Assessment of a novel geothermal powered polygeneration system with zero liquid discharge

Abstract

Energy, exergy, economic, exergoenvironmental, and environmental analyses are reported for a novel polygeneration system consisting of a geothermal cycle, a CO2 cycle, a reverse osmosis unit, an electrodialysis unit, a lithium bromide absorption chiller, and a liquefaction unit for natural gas. The proposed system is able to produce electricity, cooling, desalinated water, sodium hydroxide, and hydrogen. To study the environmental aspects of the proposed facility, the associated social cost of air pollution is determined. This parameter implies a comparison between nonrenewable and renewable energy systems to produce the same amount of electricity, while the amount of air pollutants generated and their associated costs are considered. Three scenarios are introduced. The results indicate that the system produces 631 GWh/year electrical energy, 465 GWh/year cooling, 6.22 ‎ton/year NaClO, 1.57 × 108 m3/year hydrogen, and 386,000 m3/year potable water for a geothermal working fluid supplied with mass flow rate of 100 kg/s at a temperature of 150°C and a pressure of 457.5 kPa. Also, the calculated values of the energy and exergy efficiencies are 58.3% and 94.2%, respectively. The payback period is determined to be 5.3 years. The net present value ‎is found to be ‎113.6 million US$ which is lower than that for all the nonrenewable‐based scenarios considered.

The feasibility study of the production of Bitcoin with geothermal energy: Case study

“…They optimized their proposed system, and at the optimum point, thermal efficiency and unit cost of production were calculated at 23.35% and 17.07 $/GJ, respectively. Afshari et al 36 examined an integrated geothermal system connected to a CO 2 cycle, an RO system, an electrodialysis unit, a lithium bromide absorption chiller, and a liquefaction unit for natural gas. The objective was to generate electricity, cooling, desalinated water, sodium hydroxide, and hydrogen.…”