Discussion on a thermobaric adsorption test method and its data processing for coal

•To study the adsorption of coal under the comprehensive influence of temperature and pressure, one thermobaric adsorption experiment has been introduced. The unique characteristic of thermobaric is one adsorption at a pair of temperature and pressure. Its main advantage of thermobaric adsorption is to simulate temperatures and pressures corresponding to coal reservoirs at different depths. To verify the thermobaric adsorption's data, it is acquired new theory and improved the experimental method, this paper will briefly describe adsorption instruments and procedure, mathematically analyze the differences between isothermal adsorption and thermobaric adsorption in complexity of test procedure. A temperature-pressure-adsorption equation (TPAE) has been used to regress the measured data and error calculation and expand the application probability of thermobaric adsorption. The 3-dimensional TPAE surface is also used for verification. The other 3 sets of optimized thermobaric adsorptions (10 pairs, 8 pairs, and 6 pairs) have been created. To cover a range of temperature (18∼72 °C) and pressure (1∼19 MPa), there must be at least the minimum 6 pairs of thermobaric adsorptions including the lowest temperature 18 °C and pressure 1 MPa, and the highest temperature 72 °C and pressure 19 MPa.