A carregar...
Publicação
Estudo de Melhoria de Tratamento de Efluentes da Refinaria de Sines: Foco no Tratamento Primário
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 2.42 MB | Adobe PDF |
Orientador(es)
Resumo(s)
A refinaria de Sines não possui uma estação de tratamento de efluentes completa, mas apenas uma estação de pré-tratamento com etapas de separação gravítica e flotação. Por funcionar há mais de 40 anos, os equipamentos foram sofrendo algumas degradações e alterações para atender às necessidades da refinaria, resultando em etapas de separação gravítica menos eficientes e na acumulação de matéria oleosa
não removida, o que se traduz em taxas e penalizações quando o efluente é enviado
para a estação de tratamento de efluentes exterior, Águas de Santo André, AdSA.
No espaço de um ano, em 161 amostras enviadas para a AdSA, 49% corresponderam a descargas penalizantes, sendo que a matéria oleosa teve impacto em 44% dessas descargas. O OP-V11, órgão responsável por tratar o efluente enviado da fábrica 1, teve impacto em 31% das descargas penalizantes por matéria oleosa, evidenciando a necessidade de melhorar a primeira etapa de tratamento de efluentes: a separação gravítica.
Para o dimensionamento de dois tipos de separadores gravíticos, API e CPI, foi calculado o caudal e a concentração de matéria oleosa a serem considerados para este cálculo, sendo obtidas as dimensões dos equipamentos seguindo a lei de Stokes. Foram considerados a fase dispersa, o coeficiente da fase dispersa, a velocidade horizontal e o número de Reynolds, com o objetivo de prever o comportamento do efluente
ao longo do processo de separação. Foram utilizados os modelos de dimensionamento
API 421, bem como um modelo Novel de dimensionamento para os cálculos das dimensões base dos separadores.
Para uma avaliação económica, foi realizado um estudo de CAPEX-OPEX através
do método dos fatores e derivados, com o intuito de obter o custo de implementação
de cada um dos equipamentos. Foi desenvolvida uma simulação considerando dados
extraídos do software Aspen Process Explorer e LIMS, relativos ao caudal de efluente e à concentração de matéria oleosa do órgão OP-V11, assim como uma média calculada
através de balanços mássicos e do método IQR para os restantes OP-Vs.
Dessa forma, foi possível prever o impacto económico no final do processo,
considerando essas condições. Assim, foi possível calcular o valor economizado em
cada um dos cenários de implementação e a redução de classes e descargas penalizantes.
A maior contenção refere-se à implementação de dois separadores CPI, resultando Numa economia de 360 mil euros em agravamentos e uma redução de 8 descargas penalizantes para apenas 1. Além disso, houve uma economia no envio de efluente sem agravamentos de 470 mil euros comprovando a redução das restantes classes de descargas. Este cenário possui um período de payback de um ano e meio.
O cenário com menor valor economizado é a implementação de apenas um
separador API, que resulta numa redução de 38% nas descargas penalizantes, com uma
economia de 210 mil euros em agravamentos e um total de 590 mil euros na implementação, resultando em um período de payback de sete meses.
Embora a implementação de separadores CPI ofereça um maior valor economizado, é importante considerar que estes exigem uma manutenção mais frequente, o que se torna uma desvantagem para a refinaria.
Assim, apresenta-se a instalação de dois separadores API como a melhor opção,
promovendo redundância, um sistema adicional que garante a continuidade das operações em caso de falhas ou necessidade de manutenção. Com essa opção, a refinaria poderia reduzir as descargas penalizantes para apenas 2, com um valor total poupado de 740 mil euros.
Essa implementação resultaria em uma melhoria significativa na qualidade do
efluente, especialmente em situações de upsets e picos de contaminação, além de uma
redução nas taxas e no valor a ser pago ao enviar o efluente para o exterior.
The Sines Refinery does not have a complete wastewater treatment station; it only possesses a pre-treatment station with gravity separation and flotation stages. Having operated for over 40 years, the equipment has undergone various degradations and modifications to meet the refinery's needs, resulting in less efficient gravity separation stages and an accumulation of unrecovered oily matter, which leads to fees and pen- alties when sent to the external wastewater treatment station, Águas de Santo André, AdSA. Over the span of one year, out of 161 samples sent to AdSA, 49% corresponded to penalizing discharges, with oily matter impacting 44% of those penalizing dis- charges. The OP-V11, responsible for treating the effluent sent from Factory One, ac- counted for 31% of the penalizing discharges due to oily matter, highlighting the need to improve the first step of wastewater treatment: gravity separation. To size two types of gravity separators, API and CPI, the flow rate and concentra- tion of oily matter to be considered for this calculation were determined, and the di- mensions of the equipment were obtained following Stokes' law. This involved consid- ering the dispersed phase, calculating the coefficient of the dispersed phase, the hori- zontal velocity, and the Reynolds number to predict how the effluent will behave throughout the separation process. The API 421 sizing models were utilized, along with a novel sizing model for the base dimensions of the separators. For an economic assessment, a CAPEX-OPEX study was conducted using the fac- tor method to determine the implementation cost of each equipment, along with a simulation based on data extracted from the Aspen Process Explorer and LIMS, relating to the flow rate and concentration of oily matter from the OP-V11, as well as an average calculated using mass balances and the IQR method for the other OP-Vs. This made it possible to predict the fees that would be incurred at the end of the process under these conditions. Consequently, the savings for each implementation scenario and the reduction in classes and penalizing discharges were calculated.The greatest savings pertain to the implementation of two CPI separators, saving 360 thousand euros in penalties and reducing the penalizing discharges from 8 to just 1, while also saving 470 thousand euros on the disposal of effluent without penalties, leading to a reduction in the remaining classes. This scenario has a payback period of one and a half years. In contrast, the scenario with the lowest savings is the implemen- tation of just one API separator, which achieves a 38% reduction in penalizing dis- charges, saving 210 thousand euros in penalties and 590 thousand euros in total, re- sulting in a payback period of seven months. Despite a greater total saved in the implementation of CPI separators, they re- quire more maintenance, which becomes a disadvantage for the refinery. Thus, in- stalling two API separators emerges as a better option to promote redundancy where redundancy refers to the presence of additional components in a system that allows it to continue operating efficiently even in the event of failures or upsets. This would reduce the number of penalizing discharges to just 2, with a total savings of 740 thou- sand euros. This implementation would lead to improved effluent quality, especially in cases of upsets and contamination peaks, as well as a reduction in fees and amounts payable when sending effluent externally.
The Sines Refinery does not have a complete wastewater treatment station; it only possesses a pre-treatment station with gravity separation and flotation stages. Having operated for over 40 years, the equipment has undergone various degradations and modifications to meet the refinery's needs, resulting in less efficient gravity separation stages and an accumulation of unrecovered oily matter, which leads to fees and pen- alties when sent to the external wastewater treatment station, Águas de Santo André, AdSA. Over the span of one year, out of 161 samples sent to AdSA, 49% corresponded to penalizing discharges, with oily matter impacting 44% of those penalizing dis- charges. The OP-V11, responsible for treating the effluent sent from Factory One, ac- counted for 31% of the penalizing discharges due to oily matter, highlighting the need to improve the first step of wastewater treatment: gravity separation. To size two types of gravity separators, API and CPI, the flow rate and concentra- tion of oily matter to be considered for this calculation were determined, and the di- mensions of the equipment were obtained following Stokes' law. This involved consid- ering the dispersed phase, calculating the coefficient of the dispersed phase, the hori- zontal velocity, and the Reynolds number to predict how the effluent will behave throughout the separation process. The API 421 sizing models were utilized, along with a novel sizing model for the base dimensions of the separators. For an economic assessment, a CAPEX-OPEX study was conducted using the fac- tor method to determine the implementation cost of each equipment, along with a simulation based on data extracted from the Aspen Process Explorer and LIMS, relating to the flow rate and concentration of oily matter from the OP-V11, as well as an average calculated using mass balances and the IQR method for the other OP-Vs. This made it possible to predict the fees that would be incurred at the end of the process under these conditions. Consequently, the savings for each implementation scenario and the reduction in classes and penalizing discharges were calculated.The greatest savings pertain to the implementation of two CPI separators, saving 360 thousand euros in penalties and reducing the penalizing discharges from 8 to just 1, while also saving 470 thousand euros on the disposal of effluent without penalties, leading to a reduction in the remaining classes. This scenario has a payback period of one and a half years. In contrast, the scenario with the lowest savings is the implemen- tation of just one API separator, which achieves a 38% reduction in penalizing dis- charges, saving 210 thousand euros in penalties and 590 thousand euros in total, re- sulting in a payback period of seven months. Despite a greater total saved in the implementation of CPI separators, they re- quire more maintenance, which becomes a disadvantage for the refinery. Thus, in- stalling two API separators emerges as a better option to promote redundancy where redundancy refers to the presence of additional components in a system that allows it to continue operating efficiently even in the event of failures or upsets. This would reduce the number of penalizing discharges to just 2, with a total savings of 740 thou- sand euros. This implementation would lead to improved effluent quality, especially in cases of upsets and contamination peaks, as well as a reduction in fees and amounts payable when sending effluent externally.
Descrição
Palavras-chave
Separação Gravítica Eficiência Dimensionamento Redundância