Ecological problems of natural gas cleansing

Full text: Chemical-technology approaches allowing to intensification the prevention processes of gas hydrates formation at motion of gas-liquid stream of natural gas in system natural gas well - gas wire have been worked up. Technological regimes of treatment of gas stream have been determined. Linear correlation dependences inhibitor electrolytes contained hydrated ions with different ion radii and charges of subgroups of alkali elements with one - type electron configuration were obtained. Important physico-chemical parameters of electrolytes have been determined: activity; coefficients of activity, viscosity, diffusion; density; heat capacity; heat conductivity; surface tension and freezing-point. The features of continuous influence of inhibitory factors on process of gas flow at low temperatures and relatively high pressure differences ΔP have been studied by using of technological installation modulating the system natural gas well - gas wire. The dependences of gas quantity flowing from installation on ΔP at low temperatures have been studied with consideration of real states of process of gas - liquid phase flowing. Obtained experimental data for non-inhibitory and inhibitory processes have been compared under the same conditions. It was established that more high intensification of prevention process of gas hydrates formation is observed at the same thermodynamic conditions due to continuous treatment of gas by methanol and polyvinyl alcohol, which are absorbed into the bentonite, by glycigol, absorbed into the silica gel, and by calcium chloride. Vibration conjugate process of gas hydrates formation and break-up taking place in gas-liquid system with using of membrane electrode of electrochemical cell has been found. Periodic vibrations of membrane potential have been found at treatment of natural gas by methanol at low temperatures. Periodic character of vibration effect is determined by conjugate variations of equilibrium concentrations of components gas hydrates formation and break - up. Dependence of potential value on time of gas stream current across gas pipeline is given in temperature interval 262 -293 K and at pressures from 0.15 to 0.5 MPa. The parameters of membrane potential vibrations in stream of treated natural gas in hydrate formation regime have been determined: amplitude (a= 6.4 mV), period (t = 6·10'2 s), frequency (ν=1.67·10-3 Hz) and cyclic of frequency vibrations (ω0=1.05·10-2 Hz) at temperature 262 K and Δp=0.5 MPa