No abstract

Esta dissertação representa o fim de um ciclo de dois anos, repleto de desafios. Como não percorri este caminho sozinha, deixo os meus agradecimentos a algumas pessoas e instituições que me ajudaram a cumprir meus objetivos e a concretizar mais esta etapa da minha formação acadêmica.Primeiramente, agradeço a Deus por me guiar ao longo de toda a minha vida e por ter colocado pessoas tão especiais ao meu lado, a minha família.Aos meus pais, Emanuel e Rosa, agradeço pelo apoio, paciência e carinho, não só neste período, mas em toda minha vida. Aos meus irmãos, Pedro e Isabela, pelo carinho e cumplicidade.Ao meu orientador, Carlos Henrique Ataíde, e à minha coorientadora, Marina Seixas Pereira, expresso minha gratidão por aceitarem me orientar. Agradeço pelo apoio, atenção, confiança e colaboração no solucionar de dúvidas e problemas que surgiram ao longo da realização deste trabalho. Agradeço também ao professor Cláudio Roberto Duarte pela colaboração e apoio.

The main objective of the present work was to study the influence of different operating conditions in the microwave drying of drill cuttings and an eventual degradation of the condensed liquid collected during this operation. For this, a Central Composite Design (CCD) was used, considering three independent variables at three levels: initial olefin content (7.5, 10, and 12.5% w/w), power (250, 500, and 750 W), and time (5, 10, and 15 min); the residual olefin content being the response analyzed in the conducted tests without monitoring or control of the cutting’s temperature. All three variables studied were statistically significant, presenting a positive or negative effect on residual olefin content. As expected, the initial olefin content had a negative effect on the response. On the other hand, when considering the applied power and the drying time, the effect on decontamination yield was positive. The results showed that cuttings can be decontaminated at lower levels than those required by environmental legislation (offshore drilling), reaching residual olefin mass contents of less than 1%. Finally, the organic phase of recovered liquids, after the condensation of vapors produced during drying, was analyzed by gas chromatography technique. It was observed greater olefin degradation in the longer and higher power tests, especially in samples of condensed liquid collected inside the microwave oven.

No abstract

With the increasing severity of environmental legislation, the disposal of drill cuttings has become a critical issue. Once the solids control system reaches contaminant contents close to the established limit value, alternative treatment technologies have been studied, such as microwave drying. In this scope, dielectric properties of two distinct cuttings, one obtained from clay formations and the other from reservoir, were measured in different conditions. It could be inferred from the results that the cuttings are absorbent materials and the loss tangent is directly proportional to their contaminant content. Additionally, a predictive kinetic model previously designed for clay cuttings was tested for reservoir cuttings, showing that the model is also aplicable in the analysis of the drying behavior of reservoir cuttings for low values of applied power. It was concluded that the insertion of dielectric parameters into the kinetic models enabled not only yield prediction, but also provided a better understanding of how the selected materials behave under different microwave process conditions, both qualitatively and quantitatively. It is important to highlight that this knowledge on microwave drying is fundamental not only to the optimization and control of the process, but also to the development of new technologies that make use of specific characteristics of the phenomena.