Raw data of methane hydrate equilibrium measurements in the systems of CH4 – H2O – THI and hydrate nucleation/growth in the systems of CH4 – H2O – KHI – THI

Published: 21 November 2022| Version 1 | DOI: 10.17632/zwpgb24f9j.1
Contributor:
Anton Semenov

Description

The raw data of Part 1 of the work devoted to the study of the methane hydrate equilibrium conditions in the systems of CH4 – H2O and CH4 – H2O – THI (THI = MeOH, MEG, DEG) are given in the “CH4 hydrate equilibrium measurements” archive. Each file with the .xlsx extension corresponds to data obtained from a single equilibrium point measurement and includes columns for time, temperature (°C), and gauge pressure (bar) in the GHA350 autoclave. The file name represents the system under study and the point number for it. For example, the file name “30% DEG_point 4” corresponds to the raw data obtained from measurements of the fourth equilibrium point for a 30 mass% aqueous solution of diethylene glycol. Each file contains the masses of the components taken to prepare an aqueous solution and their concentrations in mass%. The raw data presented in the archive “CH4 hydrate nucleation&growth” are from Part 2 related to the study of the kinetics of methane hydrate formation in the systems of CH4 – H2O, CH4 – H2O – KHI, and CH4 – H2O – KHI – THI (KHI = copolymer of N-vinylpyrrolidone and N-vinylcaprolactam). Each file with the .xlsx extension contains data obtained in one of the cooling-heating cycles for a specific inhibitor sample. The data in the file includes time (since the start of the cycle), thermostatic bath temperature (°C), and gauge pressure (bar) for each of the six test cells of the RCS6 setup. The file name corresponds to the test sample and the cooling-heating cycle number for it. For example, the file name “0.5%KHI+10% MeOH_1 cycle” corresponds to the raw data obtained in the first cooling-heating cycle for a sample containing 0.5 mass% kinetic inhibitor and 10 mass% methanol in water. Each file contains the exact values of the masses and concentrations of the components. The raw data are associated with the articles: [1] A.P. Semenov, Y. Gong, V.I. Medvedev, A.S. Stoporev, V.A. Istomin, V.A. Vinokurov, T. Li, Dataset for the new insights into methane hydrate inhibition with blends of vinyl lactam polymer and methanol, monoethylene glycol, or diethylene glycol as hybrid inhibitors, Data Br. (2023) in Press. [2] A.P. Semenov, Y. Gong, V.I. Medvedev, A.S. Stoporev, V.A. Istomin, V.A. Vinokurov, T. Li, New insights into methane hydrate inhibition with blends of vinyl lactam polymer and methanol, monoethylene glycol, or diethylene glycol as hybrid inhibitors, Chem. Eng. Sci. (2023) in Press (CES-D-22-02554).

Files

Steps to reproduce

Part 1 (Determination of methane hydrate equilibrium pressure and temperature from “CH4 hydrate equilibrium measurements” archive). To extract the equilibrium point (P, T) from a single experimental pressure temperature trajectory as follows: 1) Convert gauge pressure (bar) to absolute pressure (bar) by adding 1 to all gauge pressure values in column “Pressure (bar)”. 2) Plot the experimental P T trajectory (column with absolute pressure is from step 1, and the temperature is from column “Temperature (ーC) Bath”). 3) Approximate the segments of the experimental P T trajectory before and after hydrate complete dissociation at a slow heating stage with linear functions. 4) Determine the coordinates of the endpoint of the methane hydrate dissociation as the intersection of two linear approximations. 5) Convert the obtained values of the hydrate equilibrium temperature (°C) to (K), and the hydrate equilibrium pressure (bar) to (MPa). Part 2 (Determination of methane hydrate onset pressure and temperature from “CH4 hydrate nucleation&growth” archive). 1) Convert gauge pressure (bar) to absolute pressure (bar) in each of the six cells by adding 1 to all gauge pressure values in columns “Pressure (bar) Cell 1” - “Pressure (bar) Cell 6”. 2) Plot the experimental P T trajectory for Cell 1 (column with absolute pressure is from step 1, the temperature is from column “Temperature (ーC) Bath”). 3) Approximate the segment of the experimental P T trajectory before hydrate onset at a slow cooling stage (rate 1 K/h) with a linear function. 4) Hydrate onset point on the P T trajectory can be detected by the deviation of the experimental pressure in Cell 1 from the approximated value by more than 0.05 bar (and the subsequent stable growth of this difference). 5) Convert absolute pressure (bar) and temperature (°C) of hydrate onset to (MPa) and (K), respectively. 6) Repeat steps #2 – 5 for data from test cells 2, 3, 4, 5, and 6.

Institutions

Rossijskij gosudarstvennyj universitet nefti i gaza imeni I M Gubkina

Categories

Physical Chemistry, Nucleation, Crystallization Kinetics, Gas Hydrate, Phase Equilibrium Experimental Data

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