ABSTRACT
An essential part for crude oil extraction is flow assurance, being critical to maintain a financially sustainable flow while getting the petroleum to the surface. When not well managed, it can develop into a significant issue for the O&G industry. By heating the fluids, problems with flow assurance, including paraffin deposition, asphaltene, and methane hydrate, can be reduced. Also, as the temperature rises, a liquid's viscosity decreases. Research focusing on the application of magnetic nanoparticles (NPs) in the oil industry is very recent. When magnetic nanofluids are exposed to an alternating magnetic field, the viscosity decreases by several orders of magnitude as a result of the fluid's temperature rising due to a phenomenon known as magnetic hyperthermia. This work focuses on the use of magnetic NPs (9 nm) in heavy crude oil (API 19.0). The frequency and strength of the magnetic field, as well as the characteristics of the fluid and the NPs intrinsic properties all affect the heating efficiency. For all of the experimental settings in this work, the flowloop's temperature increased, reaching a maximum of ΔT = 16.3 °C, using 1% wt NPs at the maximum available frequency of the equipment (533 kHz) and the highest field intensity for this frequency (14 kA/m), with a flow rate of 1.2 g/s. This increase in temperature causes a decrease of nearly 45% on the heavy crude oil viscosity, and if properly implemented, could substantially increase oil flow in the field during production.
ABSTRACT
The reverse water gas shift (RWGS) reaction converts carbon dioxide (CO2) and hydrogen (H2) to syngas, which is used to produce various high-added-value chemicals. This process has attracted great interest from researchers as a way of mitigating the potential environmental impacts of this greenhouse gas, with emphasis on global warming. This work aims to model and simulate an industrial catalytic reactor using kinetic data for the RWGS reaction. The simulation was carried out in Aspen Plus® v10. The thermodynamic analysis showed that the appropriate conditions for the reaction are feed molar ratio (H2/CO2) of 0.8:1, 750 °C, and 20 bar. The RWGS process proceeds in a multi-tubular fixed bed reactor with 36.26% CO2 conversion and 96.41% CO selectivity, at residence times in the order of 2.7 s. These results are at near-equilibrium CO2 conversion with higher CO selectivity.
Subject(s)
Carbon Dioxide , Water , Hydrogen , Thermodynamics , Computer SimulationABSTRACT
RESUMO: Este trabalho aborda a questão do gerenciamento de embalagens pós-consumo de lubrificantes automotivos, considerando as dificuldades inerentes à implementação do sistema de logística reversa - prática compulsória por força de lei (Brasil, Lei 12.305/2010) - e a ineficácia dos atuais métodos utilizados para remoção da fração oleosa residual, necessária ao reprocessamento do material plástico por reciclagem mecânica direta. Para determinar metodologia apropriada para limpeza dos frascos de lubrificantes foram conduzidos experimentos para avaliar a influência do aquecimento e da posição das embalagens durante o processo de drenagem gravitacional. O procedimento analítico realizado proporcionou a escolha de uma combinação de variáveis capaz de assegurar remoção de elevado teor do resíduo oleoso com menor gasto energético. A otimização foi feita utilizando um planejamento experimental do tipo composto central com triplicata no ponto central. Os dados obtidos nos ensaios foram analisados com recursos estatísticos e demonstraram que ambos os parâmetros avaliados interferem, de forma significativa, no processo em estudo. Os resultados apontaram aumento da eficácia do processo quando a drenagem é realizada em temperaturas superiores a 35ºC e com a embalagem inclinada em ângulos próximos a 70º em relação à horizontal. Nessas condições, percentuais de remoção de óleo residual superaram 95% após 35 minutos de drenagem.
ABSTRACT: This work addresses the management of automotive lubricants packages after lubricant use, considering the difficulties of implementing reverse logistics system - compulsory practice by virtue of Law (Brazil, Law 12,305/2010) - and the poor effectiveness of the current methods for removing residual oil from packages, which is required before reprocessing plastic material in direct mechanical recycling. Experiments were conducted in order to determine the appropriate methodology for cleaning the lubricant bottles, evaluating the influence of temperature and package position in the gravitational drainage. This analytical procedure elicited a combination of variables and conditions capable of improving the removal of oily residue with less energy. The experimental optimization was performed using a central composite model with triplicate center point. The test results were statistically analyzed and showed that both parameters have significant influence on the separation process. The data indicated that the process is more effective when the drainage is performed above 35ºC and the packaging inclined at angles close to 70º relative to horizontal. Under these conditions, the oil removal is greater than 95% after 35 minutes of drainage.
