Valorization strategies for pyrolytic lignin

Pressing environmental concerns have encouraged research towards the development of sustainable alternatives for the current petroleum-based industry. In this context, lignocellulosic biomass (plant matter) is expected to play an important role in decarbonizing the economy due to its high availability, renewable character and rich chemical structure. Lignocellulose is mainly composed of carbohydrates (cellulose and hemicellulose fractions) and aromatic biopolymers (lignin fraction). Through the well-established pyrolysis technology, it is thermally deconstructed into a liquid that can be fractionated into a water-soluble sugar phase and a lignin phase (pyrolytic lignin). While biobased sugars are used in various processes, lignin has been overlooked due to its complex structural features and treated as residue that is burned for low-value energy generation. Nonetheless, it has great potential as a source of biofuels and biobased chemicals with a range of applications. In this thesis, reductive (catalytic, using hydrogen) and oxidative (non-catalytic, using ozone) strategies for pyrolytic lignin depolymerization into value-added products were experimentally evaluated. Studies include the detailed characterization of a typical pyrolytic lignin structure followed by catalyst screenings for reductive upgrading, as well as ozonation in batch and continuous set-ups. This led to the development of a two-step oxidative-reductive system for improved depolymerization to low molecular weight biobased chemicals. Furthermore, the biomass source influence was evaluated, as well as extension of novel strategies to other lignin types. The promising results reported will contribute to the development of biorefineries, whose realization ultimately depends on maximum value extraction from the lignin fraction

In-depth structural characterization of the lignin fraction of a pine-derived pyrolysis oil

Pyrolytic lignin (PL) is the collective name of the water-insoluble fraction of pyrolysis oils produced from the fast pyrolysis of lignocellulosic biomass. As the name suggests, PL is composed by fragments derived from lignin, which is the largest natural source of aromatic carbon. Its valorization is of major importance for the realization of economically competitive biorefineries. Nonetheless, the valorization of PL is hindered by its complex structure, which makes the development of tailored strategies for its deconstruction into valuable compounds challenging. In this work, we provide an in-depth analysis of the structural composition of PL obtained from a commercially available pine-derived pyrolysis oil obtained at 500 °C (Empyro B.V., the Netherlands). Molecular weight distribution and thermal stability were accessed by GPC and TGA, respectively, and the monomers present in the PL (≈ 15 wt%) were identified and quantified by chromatographic analyses (GCxGC–FID, GCxGC/TOF–MS, GC–MS and HPLC). Together with FTIR, Py-GC–MS, TAN, elemental analysis and various advanced NMR techniques (13C NMR, 31P NMR, 19F NMR, HSQC NMR, HMBC NMR), structural features of the PL oligomers were elucidated, revealing a guaiacyl backbone linked by alkyl, ether, ester and carbonyl groups, with none of the typical native lignin linkages (i.e. β–O–4, β–β, β–5) present. Furthermore, 72.3 % of the oxygen content in PL could be assigned to specific motifs by the quantitative analyses performed, and oligomeric models were proposed based on the obtained information. We expect that this characterization work can support future research on the development of valorization pathways for PL, allowing the feasible conversion of this promising feedstock into valuable biobased products with a wide range of possible applications, e.g. fuels, materials and specialty chemicals

Treze de Maio beco do teatro: um estudo de casos sobre a manipulação de uma estrutura aberta no centro do Rio de Janeiro

O trabalho tem como objetivo estudar soluções e estruturas que sejam abertas à mudanças e respondam à necessidade da cidade contemporânea, a qual passa por transformações ao longo do tempo que alteram sua morfologia, suas formas de ocupação e de vivência do espaço, e propor um projeto suficientemente aberto e flexível a diferentes usos em um terreno de esquina na Cinelândia, centro do Rio de Janeiro

Melhoria da atenção à saúde do idoso na Estratégia de Saúde da Família Francisco Pereira Batista, COARI/AM

A principal causa de morte no Brasil e no mundo são as doenças cardiovasculares, tanto em homens quanto em mulheres muitas dessas doenças são complicações que podem ser prevenidas ao manejarmos adequadamente a população idosa ou indivíduos com comorbidades que predispõe a essas complicações. Este trabalho foi desenvolvido no bairro de Chagas Aguiar, na UBS Francisco Pereira Batista, no município de Coari/Am. Ao analisarmos a situação da Saúde do município, evidenciou-se que se fazia necessária a organização dos serviços e padronização da assistência através de registros específicos. O projeto utilizou-se das fichas espelhos fornecidas pela UFPEL, traçamos metas e priorizamos alguns objetivos na atenção básica oferecida aos idosos. Ao final dos 3 meses de intervenção coletamos dados e acompanhamos 121 pacientes, obtivemos alcances significativos na avaliação clínica desses pacientes e na promoção em saúde orientada a eles. Como resultados ampliamos a cobertura do atendimento aos idosos qualificamos os atendimentos clínicos, aproximamos a comunidade da unidade de saúde e buscamos o engajamento público O real motivo do início da intervenção foi o modelo precário adotado anteriormente na unidade supracitada, com pouco ou nenhum acompanhamento dos pacientes . A importância do fortalecimento das ações e da equipe de saúde corresponde a uma das principais ferramentas para o controle e redução da morbimortalidade relacionada as doenças dessa idade. Ao longo da intervenção verificamos entre outros pontos uma melhora na adesão medicamentosa, do seguimento às consultas de retorno, da busca ativa realizada pelos profissionais da unidade de saúde e um melhor acolhimento com a população

A Two‐Step Approach for the Conversion of Technical Lignins to Biofuels

Lignocellulose is a widely available carbon source and a promising feedstock for the production of advanced second‐generation biofuels. Nonetheless, lignin, one of its major components, is largely underutilized and only considered an undesired byproduct. Through catalytic hydrotreatment, the highly condensed lignin can be partially depolymerized into a range of monomers. However, its recalcitrance and the presence of aromatic fragments linked by C-C bonds require extensive cracking, which is challenging to achieve. Here, a two‐step strategy is reported in which an initial pretreatment step with ozone is used prior to catalytic hydrotreatment to boost lignin depolymerization. Three types of lignin (Kraft, pyrolytic, and Fabiola organosolv) are used as feedstocks and the ozonation step is performed under ambient conditions with either methanol or ethanol as the solvent. The pretreatment is shown to have a positive effect on the subsequent hydrotreatment reaction (Pd/C, 350 °C, 100 bar H2) and gives product oils with significantly lower Mw (up to 43% lower), higher volatility, and improved calorific values (up to 45.3 MJ kg−1) compared to a direct hydrotreatment

Score for atrial fibrillation detection in acute stroke and transient ischemic attack patients in a Brazilian population: The acute stroke atrial fibrillation scoring system

OBJECTIVE: Atrial fibrillation is a common arrhythmia that increases the risk of stroke by four- to five-fold. We aimed to establish a profile of patients with atrial fibrillation from a population of patients admitted with acute ischemic stroke or transient ischemic attack using clinical and echocardiographic findings.METHODS: We evaluated patients consecutively admitted to a tertiary hospital with acute ischemic stroke or transient ischemic attack. Subjects were divided into an original set (admissions from May 2009 to October 2010) and a validation set (admissions from November 2010 to April 2013). The study was designed as a cohort, with clinical and echocardiographic findings compared between patients with and without atrial fibrillation. A multivariable model was built, and independent predictive factors were used to produce a predictive grading score for atrial fibrillation (Acute Stroke AF Score-ASAS).RESULTS: A total of 257 patients were evaluated from May 2009 to October 2010 and included in the original set. Atrial fibrillation was diagnosed in 17.5% of these patients. Significant predictors of atrial fibrillation in the multivariate analysis included age, National Institutes of Health Stroke Scores, and the presence of left atrial enlargement. These predictors were used in the final logistic model. For this model, the area under the receiver operating characteristic curve was 0.79. The score derived from the logistic regression analysis waThe model developed from the original data set was then applied to the validation data set, showing the preserved discriminatory ability of the model (c statistic = 0.76).CONCLUSIONS: Our risk score suggests that the individual risk for atrial fibrillation in patients with acute ischemic stroke can be assessed using simple data, including age, National Institutes of Health Stroke Scores at admission, and the presence of left atrial enlargement.Universidade Federal de São Paulo (UNIFESP) Departamento de Neurologia e NeurocirurgiaHospital Israelita Albert Einstein Setor de EcocardiografiaHospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Radiologia Setor de EcocardiografiaHospital Israelita Albert Einstein Programa Integrado de NeurologiaUNIFESP, Depto. de Neurologia e NeurocirurgiaSciEL

Score for atrial fibrillation detection in acute stroke and transient ischemic attack patients in a Brazilian population: The acute stroke atrial fibrillation scoring system

OBJECTIVE: Atrial fibrillation is a common arrhythmia that increases the risk of stroke by four- to five-fold. We aimed to establish a profile of patients with atrial fibrillation from a population of patients admitted with acute ischemic stroke or transient ischemic attack using clinical and echocardiographic findings. METHODS: We evaluated patients consecutively admitted to a tertiary hospital with acute ischemic stroke or transient ischemic attack. Subjects were divided into an original set (admissions from May 2009 to October 2010) and a validation set (admissions from November 2010 to April 2013). The study was designed as a cohort, with clinical and echocardiographic findings compared between patients with and without atrial fibrillation. A multivariable model was built, and independent predictive factors were used to produce a predictive grading score for atrial fibrillation (Acute Stroke AF Score-ASAS). RESULTS: A total of 257 patients were evaluated from May 2009 to October 2010 and included in the original set. Atrial fibrillation was diagnosed in 17.5% of these patients. Significant predictors of atrial fibrillation in the multivariate analysis included age, National Institutes of Health Stroke Scores, and the presence of left atrial enlargement. These predictors were used in the final logistic model. For this model, the area under the receiver operating characteristic curve was 0.79. The score derived from the logistic regression analysis was The model developed from the original data set was then applied to the validation data set, showing the preserved discriminatory ability of the model (c statistic = 0.76). CONCLUSIONS: Our risk score suggests that the individual risk for atrial fibrillation in patients with acute ischemic stroke can be assessed using simple data, including age, National Institutes of Health Stroke Scores at admission, and the presence of left atrial enlargement

Efficient depolymerization of lignin to biobased chemicals using a two-step approach involving ozonation in a continuous flow microreactor followed by catalytic hydrotreatment

Lignin is a promising feedstock for the replacement of conventional carbon sources for the production of chemicals and fuels. In this paper, results are reported for the depolymerization of various residual lignins in the absence of a catalyst by utilizing ozone. Reactions were performed in a microreactor setup ensuring high gas-liquid mass transfer rates, a low inventory of ozone, and straightforward scale-up possibilities. The ozonation is demonstrated using a representative model compound (vanillin) and various lignins (pyrolytic and organosolv) dissolved in methanol (2.5 wt %). Experiments were performed under ambient conditions, at gas-liquid flow ratios ranging from 30 to 90 and short residence times on the order of 12-24 s. Analyses of the products after methanol removal revealed the presence of (di)carboxylic acids, methyl esters, and acetals. Extensive depolymerization was achieved (i.e., up to 30% for pyrolytic lignin and 70% for organosolv lignins). Furthermore, a two-step approach in which the ozonated lignin is further hydrotreated (350-400 degrees C, 100 bar H-2, 4 h, Pd/C as catalyst) showed a substantial increase in depolymerization efficiency, yielding a 2.5-fold increased monomer yield in the product oil compared to a hydrotreatment step only