Gasification is a process used to convert any carbonaceous species through heterogeneous reaction to obtain the desired gaseous products of H2 and CO which are used to make chemicals, liquid transportation fuels, and power. Both pyrolysis and heterogeneous gasification occur in commercial entrained-flow gasifiers at pressures from 4 to 65 atm with local gas temperatures as high as 2000 °C. Many gasification studies have been performed at moderate temperatures, heating rates, and pressures. In this work, both pyrolysis and char gasification experiments were performed on coal, petroleum coke, and biomass at conditions pertinent to commercial entrained-flow gasifiers. Rapid biomass pyrolysis experiments were performed at atmospheric pressure in an entrained-flow reactor for sawdust, switchgrass, corn stover, and straw mostly using a peak gas temperature of 1163 K at particle residence times ranging from 34 to 113 ms. Biomass pyrolysis was modeled using the Chemical Percolation Devolatilization model assuming that biomass pyrolysis occurs as a weighted average of its individual components (cellulose, hemicellulose, and lignin). Thermal cracking of biomass tar into light gas was included using a first-order model with kinetic parameters regressed in the current study. Char gasification rates were measured for biomass, petroleum coke, and coal in a pressurized entrained-flow reactor at high heating-rate conditions at total pressures between 10 and 15 atm. Peak centerline gas temperatures were between 1611 and 1879 K. The range of particle residence times used in the gasification experiments was 42 to 275 ms. The CO2 gasification rates of biomass and petroleum coke chars were measured at conditions where the reaction environment consisted of approximately 40 and 90 mol% CO2. Steam gasification rates of coal char were measured at conditions where the maximum H2O concentration was 8.6 mol%. Measured data was used to regress apparent kinetic parameters for a first-order model that describes char conversion. The measured char gasification rates were far from the film-diffusion limit, and are pertinent for pulverized particles where no internal particle temperature gradients are important. The modeling and measured data of char gasification rates in this research will aid in the design and efficient operation of commercial entrained-flow gasifiers, as well as provide validation for both existing and future models at a wide range of temperatures and pressures at high heating-rate conditions.

Магистерская диссертация посвящена вопросу оценки социального инвестирования. Целью исследования является разработка проекта социальной направленности в области доставки газа для отдаленного региона России. Автором была предложена конкретная система показателей оценки социальной эффективности проекта в краткосрочной, так и в долгосрочной перспективе. / The master's thesis is devoted to the evaluation of social investment. The aim of the study is to develop a project of social orientation in the field of gas delivery for a remote region of Russia. The author proposed a specific indicator system for assessing the social effectiveness of the project in the short and long term.

Utsläppen av växthusgaser ökar över hela världen och nya tekniker används för att minska utsläppen. 7% av utsläppen kommer från stålsektorn. 25% av världens stålproduktion görs via återvinningstekniken ljusbågsugn. Genom återvinningsprocessen släpps det ut 500kg CO2 per ton producerat flytande stål. En möjlighet att sänka dessa direkta utsläppär att koppla ljusbågsugnsprocessen med biomassa förgasnings och koldioxidavskiljning. Den föreslagna lösningen i denna avhandling är att utnyttja avgaserna från stålsmältningen i förgasningsprocessen och skapa värdefulla produkter. Projektet utvärderar den tekniska genomförbarheten i form av energieffektivitet och kolutnyttjande. Den föreslagna processen simulerades med Aspen Plus. Ett problem med ljusbågsugnens avgaser är fluktuationen i sammansättningen. Tre fall avavgassammansättning undersöktes. Fall 1 var den genomsnittliga avgassammansättningen, medan fall 2 och 3 var extrema med högt CO- respektive CO2-innehåll. Resultatet visade att syntetsgassammansättningen starkt beror på förgasningsmedlet. I samtliga fall ökade energieffektiviteten och de direkta utsläppen minskade, jämfört med nuvarande process. Fall 1 visade generellt högst effektivitet och kolutnyttjande, medan det CO2 rika fallet (fall 3) hade lägst. Ett kontinuerligt flöde av förgasningsmedel krävs för att driva förgasningsprocessen. Eftersom ljusbågsugn är en satsvis process, sker luftförgasning när avgaser inte är tillgängliga. Det önskade resultatet av luftförgasning är att producera syntetsgas som liknar avgasförgasningens syntesgas. Resultaten visade att luftinfiltration i avgaser är gynnsamt för mer liknande syntesgas . / Greenhouse gas emissions are increasing worldwide, and new techniques are being adopted to suppress the emissions. The steel sector is responsible for 7% of the emissions. 25% ofthe world’s steel production is made through the recycling technique EAF. Throughout the recycling process, 500 kg CO2 gets emitted per ton of liquid steel produced. An opportunity to lower these direct emissions is to couple the EAF process to biomass gasification and CO2 utilisation process. The proposed solution in this thesis is to utilise the off-gases in the gasification process and create high-valuable products. The project evaluates the technical feasibility via energy efficiency and carbon utilisation. The proposed process was simulated using Aspen Plus. A problem with the off-gases from EAF gasification is the fluctuation in composition. Three cases of off-gas composition were therefore investigated. Case 1 was the average off-gas composition, while cases 2 and 3 were extreme with high CO and CO2 content, respectively. The result showed that the syngas composition strongly depends on the gasifying agent. In all cases, the energy efficiency increased, and the direct emissions decreased. Case 1 generally showed the highest efficiency and carbon utilisation, while the CO2 heavily case (case 3) had the lowest. A continuous flow of gasifying agents is required to run the gasification process. Since EAF is a batch process, air gasification runs when off-gases are unavailable. The desired outcome of air gasification is to produce syngas similar to off-gas gasification. The results showed that air infiltration in off-gases is favourable for more similar syngas composition.

This study examines the ecological impact of exemplary processes for the feedstock recycling of waste fractions. It is shown that the material process efficiency of gasification and pyrolysis has a low impact on the greenhouse gas balance in the short term, but that high product yields are necessary in the long term to avoid an increasing climate impact. In a systemic context, different process routes of syngas and pyrolysis oil utilization are compared, and their efficiency and quantitative potential for greenhouse gas reduction compared to electricity-based alternatives of process direct heating of conventional processes and electrolysis-based process chains are classified. It is shown that direct utilization options with few process steps are ecologically more efficient. Feedstock recycling shows a similar reduction potential to direct heating, while the use of electrolysis-based process chains is inefficient but necessary to achieve systemic climate neutrality.:1. Introduction and outline 1 2. Life cycle assessment methodology 5 2.1. Previous LCA investigation on feedstock recycling 7 2.2. Assessment scope 9 2.3. Attributional vs. consequential LCI modelling 11 2.4. Inventory modelling consistency 12 2.5. Prospective technology assessment 13 2.6. Conclusions for the applied methodology 14 3. Process description and modelling 16 3.1. Feedstock recycling technologies 18 3.1.1. Gasification 18 3.1.2. Syngas conditioning and purification 23 3.1.3. Pyrolysis 29 3.1.4. Pyrolysis oil hydroprocessing 32 3.2. Chemical production technologies 34 3.2.1. Steam cracking 35 3.2.2. Catalytic reforming 37 3.2.3. Olefin and BTX recovery 38 3.2.4. Conventional syngas production 41 3.2.5. Methanol and methanol-based synthesis 43 3.2.6. Ammonia synthesis 48 3.3. Electric power integration options 49 3.4. Conventional waste treatment processes 53 3.4.1. Mechanical biological treatment and material recovery 54 3.4.2. Waste incineration 57 3.5. Utility processes and process chain balancing 59 3.6. Electricity and heat supply modelling 65 4. Individual assessment of feedstock recycling processes 68 4.1. Goal and scope definition 68 4.2. Life cycle inventory 68 4.3. Impact assessment 72 4.4. Interpretation 80 5. System-based assessment of feedstock recycling processes 82 5.1. Goal and scope definition 82 5.2. Life cycle inventory 86 5.2.1. Utility, background system inventory and system integration 88 5.2.2. Assessment scenario definition and parameter variation 90 5.3. Impact assessment 93 5.3.1. Framework Status Quo (FSQ) 93 5.3.2. Framework Energy Integration (FEI) 99 5.4. Interpretation 106 6. Summary and conclusion 109 6.1. Results 110 6.2. Recommendations and outlook 111 References 113 Supplementary Material 136

This paper introduces an energy-saving biomass stove. The principle of energy-saving biomass stove is gasification. It is a chemical process, transforms solid fuel into a gas mixture, called (CO + H2 + CH4) gas. Emission lines in the stove chimneys typically remain high temperatures around 900 to 1200C. The composition of the flue gas consists of combustion products of rice husk which are mainly CO2, CO, N2. A little volatile in the rice husk, which could not burn completely, residual oxygen and dust will fly in airflow. The amount of dust in the outlet gas is a combination of unburnt amount of impurity and firewood, usually occupied impurity rate of 1 % by weight of dry husk. Outlet dust of rice husk furnace has a normal size from 500μm to 0.1 micron and a particle concentration ranges from 200-500 mg/m3. Gas emissions is created when using energy-saving stove and they will be used as the main raw material in combustion process Therefore the CO2 emission into the environment when using the stove will be reduced up to 95% of a commonly used stove. / Bài báo giới thiệu một bếp tiết kiệm dùng năng lượng sinh khối. Bếp tiết kiệm năng lượng thực hiện nguyên lý khí hóa sinh khối. Đó là một quá trình hóa học, chuyển hóa các loại nhiên liệu dạng rắn thành một dạng hỗn hợp khí đốt, gọi là khí Gas (CO + H2 + CH4). Dòng khí thải ra ở ống khói của bếp thông thường có nhiệt độ vẫn còn cao khoảng 900 ~ 1200C. Thành phần của khói thải bao gồm các sản phẩm cháy của trấu, chủ yếu là các khí CO2, CO, N2, một ít các chất bốc trong trấu không kịp cháy hết, oxy dư và tro bụi bay theo dòng khí. Lượng bụi tro có trong khói thải chính là một phần của lượng không cháy hết và lượng tạp chất không cháy có trong củi, lượng tạp chất này thường chiếm tỷ lệ 1% trọng lượng trấu khô.Bụi trong khói thải lò đốt trấu thông thường có kích thước hạt từ 500μm tới 0,1μm, nồng độ dao động trong khoảng từ 200-500 mg/m3. Lượng khí thải được sinh ra khi sử dụng bếp tiết kiệm năng lượng, sẽ được dùng làm nguyên liệu đốt cháy chính của quá trình đó. Do đó lượng khí CO2 thải ra môi trường khi sử dụng bếp tiết kiệm sẽ được giảm xuống 95 % so với sử dụng bếp thường.

[pt] A industrialização e a crescente preocupação com o meio ambiente geram, cada vez mais, a busca por fontes de energia que emitam menos gases efeito estufa. A biomassa, devido a sua grande ocorrência ao redor do mundo e a sua diversidade, é uma forte alternativa aos combustíveis fósseis. Sua gaseificação gera um combustível gasoso chamado syngas. A problemática no manejo dos resíduos sólidos urbanos (RSU) e a grande disponibilidade do bagaço de cana-de-açúcar no Brasil fizeram deles tipos de biomassa de interesse para este trabalho. Objetivou-se simular no MATLAB® a gaseificação cocorrente de biomassa com ar a partir de uma abordagem cinética. O modelo foi validado com dados da literatura e aplicado à simulação da co-gaseificação de RSU e bagaço de cana-de-açúcar, na qual a razão de co-gaseificação (RCG) representou a percentagem de RSU na biomassa de entrada. Um planejamento composto central com 3 fatores e 3 níveis foi realizado, resultando em 27 ensaios variando os fatores RCG, umidade da biomassa e razão de equivalência. Foram criados modelos polinomiais para a composição do syngas obtido, o PCI do syngas, a eficiência energética do processo e a soma das frações molares de CO e H2 em base úmida. Os modelos foram considerados robustos, com valores de R2 e R2 ajustado variando de 0,96082 a 0,99345 e 0,94007 a 0,98998, respectivamente. O impacto dos fatores escolhidos nas respostas foi analisado, e os modelos de eficiência energética e soma das frações molares de CO e H2 foram maximizados. O caso otimizado, com RCG 7,98 porcento, umidade 5,00 porcento e razão de equivalência 0,18, resultou em um syngas de composição 3,72 porcento H2O, 29,68 porcento CO, 7,87 porcento CO2, 19,07 porcento H2 e 0,80 porcento de CH4 em mol, correspondendo a um PCI de 6,56 MJ/Nm3 e uma eficiência energética de 37,66 porcento. Por fim, o processo demonstrou bom potencial para geração de um gás rico em CO e H2. / [en] Industrialization and growing environmental concern are increasingly leading to the search for energy sources that emit less greenhouse gases. Biomass, due to its great accessibility around the world and its diversity, is a strong alternative to fossil fuels. Its gasification produces a gaseous fuel called syngas. The urban solid waste (MSW) management problems and the wide availability of sugarcane bagasse in Brazil made them types of biomass of interest for this work. This work aimed to model biomass gasification in MATLAB ® for a downdraft gasifier and air as gasifying agent, using a kinetic approach. The model was validated with experimental and numerical data from the literature and was then applied to MSW and sugarcane bagasse co-gasification simulation, in which co-gasification ratio (CGR) represented MSW percentage in the incoming biomass. A central composite design of experiments with 3 factors and 3 levels was carried out, resulting in 27 tests varying CGR, biomass moisture and equivalence ratio. Polynomial models were created for syngas composition, syngas LHV, process energy efficiency and sum of CO and H2 molar fractions on a wet basis. The models were considered robust, with values of R2 and adjusted R2 ranging from 0,96082 to 0,99345 and 0,94007 to 0,98998, respectively. The impact of each chosen factor was investigated, and the energy efficiency and sum of CO and H2 molar fractions models were maximized. The optimized case, with CGR 7,98 percent, biomass moisture 5,00 percent and equivalence ratio 0,18, resulted in a syngas composition of 3,72 percent H2O, 29,68 percent CO, 7,87 percent CO2, 19,07 percent H2 and 0,80 percent CH4 in molar basis, corresponding to a LHV of 6,56 MJ/Nm3 and an energy efficiency of 37,66 percent. By the end, the process showed great potential to produce a syngas rich in CO and H2.

Utsläpp av CO2 till atmosfären bidrar till ökningen av globala temperaturer. Industrisektorn står för 20 % av utsläppen och utav dessa kommer 6 % från pappers- och massaindustrin. För att lyckas minska den globala temperaturhöjningen till under 1,5 °C hjälper det inte bara att minska utsläppen. Även negativa utsläpp måste genereras. Syftet med denna studie är att undersöka implementeringen av CLG för att separera CO2 på ett energieffektivt sätt och samtidigt generera H2 och elektricitet. Processanalyser genomfördes för att undersöka möjligheten att implementera CLG-processen till ett typiskt massabruk. Processmodeller togs fram for att undersöka CLG, värmeåtervinning samt elektricitetsgenerering. Processmodellerna utvecklades med hjälp av Aspen Plus och Aspen HYSYS. De framtagna modellerna analyserades sedan med avseende på olika designparametrar inom CLG-processen. På ett typiskt massabruk som producerar 800 000 adt varje ˚ar kan 375 kg CO2/adt separeras och då uppnå negativa utsläpp, genom att byta ut multi-fuel forsrännaren med en CLG process. Den framtagna processmodellen skulle också kunna generera 360-504 kWh/adt av H2 beroende på de designparametrar som används för CLG-processen. Enligt modellen kan värme som ˚återvinns från processen användas för att fånga upp ytterligare 13 % av CO2 från andra delar av bruket. Processanalys för olika designparametrar inom CLG systemet så som temperatur, luftflöde och flödet av syrgasbärare har presenterats. Nyckeltalen som undersöktes var den mängd CO2 som kunde fångas upp, mängd H2 genererad samt överskottet av elektricitet som produceras när multi-fuel förbränningen byts ut mot en CLG-process på ett typiskt massa bruk. / Emissions of CO2 to the atmosphere are contributing to the global temperature rise. The industrial sector contributed to 20 % of the emissions and out of that, 6 % are generated from the pulp and paper industry. To limit the temperature increase below 1,5 °C, the emissions not only need to be reduced but also negative emissions should be generated from different sectors. The purpose of this study is to realize the implementation of Chemical Looping Gasification (CLG) to separate CO2 (for permanent storage) in an energy-efficient way while co-generating H2 as well as electricity. Process analysis was carried out to investigate the possibility of substituting the multifuel boiler in a typical pulp mill with a CLG process. Process models for the CLG, heat recovery and electricity generation process were developed using Aspen  Plus and Aspen HYSYS. The process was analysed for different design conditions (temperature, autothermal condition, air flow, oxygen carrier flow) in the CLG process. It was found that in a typical pulp mill producing 800 000 adt per year, 375 kg- CO2/adt (14 % of total emissions from the process) can be inherently separated for storage to achieve negative emissions, if the multi-fuel boiler is replaced with a CLG unit. This process will also be able to generate 360-504 kWh/adt H2 depending on the design conditions in the CLG process. Heat recovered from the CLG unit can be utilized in capturing approximately 13 % additional CO2 from other sources in the pulp mill. Process analysis for different design conditions in CLG (temperature, airflow, oxygen carrier flow) have been presented. The key performance indicators were CO2 capture rates, H2 generated and net electrical output from the process.

In this project, a numerical model describing the reaction mechanism and the mass and energy transport in wood pyrolysis is studied. The applicability of the model in predicting actual biomass pyrolysis assessed by comparing the model to TGA experimental measurements. The comparison to experiments is done in relation to the mass loss characteristics of chips of varying sizes. The mass loss is of interest as it is a variable necessary in the coupling of reactor and particle models. Three reaction models were simulated and results compared to experimental data, namely, the reaction model developed by Park et al. [Combustion and Flame 157 (2010) 481-494], a simple multicomponent parallel reaction model, and a competitive reaction model. The model of Park et al. did not fit with the experimental data as it underestimates the char yield. The parallel reaction model, which is based on hemicellulose and cellulose decomposition to char and volatiles, also did not agree with the experiments even when fitting the parameters to the data. The downward trend of char yield with increasing temperature suggests there exists competition between the volatiles and char in wood pyrolysis. The proposed competitive reaction model which consists of a hemicellulose reaction to volatiles and a cellulose reaction to volatiles and char is in good agreement with the experimental data. The mass loss characteristics in the experimental temperature range is fairly predicted within reasonable accuracy.

Computational Fluid Dynamics (CFD) simulations are presented within this study for super-cooled liquid oxygen atomisation and gasification in a subcritical chamber operating at 1MPa. Relatively low cost simulation techniques have been used and their accuracy evaluated. Gasification efficiency expected from theory is compared with simulation results and physical limitation in addition to modelling limitations are discussed. Impinging jets have been used within the simulations with the intent of atomising the incoming liquid oxygen, followed by injection of hot water vapour perpendicularly, to increase turbulent mixing, residence time and in turn expected gasification efficiency. A computational fluid dynamics heating analysis is also included in order to highlight constraints on the chamber geometry imposed by transient rapid oxidation material limits. 316 stainless steel and 3D printed Inconel 718 were investigated experimentally to identify their transient macroscopic rapid oxidation limits. This information supplements existing published literature for operation at high temperatures for a transient period of time in oxygen rich environments. ANSYS Fluent 2020R1, and its newly included Volume of Fluid to Discrete Particle (VOF-DPM) Model, is used for CFD simulation of LOx atomisation and vaporisation. The CFD simulation technique is discussed in detail in order to allow the reader to gain knowledge into areas where computational power can be saved while still allowing assessment of trends for conducting relatively quick feasibility reviews e.g. for different chamber configurations. The CFD simulation results are compared with published experimental data and its accuracy when extended to this application is discussed. Results indicate that gasification of LOx within a compact chamber may be feasible if sufficient turbulence, resulting in longer residence times is present providing sufficient time for heat and mass transfer from the continuous phase. Simulations indicate that due to the mixing and gasification process the LOx particles within the chamber that have not entered the gaseous phase are smaller than that from pure atomisation and therefore more susceptible to gasification if injected into the main motor combustion chamber. Results hint at the potential benefit of swirl injection of hot gases to increase residence time and in turn the gasification efficiency, therefore, this is recommended for the topic of future research. / Computational Fluid Dynamics (CFD) simuleringar presenteras i denna studie för superkyld flytande syreförstoftning och förgasning i en underkritisk kammare som arbetar vid SI 1 MPa. Relativt billiga simuleringstekniker har använts och deras noggrannhet utvärderats. Förgasningseffektivitet som förväntas från teorin jämförs med simuleringsresultat och fysisk begränsning utöver detta diskuteras modelleringsberäkningarna. Stötstrålar har använts inom simuleringarna med avsikt att finfördela det inkommande flytande syret, följt av injektion av varm vattenånga vinkelrätt, för att öka turbulent blandning, uppehållstid och i sin tur förväntad förgasningseffektivitet. En beräkningsenhetsanalys för uppvärmningsdynamik ingår också för att belysa begränsningar för kammargeometri som införs genom övergående gränser för snabb oxidation. 316 rostfritt stål och 3D-printad Inconel 718 undersöktes experimentellt för att identifiera deras övergående makroskopiska snabba oxidationsgränser. Denna information kompletterar befintlig publicerad litteratur för drift vid höga temperaturer under en kort tid i syrgasrika miljöer. ANSYS Fluent 2020R1, och dess nyligen inkluderade volym av vätska till diskret partikel (VOF-DPM) -modell, används för CFD-simulering av LOxatomisering och förångning. CFD-simuleringstekniken diskuteras i detalj för att göra det möjligt för läsaren att få kunskap om områden där beräkningskraft kan sparas medan man fortfarande tillåter bedömning av trender för att göra relativt snabba genomförbarhetsgranskningar, t.ex. för olika kammarkonfigurationer. CFD-simuleringsresultaten jämförs med publicerade experimentella data och dess noggrannhet när den utvidgas till denna applikation diskuteras. Resultaten indikerar att förgasning av LOx i en kompakt kammare kan vara möjlig vid tillräcklig turbulens, vilket resulterar i längre uppehållstider är närvarande som ger tillräcklig tid för värme och massöverföring från den kontinuerliga fasen. Simuleringar indikerar att på grund av blandnings- och förgasningsprocessen är LOx-partiklarna i kammaren som inte har gått in i gasfasen mindre än den från ren förgasning och därför mer mottagliga för förgasning om de injiceras i huvudmotorns förbränningskammare. Resultat antyder den potentiella fördelen med virvelinjektion av heta gaser för att öka uppehållstiden och i sin tur förgasningseffektivitet, därför rekommenderas detta för ämnet för framtida forskning.

[ES] Resumen Casi la mitad de la población mundial no tiene acceso a energías como la electricidad o el gas y tienen que utilizar forzosamente biomasa para cocinar, principalmente leña y carbón. Lo que en países desarrollados parece un lujo, en otros muchos es una obligación, ya que no hay otra alternativa. Con un pequeño ahorro en el combustible que utilizan estas estufas de los países sin acceso a otro tipo de energía, el resultado global es extraordinario. En el caso de la República Democrática del Congo más del 80% de la población realiza sus actividades culinarias utilizando biomasa sólida (leña, carbón vegetal, etc.) Para cocinar en las zonas rurales y los extrarradios de las grandes ciudades se utiliza la tradicional estufa de tres piedras TCS-3P y en las zonas urbanas la tradicional estufa de carbón vegetal TCS-C. La principal desventaja de esta práctica es una combustión de baja eficiencia energética, con la consecuencia directa de un consumo excesivo de materias primas como carbón y leña y la correspondiente deforestación. Estos equipos de cocina tradicionales emiten muchos contaminantes perjudiciales para la salud (CO y PM), así como y emisiones que contribuyen al calentamiento global y al cambio climático (CO2 y BC). En este trabajo proponemos modelos para mejorar la eficiencia energética utilizando el modelo tradicional como punto de partida, tal como lo utiliza la comunidad local. Para las poblaciones que viven en condiciones muy críticas y precarias, se han propuesto "insertos de cerámica" que pueden fabricarse y añadirse a las estufas que utilizan en la actualidad. Estos insertos pueden actuar sobre el rendimiento con mejoras del 15%. Se ha propuesto y analizado una segunda mejora basada en la combustión natural de la estufa de carbón ICS-C. El modelo más prometedor es la estufa que utiliza el principio de micro gasificación de la biomasa. Se han diseñado dos modelos de esta estufa, el modelo ICS-G1 con un solo reactor de combustión y el modelo ICS-G2 con dos reactores de combustión, y se han realizado análisis de sostenibilidad con aplicación directa a las comunidades locales. El modelo de micro gasificación propuesto funciona con un suministro de aire forzado con una gran flexibilidad de variación de la potencia de fuego según el tipo de comida a cocinar. El sistema de suministro de aire es provisto por un pequeño motor alimentado por energía solar con autonomía proporcionada por una pequeña batería de litio recargable. Los modelos de gasificación muestran importantes ventajas en comparación con el sistema tradicional, mejor eficiencia energética, al necesitar menos de la mitad de leña que con la tradicional, reducciones drásticas de las emisiones contaminantes y atmosféricas, con un ahorro de emisiones de CO2 en la ciudad de Kinshasa estimadas en 3405 kton/año y una reducción de casi la mitad del tiempo dedicado a la preparación de alimentos. Estas estufas pueden utilizar todo tipo de combustibles sólidos, además del carbón, se realizaron ensayos con combustibles alternativos que provienen de residuos agrícolas (BSW3) de esta forma se limita la presión ejercida sobre los bosques debido al uso de leña para cocinar. Los métodos de prueba utilizados son la prueba de ebullición del agua y la prueba de cocción controlada, con esta última se realiza una preparación de alimentos en un ambiente controlado. Los resultados de estas mejoras se han aplicado a casos reales en Kinshasa y Bandundu. / [CA] Quasi la meitat de la població mundial no té accés a energies com l'electricitat o el gas i han d'utilitzar forçosament biomassa per a cuinar, principalment llenya i carbó. El que en països desenvolupats sembla un luxe, en molts altres és una obligació, ja que no hi ha una altra alternativa. Amb un xicotet estalvi en el combustible que utilitzen aquestes estufes dels països sense accés a una altra mena d'energia, el resultat global és extraordinari. En el cas de la República Democràtica del Congo més del 80% de la població realitza les seues activitats culinàries utilitzant biomassa sòlida (llenya, carbó vegetal, etc.) Per a cuinar en les zones rurals i els extraradis de les grans ciutats s'utilitza la tradicional estufa de tres pedres (TCS-3P) i en les zones urbanes la tradicional estufa de carbó vegetal (TCS-C). El principal desavantatge d'aquesta pràctica és una combustió de baixa eficiència energètica, amb la conseqüència directa d'un consum excessiu de matèries primeres com a carbó i llenya i la corresponent desforestació. Aquests equips de cuina tradicionals emeten molts contaminants perjudicials per a la salut (CO i PM), així com i emissions que contribueixen al calfament global i al canvi climàtic (CO₂ i BC). En aquest treball proposem models per a millorar l'eficiència energètica utilitzant el model tradicional com a punt de partida, tal com ho utilitza la comunitat local. Per a les poblacions que viuen en condicions molt crítiques i precàries, s'han proposat "inserits de ceràmica" que poden fabricar-se i afegir-se a les estufes que utilitzen en l'actualitat. Aquests inserits poden actuar sobre el rendiment amb millores del 15%. S'ha proposat i analitzat una segona millora basada en la combustió natural de l'estufa de carbó ICS-C. El model més prometedor és l'estufa que utilitza el principi de micro gasificació de la biomassa. S'han dissenyat dos models d'aquesta estufa, el model (ICS-G1) amb un sol reactor de combustió i el model (ICS-G2) amb dos reactors de combustió, i s'han realitzat anàlisi de sostenibilitat amb aplicació directa a les comunitats locals. El model de micro gasificació proposat funciona amb un subministrament d'aire forçat amb una gran flexibilitat de variació de la potència de foc segons la mena de menjar a cuinar. El sistema de subministrament d'aire és proveït per un xicotet motor alimentat per energia solar amb autonomia proporcionada per una xicoteta bateria de liti recarregable. Els models de gasificació mostren importants avantatges en comparació amb el sistema tradicional, millor eficiència energètica, en necessitar menys de la meitat de llenya que amb la tradicional, reduccions dràstiques de les emissions contaminants i atmosfèriques, amb un estalvi d'emissions de CO₂ a la ciutat de Kinshasa estimades en 3405 kton/any i una reducció de quasi la meitat del temps dedicat a la preparació d'aliments. Aquestes estufes poden utilitzar tot tipus de combustibles sòlids, a més del carbó, es van realitzar assajos amb combustibles alternatius que provenen de residus agrícoles (BSW3) d'aquesta forma es limita la pressió exercida sobre els boscos a causa de l'ús de llenya per a cuinar. Els mètodes de prova utilitzats són la prova d'ebullició de l'aigua i la prova de cocció controlada, amb aquesta última es realitza una preparació d'aliments en un ambient controlat. Els resultats d'aquestes millores s'han aplicat a casos reals a Kinshasa i Bandundu. / [EN] Abstract Almost half of the world's population does not have access to energy such as electricity or gas and they have to use biomass for cooking, mainly firewood and charcoal. What in developed countries seems a luxury, in many others is an obligation, since there is no other alternative. With a small saving in the fuel used by these stoves in countries without access to other types of energy, the overall result is extraordinary. In the case of the Democratic Republic of the Congo, more than 80% of the population carries out their culinary activities using solid biomass (firewood, charcoal, etc.). The traditional stove is used to cook in rural areas and on the outskirts of large cities. three-stone TCS-3P and in urban areas the traditional TCS-C charcoal stove. The main disadvantage of this practice is low energy efficiency combustion, with the direct consequence of excessive consumption of raw materials such as coal and firewood and the corresponding deforestation. These traditional kitchen equipment emits many harmful pollutants for health (CO and PM), as well as emissions that contribute to global warming and climate change (CO2 and BC). In this work we propose models to improve energy efficiency using the traditional model as a starting point, as used by the local community. For populations living in very critical and precarious conditions, "ceramic inserts" have been proposed that can be manufactured and added to the stoves they use today. These inserts can act on performance with improvements of 15%. A second improvement based on the natural combustion of the ICS-C coal stove has been proposed and analyzed. The most promising model is the stove that uses the principle of microgasification of biomass. Two models of this stove have been designed, the ICS-G1 model with a single combustion reactor and the ICS-G2 model with two combustion reactors, and sustainability analyzes have been carried out with direct application to local communities. The proposed micro gasification model works with a forced air supply with great flexibility of variation of the fire power according to the type of food to be cooked. The air supply system is provided by a small motor powered by solar energy with autonomy provided by a small rechargeable lithium battery. The gasification models show important advantages compared to the traditional system, better energy efficiency, since it requires less than half as much firewood than with the traditional system, drastic reductions in pollutant and atmospheric emissions, with savings in CO2 emissions in the city of Kinshasa estimated at 3405 kton / year and a reduction of almost half the time spent on food preparation. These stoves can use all types of solid fuels, in addition to coal, tests were carried out with alternative fuels that come from agricultural residues (BSW3) in this way the pressure exerted on the forests due to the use of firewood for cooking is limited. The test methods used are the water boiling test and the controlled cooking test, with the latter a food preparation is performed in a controlled environment. The results of these improvements have been applied to real cases in Kinshasa and Bandundu. / Mulumba Ilunga, Ó. (2021). Estudio de la optimización de estufas de cocción tradicionales empleadas en países en desarrollo utilizando biomasa leña gasificada (aplicado a la R.D.Congo) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/163655