Um dos grandes desafios para os próximos anos é desenvolver alternativas de produção para energias sustentáveis. O biodiesel vem se posicionando como uma opção para a substituição dos combustíveis fósseis. Sua produção se dá pela transesterificação entre uma gordura e um monoálcool, liberando glicerol, que corresponde a 10% do volume da reação. Grandes incrementos na produção de biodisel resultarão em volumes proporcionais de glicerol residual. Estudos têm mostrado que bactérias anaeróbias estritas e bactérias fermentativas são capazes de produzir hidrogênio, um combustível de alto valor energético, que não gera gases poluentes durante a sua queima. Visto a importância de aumentar o valor agregado do glicerol residual, o presente trabalho teve como objetivo isolar e identificar por técnicas moleculares, bactérias presentes em lodos de estações de tratamento de resíduos, capazes de produzir hidrogênio utilizando glicerol residual da indústria de biodiesel como fonte de carbono. As amostras foram submetidas a choque térmico para eliminação de bactérias hidrogenotróficas, crescidas em meio contendo glicerol em condições de anaerobiose e analisadas para a formação de hidrogênio. Foram identificadas por sequenciamento do gene 16S rRNA, quinze espécies bacterianas capazes de crescer em meio com glicerol, sendo que destas nove apresentaram capacidade de produção de hidrogênio, correspondendo a Enterobacter ludwigii, Shigella sonnei, Bacillus licheniformis, Bacillus amyloliquefaciens, Staphylococcus warneri, Alcaligenes faecalis, Bacillus subtilis, Bacillus atrophaeus e Citrobacter freundii. Os isolados de Bacillus amyloliquefaciens mostraram maior rendimento na produção de hidrogênio com valores de 0,50±0,20 mol H2/mol de glicerol, utilizando o meio enriquecido com 1,5% de glicerol residual. Adicionalmente, foi realizada análise de BLAST para verificar a presença dos genes HycC, HycE, HycF, HyfC, HyfF e HyfH relacionados à produção de hidrogênio. Este estudo foi desenvolvido utilizando apenas os microrganismos do gênero Bacillus, uma vez que, dentre os microrganismos isolados, apenas os Bacillus apresentam sequenciamento completo disponível na rede de bioinformática. Foi verificado que B. amyloliquefaciens, B. licheniformis e B. artrophaeus não possuem os genes específicos analisados, mas estes genes possuem similaridade com outros genes e proteínas que parecem desempenhar funções no transporte de hidrogênio para exterior da célula. Os resultados indicam que existe um grande potencial para a seleção de bactérias produtoras de hidrogênio nos efluentes avaliados que são capazes de metabolizar o glicerol residual com a geração de hidrogênio, como combustível de energia renovável. / Petrobras / One of the major challenges for the coming years is to develop alternative forms of production for sustainable energy. The biodiesel is positioning itself as an option for the replacement of fossil fuels. Its production is by transesterification between a fat and a monoalcohol, releasing glycerol, which corresponds to 10% of the volume of the reaction. Large increases in the production of biodiesel result in proportional amounts of crude glycerol.Studies have shown that strict anaerobic and fermentative bacteria are able to produce hydrogen, a fuel of high energy value, which does not generate polluting gases, during its burning. Given the importance of increasing the added value-added of crude glycerol, the purpose of this study was to isolate and identify by molecular techniques, bacteria present in sewage sludge from waste treatment plants, it is capable of producing hydrogen using crude glycerol of biodiesel industry, as a carbon source. The samples were subjected to thermal shock to eliminate hydrogenotrophic bacterias, grown in the medium containing glycerol under anaerobic conditions and analyzed to produce hydrogen. Were identified by sequencing of the 16S rRNA gene , 15 bacterial species able to grow in medium with glycerol, and from these, nine showed the ability of hydrogen production, corresponding to Enterobacter ludwigii, Shigella sonnei, Bacillus licheniformis, Bacillus amyloliquefaciens, Staphylococcus warneri, Alcaligenes faecalis, Bacillus subtilis, Bacillus atrhopheus and Citrobacter freundii. The Bacillus amyloliquefaciens isolate showed higher yield in the production of hydrogen , with values of 0.50±0.20 mol H2/mol of glycerol, using the enriched medium with 1.5% crude glycerol. In addition, BLAST analysis were performed to check the presence of genes HycC, HycE, HycF, HyfC, HyfF and HyfH related to hydrogen production. This study was developed using microorganisms of genus Bacillus, since, among the isolated microorganisms, only the Bacillus have complete DNA sequencing available. It was found that B. amyloliquefaciens, B. licheniformis and B. artrophaeus do not have the specific genes analyzed, but these genes have similarity with other genes and proteins that appear to perform roles in the transport of hydrogen to outside the cell. The results indicate that there is a great potential for the selection of bacteria producing hydrogen in the effluents evaluated, that are able to metabolize crude glycerol with the generation of hydrogen as a fuel for renewable energy.

O aumento global da utilização de combustíveis tem por consequência maior demanda energética, seja ela renovável ou não. Posto que nossa matriz energética ainda é baseada em combustíveis fosseis, isso significa que há um aumento no impacto ambiental causado pela queima de fontes derivadas de petróleo e carvão. Neste contexto, destaca-se hidrogênio, um gás que pode desempenhar papel significativo na redução das emissões de gases de efeito estufa (GEE) e produção energética limpa, pois a síntese de hidrogênio pode ser realizada a partir de resíduos orgânicos aplicando o processo de digestão anaeróbia. Em nível nacional, dois resíduos se destacam nesse contexto: glicerol e vinhoto. O primeiro é o principal subproduto da indústria do biodiesel, o segundo é o principal resíduo da indústria sucroalcooleira. Assim, essa pesquisa se focou em estabelecer os melhores parâmetros influência no processo de produção de hidrogênio utilizando vinhoto e glicerol em reatores de modo de operação de batelada. Concluiu-se que a produção de hidrogênio somente utilizando vinhoto tem seus melhores resultados usando pH 6,0 e pH 6,5, sendo que o primeiro estudo obteve maior produção total acumulada (7.585 mL H2) e o segundo obteve maior taxa de produção (0,88 mmol H2.gSSV-1.h-1). Os estudos com mistura dos substratos mostram que a produção de H2 pode ser ainda mais eficiente em comparação com vinhoto bruto, sendo que a melhor razão de mistura foi com 80% de DQO decorrente do glicerol e 20% de vinhoto em que houve produção total acumulada de 10.070 mL H2 e 0,85 mmol H2.gSSV-1.h-1. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / The fuel use increase in a global scale have caused rising energy demand, whether it's renewable or not. Since our energy matrix is still based on fossil fuels, it also means an increase in the environmental impact caused by burning sources derived from oil and coal. In this context, hydrogen is highlighted, as a gas that could play a significant role in the reduction of greenhouse gas (GHG) emissions and clean energy production, since hydrogen synthesis can be performed from organic waste using the anaerobic digestion process. At the national level, two residues stand out: glycerol and sugarcane vinasse. The first is the main by-product of the biodiesel industry, the second is the main residue of the sugar and ethanol industry. Thus, this research focused on establishing the best influence parameters in the hydrogen production process using vinasse and glycerol in batch mode operation reactors. It was concluded that the production of hydrogen only using vinasse had better results using pH 6.0 and pH 6.5, and the first study obtained higher accumulated total production (7,585 mL H2) and the second obtained a higher specific production rate (0.88 mmol H2.gSSV-1.h-1). The studies with mixture of the substrates shown that H2 production can be even more efficient in comparison with crude vinasse, and the best mixing ratio was with 80% of COD due to glycerol and 20% to vinhoto, in which there was total accumulated production 10.070 mL H2 and 0.85 mmol H2.gSSV-1.h-1.

Orientador: Newton Pimenta Neves Jr. / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T23:02:40Z (GMT). No. of bitstreams: 1 Furlan_AndreLuis_M.pdf: 1695609 bytes, checksum: 48d87be00886364fd71f3b6d85df3348 (MD5) Previous issue date: 2008 / Resumo: Neste trabalho foram feitas análises comparativas entre as formas de armazenamento de energia elétrica fotovoltaica pela forma tradicional, através de baterias de chumbo-ácido, e por meio de hidrogênio eletrolítico para posterior reconversão em eletricidade utilizando células a combustível. Para tanto, foi desenvolvido um modelo matemático para o dimensionamento dos sistemas, implementado numa planilha eletrônica, onde foram consideradas as principais características e eficiências dos equipamentos que compõem os sistemas, bem como o perfil de carga característico das comunidades da Região Amazônica. A seguir, foi realizada uma análise econômica de ambos os sistemas para uso em comunidades isoladas, tendo sido verificado que nas condições estabelecidas o sistema utilizando baterias apresenta uma vantagem de 20%. No entanto, observou-se que uma redução de aproximadamente 35% nos custos do conjunto eletrolisador/reservatório/célula a combustível, tecnologias ainda em processo de grande evolução tecnológica, torna o sistema a hidrogênio bastante competitivo, podendo-se constituir na melhor opção para o armazenamento de energia de origem fotovoltaica, principalmente devido aos riscos ambientais associados ao manejo de grandes bancos de baterias em regiões isoladas / Abstract: In this work, comparative analyses of photovoltaic power storage were made, first by the traditional means employing lead-acid batteries, and second by means of electrolytic hydrogen which was later reconverted to power in a fuel cell. In order to design the two systems, it was used a load profile of the communities in Amazon region and by means of a mathematical model, implemented in a spreadsheet, that considers the several devices and their efficiencies in order to make it possible to specify the system components. This was followed by an economical analysis of the two systems for use in remote communities. Considering the present conditions, it was verified that the battery system is 20% more advantageous. However, it was also observed that a reduction of about 35% in the cost of the electrolyzers/buffer/fuel cell, technologies still in processes of development, would make the hydrogen system very competitive, becoming the best option for photovoltaic power storage, especially due to the environmental risks associated with the use of large battery banks in remote regions / Mestrado / Mestre em Planejamento de Sistemas Energéticos

Two main subjects are addressed in this study. The ability of a bright red material with metallic behaviour to be used as a visible light photocatalyst for hydrogen evolution and the feasibility of visible light photocatalytic water splitting using Z-schemes constituted from different kinds of photocatalysts and materials used as mediators. Strontium niobate (Sr₁₋ₓNbO₃) is an A-site deficient perovskite with intense red colour. It is an unusual material that displays both metallic type conduction and- as we present- photocatalytic activity. Specifically, photocatalytic visible light hydrogen production with oxalic acid as a sacrificial reagent is achieved from this material even without the need for a co-catalyst or other alteration. This photocatalytic activity is screened with time and related to different parameters that might influence it, like crystal structure, surface area and surface chemistry. The crystal structure of strontium niobate is A site stoichiometry dependant and the materials acquires a cubic symmetry for Sr≤ 0.92 and orthorhombic for 0.92≤ Sr≤ 0.97. The change of crystal structure from cubic to orthorhombic symmetry seems to have a negative effect on the photocatalytic activity, as the NbO₆ octahedra become distorted and unfavourable for d-orbital overlapping. The highest photocatalytic activity is exhibited at the turning point of one structure to the other. Increase in the photocatalytic activity is also exhibited by enlarging the surface area through ball milling, nevertheless, a clear trend for surface area effect on activity is not obtained among samples with different Sr content. Additionally, an enrichment of Sr on the surface of strontium niobate is observed by XPS, which apart from the fact that seems to be a governing factor improving stability it is also considered a key point for the exhibited photocatalytic activity altogether. Full water splitting under visible light from Z-schemes is studied by fabricating three general categories of systems. These three different categories depend on the mediator used to fabricate the Z-schemes and are: redox couple Z-schemes (with Fe⁺³/Fe⁺²), solid mediator Z-schemes (with GO) and no mediator Z-schemes. The materials used as photocatalysts for the fabrication of the Z-schemes are: Sr₀.₉₂NbO₃ for hydrogen production and both WO₃ and BiVO₄ independently for oxygen production. The photocatalytic activity for water splitting is evaluated in production of hydrogen and oxygen with time and the ratio of their production rates is frequently checked to see whether the ideal hydrogen to oxygen 2:1 is achieved. The general idea acquired from the results of all the three types of systems is that, water splitting with Z-schemes is a complicated process and in most cases governed by many subreactions. More specifically, in all cases of redox couple Z-schemes we got hydrogen to oxygen ratio imbalances and with the most prominent one being the lack of hydrogen production. Thankful is the fact that a certain type of system, the one consisting of WO₃ as oxygen photocatalyst and Fe⁺² as initial mediator species gives results very close to the ideal one and with a high degree of reproducibility indicating this way the probable formation of a Z-scheme that has overcome more of the imbalances. In between the two other categories, solid mediator and no mediator Z-schemes, subreactions seem to be the governing factor hence imbalances are always present. A case study in the no mediator Z-schemes on an attempt to investigate sources of imbalances, reveals that a big source of imbalance is most probably from the trapping of protons from WO₃.

Thesis(M.Sc.(Chemistry)) -- University of Limpopo, 2019 / The quest for renewable, sustainable and environmentally compatible energy sources have been on-going for decades. Green technology such as hydrogen fuel cell has attained much attention as an alternative energy carrier to carbon-based fuels owing to its renewability and cleanliness. However, hydrogen gas feed to the fuel cell can easily be ignited if its concentration is above 4 wt.% at room temperature. Thus, hydrogen safety mechanisms such as hydrogen sensors are vital to guarantee people‘s safety in the hydrogen infrastructure. Sensors based on metals and metal oxides have been widely applied for hydrogen gas detection. Nonetheless, these materials are only sensitive to hydrogen gas at elevated temperatures (˃ 100 °C) and they also possess low surface area (< 20 m2/g). Hence in this work, we present polyaniline (PANI) doped with cobalt-based zeolitic benzimidazolate framework (CoZIF) and zinc-ZIF to fabricate (PANI-CoZIF and PANIZnZIF) composite nanofibers as effective electrocatalysts for hydrogen gas sensing application. The composites were synthesised through chemical oxidative polymerisation of aniline monomer in the presence of 3.6 wt.% CoZIF and ZnZIF, respectively. The structural properties of the synthesised materials were studied using Ultraviolet visible (UV-vis), X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman spectroscopy and simultaneous thermal analysis (STA). FTIR, Raman and XRD studies showed successful synthesis of CoZIF, ZnZIF and their composites. Furthermore, the studies indicated the co-existence of both CoZIF and ZnZIF in the PANI matrix upon composites formation, indicated by reduction in crystalline size, decrease in band gap and increase in thermal stability. as compared to the neat PANI. Morphological characteristics of the prepared samples were investigated usingscanning electron microscopy (SEM) and transmission electron microscopy (TEM) coupled with both energy dispersive spectroscopy and X-ray (EDS/EDX). PANICoZIF revealed the grafting of CoZIF on to the surface of PANI matrix while PANI-ZnZIF composite showed that PANI is wrapping the cube nanofiber-like structures of ZnZIF also supported by selected area electron diffraction (SAED). Cyclic voltammetry (CV), Tafel analysis and turn over frequencies (TOFs) were performed to study the electrochemical performance of the synthesised materials through hydrogen evolution reaction (HER) for gas sensing. Both composites presented drastic enhancement in the catalytic H2 evolution at 0.033 mol.L-1 H2SO4 with the Tafel slope of 160 mV/dec and exchange current density of 3.98 A.m-2 for PANI-CoZIF composite, while the Tafel slope and exchange current density for PANIZnZIF composite were 246 mV/dec and 5.01 A.m-2, respectively. Moreover, the TOFs of the PANI-CoZIF composite (0,117 mol H2.s-1) was higher as compared to neat PANI (0.040 mol H2.s-1). The TOF values for PANI and PANI-ZnZIF composite were 0.04 and 0.45 mol H2.s-1, respectively. In addition, the chronoamperometric (CA) results exhibited the significant improvement in the electrochemical hydrogen sensing ability of PANI-CoZIF and PANI-ZnZIF composites with higher current response and sensitivity values of 12 and 10.8 µA.mmol.L-1 H2, respectively. The composites exhibited faster steady state response time of 5 s for PANI-CoZIF composite and 4 s for PANI-ZnZIF composite accompanied by lower detection limit (5.27 µmol.L-1) as compared to the neat PANI matrix. The high electrochemical current response is due to extraordinary specific surface area, more accessible active sites available for the electrolyte provided by CoZIF and ZnZIF and high conductivity supplied by PANI. These results proved that the PANI-CoZIF and PANI- ZnZIF composites are suitable electrocatalytic materials for hydrogen gas sensing application through HER in acidic medium. These results further suggest that the safety of people in mining sectors and other industries can be addressed through simple electrocatalytic gas sensing systems.

The strength and success of the hydrogen economy relies heavily on the storage of hydrogen. Storage systems in which hydrogen is sequestered in a solid material have been shown to be advantageous over storage of hydrogen as a liquid or compressed gas. Many different types of materials have been investigated, yet the desired capacity and uptake/release characteristics required for implementation have not been reached. In this work, porphyrin aggregates were investigated as a new type of material for hydrogen storage. The building blocks of the aggregates are porphyrin molecules that are planar and can assume a face to face arrangement that is also known as H-aggregation. The H-aggregates were formed in solution, upon mixing of aqueous solutions of two different porphyrins, one carrying positively charged and the other one carrying negatively charged functional groups. The cationic porphyrin used was meso-tetra(4- N,N,N-trimethylanilinium) porphine (TAP) and it was combined with four different anionic porphyrins, meso-tetra(4-sulfonatophenyl)porphine (TPPS), meso-tetra(4-carboxyphenyl) porphine (TCPP), Cu(II) meso-tetra(4-carboxyphenyl) porphine, and Fe(III) meso-tetra(4- carboxyphenyl) porphine. The force of attraction that held two oppositely charged porphyrin molecules together was electrostatic attraction between the peripheral groups. Solid state aggregates were successfully isolated either by solvent evaporation or by centrifuging and freeze drying. TCPP-TAP and Cu(II)TCPP-TAP aggregates were shown to interact with hydrogen starting from 150 °C up to 250 °C. The uptake capacity was about 1 weight %. Although this value is very low, this is the first observation of porphyrin aggregates absorbing hydrogen. This opened the way for further research to improve hydrogen absorption properties of these iv materials, as well as other materials based on this model. Two other materials that are also based on planar building blocks were selected to serve as a comparison to the porphyrin aggregates. The first of those materials was metal intercalated graphite compounds. In such compounds, a metal atom is placed between the layers of graphene that make up the graphite. Lithium, calcium and lanthanum were selected in this study. Theoretical hydrogen capacity was calculated for each material based on the hydriding of the metal atoms only. The fraction of that theoretical hydrogen capacity actually displayed by each material increased from La to Ca to Li containing graphite. The weight % hydrogen observed for these materials varied between 0.60 and 2.0 %. The other material tested for comparison was KxMnO2, a layered structure of MnO2 that contained the K atoms in between oxygen layers. The hydrogen capacity of the KxMnO2 samples was similar to the other materials tested in the study, slightly above 1 weight %. This work has shown that porphyrin aggregates, carbon based and manganese dioxide based materials are excellent model materials for hydrogen storage. All three materials absorb hydrogen. Porphyrin aggregates have the potential to exhibit adjustable hydrogen uptake and release temperatures owing to their structure that could interact with an external electric or magnetic field. In the layered materials, it is possible to alter interlayer spacing and the particular intercalates to potentially produce a material with an exceptionally large hydrogen capacity. As a result, these materials can have significant impact on the use of hydrogen as an energy carrier.

Thermochemical water splitting cycles have been conceptualized and researched for over half a century, yet to this day none are commercially viable. The heavily studied Sulfur-Iodine cycle has been stalled in the early development stage due to a difficult HI-H₂O separation step and material compatibility issues. In an effort to avoid the azeotropic HI-H₂O mixture, an imidazolium-based ionic liquid was used as a reaction medium instead of water. Ionic liquids were selected based on their high solubility for SO₂, I₂, and tunable miscibility with water. The initial low temperature step of the Sulfur-Iodine cycle was successfully carried out in ionic liquid reaction medium. Kinetics of the reaction were investigated by I₂ colorimetry. The reaction also evolved H₂S gas, which led to the conceptual idea of a new Sulfur-Sulfur thermochemical cycle, shown below: / 4I₂(l)+4SO₂(l)+8H₂O(l)↔4H₂SO₄(l)+ 8HI(l) / 8HI(l)+H₂SO₄(l)↔ H₂S(g)+4H₂O(l)+4I₂(l) / 3H₂SO₄(g)↔ 3H₂O(g)+3SO₂(g)+1½O₂(g) / H₂S(g)+2H₂O(g)↔ SO₂(g)+3H₂(g) / The critical step in the Sulfur-Sulfur cycle is the steam reformation of H₂S. This highly endothermic step is shown to successfully occur at temperatures in excess of 800˚C in the presence of a molybdenum catalyst. A parametric study varying the H₂O:H₂S ratio, temperature, and residence time in a simple tubular quartz reactor was carried out and Arrhenius parameters were estimated. All reactive steps of the Sulfur-Sulfur cycle have been either demonstrated previously or demonstrated in this work. A theoretical heat-to-hydrogen thermal efficiency is estimated to be 55% at a hot temperature of 1100 K and 59% at 2000 K. As a highly efficient, all-fluid based thermochemical cycle, the Sulfur-Sulfur cycle has great potential for feasible process implementation for the transformation of high quality heat to chemical energy. / Graduation date: 2012

The hydrogen economy is a possible component of an energy future based on use of alternative and renewable energy sources, deemed desirable from the general consensus of the worldwide community that we do not want to further exacerbate the climate problems that we have introduced over the last two centuries from burning fossil fuels. The burning of fossil fuels emits toxic pollutants into the air, such as sulfur compounds and oxidized forms of nitrogen (NOx) but also emit copious amounts of the inert carbon dioxide. The latter is widely recognized as the major cause of the global warming phenomenon. For a hydrogen economy to develop, efficient means of hydrogen generation are required. Thermochemical cycles were conceived in the 1960s but only one operating pilot plant and no commercial installations based on the processes have been built. In the present work the use of a membrane reactor to enable the newly conceived Sulfur-Sulfur cycle, based on equations 1 - 3 is modeled. / 4H₂O+4SO₂ -> H₂S + 3H₂SO₄ Eq. 1 / H₂SO₄ -> SO₂ + H₂O + 1/2O₂ Eq. 2 / H₂S + 2H₂O -> SO₂ + 3H₂ Eq. 3 / The rationale for the use of a membrane reactor to enable the cycle is based on enhancing extent of reaction beyond its predicted equilibrium point due to the severely unfavorable thermochemical parameters for the steam reforming of hydrogen sulfide reaction (Eq. 3 above) which has a low equilibrium concentration of products. The membrane reactor will employ a molybdenum sulfide catalyst driving the steam reformation of hydrogen sulfide reaction and simultaneous extraction of hydrogen (one of the products) will allowing for the reaction to occur to higher extent. A computational model of a catalytic membrane reactor was constructed using the well-known finite element model package Comsol v4.1 in which a catalytic microchannel reactor separated from a sweep gas by a thin hydrogen permeable membrane is built and parametric sweeps to evaluate the effect of membrane transport parameters, pressure and gas feed velocities are calculated. Though the steam reforming of hydrogen sulfide reaction has a competing thermal cracking reaction, the present work focuses on modeling one reaction only (the steam reformation reaction) for simplicity. Fully dense metallic membranes with chemselective permeability to hydrogen are modeled with transport parameters derived from reported literature values for similar applications. The results show that employing a membrane reactor does significantly affect the completeness of the reaction by product extraction (if you do run the model with membrane transport set to zero, compare the extent at zero with extent at 3.6x10⁻⁶ mol.s⁻¹.m⁻²). The effect of changing sweep gas velocity is contingent on membrane properties, and membranes with small diffusion coefficients severely limit the ability of extraction of hydrogen from the feed. Therefore, it is more important that membranes with very high hydrogen permeability be employed in designing a reactor to implement this process, allowing for effective hydrogen separation and high conversion of the reactants in the process. Reactor pressure has minimal effect on the extent of reaction and therefore reactors designed to implement the process may be designed to operate at close to ambient pressure. / Graduation date: 2012

The significance of hydrogen production is increasing as fossil fuels are being depleted and energy security is of increasing importance to the United States. Furthermore, its production offers the potential to alleviate concerns regarding global warming and air pollution. In this thesis we focused on examining the efficiency of hydrogen production from current biomass compared to that from fossil fuel coal. We explored the efficiencies of maximum hydrogen production from biomass and from coal under current technology, namely coal gasification and biomass pyrolysis, together with following-up technologies such as steam reforming (SR). Bio-oil, product from pyrolysis and precursor for steam reforming, is hard to define. We proposed a simulation tool to estimate the pyrolytic bio-oil composition from various biomasses. The results helped us understand the accuracy that is needed for bio-oil composition prediction in the case it is converted to hydrogen. Hydrogen production is energy intensive. Therefore, heat integration is necessary to raise the overall thermodynamic efficiencies for both coal gasification and biomass pyrolysis. The results showed that considering the ultimate energy source, sunlight, about 6-fold more sunlight would be required for the coal to hydrogen than that for biomass to hydrogen. The main difference is in the efficiency of conversion of the ancient biomass to coal and therefore, for modern mankind, this loss has already been incurred.

Aqueous-phase reforming (APR) is reported for the first time for the production of H2 from actual biomass. The experiments are carried out in batch using a 100mL Parr microreactor heated to 225C. In this one-pot, two-step process, acid hydrolysis is used to break down the polymeric constituents of biomass to smaller soluble molecules and these species are reformed using a Pt/Al2O3 catalyst. The experiments show that increasing the acid concentration from 1% to 5% causes more than a twelve-fold increase in H2 concentration, with hydrogen a minor product accounting for 18% of the non-condensable gas phase and CO2 as the major product. In the presence of the Pt/Al2O3 reforming catalyst, both the selectivity and yield of hydrogen in the gas phase increase. This is accompanied by a noticeable decrease in carbon monoxide production. Comparison with other feeds such as glucose, wastepaper and ethylene glycol showed that the amount of hydrogen produced from biomass is of a comparable magnitude per gram of feed, although biomass yields more hydrogen per gram of carbohydrate than either glucose or wastepaper. Baseline experiments with only the catalysts in the absence of any biomass show no increase in the reactor system pressure when only water and helium are present, indicating that the observed hydrogen produced is sourced form the biomass.