Characterization of the methanol recovery process at Prio Biocombustíveis S. A.

In a industrial environment, to know the process one is working with is crucial to ensure its good functioning. In the present work, developed at Prio Biocombustíveis S.A. facilities, using process data, collected during the present work, and historical process data, the methanol recovery process was characterized, having started with the characterization of key process streams. Based on the information retrieved from the stream characterization, Aspen Plus® process simulation software was used to replicate the process and perform a sensitivity analysis with the objective of accessing the relative importance of certain key process variables (reflux/feed ratio, reflux temperature, reboiler outlet temperature, methanol, glycerol and water feed compositions). The work proceeded with the application of a set of statistical tools, starting with the Principal Components Analysis (PCA) from which the interactions between process variables and their contribution to the process variability was studied. Next, the Design of Experiments (DoE) was used to acquire experimental data and, with it, create a model for the water amount in the distillate. However, the necessary conditions to perform this method were not met and so it was abandoned. The Multiple Linear Regression method (MLR) was then used with the available data, creating several empiric models for the water at distillate, the one with the highest fit having a R2 equal to 92.93% and AARD equal to 19.44%. Despite the AARD still being relatively high, the model is still adequate to make fast estimates of the distillate’s quality. As for fouling, its presence has been noticed many times during this work. Not being possible to directly measure the fouling, the reboiler inlet steam pressure was used as an indicator of the fouling growth and its growth variation with the amount of Used Cooking Oil incorporated in the whole process. Comparing the steam cost associated to the reboiler’s operation when fouling is low (1.5 bar of steam pressure) and when fouling is high (reboiler’s steam pressure of 3 bar), an increase of about 58% occurs when the fouling increases.

Aplicação da metodologia Advanced Product Quality Planning no desenvolvimento de um novo produto no setor automóvel

Este projeto surgiu com a necessidade da constituição de uma equipa multidisciplinar, incluindo uma pessoa responsável pela qualidade no desenvolvimento de um novo produto da fábrica. O produto é a estrutura metálica de um encosto de trás de um automóvel. Para o desenvolvimento do produto foi usado o método Advanced Product Quality Planning, vastamente utilizado no setor automóvel. Com o intuito de melhor perceber os problemas que podem surgir no novo produto foi estudado um produto fabricado no local de estágio e outro produzido numa outra fábrica do mesmo grupo, que têm algumas semelhanças a nível de processo e de design, respetivamente. Foram utilizadas algumas ferramentas da qualidade para explorar os problemas existentes na fábrica a nível do produto já existente e comprovado se algumas ações de melhoria propostas foram, ou não, bem-sucedidas. Com os outputs retirados da análise dos defeitos internos e externos foi elaborado o Plano de Controlo, que inclui a listagem de controlos necessários para se conseguir prever a qualidade do novo produto.

The eutrophication in the river Vouga basin: impacts on the quality of water for public supply

The aim of this paper is to make a characterization of water quality problems, in the river Vouga, regarding its use for public water supply. The river Vouga basin is located in a mountainous area, draining to the coastal lagoon of the Ria de Aveiro. Other medium size rivers also contribute to the load of pollution entering the estuarine system of the Ria de Aveiro. Two major impacts of the pollution in the river Vouga basin were identified. One is the eutrophication process of the lower reach of the river, including the Ria de Aveiro; the other is the occasional deterioration in the quality of the water abstracted from the medium reach of river Vouga. The causes of this deterioration are related to the enrichment of the river water with organic material. To improve the river water quality, both urban wastewater and agriculture related sources, must be controlled.