Revamping a biodiesel plant by adding a new esterification unit

Identifier:  TFG:9323

Handle: https://hdl.handle.net/20.500.11797/TFG9323

Authors:  Latorre Gimenez, Lorena

Abstract:
The current context of global energy crisis and the urgent need to reduce dependence on fossil fuels have placed biofuels at the center of energy transition strategies. In this scenario, biodiesel stands out as one of the most viable renewable options, as it can be produced from natural and sustainable sources such as vegetable oils, animal fats, and waste oils. Moreover, its use significantly reduces greenhouse gas emissions, contributing positively to the climate goals set by the European Union and other international bodies. However, the efficient production of biodiesel is often limited by the quality of the raw materials. Waste oils and other low-cost byproducts typically have a high content of free fatty acids (FFA), which negatively interfere with the transesterification process, leading to soap formation and reducing conversion yield. To address this issue, one of the most effective solutions is the incorporation of a preliminary esterification stage, which reduces FFA content and broadens the range of usable feedstocks. In this context, the present bachelor’s thesis proposes the revamping of a biodiesel plant through the integration of a new esterification unit, with the aim of improving operational flexibility and the capacity to process low-quality raw materials. This modification represents a strategic move to adapt the facilities to current industry demands, promoting a more efficient and sustainable production model aligned with the principles of the circular economy. The study presents a comprehensive view of the project, covering all key stages: from the selection of the most appropriate kinetic and thermodynamic models to the detailed design of the main equipment and its integration into the existing process. Using advanced simulation tools such as Aspen Plus, the behavior of the system under real operating conditions has been analyzed, and material and energy balances have been obtained to support design decisions. The selected reactor is of the PFR (plug flow reactor) type, operating at high temperatures and pressures, and uses methanesulfonic acid (MSA) as a homogeneous catalyst, combined with excess methanol to ensure high conversion. In addition to the reactor, the project includes the sizing and configuration of other essential units such as heat exchangers, a feed pump, a flash vessel for vapor-liquid separation, a decanter for separating immiscible phases, and a distillation column for methanol recovery and reuse. All equipment has been designed according to internationally recognized standards and codes (ASME, TEMA, API), ensuring compliance with safety, efficiency, and maintainability criteria. The work also includes the development of process flow diagrams (PFD) and piping and instrumentation diagrams (P&ID), as well as a HAZOP analysis to identify potential operational deviations and associated risks, and to propose the necessary safeguards. Finally, an economic evaluation of the project is presented, including an estimate of the investment, operating costs, and profitability indicators such as NPV, IRR, and payback period, in order to assess its economic viability. Thus, this thesis offers a complete and feasible technical solution for the modernization of a biodiesel plant, contributing to the improvement of both performance and sustainability, and positioning it to meet the current challenges of the energy sector.