Oil refinery | EPFL Graph Search

An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into useful products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquefied petroleum gas and petroleum naphtha. Petrochemical feedstock like ethylene and propylene can also be produced directly by cracking crude oil without the need of using refined products of crude oil such as naphtha. The crude oil feedstock has typically been processed by an oil production plant. There is usually an oil depot at or near an oil refinery for the storage of incoming crude oil feedstock as well as bulk liquid products. In 2020, the total capacity of global refineries for crude oil was about 101.2 million barrels per day. Oil refineries are typically large, sprawling industrial complexes with extensive piping running throughout, carrying streams of fluids between large chemical processing units, such as distillation columns. In many w

Process Integration and Energy Conversion in a Natural Gas Refinery

The aim of this project was to reduce the fuel gas consumption of an existing gas refinery. Using pinch technology, it was found that energy savings up to 20% were possible on the process side. The entire plant was modeled in an energy integration tool in order to estimate the savings by a better integration of the utility system. It was found that the overall fuel gas consumption can be reduced up to 42%, by maximising the heat recovery on the process side and by improving the performance of the utility system.

2010

A risk-based multi-level stress test methodology: application to six critical non-nuclear infrastructures in Europe

José Pedro Gamito de Saldanha Calado Matos, Daniela Rodrigues, Anton Schleiss

Recent natural disasters that seriously affected critical infrastructure (CI) with significant socio-economic losses and impact revealed the need for the development of reliable methodologies for vulnerability and risk assessment. In this paper, a risk-based multi-level stress test method that has been recently proposed, aimed at enhancing procedures for evaluation of the risk of critical non-nuclear infrastructure systems against natural hazards, is specified and applied to six key representative CIs in Europe, exposed to variant hazards. The following CIs are considered: an oil refinery and petrochemical plant in Milazzo, Italy, a conceptual alpine earth-fill dam in Switzerland, the Baku–Tbilisi–Ceyhan pipeline in Turkey, part of the Gasunie national gas storage and distribution network in the Netherlands, the port infrastructure of Thessaloniki, Greece, and an industrial district in the region of Tuscany, Italy. The six case studies are presented following the workflow of the stress test framework comprised of four phases: pre-assessment phase, assessment phase, decision phase and report phase. First, the goals, the method, the time frame and the appropriate stress test level to apply are defined. Then, the stress test is performed at component and system levels and the outcomes are checked and compared to risk acceptance criteria. A stress test grade is assigned, and the global outcome is determined by employing a grading system. Finally, critical components and events and risk mitigation strategies are formulated and reported to stakeholders and authorities.

2020

An octree-based adaptive semi-Lagrangian free surface flow solver

Viljami Henrikki Laurmaa

A numerical method based on an adaptive octree space discretization for the simulation of 3D free-surface fluid flows is proposed. The Navier-Stokes equations are solved with a time-splitting scheme, which decouples advection from diffusion/incompressibility. The advection step is solved with a semi-Lagrangian VOF-based scheme on the octree. An interface prediction algorithm is used to refine the octree at the predicted location of the interface in order to ensure detail preservation. Subsequently, the fluid is advected and a coarsening algorithm adapts the mesh to avoid excess refinement in non-interfacial regions. SLIC and decompression algorithms are used for post-processing to limit numerical diffusion and correct numerical compression of the VOF function. The octree scheme allows anisotropy, refinement of interfacial cells to an arbitrary level and supports arbitrary complex domains. It does not require a 2:1 cell size ratio condition between adjacent cells. The octree is then coupled with a tetrahedral mesh on which we solve the second step of the splitting algorithm, the Stokes' equations. Numerical validation is done on both advection benchmark test cases and results are compared with the uniform cell grid scheme. Paddle-generated water waves are also simulated and results are compared with experimental water wave profile measurements. \bigskip First order finite element stabilization schemes for the time-dependent Stokes' equations are studied. A unified proof of stability and convergence of velocity and pressure for consistent and non-consistent PSPG schemes for the time-dependent Stokes' equations is given with explicit dependence on viscosity and stabilization parameter. The link between bubble enrichment and Pressure Stabilized Petrov-Galerkin (PSPG) schemes in the context of time-dependent Stokes' equations is discussed and two bubble-based PSPG-type schemes are studied. Different possibilities for stabilization parameters are discussed. Numerical comparisons are done to determine stability, convergence and conditioning issues associated with different PSPG schemes, bubble-based schemes and local pressure projection schemes in different settings.

EPFL2016

An octree-based adaptive semi-Lagrangian free surface flow solver

Viljami Henrikki Laurmaa

EPFL2016