This work presents a comprehensive model for lignocellulosic biomass pyrolysis, addressing kinetics, energy balances, and gas product composition with the aim of its application in wood combustion. The model consists of a two-stage global mechanism in which biomass initially reacts into tar, char, and light gases (non-condensable gases), which is followed by tar reacting into light gases and char. Experimental data from the literature are employed for determining Arrhenius kinetic parameters and key energy parameters, like tar and char heating values and the specific enthalpy of primary and secondary reactions. A methodology is introduced to derive correlations, allowing the model’s application to diverse biomass types. This work introduces several novel approaches. Firstly, a pyrolysis model that determines the composition of light gases by solving mass, species, and energy balances is developed, limiting the use of correlations from the literature only for tar and char elemental composition. The mass rate of light gases, tar, and char being produced is also determined. Secondly, kinetic parameters for primary and secondary reactions are determined following a Shafizadeh and Chin scheme but with a modified Arrhenius form dependent on $T^n$, significantly enhancing the accuracy of product composition prediction. Additionally, correlations for the enthalpies of reactions, both primary and secondary, are determined as a function of pyrolysis temperature. Primary reactions exhibit an overall endothermic behavior, while secondary reactions exhibit an overall exothermic behavior. Finally, the model is validated using cases reported in the literature, and results for light gases composition are presented.

This study assesses the feasibility of installing concentrated solar power plants in subtropical South America, particularly in Uruguay, by numerical simulations. Parabolic trough and solar power tower technologies are examined. A comprehensive literature analysis is conducted in order to evaluate initial investment, operation, and maintenance costs. Simulation models are validated in order to ensure results accuracy. The study is focused on the optimization of solar fields and storage sizes for five locations. The target set is to minimize the levelized cost of energy. In addition, energy losses and efficiencies are compared between parabolic trough and solar power tower technologies. Salto region in Uruguay is identified as the most suitable location for concentrated solar power projects. Optimized plants yield solar multiples of 3 or higher for solar power tower and around 4 for parabolic trough, with storage sizes ranging from 12 to 15 h, depending on the location. In Salto, the levelized cost of energy ranges from 148 to 175 USD/MW h for 110 MW solar power tower and from 169 to 220 USD/MW h for 55 MW parabolic trough plants, considering different investment cost scenarios. Levelized cost of energy is comparable for other locations, with a slight increase of approximately 10% for the least favorable location, Rocha. This work shows that while not yet competitive with photovoltaic or wind technologies, concentrated solar power plants show promise against fossil-fueled power plants and are expected to decrease further in cost.

A thermodynamic model for a hybrid thermo-solar externally fired gas turbine power plant fueled with biomass is presented. This technology represents a fully renewable way of obtaining electric power relying mainly in biomass with an extra advantage of decreasing its consumption at good radiative conditions. A concentrated solar power plant is implemented considering the Solugas project situated in Abengoa’s Solúcar Platform near Seville. To predict its behavior two models were implemented and compared with experimental data. Typical daily evolution of the output power, biomass mass flow, overall efficiency and biomass conversion efficiency for a typical Uruguayan year is presented. In addition, global results are presented leading to a 1.5% biomass saving increasing the economic efficiency a 0.34% what denotes the solar field and thermal power of receiver seem to be undersized.