Energy Return on Energy Invested (EROI) for the Electrical Heating of Methane Hydrate Reservoirs

• Published in: Sustainability
• Main Author: Roberto Cesare Callarotti
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2011
• Subjects: EROI; methane hydrates; electrical heating; electromagnetic heating; moving boundary problems; enthalpy method; Environmental effects of industries and plants; TD194-195; Renewable energy sources; TJ807-830; Environmental sciences; GE1-350; Methane hydrate
• Online Access: https://doi.org/10.3390/su3112105; https://doaj.org/article/6df4b53f010d4695827c6c4ab486ba86

We model the low frequency electrical heating of submarine methane hydrate deposits located at depths between 1000 and 1500 m, and determine the energy return on energy invested (EROI) for this process. By means of the enthalpy method, we calculate the time-dependent heating of these deposits under applied electrical power supplied to a cylindrical heater located at the center of the reservoir and at variable depths. The conversion of the produced water to steam is avoided by limiting the heater temperature. We calculate the volume of methane hydrate that will melt and the energy equivalent of the gas thus generated. The partial energy efficiency of this heating process is obtained as the ratio of the gas equivalent energy to the applied electrical energy. We obtain EROI values in the range of 4 to 5, depending on the location of the heater. If the methane gas is used to generate the electrical energy required in the heating (in processes with a 33% efficiency), the effective EROI of the process falls in the range of 4/3 to 5/3.