Analysis of a feasible trigeneration system taking solar energy and biomass as co-feeds

The trigeneration systems are widely used owing to high efficiency, low greenhouse gas emission and high reliability. Especially, those trigeneration systems taking renewable energy as primary input are paid more and more attention. This paper presents a feasible trigeneration system, which realizes biomass and solar energy integrating effective utilization according to energy cascade utilization and energy level upgrading of chemical reaction principle. In the proposed system, the solar energy with mid-and-low temperature converted to the chemical energy of bio-gas through gasification process, then the bio-gas will be taken as the fuel for internal combustion engine (ICE) to generate electricity. The jacket water as a byproduct generated from ICE is utilized in a liquid desiccant unit for providing desiccant capacity. The flue gas is transported into an absorption chiller and heat exchanger consequently, supplying chilled water and domestic hot water. The thermodynamic performance of the trigeneration system was investigated by the help of Aspen plus. The results indicate that the overall energy efficiency and the electrical efficiency of the proposed system in case study are 77.4% and 17.8%, respectively. The introduction of solar energy decreases the consumption of biomass, and the solar thermal energy input fraction is 8.6%. In addition, the primary energy saving ratio and annual total cost saving ratio compared with the separated generation system are 16.7% and 25.9%, respectively.