Modeling of a bio-methane solar system driven by solar energy and heat pump

Abstract

The paper presents a novel thermodynamic modeling approach of a pilot solar biomass system for bio-methane energy production and wastewater treatment by creation of two packages (STSB and MHPB) modeling platform under TRNsys studio software. Indeed, several newly developed mathematical schemes using the communicating elements: a new Multi-stage air to water Heat Pump, a new Vacuum Tube solar Collector (VTC), thermodynamic storage, and a biogas reactor) have been validated by experiment. The work presents and discusses two scenarios (packages), the first one –STSB- concerns the pilot solar-biomass system, and uses only renewable energy for the bio-methane production by anaerobic digestion mechanism under the mesophilic conditions (±35 °C to ±42 °C), The second scenario consists of a modeling Multi-stage Heat Pump Biomass reactor (MHPB). The packages developed have been tested for industrial case study. A validation process of two scenarios with experimental tests of a 500 L reactor -for the biomass of the cardboard paper-proves a good agreement, where the errors band is about 1% for STSB and 1.5% for the MHPB package. The biogas reactor treats about 900 (m3/year) liquid biomass (3 m3/day). The prediction results indicate that the biogas production attaint 51 (m3) per year. According to the biogas composition analysis, the bio-methane represents 74%, leading to prediction results of 38 (m3) per year of bio-methane for the case study. . Further, the extended results from the modeling packages platform indicate that for this installation type of 700 m3, the bio-methane (CH4) production is estimated of 52 836 (m3) per year, representing 64% of the total fuel consumption for the current case of cardboard recycling and packaging company.