Simulation and modeling of hydrogen production and power from wheat straw biomass at supercritical condition through Aspen Plus and ANN approaches

Abstract

In this study, the effects of temperature, flow rates of water, and biomass on the production of hydrogen, methane, and carbon monoxide in the presence of supercritical water were investigated. The wheat straw was used as biomass in the process. The hydrothermal gasification method was applied in a Gibbs reactor to produce the gases. The results revealed that with increasing temperature, the conversion of the hydrogen and carbon monoxide gases increased while that of the methane gas decreased. In addition, the flow rate of water had a significant role in producing the hydrogen gas. Finally, power was generated in a turbine for optimal use of the output gases. Aspen Plus software simulated the process. Moreover, to compare and test the Aspen Plus outputs, an artificial neural network (ANN) was developed. The Aspen Plus evaluated the experimental data with a good agreement but was limited to using default model. The ANN approach overcame the problem by making different weights and biases. The hydrogen gas as desired product was attained at 32.7 kg/h at a temperature of 700 °C, flow rates of water 2000 kg/h, and biomass of 1500 kg/h. The thermodynamic analyses determined the efficiencies of the energy and exergy as 17.2% and 22.1%, respectively.