH₄ and C₃H_{8 f}rom simulated reactive inlet mixtures. The different discharge reactors were all powered by an arrangement of commercially available Tesla coil units capable of high-voltage high-frequency output. The results from each of the different experiments are limited and sometimes only qualitative, but show a tendency that the both CH₄ and C₃H₈are reduced in a matter of a 3-6 min. retention time. The most plausible mechanism for explaining the current achievements is the decomposition by direct electron impact.</p>

This dissertation was undertaken to study two different subjects both related to molecular decomposition by applying a shock tube and non-thermal plasma to decompose selected hydrocarbons. The first approach to molecular decomposition concerned thermal decomposition and oxidation of highly diluted nitromethane (NM) in a shock tube. Reflected shock tube experiments on NM decomposition, using mixtures of 0.2 to 1.5 vol% NM in nitrogen or argon were performed over the temperature range 850-1550 K and pressure range 190-900 kPa, with 46 experiments diluted in nitrogen and 44 diluted in argon. By residual error analysis of the measured decomposition profiles it was found that NM decomposition (CH3NO2 + M -&gt; CH3 + NO2 + M, where M = N2 /Ar) corresponds well to a law of first order. Arrhenius expressions corresponding to NM diluted either in N2 or in Ar were found as kN2 = 1017.011×exp(-182.6 kJ/mole / R×T &lt;cm3/mole×s&gt; and kAr = 1017.574×exp(-207 kJ/mole / R×T )&lt;cm3/mole×s&gt;, respectively. A new reaction mechanism was then proposed, based on new experimental data for NM decomposition both in Ar and N2 and on three previously developed mechanisms. The new mechanism predicts well the decomposition of NM diluted in both N2 and Ar within the pressure and temperature range covered by the experiments. In parallel to, and following the decomposition experiments, oxidative experiments on the ignition delay times of NM/O2/Ar mixtures were investigated over high temperature and low to high pressure ranges. These experiments were carried out with eight different mixtures of gaseous NM and oxygen diluted in argon, with pressures ranging between 44.3-600 kPa, and temperatures ranging between 842-1378 K. The oxidation experiments were divided into different categories according to the type of decomposition signals achieved. For signals with and without emission, the apparent quasi-constant activation energy was found from the correlations, to be 64.574 kJ/mol and 113.544 kJ/mol, respectively. The correlations for the ignition delay for time signals with and without emission were deduced as τemission = 0.3669×10-2×[NM]-1.02[O2]-1.08×[Ar]1.42×exp(7767/T) and τno emission = 0.3005×10-2×[NM]-0.28[O2]0.12×[Ar]-0.59×exp(13657/T), respectively. The second approach to molecular decomposition concerned the application of non-thermal plasma to initiate reactions and decompose/oxidize selected hydrocarbons, methane and propane, in air. Experiments with a gliding arc discharge device were performed at the university of Orléans on the decomposition/reforming of low-to stoichiometric concentration air/CH4 mixtures. The presented results show that complete reduction of methane could be obtained if the residence time in the reactor was sufficiently long. The products of the methane decomposition were mainly CO2, CO and H2O. The CH4 conversion rate showed to increase with increasing residence time, temperature of the operating gas, and initial concentration of methane. To achieve complete decomposition of CH4 in 1 m3 of a 2 vol% mixture, the energy cost was about 1.5 kWh. However, the formation of both CO and NOx in the present gliding discharge system was found to be significant. The produced amount of both CO (0.4-1 vol%) and NOx (2000-3500 ppm) were in such high quantities that they would constitute an important pollution threat if this process as of today was to be used in large scale CH4 decomposition. Further experimental investigations were performed on self-built laboratory scale, single- and double dielectric-barrier discharge devices as a means of removing CH4 and C3H8 from simulated reactive inlet mixtures. The different discharge reactors were all powered by an arrangement of commercially available Tesla coil units capable of high-voltage high-frequency output. The results from each of the different experiments are limited and sometimes only qualitative, but show a tendency that the both CH4 and C3H8 are reduced in a matter of a 3-6 min. retention time. The most plausible mechanism for explaining the current achievements is the decomposition by direct electron impact.

Rapporten avhandlar en konceptstudie för omvandling av termisk energi till elektrisk samt mekanisk energi, i den autonoma undervattensfarkosten SAPPHIRES. Inledningsvis utreds vilka förväntningar och krav som finns på konceptet för energiomvandling samt om där finns någon publicerad litteratur som redan gjort ansträngningar för att lösa det aktuella problemet. Allmän teori kring värmemotorer och en bred, systematisk litteratursökning inkluderas även i det arbetet. Energiomvandlingen antas kunna ske enligt två fall kallade ”hög-prestanda” och ”låg/medel-prestanda”, vilka innebär att mekanisk samt elektrisk effekt, respektive endast elektrisk effekt ska kunna levereras av konceptet. De mekaniska samt elektriska effekterna ska, vidare, kunna levereras om maximalt 600, respektive 6 kW, och konceptet ska åtminstone kunna uppfylla ett av energiomvandlingsfallen. Den faktiska konceptstudien utgörs av två iterationer av konceptgenereringar, -utvärderingar och -val och de visar att ett koncept kallat ”Öppet system inspirerat av nukleär värmeframdrivning” förefaller vara det bästa sättet att omvandla termisk energi i SAPPHIRES. Därtill indikerar en mer detaljerad analys, bestående av bland annat matematisk modellering och konceptuell konstruktion, att konceptet möjligen skulle kunna uppfylla så kallad ”hög-prestanda” och sedermera leverera både mekanisk och elektrisk effekt om 600, respektive 6 kW. Mer specifikt visar en matematisk analys, med hjälp av vissa antaganden rörande konceptets funktion, att ett ”Öppet system inspirerat av nukleär värmeframdrivning” skulle kunna leverera en mekanisk effekt om 1025 kW samt en elektrisk effekt om 141 kW. En grov, konceptuell konstruktion bekräftar också att konceptets vitala, ingående komponenter faktiskt kan rymmas inom de specificerade dimensionskraven (en cylinderformad volym med en längd och diameter om 1,7, respektive 0,5 m.). Det står dock klart att de möjliga koncepten för energiomvandling kraftigt begränsas av deras möjligheter att leverera tillräcklig mekanisk effekt, för att uppnå ”hög-prestanda”. Om endast ”låg/medel-prestanda” ska uppfyllas tillåts fler av de möjliga koncepten och i ett sådant fall skulle faktorer som underhåll, miljöpåverkan och SAPPHIRES signatur kunna prioriteras i högre utsträckning. / The report discusses a concept study regarding the conversion of thermal energy into electrical and mechanical energy, in the autonomous underwater vehicle SAPPHIRES. First, the requirements and expectations regarding the concept of energy conversion are investigated and efforts are made to identify any published literature, which has already made attempts of solving the issue. General theory regarding heat engines and an extensive literature study are also included in this work. The energy conversion is assumed to perform according to two cases called "high-performance" and "low/medium-performance", meaning mechanical and electrical energy or electrical power should be delivered by the concept, respectively. More specifically, the mechanical and electrical powers should be delivered of a maximum of 600 and 6 kW, respectively and the concept should at least fulfill one of the performance settings. The actual concept study comprises of two iterations of concept generations, evaluations and selections and shows that a concept called "Open system inspired by nuclear thermal propulsion" seems to be the best way of converting thermal energy on-board SAPPHIRES. Moreover, a more detailed analysis, comprising of, inter alia, mathematical modelling and conceptual design, indicates that the concept possibly can meet the so-called "high-performance" and thus, deliver both mechanical and electrical powers of 600 and 6 kW, respectively. More specifically, a mathematical analysis, based on some assumptions regarding the concept's functionality, shows that an "Open system inspired by nuclear thermal propulsion" could deliver a mechanical power of 1025 kW and an electrical power of 141 kW. Rough conceptual design also shows that the vital parts of the concept could fit within the specified maximal dimensions (a cylinder-shaped volume with a length and diameter of 1.7 and 0.5 m, respectively). However, it is clear the possible concepts of energy conversion are severely limited by their capacities of delivering enough mechanical energy, to meet the "high-performance" demands. Assuming only the "low/medium-performance" has to be met, more possible concepts becomes available and in that case, factors such as maintenance, environmental impact and signature of SAPPHIRES could be considered to a greater extent.

Renewable energy for energy production, like Solar, is turning out to be very pertinent in today's world [1]. It is very clear that Solar Energy is going to emerge as one of the key sources of energy in future. Moreover, the storage option is going to play an essential role to the future deployment of solar power plants. Concentrated solar power plants with thermal storage, photovoltaic plants integrated with battery energy storage, and hybrid plants are attractive solutions to obtain a stable and dispatchable energy production. Investors or policymakers usually find it challenging to come up with the most feasible solar storage technology because they need to consider techno-economic feasibility, and at the same time, from a market or administrative perspective as well. So, this thesis study will address the key problem which is aimed at investors or policymakers since there is a need to choose the best solar storage technology at a utility level in future based on so many attributes. The thesis project was carried out in two phases which includes forecast modelling &amp; estimations and techno-economic assessment of virtual plants. These two phases helped to address various questions in relation to the problem statement of this study. The entire thesis study broadly covered seven countries spanning across four major regions around the world. The first phase of the thesis, forecast modelling estimations shows how the seven countries will look in future (2020 – 2050) with respect to installed capacity and costs for PV, CSP, and BESS technologies. Some major results from phase 1 include, in low-cost estimates, China will remain to be the market leader in PV &amp; CSP by 2050. In U.S.A and India, the installed costs of PV are projected to decline by 70% by 2050. By 2050, the installed costs of Solar Tower technology are estimated to drop by about 65% in China and Spain. In U.S.A, the prices of BESS technology are likely to fall by around 58 – 60 % by 2050. In the second phase of thesis study, a techno-economic evaluation of virtual plants addressed the aspects which are to be considered for a solar project if it is deployed in future across seven specific countries. Results from this analysis helps investors or policymakers to choose the cheapest solar storage technology at a utility level across seven specific countries in future (2020 – 2050). Key results from this analysis show that, in the U.S.A, by 2050, PV+BESS will be the cheapest storage technology for 4 – 10 storage hours. Addition of another renewable technology will add up more viability to the comparison. In China, Hybrid will be the cheapest storage technology for 4 – 8 hrs by 2050. There is huge potential for deployment of CSP &amp; hybrid plants in future than PV. In South Africa, CSP will be the cheapest storage technology by 2050 for 4 – 10 hours of storage. It is assumed that deployment of BESS projects at utility level starts from 2025 in South Africa. Beyond this, market forces analysis was carried out which offers insights especially for the policymakers of how various drivers and constraints are influencing each solar technology across the specific countries in future. Overall, the entire thesis study provides guidelines/insights to investors or policy makers for choosing the best solar storage technology in future at a utility scale for a particular country. / Förnybar energi för energiproduktion, liksom Solar, visar sig vara mycket relevant i dagens värld [1]. Det är mycket tydligt att solenergi kommer att framstå som en av de viktigaste energikällorna i framtiden. Dessutom kommer lagringsalternativet att spela en väsentlig roll för den framtida distributionen av solkraftverk. Koncentrerade solkraftverk med värmelagring, solcellsanläggningar integrerade med batterilagring och hybridanläggningar är attraktiva lösningar för att få en stabil och skickbar energiproduktion. Investerare eller beslutsfattare brukar tycka att det är utmanande att komma på den mest genomförbara solcellstekniken eftersom de måste överväga teknikekonomisk genomförbarhet, och samtidigt, ur ett marknads- eller administrativt perspektiv också. Så denna avhandlingsstudie kommer att ta itu med nyckelproblemet som riktar sig till investerare eller beslutsfattare eftersom det finns ett behov av att välja den bästa solenergilagringstekniken på en användningsnivå i framtiden baserat på så många attribut. Avhandlingsprojektet genomfördes i två faser som inkluderar prognosmodellering och uppskattningar och teknikekonomisk bedömning av virtuella anläggningar. Dessa två faser hjälpte till att ta itu med olika frågor i samband med problemstudien i denna studie. Hela avhandlingsstudien omfattade i stort sju länder som sträcker sig över fyra stora regioner runt om i världen. Den första fasen i avhandlingen, prognosmodelleringsuppskattningar visar hur de sju länderna kommer att se ut i framtiden (2020 - 2050) med avseende på installerad kapacitet och kostnader för PV-, CSP- och BESS -teknik. Några viktiga resultat från fas 1 inkluderar, i lågkostnadsuppskattningar, att Kina kommer att vara marknadsledande inom PV och CSP år 2050. I USA och Indien beräknas de installerade kostnaderna för PV minska med 70% år 2050. Av 2050 beräknas de installerade kostnaderna för Solar Tower -teknik sjunka med cirka 65% i Kina och Spanien. I USA kommer priserna på BESS -teknik sannolikt att sjunka med cirka 58 - 60 % år 2050. I den andra fasen av avhandlingsstudien behandlade en teknikekonomisk utvärdering av virtuella anläggningar de aspekter som ska övervägas för ett solprojekt om det används i framtiden i sju specifika länder. Resultaten från denna analys hjälper investerare eller beslutsfattare att välja den billigaste solenergilagringstekniken på en användningsnivå i sju specifika länder i framtiden (2020 - 2050). Viktiga resultat från denna analys visar att i USA, år 2050, kommer PV+BESS att vara den billigaste lagringstekniken på 4 - 10 lagringstimmar. Tillägg av en annan förnybar teknik kommer att öka jämförbarheten. I Kina kommer Hybrid att vara den billigaste lagringstekniken i 4-8 timmar fram till 2050. Det finns en enorm potential för distribution av CSP &amp; hybridanläggningar i framtiden än PV. I Sydafrika kommer CSP att vara den billigaste lagringstekniken år 2050 för 4 - 10 timmars lagring. Det antas att distributionen av BESS -projekt på verktygsnivå börjar från 2025 i Sydafrika. Utöver detta genomfördes marknadskravsanalys som ger insikter speciellt för beslutsfattarna om hur olika drivkrafter och begränsningar påverkar varje solteknik i de specifika länderna i framtiden. Sammantaget ger hela avhandlingsstudien riktlinjer/insikter till investerare eller beslutsfattare för att välja den bästa solenergitekniken i framtiden i en nyttoskala för ett visst land.

In this thesis, the potential to purify water utilizing waste heat from a unit which stores thermal energy and converts it to electricity is studied. The unit, called TES.POD, is developed by Azelio AB and is in this thesis used as a heat source to drive an air gap membrane distillation (AGMD) unit developed by Scarab Development AB. Heat from the TES.POD and ambient air temperature constitutes a temperature difference over a membrane used as a driving force to vaporize a part of the water that transfer through the membrane, and later condensates as clean distilled water as the contaminations stays in the hot stream of feed water. An analysis has been conducted to determine quasi-steady performance of the combined system for estimating the amount of purified water that can be supplied when the TES.POD unit is in peak electricity discharge mode. The 26 kW of waste heat accessible from the TES.POD is shown to enable two AGMD-modules producing purified water at a production of 7, 1l/h per unit having the feed water at 50°C and cooling water at 25°C. A correlation between the amount of waste heat and distilled water production is determined, as the TES.POD could be configured to produce less electricity and more waste heat at a higher temperature. The correlation showed that an 9% increase in cooling temperature, lead to an 30% increase in pure water output and a 33% decrease in electricity output. The results show that when implementing the two companies’ units together, a system that both provides electricity and distilled water is obtained. This is a system with a high demand, especially in off-grid areas with lack of both resources but with accessible renewable energy sources. Moreover, by using waste heat to purify water, it can also reduce the production cost compared to cases where conventional energy sources are used. The potential revenue of the production was estimated to 673 790 SEK/year with an implementation cost of 93 861 SEK with yearly operational expenses estimated to 14 080 SEK/year. / I detta arbete undersöks möjligheten att rena vatten med spillvärme från ett system vilket lagrar termisk energi och av den producerar elektricitet, när det behövs. Systemet är utvecklat av Azelio AB och har produktnamnet TES.POD. Vattendestillationen utförs med en så kallad air gap membrane distillation (AGMD) modul, utvecklad av Scarab Development AB. Värmen från TES.POD och omgivningstemperaturen utgör, i AGMD-modulen, en temperaturdifferens vilken i sin tur skapar en partielltryckskillnad över membranet. Denna partielltryckskillnad låter en del av det förorenade vattnet som flödar i AGMD-modulen att förångas och passera genom membranet. Föroreningarna stannar kvar i det strömmande vattnet och ångan kondenserar som renat vatten.  Arbetet visar att de 26kW som finns att tillgå i form av spillvärme är tillräckligt för att driva två AGMD-moduler att producera 7,1 l/h destillerat vatten per modul. Detta är under förutsättningar att det förorenade vattnet är 50°C och kylvattnet är 25°C. I rapporten återfinns också ett samband mellan mängden spillvärme och produktionen av destillerat vatten, eftersom TES.POD kan konfigureras till att producera spillvärme vid en högre temperatur. Sambandet visade på att 9% ökning av spillvärmens temperatur motsvarar 30% ökning i produktionen av destillerat vatten och en minskad elektricitetsproduktion på 33%.  Resultatet visar på att integrationen av dessa två produkter bildar ett system som både producerar rent vatten och elektricitet när så önskas. Detta system har till synes en stor efterfrågan, speciellt i områden utanför fast el- och vattennätverk men med goda förnyelsebara energikällor. Dessutom, eftersom vattendestillationen sker med spillvärme, kan produktionskostnaderna vara lägre än då konventionella energikällor används. Den potentiella inkomsten från produktionen estimeras till 673 790 SEK/year med en inköpskostnad om 93 861 SEK samt årliga omkostnader om 14 080 SEK/year.

See file / Se bif. fil