Domingos Fabiano de Santana Souza

Modeling and simulation of Bacillus cereus chitosanase activity during purification using expanded bed chromatography

A phenomenological model was used to describe sequentially the three steps (flowthrough, washing and elution) of expanded bed adsorption chromatography for recovery of chitosanases from Bacillus cereus. Additionally, a hybrid strategy for model parameter estimation was carried out using particle swarm optimization and Gauss-Newton algorithms. The model was validated with independent experimental data and the statistical criteria (χ2 and mean squared error tests) showed that the hybrid strategy was more promising than just the heuristic method. With the calibrated model, surface response methodology was applied to obtain the optimal operational conditions, and experiments were performed to confirm these results. Overall, a value of 41.08% for yield was obtained using 700 mM NaCl during elution. In summary, all approach employed in this work was relevant for maximizing the yield of the chromatographic process.

Dynamic Simulation of a Compressor Located in a Natural Gas Processing Unit Using EMSO Simulator

Abstract Nowadays, a profound knowledge of all the stages involved in large scale processing of oil, natural gas or other fuels is necessary, due to the increased preoccupation with how to use the natural resources in a responsible way. The facilities for processing natural gas can be divided in two main parts, the first one responsible for the condensation of larger hydrocarbons (ethane, propane, butane, and the like) and the second one for the distillation of these larger hydrocarbons obtained. The first part of these facilities achieves a minimum temperature of -90°C due to a propane refrigeration system. This work studies a centrifugal compressor situated in the propane refrigeration system of a Natural Gas Liquid Recovery Unit (LRU) located in Macae (Rio de Janeiro, Brazil) -Petrobras Transporte S.A. (Transpetro). This compressor is one of the most complex and important equipments of the LRU. The main contribution of this paper is to propose a dynamic model for this centrifugal compressor based on mass and energy balance coupled with thermodynamics equations for the nonidealities of the gas. This dynamic model was used to simulate real conditions in some situations observed in the LRU, analyzing its open loop behavior and investigating its automatic control (controller tuning and closed loop behavior). The situations studied consisted in applying step disturbances to the centrifugal compressor and then interpreting the results in the light of the developed model. The modeling, simulation and control investigations were achieved using a Brazilian simulator called EMSO (Environment for Modeling, Simulation and Optimization), which is a graphical environment that can be freely modified by all users. In this environment, the language is fully object-oriented, allowing the user to develop complex dynamic or steady models by composing them with existent small models or build specific models by deriving standard ones. EMSO was developed by the ALSOC Project (Free Environment for Simulation, Optimization and Control of Processes) which supplies this software without costs for partners and universities, aiming therefore to standardize and spread out its use. The present work provides information on the operation and control of the compressor allowing the further development of abnormal situation management tools that will support the control system and provide an easier and safer operation of the LRU.

Enhancing the recovery and concentration of polyphenols from camu-camu (Myrciaria dubia H.B.K. McVaugh) by aqueous two-phase flotation and scale-up process

ABSTRACT In this study, polyphenols obtained from camu-camu pulp residue were recovered and concentrated from aqueous two-phase flotation (ATPF) by evaluating different operating conditions, such as solvent type, pH, ammonium sulfate concentration, flotation time, air flow, and volumetric ratio. Under optimal conditions, the polyethylene glycol 400/ammonium sulfate ATPF system showed an efficiency of 81.02% and a concentration coefficient two times higher than traditional aqueous two-phase extraction. Experiments were also carried out on a semi-pilot scale, using an apparatus with a 2.5-L working volume. The results showed that the semi-pilot system was comparable to the smaller scale system.

Mathematical modeling of the whole expanded bed adsorption process to recover and purify chitosanases from the unclarified fermentation broth of Paenibacillus ehimensis

In this study, a general rate model was applied to the entire process of expanded bed adsorption chromatography (EBAC) for the chitosanases purification protocol from unclarified fermentation broth produced by Paenibacillus ehimensis using the anionic adsorbent Streamline® DEAE. For the experiments performed using the expanded bed, a homemade column (2.6cm×30.0cm) was specially designed. The proposed model predicted the entire EBA process adequately, giving R2 values higher than 0.85 and χ2 as low as 0.351 for the elution step. Using the validated model, a 33 factorial design was used to investigate other non-tested conditions as input. It was observed that the superficial velocity during loading and washing steps, as well as the settled bed height, has a strong positive effect on the F objective function used to evaluate the production of the purified chitosanases.

SECAGEM DE ALIMENTOS EM LEITO DE JORRO SOB A ÓTICA DA ANÁLISE DE PATENTES

Os processos de secagens sao bastante utilizados na industria de alimentos, pois prolongam a vida de prateleira de alimentos, principalmente frutas e vegetais, por meio da reducao de agua da matriz alimenticia. Existem inumeros tipos de secadores e cada um e utilizado de acordo com as propriedades dos alimentos e produto final. Dentre eles, o leito de jorro e um secador que vem sendo vastamente utilizado devido ao seu custo relativamente baixo e facilidade de operacao, alem de produzir alimentos com boas qualidades sensoriais. Diante disto, o presente trabalho objetivou realizar uma analise de patentes para verificar as tendencias do desenvolvimento tecnologico de secagem em alimentos com o leito de jorro. A busca de patentes foi realizada com o software AcclaimIP ® versao Trial utilizando palavras-chaves e associacoes em ingles relacionadas com tema do presente trabalho. Foram encontradas 15 patentes especificas de secagem de alimentos com o uso de leito de jorro. Dentre as classes com mais depositos estao A23B7 (Conservacao ou amadurecimento quimico de frutas ou legumes) e A23L19 (Produtos a base de frutas ou legumes; Seu preparo ou tratamento) ambas com 5 patentes. Alem disso, nota-se que a maioria das patentes relata a combinacao da secagem em leito de jorro com outros processos, como micro-ondas e vacuo. Palavras-chave — Alimentos, conservacao, patenteamento, secadores.

A PRODUÇÃO TECNOLÓGICA DE PATENTES DA UFS E UFPE ENTRE 2009 E 2013

As universidades possuem um importante papel no desenvolvimento cientifico da regiao onde estao inseridas. Este desenvolvimento torna-se evidente com as acoes patentearias e os seus desdobramentos no âmbito da pesquisa academica. Neste sentido, a Universidade Federal de Pernambuco possui uma posicao de destaque em relacao as demais universidades do Nordeste, promovendo o incentivo e o desenvolvimento de pesquisas em inumeras areas de conhecimento. O presente estudo realiza uma analise comparativa entre as patentes requeridas e fora do sigilo da Universidade Federal de Pernambuco e Universidade Federal de Sergipe de modo a identificar areas em comum e areas carentes de pesquisa. A busca foi delimitada para os depositos no periodo de 2009 a 2013.

PROSPECÇÃO TECNOLÓGICA DA JABUTICABA (Myrciaria Cauliflora)

A jabuticaba ( Myrciaria Cauliflora ) e uma fruta nativa do Brasil, comum em regioes da Mata Atlântica. Apesar de conhecida, possui um potencial quimico pouco explorado. O presente trabalho tem como objetivo realizar uma prospeccao tecnologica afim de se avaliar o perfil quantitativo das publicacoes e patentes com o genero Myrciaria da especie Myrciaria Cauliflora no indexador de citacoes cientificas Web of Science e no banco de dados do Instituto Nacional de Propriedade Industrial (INPI) do Brasil. Ao utilizar a base de periodicos Web of Science com os topicos de pesquisa “Jabuticaba” e “Myrciaria Cauliflora“ presente no titulo e/ou no resumo, foram encontrados 31 artigos e participacoes em congressos, utilizando um refinamento de pesquisa direcionado a processamento. Ja na busca por patentes utilizando o banco de dados do INPI, foram encontradas somente 2 patentes registradas com os topicos de pesquisa “Jabuticaba” e “Myrciaria Cauliflora“.