This research investigates a novel approach to methanol production from methane. The high use of fossil fuels in New Zealand and around the world causes global warming. Using clearer, renewable fuels the problem could potentially be reduced. Biomass energy is energy stored in organic matter such as plants and animals and is one of the options for a cleaner, renewable energy source. A common biofuel is methane that is produced by anaerobic digestion. Although methane is a good fuel, the energy is more accessible if it is converted to methanol. While technology exists to produce methanol from methane, these processes are thermo-chemical and require large scale production to be economic. Nitrosomonas europaea, a nitrifying bacterium, has been shown to oxidize methane to methanol (Hyman and Wood 1983). This research investigates the possibility of converting methane into methanol using immobilized N. europaea for use in smaller applications. A trickle bed bioreactor was developed, containing a pure culture of N. europaea immobilized in a biofilm on ceramic raschig rings. The reactor had a biomass concentration of 7.82 ± 0.43 g VSS/l. This was between 4 – 15 times higher than other systems aimed at biologically producing methanol. However, the immobilization dramatically affected the methanol production ability of the cells. Methanol was shown to be produced by the immobilized cells with a maximum production activity of 0.12 ± 0.08 mmol/gVSS.hr. This activity was much lower than the typical reported value of 1.0 mmol/g dry weight.hr (Hyman and Wood 1983). The maximum methanol concentration achieved in this system was 0.129 ± 0.102 mM, significantly lower than previous reported values, ranging between 0.6 mM and 2 mM (Chapman, Gostomski, and Thiele 2004). The results also showed that the addition of methane had an effect on the energy gaining metabolism (ammonia oxidation) of the bacteria, reducing the ammonia oxidation capacity by up to 70%. It was concluded, because of the low methanol production activity and the low methanol concentrations produced, that this system was not suitable for a methanol biosynthesis process.

At present, more than 80% of the world’s energy consumption and production of chemicals is originated from the use of fossil resources. There is a tremendous growing interest in utilising biomass molecules for energy provision due to their carbon neutrality. Lower alcohols such as methanol and ethanol if produced from biomass as transportation fuels as well as platform chemicals, can become strategically important for many energy/chemically starved countries. Currently, they are synthesised by indirect and inefficient processes. We show for the first time in this thesis study that ethylene glycol, the simplest representative of biomass-derived polyols, can be directly converted to these two lower alcohols by selective hydrogenolysis over modified Raney Ni and Cu catalysts in hydrogen atmosphere. This work provides essential information that may lead to the development of new catalysts for carbohydrate activation to methanol, a novel but important reaction concerning the important biomass conversion to transportable form of energy. Modification of electronic structure and the adsorption properties of Raney catalysts have therefore been achieved by blending with second metal(s). It is found that the activity and selectivity of this reaction can be significantly affected by this approach. In contrast, there is no subtle effect on methanol selectivity despite a great variation in the d-band centre positions of metal catalysts which show a distinctive effect on other products. Our result suggests that methanol is produced on specific surface sites independent from the other sites at an intrinsic rate and will not be converted to other products by the d-band alteration. On the other hand, it is reported in this thesis that a dramatic improvement in the combined selectivity to methanol/ethanol reaching 80% can be obtained over a Pd/Fe₃O₄ catalyst under relatively milder conditions (20 bar and 195 oC). This direct production of the non-enzymatic bio-alcohols is established over a carefully prepared co-precipitated Pd/Fe₃O₄ catalyst which gives a metallic phase of unexpectedly high dispersion ranging from small clusters to individual metal adatoms on defective iron oxide to give the required metal-support interaction for the novel synthesis. It is demonstrated that the small PdFe clusters on iron oxide surface provide the active species responsible for methanol production. In addition, a related Rh/Fe₃O₄ catalyst synthesised by co-precipitation is also shown to be selective for CO₂ and H₂ production from a direct methane-oxygen oxidation reaction. As a result, 2.7% conversion of methane with selectivity ratio of CO₂/H₂ = 4 in a mixed gas feed stream of CH₂/O₂ = 30 at 300 ^oC is obtained. The reaction is operated in a kinetically controlled regime at 300^oC, where the CO formation from reverse water gas shift reaction is greatly suppressed. It is evident that the Rh/Fe₃O₄ acts as an interesting bifunctional catalyst for this reaction. This catalyst firstly gives a high dispersion of Rh which is expected to deliver a higher surface energy with enhanced activity. The Rh metal surface provides catalytically active sites for dissociation of methane to adsorbed hydrogen and carbon atoms effectively, and active oxygen on metal surface readily catalyses the carbon atoms to CO. Following these elementary reactions, the surface oxygen from Fe₃O₄ subsequently converts it to CO₂ selectively at the metal-support interface. As a result, the novel study of catalytic biomass conversion and the discoveries of new catalysts are reported in this thesis.

Em face ao aumento do preço de energia e combustíveis fósseis o conceito de biorrefinaria vem sendo foco de atenção das indústrias de celulose e papel. Esse conceito visa a obtenção de co-produtos a partir de um processo industrial pré-estabelecido sendo necessários alguns ajustes e investimentos. A possibilidade de recuperação do metanol contido no licor negro traz ao setor de celulose e papel o conceito de biorrefinaria florestal. O metanol celulósico contido no licor negro de fábricas de celulose e papel é o principal composto orgânico volátil responsável por mais de 90 % das emissões nessas fábricas. De forma semelhante aos compostos reduzidos de enxofre a formação do metanol ocorre durante a polpação alcalina em digestores, mas seu potencial para recuperação é desconhecido. Por isso, este trabalho teve como finalidade quantificar o metanol presente nos licores negros industriais provenientes de processo de polpação kraft convencional. Os licores negros industriais foram cedidos por fábricas brasileiras de celulose e papel. Para a quantificação desse álcool um método analítico foi otimizado e validado. Além disso, realizou-se o estudo de formação do metanol em licor negro durante a polpação alcalina para verificação dos parâmetros que determinam a concentração desse álcool no licor. O método otimizado mostrouse adequado à análise de metanol em licor negro e com potencial para amostras de condensados. A quantidade de metanol determinada em licor negro industrial mostrou-se passível de recuperação e sua formação durante a polpação foi influenciada pela intensidade da deslignificação do processo. / Given the rising price of energy and fossil fuels the concept of bio-refinery has been the focus of attention from the pulp and paper industries. This concept aims to achieve by-products from a pre-established industrial process which requires adjustments and investments. The recoverability of methanol contained in black liquor brings to the pulp and paper business sector the concept of forest bio-refinery. The cellulosic methanol contained in black liquor from pulp and paper mills is the main volatile organic compound responsible for more than 90% of emissions in these processing plants. Similarly to reduced sulfur compounds, the formation of methanol occurs during alkaline pulping in digesters but its potential for recovery is unknown. Therefore, this work aimed at quantifying the methanol present in industrial black liquor from conventional kraft pulping process. The black liquors were provided by Brazilian pulp and paper mills. To quantify this alcohol, an analytical method was optimized and validated. Moreover, we carried out a study on formation of methanol in black liquor during the alkaline pulping to specify the parameters to determine the concentration of this alcohol in the black liquor. The optimized method was adequate for the analysis of methanol in black liquor and showed potential to evaluate samples of condensates. The amount of methanol in black liquor has shown to be able to be recovered and its formation during pulping was influenced by the intensity of the delignification process.

Em face ao aumento do preço de energia e combustíveis fósseis o conceito de biorrefinaria vem sendo foco de atenção das indústrias de celulose e papel. Esse conceito visa a obtenção de co-produtos a partir de um processo industrial pré-estabelecido sendo necessários alguns ajustes e investimentos. A possibilidade de recuperação do metanol contido no licor negro traz ao setor de celulose e papel o conceito de biorrefinaria florestal. O metanol celulósico contido no licor negro de fábricas de celulose e papel é o principal composto orgânico volátil responsável por mais de 90 % das emissões nessas fábricas. De forma semelhante aos compostos reduzidos de enxofre a formação do metanol ocorre durante a polpação alcalina em digestores, mas seu potencial para recuperação é desconhecido. Por isso, este trabalho teve como finalidade quantificar o metanol presente nos licores negros industriais provenientes de processo de polpação kraft convencional. Os licores negros industriais foram cedidos por fábricas brasileiras de celulose e papel. Para a quantificação desse álcool um método analítico foi otimizado e validado. Além disso, realizou-se o estudo de formação do metanol em licor negro durante a polpação alcalina para verificação dos parâmetros que determinam a concentração desse álcool no licor. O método otimizado mostrouse adequado à análise de metanol em licor negro e com potencial para amostras de condensados. A quantidade de metanol determinada em licor negro industrial mostrou-se passível de recuperação e sua formação durante a polpação foi influenciada pela intensidade da deslignificação do processo. / Given the rising price of energy and fossil fuels the concept of bio-refinery has been the focus of attention from the pulp and paper industries. This concept aims to achieve by-products from a pre-established industrial process which requires adjustments and investments. The recoverability of methanol contained in black liquor brings to the pulp and paper business sector the concept of forest bio-refinery. The cellulosic methanol contained in black liquor from pulp and paper mills is the main volatile organic compound responsible for more than 90% of emissions in these processing plants. Similarly to reduced sulfur compounds, the formation of methanol occurs during alkaline pulping in digesters but its potential for recovery is unknown. Therefore, this work aimed at quantifying the methanol present in industrial black liquor from conventional kraft pulping process. The black liquors were provided by Brazilian pulp and paper mills. To quantify this alcohol, an analytical method was optimized and validated. Moreover, we carried out a study on formation of methanol in black liquor during the alkaline pulping to specify the parameters to determine the concentration of this alcohol in the black liquor. The optimized method was adequate for the analysis of methanol in black liquor and showed potential to evaluate samples of condensates. The amount of methanol in black liquor has shown to be able to be recovered and its formation during pulping was influenced by the intensity of the delignification process.

As society grapples with challenges of net zero emission, one big remaining challenge is heavy and aviation traffic due to the associated challenge of electrifying these sectors. One potential solution for this is E-fuels. E-fuels are hydrocarbon produced from electrolysis hydrogen and carbon dioxide that receive all their energy from renewable non-organic sources. The simplest E-fuel is methanol. Currently methanol is mainly produced from syngas derived from natural gas reforming also known as steam-methane reforming (SMR). A SMR process break down methane into hydrogen, CO2, and CO with the uses of steam. This syngas is then hydrogenated and forms methanol. One alternative production route to the classic syngas hydrogenation is to capture CO2 and add electrolysis hydrogen and then hydrogenate the mixture to from E-methanol.  This thesis aims to compare the traditional production method with joint SMR-flue gas CO2 hydrogenation plant as well as a direct air capture (DAC) CO2 hydrogenation plant. This comparison will be evaluated by their engineering performance, economic performance, and environmental performance.  This evaluation is done with process simulations in Chemcad as well as Excel. In Chemcad the desulfurization step, SMR, carbon capture, and distillation is simulated. The hydrogenation reactors are simulated in Excel with kinetic data. This process data in the foundation of the engineering performance and is used to determine hydrogen and carbon utilization along with energy and water demand. For the economic evaluation CAPEX is calculated from prices of related units adjusted for size and inflation. The OPEX is based on simulation data and modelled in Excel along with net present value (NPV). The environmental performance focuses on global warming potential as well as fossil resources depletion (FD).  The DAC system has both the highest hydrogen and carbon utilization at 98% and 96,9% respectively but suffer from the highest energy and water demand. Both flue gas method and syngas method have similar hydrogen utilization at around 83,5%, but they differ significantly with carbon utilization with 87,2% and 64,7 respectively. The syngas method has the highest net profit per ton methanol along with the highest NPV and the lowest CAPEX cost out of all three methods. The flue gas method still produces a net profit, but significantly lower than the syngas method. Its CAPEX is also significantly higher than its NPV. The DAC system as negative net profit as well as the highest CAPEX by a wide margin. The environmental impact of the flue gas system is significantly lower than that of the syngas route with less than a fourth of the CO2 eq. emissions. It also has a lower FD due to its higher carbon utilization which results in a higher yield methanol per ton natural gas.  Whilst the flue gas hydrogenation has several advantages over the syngas route and the economic improvements with better optimization for the carbon capture units would bring the net profit per ton methanol more in line with the syngas route, as of today it still is not economically defensible. / När samhället kämpar med utmaningarna kring nettonollutsläpp, kvarstår en stor utmaning inom tung- och flygtrafik på grund av den associerade svårigheten med att elektrifiera dessa sektorer. En potentiell lösning för detta är E-bränslen. E-bränslen är kolväten producerade från elektrolysväte och koldioxid som får all sin energi från förnybara icke-organiska källor. Den enklaste E-bränslen är metanol. För närvarande produceras metanol främst från syntes gas som kommer från naturgasreformering, även känd som ångmetanreformering (SMR). En SMR-process bryter ner metan till väte, CO2 och CO med hjälp av ånga. Denna syntes gas får sedan genomgå hydrering för att bilda metanol. Ett alternativa till denna produktionsmetod är att fånga CO2 och tillsätta elektrolysväte och sedan låta blandningen hydrera för att bilda E-metanol.  Detta examensarbete syftar till att jämföra den traditionella produktionsmetoden med en gemensam SMR-rökgas-CO2-hydreringanläggning samt en direkt luftinfångning (DAC) CO2-hydreringanläggning. Denna jämförelse kommer att utvärderas utifrån deras tekniska prestanda, ekonomiska prestanda och miljöprestanda.  Denna utvärdering görs med processimuleringar i Chemcad samt Excel. I Chemcad simuleras avsvavlingssteget, SMR, koldioxidsinfångning och destillation. Hydreringsreaktorerna simuleras i Excel med kinetiska data. Processdata från dessa simuleringar utgör grunden för den tekniska prestandan och används för att bestämma väte- och kolutnyttjande tillsammans med energi- och vattenbehov. För den ekonomiska utvärderingen beräknas CAPEX från priser på relaterade enheter justerade för storlek och inflation. OPEX baseras på simuleringsdata och modelleras i Excel tillsammans med nettonuvärde (NPV). Miljöprestandan fokuserar på den globala uppvärmningspotentialen samt utarmningen av fossila resurser (FD).  DAC-systemet har både den högsta väte- och kolutnyttjande på 98 % respektive 96,9 %, men lider av det högsta energi- och vattenbehovet. Både rökgasmetoden och syntesgasmetoden har liknande väteutnyttjande på cirka 83,5 %, men de skiljer sig betydligt när det gäller kolutnyttjande med 87,2 % respektive 64,7 %. Syntesgasmetoden har den högsta nettoförtjänsten per ton metanol samt det högsta NPV och den lägsta CAPEX-kostnaden av alla tre metoder. Rökgasmetoden ger fortfarande en nettoförtjänst, men betydligt lägre än syntesgasmetoden. Dess CAPEX är också betydligt högre än dess NPV. DAC-systemet har negativ nettoförtjänst samt den högsta CAPEX med en bred marginal. Miljöpåverkan från rökgassystemet är betydligt lägre än den från syntes gas metoden med mindre än en fjärdedel av CO2-ekvivalenta utsläpp. Det har också en lägre FD på grund av sitt högre kolutnyttjande vilket resulterar i ett högre utbyte av metanol per ton naturgas.  Trots att rökgashydrering har flera fördelar över syntesgasvägen och de ekonomiska förbättringarna med bättre optimering för koldioxidavskiljningsenheterna som skulle få nettoförtjänsten per ton metanol mer i linje med syntesgasvägen, är metoden fortfarande inte ekonomiskt försvarbart i dagsläget.