Tesis doctoral de María Puig Arnavat
A reliable, affordable and clean energy supply is of major importance for society, economy and the environment. In this context, modern use of biomass is considered a very promising clean energy option for reduction of greenhouse gas emissions and energy dependency. Biomass gasification has been considered the enabling technology for modern biomass. cogeneration has been used for many years for biomass gasification and several plants have been implemented. However, little work has been done on trigeneration plants producing heat, cold and electricity. Trigeneration plants are of great interest for warm climate and developing countries that usually have a high cooling demand. For this reason, simple and reliable simulation tools are needed to give a better understanding of the whole process and as preliminary tools to evaluate the potential of trigeneration biomass gasification plants in a certain location. the main objective of this thesis is to develop a simplified but rigorous biomass gasification trigeneration plant model for the simulation, design and preliminary evaluation of trigeneration plants. To achieve this goal, different models for biomass gasification process have been reviewed and studied as well as different implemented biomass gasification plants configurations. A modified thermodynamic equilibrium model has been developed to account for real processes that do not achieve equilibrium. It has been validated using published experimental showing good agreement between experimental and predicted data. In addition, this model offers the opportunity to evaluate the influence of variations of the fuel and operating conditions in producer gas quality. Besides this model, two artificial neural network models, based on published experimental data, have also been developed: one for bfb gasifiers and the other for cfb gasifiers. These ann models provide better results compared with the modified equilibrium model and have proven the great potential they have in this field. In addition, they can be easily extended and improved when more data is available. because the absorption chiller is a key element in the trigeneration plant a new approach to the characteristic equation method has been developed to reduce the operating characteristics of absorption chillers into easier to handle simple algebraic equations that allow the model to be integrated in simulation and optimization programs. these previous developed models have been included in the model of the small-medium scale (250 kwe – 2 mwe) biomass gasification trigeneration plant. The trigeneration plant accounts for a downdraft or fluidised bed gasifier, heat recovery unit, clean-up section and an ice coupled with an absorption chiller. The three different configurations considered differ in how heat from exhaust gases and cooling water from the engine jacket is recovered and used in the absorption chiller. For this reason three different absorption chillers have been implemented: a single-effect hot water driven absorption chiller, a double-effect exhaust gases driven absorption chiller and a double-effect steam driven absorption chiller. These configurations have been applied to a case study of the polygeneration plant st-2 foreseen in cerdanyola del vallés in the framework of european project polycity.
Datos académicos de la tesis doctoral «Performance modelling and validation of biomass gasifiers for trigeneration plants«
- Título de la tesis: Performance modelling and validation of biomass gasifiers for trigeneration plants
- Autor: María Puig Arnavat
- Universidad: Rovira i virgili
- Fecha de lectura de la tesis: 10/10/2011
Dirección y tribunal
- Director de la tesis
- Alberto Coronas Salcedo
- Tribunal
- Presidente del tribunal: xavier Flotats ripoll
- gilles Vaitilingom (vocal)
- umberto Desideri (vocal)
- Alberto Gomez barea (vocal)