Performance investigation of a novel multi-functional system for power, heating and hydrogen with solar energy and biomass

Abstract

Multi-functional energy systems incorporating renewable energy are a promising solution to mitigate fossil energy consumptions and environmental pollution. To satisfy the seasonal clean heating demand in cold regions of Northern China, a novel multi-functional system with input sources of solar energy and biomass and output products of power, heating and hydrogen is proposed. The system takes advantage of the complementary properties of solar-driven biomass gasification, concentrated solar energy is stored as chemical energy in the form of syngas, which gains a significant upgrade regarding the energy level. The gasified syngas is used to produce power and heating via a power cycle unit during the heating periods and to produce hydrogen via a water-gas shift reactor during the non-heating periods. The design and off-design thermodynamic performances of the system are numerically studied with a focus on time-varying heating loads. The system achieves a primary energy efficiency of 44.26% and the power to heat ratio is 69.98% under the designed conditions. The primary energy efficiency is insensitive to the intermittency of solar energy as a result of the introduction of a chemical energy storage module. The annual average hydrogen production efficiency of the system reaches 64.97%. The proposed multi-functional energy system achieves favorable thermodynamic performances and provides an attractive option for efficient utilization of abundant solar and biomass resources in China.