Testing Method and Data Treatment for Thermobaric Adsorption Model Case Study: Adsorption of Methane onto Long Flame Coal

To study the adsorption of coal under the comprehensive influence of temperature and pressure, a thermobaric adsorption experiment has been conducted. The unique characteristic of thermobaric is one adsorption at one temperature and pressure (a pair). The main advantage of thermobaric adsorption is to simulate temperatures and pressures corresponding to coal reservoirs at different depths. The measured thermobaric adsorption of long flame coal “Vmeas” contains 12 points of different temperatures (18~72 °C) and corresponding pressures (1~19 MPa) test conditions, simulating the buried depth of 100~1900 meters. A temperature-pressure-adsorption equation has been used to calculate the same 12 points of thermobaric adsorption data “Vcal”. The relative error and the standard deviation between the Vmeas and the Vcal of all 12 points of thermobaric adsorption are calculated and used to verify TPAE’s applicability. The 3-dimensional temperature-pressure-adsorption surface and a series of measured dots of thermobaric adsorptions can also be used for verification. The other 3 sets of thermobaric adsorptions (10 points, 8 points, and 6 points) have been optimized. To cover the range of temperature from 18 °C to 72 °C and a range of pressure from 1 MPa to 19 MPa, there must be mathematically at least the minimum 6 points of thermobaric adsorption. For long flame coal, both temperature and pressure have positive effects on the amount of adsorption.