In-situ upgrading of oil using hydrogen donors is a new process. In particular, very little research has been conducted with respect to in-situ oil upgrading using hydrogen donor under in-situ combustion. Several papers describe the use of metal additives mixed with oil and their influence on oil properties such as viscosity and API gravity. The main objective of my research is to determine if a catalyst mixed with a hydrogen donor (tetralin) is going to affect the Jobo crude oil properties while undergoing in-situ combustion. Six runs were performed with Jobo crude oil (9-11ºAPI) from the Orinoco Belt in Venezuela. Four of the runs were successful. Two of them are base runs; the remaining ones are with tetralin with concentration of 5 wt% (of oil) and catalyst with concentration of 750 ppm. For all runs, the following were kept constant: the air injection rate (3 std. L/min) and production (combustion tube outlet) pressure, 300 psig. Concentration by weight of oil, water, and sand in the samples were approximately 4.8%, 4.2%, and 91% respectively. Oil viscosity at the end of combustion at 40oC decreased from 42.3 and 73.6 to 16.6 and 25.2; API gravity at the end of combustion increased from 18.4 and 16.8 to 20 and 18.8. Oil recovery is higher; combustion front velocity is faster in the case of additives, water production decreased. Since oil viscosity decreased and API gravity increased oil moves faster and consequently combustion time is lower.

In-situ upgrading of oil using hydrogen donors is a new process. In particular, very little research has been conducted with respect to in-situ oil upgrading using hydrogen donor under in-situ combustion. Several papers describe the use of metal additives mixed with oil and their influence on oil properties such as viscosity and API gravity. The main objective of my research is to determine if a catalyst mixed with a hydrogen donor (tetralin) is going to affect the Jobo crude oil properties while undergoing in-situ combustion. Six runs were performed with Jobo crude oil (9-11ºAPI) from the Orinoco Belt in Venezuela. Four of the runs were successful. Two of them are base runs; the remaining ones are with tetralin with concentration of 5 wt% (of oil) and catalyst with concentration of 750 ppm. For all runs, the following were kept constant: the air injection rate (3 std. L/min) and production (combustion tube outlet) pressure, 300 psig. Concentration by weight of oil, water, and sand in the samples were approximately 4.8%, 4.2%, and 91% respectively. Oil viscosity at the end of combustion at 40°C decreased from 42.3 and 73.6 to 16.6 and 25.2; API gravity at the end of combustion increased from 18.4 and 16.8 to 20 and 18.8. Oil recovery is higher; combustion front velocity is faster in the case of additives, water production decreased. Since oil viscosity decreased and API gravity increased oil moves faster and consequently combustion time is lower.

The firing of fuel wood has been identified as one of themain causes of pollutant emissions from small-scale (<100kW) combustion of wood fuels. The emissions are a result ofinsufficient combustion efficiency. This thesis presents a newmeasurement method to analyse the thermochemical conversion ofbiofuels in general, as well as to explain the main reason ofthe inefficient combustion of fuel wood in particular. In general, small-scale combustion of biofuels are carriedout by means of packed-bed combustion (PBC)technology. Acomprehensive literature review revealed that textbooks,theories, and methods in the field of thermochemical conversionof solid fuels in the context of PBC are scarce. This authorneeded a theoretical platform for systematic research on PBC ofbiofuels. Consequently, a new system theory - the three-stepmodel - was developed, describing the objectives of, theefficiencies of, and the process flows between, the leastcommon functions (subsystems) of a PBC system. The three stepsare referred to as the conversion system, the combustionsystem, and the heat exchanger system (boiler system). A numberof quantities and concepts, such as solid-fuel convertibles,conversion gas, conversion efficiency, and combustionefficiency, are deduced in the context of the three-step model.Based on the three-step model a measurement method washypothetically modelled aiming at the central physicalquantities of the conversion system, that is, the mass flow andstoichiometry of conversion gas, as well as the air factor ofthe conversion system. An uncertainty propagation analysis ofthe constitutive mathematical models of the method was carriedout. It indicated that it should be possible to determine themass flow and stoichiometry of conversion gas within the rangesof relative uncertainties of ±5% and ±7%,respectively. An experimental PBC system was constructed,according to the criteria defined by the hypothetical method.Finally, the method was verified with respect to total massflow of conversion gas in good agreement with the verificationmethod. The relative error of mass flow of conversion gas wasin the range of ±5% of the actual value predicted by theverification method. One experimental series was conducted applying the newmeasurement method. The studied conversion concept correspondedto overfired, updraft, horizontal fixed grate, and verticalcylindrical batch reactor. The measurements revealed newinformation on the similarities and the differences in theconversion behaviour of wood chips, wood pellets, and fuelwood. The course of a batch conversion has proven to be highlydynamic and stochastic. The dynamic range of the air factor ofthe conversion system during a run was 10:1. The empiricalstoichiometry of conversion gas during a run was CH3.1O:CH0O0. Finally ,this experimental series revealed one ofthe main reasons why fuel wood is more difficult to burn thanfor example wood pellets. The relatively dry fuel wood (12-31g/m2,s) displayed a significantly lower time-integratedmean of mass flux of conversion gas than both the wood pellets(37-62 g/m2,s) and the wood chips (50-90 g/m2,s). The higher the mass flux of conversion gasproduced in the conversion system, the higher the combustiontemperature for a given combustion system, which in turn ispositively coupled to the combustion efficiency. In future work the method will be improved so thatmeasurements of combustion efficiency can be carried out. Othertypes of conversion concepts will be studied by the method. Keywords: Packed-bed combustion, thermochemical conversionof biomass, solid-fuel combustion, fuel-bed combustion, gratecombustion, biomass combustion, gasification, pyrolysis,drying.

<p>The firing of fuel wood has been identified as one of themain causes of pollutant emissions from small-scale (<100kW) combustion of wood fuels. The emissions are a result ofinsufficient combustion efficiency. This thesis presents a newmeasurement method to analyse the thermochemical conversion ofbiofuels in general, as well as to explain the main reason ofthe inefficient combustion of fuel wood in particular.</p><p>In general, small-scale combustion of biofuels are carriedout by means of packed-bed combustion (PBC)technology. Acomprehensive literature review revealed that textbooks,theories, and methods in the field of thermochemical conversionof solid fuels in the context of PBC are scarce. This authorneeded a theoretical platform for systematic research on PBC ofbiofuels. Consequently, a new system theory - the three-stepmodel - was developed, describing the objectives of, theefficiencies of, and the process flows between, the leastcommon functions (subsystems) of a PBC system. The three stepsare referred to as the conversion system, the combustionsystem, and the heat exchanger system (boiler system). A numberof quantities and concepts, such as solid-fuel convertibles,conversion gas, conversion efficiency, and combustionefficiency, are deduced in the context of the three-step model.Based on the three-step model a measurement method washypothetically modelled aiming at the central physicalquantities of the conversion system, that is, the mass flow andstoichiometry of conversion gas, as well as the air factor ofthe conversion system. An uncertainty propagation analysis ofthe constitutive mathematical models of the method was carriedout. It indicated that it should be possible to determine themass flow and stoichiometry of conversion gas within the rangesof relative uncertainties of ±5% and ±7%,respectively. An experimental PBC system was constructed,according to the criteria defined by the hypothetical method.Finally, the method was verified with respect to total massflow of conversion gas in good agreement with the verificationmethod. The relative error of mass flow of conversion gas wasin the range of ±5% of the actual value predicted by theverification method.</p><p>One experimental series was conducted applying the newmeasurement method. The studied conversion concept correspondedto overfired, updraft, horizontal fixed grate, and verticalcylindrical batch reactor. The measurements revealed newinformation on the similarities and the differences in theconversion behaviour of wood chips, wood pellets, and fuelwood. The course of a batch conversion has proven to be highlydynamic and stochastic. The dynamic range of the air factor ofthe conversion system during a run was 10:1. The empiricalstoichiometry of conversion gas during a run was CH_3.1O:CH₀O₀. Finally ,this experimental series revealed one ofthe main reasons why fuel wood is more difficult to burn thanfor example wood pellets. The relatively dry fuel wood (12-31g/m₂,s) displayed a significantly lower time-integratedmean of mass flux of conversion gas than both the wood pellets(37-62 g/m₂,s) and the wood chips (50-90 g/m₂,s). The higher the mass flux of conversion gasproduced in the conversion system, the higher the combustiontemperature for a given combustion system, which in turn ispositively coupled to the combustion efficiency.</p><p>In future work the method will be improved so thatmeasurements of combustion efficiency can be carried out. Othertypes of conversion concepts will be studied by the method.</p><p>Keywords: Packed-bed combustion, thermochemical conversionof biomass, solid-fuel combustion, fuel-bed combustion, gratecombustion, biomass combustion, gasification, pyrolysis,drying.</p>

This thesis encompasses CO2 mitigation using three different processes: i) natural gas-fired combined cycle with chemical looping combustion (CLC), ii) trigeneration of electrical power, hydrogen and district heating with extended CLC, iii) steam-based gasification of biomass integrated in an advanced power cycle. In CLC, a solid oxygen carrier circulates between two fluidised-bed reactors and transports oxygen from the combustion air to the fuel; thus, the fuel is not mixed with air and an inherent CO2 separation occurs. In this thesis, CLC has been studied as an alternative process for CO2 capture in a natural gas-fired combined cycle (NGCC). The potential efficiency of such a process using a turbine inlet temperature of 1200 °C and a pressure ratio of 13 is between 52 and 53 % when including the penalty for CO2 compression to 110 bar. It is shown that this efficiency cannot be further improved by including an additional CO2 turbine. Two conceivable reactor designs for CLC in an NGCC are presented. Top-firing has been studied as an option to overcome a temperature limitation in the CLC reactor system. The degree of CO2 capture is shown versus the temperature in the CLC reactor and its combustion efficiency. CLC has the potential to reach both a higher efficiency and a higher degree of CO2 capture than conventional post combustion CO2 capture technique. However, further research is needed to solve technical problems as, for example, temperature limitations in the reactor to reach this potential. Extended CLC (exCLC) is introduced, in which hydrogen is not only produced but also inherently purified. The potential efficiency of a novel tri-generation process for hydrogen, electricity and district heating using exCLC for CO2 capture is investigated. The results show that a thermal efficiency of about 54% might be achieved. A novel power process named evaporative biomass air turbine (EvGT-BAT) for biomass feedstock is presented. This process contains a steam-based gasification of biomass, which is integrated in an externally fired gas turbine cycle with top-firing. In the EvGT-BAT process, the steam-based gasification is conducted in an entrained-flow tubular reactor that is installed in the SFC as a heat exchanger. The EvGT-BAT process has the potential to generate electrical power from biomass with an efficiency of 41 %.

<p>This thesis encompasses CO₂ mitigation using three different processes: i) natural gas-fired combined cycle with chemical looping combustion (CLC), ii) trigeneration of electrical power, hydrogen and district heating with extended CLC, iii) steam-based gasification of biomass integrated in an advanced power cycle. </p><p>In CLC, a solid oxygen carrier circulates between two fluidised-bed reactors and transports oxygen from the combustion air to the fuel; thus, the fuel is not mixed with air and an inherent CO₂ separation occurs. In this thesis, CLC has been studied as an alternative process for CO₂ capture in a natural gas-fired combined cycle (NGCC). The potential efficiency of such a process using a turbine inlet temperature of 1200 °C and a pressure ratio of 13 is between 52 and 53 % when including the penalty for CO₂compression to 110 bar. It is shown that this efficiency cannot be further improved by including an additional CO₂ turbine. Two conceivable reactor designs for CLC in an NGCC are presented. Top-firing has been studied as an option to overcome a temperature limitation in the CLC reactor system. The degree of CO₂ capture is shown versus the temperature in the CLC reactor and its combustion efficiency. CLC has the potential to reach both a higher efficiency and a higher degree of CO₂capture than conventional post combustion CO₂ capture technique. However, further research is needed to solve technical problems as, for example, temperature limitations in the reactor to reach this potential. </p><p>Extended CLC (exCLC) is introduced, in which hydrogen is not only produced but also inherently purified. The potential efficiency of a novel tri-generation process for hydrogen, electricity and district heating using exCLC for CO₂capture is investigated. The results show that a thermal efficiency of about 54% might be achieved. </p><p>A novel power process named evaporative biomass air turbine (EvGT-BAT) for biomass feedstock is presented. This process contains a steam-based gasification of biomass, which is integrated in an externally fired gas turbine cycle with top-firing. In the EvGT-BAT process, the steam-based gasification is conducted in an entrained-flow tubular reactor that is installed in the SFC as a heat exchanger. The EvGT-BAT process has the potential to generate electrical power from biomass with an efficiency of 41 %.</p>

A diesel fuel injector has been modified to allow rotationaround its axis, driven by an electric motor. Injections at upto 6000 rpm from the rotating injector have been investigatedunder the influence of air swirl on one optical research engineand one optically accessible heavy-duty diesel engine. The experiments show that changing from a normal, staticinjection to a sweeping injection has profound effects on sprayformation, dispersion and penetration. This influences thefuel/air-mixing, autoignition, combustion rate and emissionsformation. The spray propagation is stronger influenced byinjector rotation than by air swirl. The air entrainment into the spray increases forcounter-swirl rotation of the injector and this speeds up thevaporization and decreases the formation of soot. In addition,the oxidation of soot is enhanced since the counter-swirlinjection forces the intense fuel-rich and soot containingspray core to penetrate into fresh air instead of replenishingthe rich regions in the head of the spray. Fuel accumulationalong the piston bowl wall decreases as an effect of thereduced penetration with counter-swirl injection. Altogether,this decreases the smoke emissions for low and intermediateengine loads. For the combustion system studied, counter-swirl rotation ofthe injector cannot decrease the smoke emissions at high engineload since the reduced spray penetration impairs the airutilization. Fast and efficient combustion at high loadrequires spray induced flame spread out into the squish region.Spray induced flow of cool fresh air from the bottom of thepiston bowl in towards the injector is also important for lowsoot formation rates. Co-swirl rotation of the injector reduces the airentrainment into the spray and increases the soot formation.The increased smoke and CO emissions with co-swirl injectionare also attributed to the excessively large fuel-rich regionsbuilt up against the piston bowl wall. Increased air swirl generally reduces smoke and COemissions. This is mainly an effect of enhanced burnout due tomore intense mixing after the end of fuel injection. Changes in smoke as an effect of injector rotation aregenerally accompanied with opposite, but relatively small,changes in NO. Fast and efficient burnout is important for lowsmoke emissions and this raises both the temperature andproduction of NO. NO production is strongly influenced by thein-cylinder conditions during the latter part of themixing-controlled combustion and in the beginning of theburnout. <b>Keywords:</b>diesel spray combustion, rotating injector,air swirl, air/fuel-mixing, soot, NO, CO, flame visualization,Chemkin modeling, soot deposition

<p>A diesel fuel injector has been modified to allow rotationaround its axis, driven by an electric motor. Injections at upto 6000 rpm from the rotating injector have been investigatedunder the influence of air swirl on one optical research engineand one optically accessible heavy-duty diesel engine.</p><p>The experiments show that changing from a normal, staticinjection to a sweeping injection has profound effects on sprayformation, dispersion and penetration. This influences thefuel/air-mixing, autoignition, combustion rate and emissionsformation. The spray propagation is stronger influenced byinjector rotation than by air swirl.</p><p>The air entrainment into the spray increases forcounter-swirl rotation of the injector and this speeds up thevaporization and decreases the formation of soot. In addition,the oxidation of soot is enhanced since the counter-swirlinjection forces the intense fuel-rich and soot containingspray core to penetrate into fresh air instead of replenishingthe rich regions in the head of the spray. Fuel accumulationalong the piston bowl wall decreases as an effect of thereduced penetration with counter-swirl injection. Altogether,this decreases the smoke emissions for low and intermediateengine loads.</p><p>For the combustion system studied, counter-swirl rotation ofthe injector cannot decrease the smoke emissions at high engineload since the reduced spray penetration impairs the airutilization. Fast and efficient combustion at high loadrequires spray induced flame spread out into the squish region.Spray induced flow of cool fresh air from the bottom of thepiston bowl in towards the injector is also important for lowsoot formation rates.</p><p>Co-swirl rotation of the injector reduces the airentrainment into the spray and increases the soot formation.The increased smoke and CO emissions with co-swirl injectionare also attributed to the excessively large fuel-rich regionsbuilt up against the piston bowl wall.</p><p>Increased air swirl generally reduces smoke and COemissions. This is mainly an effect of enhanced burnout due tomore intense mixing after the end of fuel injection.</p><p>Changes in smoke as an effect of injector rotation aregenerally accompanied with opposite, but relatively small,changes in NO. Fast and efficient burnout is important for lowsmoke emissions and this raises both the temperature andproduction of NO. NO production is strongly influenced by thein-cylinder conditions during the latter part of themixing-controlled combustion and in the beginning of theburnout.</p><p><b>Keywords:</b>diesel spray combustion, rotating injector,air swirl, air/fuel-mixing, soot, NO, CO, flame visualization,Chemkin modeling, soot deposition</p>

In this work is proposed the generalized powertrain of the parallel hybrid car. The powertrain is composed from the sub-models of the power sources. Each sub-model is described by the quasi-static modeling. For given routes is computed the power demand. Based on the derived power demand, three energy management systems are tested. First system is based on heuristic rules. The second one use more sophisticated control algorithms - the optimization method. Main idea is based on minimum principle, when the control algorithm tries to minimize the cost function (fuel use, emission). The last one is based on the equivalent consumption minimization strategy.

<p>Additive manufacturing of gun propellants is an emerging and promising field which addresses the limitations of conventional manufacturing techniques. Gun propellants are manufactured using wetted extrusion, which uses volatile solvents and dies of limited and constant geometries. On the other hand, additive techniques are faced with the challenges of maintaining the gun propellant’s energetic content as well as its structural integrity during high pressure combustion. The work presented in this thesis demonstrates the feasibility of producing functioning gun propellant grains using vibration-assisted 3D printing, a novel method which has been shown to extrude extremely viscous materials such as clays and propellant pastes. At first, the technique is compared to screw-driven additive methods which have been used in printing gun propellant pastes with slightly lower energetic content. In chapter two, diethylene glycol dinitrate (DEGDN), a highly energetic plasticizer, was investigated due to its potential to replace nitroglycerin in double base propellants with high nitroglycerin content. A novel isoconversional method was applied to analyze its decomposition kinetics. The ignition and lifetime values of diethylene glycol dinitrate were obtained using the new isoconversional method, in order to assess the safety of using the plasticizer in a modified double base propellant. In chapter three, a modified double base propellant (M8D) containing DEGDN was additively manufactured using VAP. The printed strands had little to no porosity, and their density was nearly equal to the theoretical maximum density of the mixture. The strands were burned at high pressures in a Crawford bomb and the burning was visualized using high speed cameras. The burning rate equation as a function of the M8D propellant as a function of pressure was obtained. Overall, this work shows that VAP is capable of printing highly energetic gun propellants with low solvent content, low porosity, with high printing speeds, and which have consistent burning characteristics at high pressures. </p>