Hydraulic debottlenecking of the circuits of an integrated unit CDU/VDU

Identifier:  TFG:3038

Handle: https://hdl.handle.net/20.500.11797/TFG3038

Authors:  Boulanouar Al Massati, Samir

Abstract:
The petroleum refinery Asfaltos Españoles S.A, is a company that processes heavy and extra-heavy crude oils with the aim of obtaining distillates and asphalt bitumens. In this Final Degree Project, the viability of two proposals aimed at solving the hydraulic bottleneck present in the exchange train prior to the distillation of crude oil is studied. On the one hand, a new line layout will be designed to reduce the pressure drop present in the aspiration of the pump P-101, which is placed inside the exchangers train. On the other hand, a flash drum separator that will extract the lighter compounds from the crude separator to enhance heat exchange will be designed. Firstly, the current line layout travels towards two equipment that are currently out of service, bypassing these. The length of this layout can be reduced, reducing the pressure dross, which eliminates de partial evaporation of the oil in the aspiration, causing the pump P-101 to cavitate. Secondly, to find the optimal characteristics of the separator, a study is carried out to find the best available technology. Next, the sizing process of the flash drum separator is detailed, as well as its control system. It will be a horizontal separator, equipped with a demister, a vortex breaker, a deflector and a demulsifying agent. To control the flash, feedback and feedforward controls will be used. In addition, a HAZOP study is carried out, through which different emergency scenarios that pose a risk to the normal operation of the plant, people’s health, and the environment are identified and given solution. Thirdly, a study of environmental aspects, in order to identify if the environment if affected as a consequence of implementing the proposals, is carried out. The study determines that the impact of the proposals regarding the evaluation of the current process is minimal. Finally, an economic feasibility study of the two proposals is carried out. The new line layout is determined to be viable, as a result of solving the economic losses of 30000 €/year due to production disruptions due to pump cavitation. Contrarily, the flash drum separator is not feasible, since the need of adding vapor and demulsifier plus the low reduction of natural gas consumption turns the economic losses higher than the benefits.