Integration Mechanism For Thermochemical Hybrid Utilization Of Solar Thermal Energy And Biomass

Solar energy and biomass are clean with abundant resource, and viewed as the promising alternatives for the alleviation of the current energy shortage, environment pollution and greenhouse effect. However, the renewable energies like solar energy and biomass maintain the natural limitations of low energy density, uneven distribution and intermittence, which exert seriously adverse influences on their effective utilization and large-scale industrial application. Therefore, the R&D of the efficient renewable energies conversion technologies has been one of the most important scientific research directions of energy science around the world in 21st century.The research projects are based on the national research projects, including the key program of "the hybrid theory and method in the utilization of solar energy and fuel" which supported by the Natural Science Foundation of China, for exploring the efficient renewable energies conversion methods of solar energy and biomass. The researches in this dissertation including the fundamental and experimental researches for the renewable energies conversion and hybrid-system integration mechanisms, in terms of the thermochemical hybrid utilization of solar thermal energy and biomass.On the basis of the concept of the energy level, the energy level coupling properties and the renewable energies conversion mechanism within the thermochemical hybrid utilization of the solar energy and biomass were analyzed. For the purpose of achieving the advantages compensation and cascade utilization of the above-mentioned renewable energies, the thermochemical conversion process of the solar-biomass gasification were developed. Apart from the energy form of solar energy could be converted into the chemical energy from the thermal heat, the chemical energy of the input biomass was indirectly released through the gasification reaction, and the chemical energy cascade utilized in which the available energy loss can be reduced. Meanwhile, the decrease procedure of the biomass chemical energy level acted as the driven force for upgrading the energy level of the concentrated solar energy. The above the theoretical research findings would lay a foundation for developing the creational thermochemical hybrid utilization for the solar energy and biomass.The researches of the hybrid-system integration for solar energy and biomass were conducted in terms of the principle of cascade conversion of material with the compositions reasonable matched. A polygeneration system based on the solar-biomass thermal gasification, for the methanol production and the power generation, was proposed. The gasified syngas can be efficiently utilized for diverse energy demand, and the effects of key operational parameters of gasification temperature and recycle ratio of the un-reacted syngas on the thermodynamic and economic performances were analyzed. For the developed technical proposals of integrated solar-biomass gasification and the Brayton-Rankine combined cycle, the off-design operational performances of the solar-biomass hybrid systems were determined, and then discussed the thermochemical hybrid utilization characters of solar energy and biomass.The key processes of hydrogen production and power generation based on mid-and low-temperature solar thermochemical reaction were experimental researched on the arctic region. The 20 kW mid- and low-temperature solar thermochemical research platform has been designed and built. This research platform is consisted of the parabolic trough solar concentrating collector incorporated with the fuel conversion, power generation unit of the internal combustion engine, the feedstock pretreatment and gas separation unit, and the pipe network and thermal control system. Presently, the basic target was achieved that the research platform can be successfully operated with full power load of 20 kW, especially located in the Northeastern China under the arctic condition in winter. Meanwhile, the operational characters and performances of the research platform have been tested, which lay a foundation for widely application in diverse region of this type solar thermochemical technology.