Xiaobai is seeking help regarding the issue of oil and gas condensation.

This is related to the components that undergo condensation; heavy oil, paraffin, gasoline, and diesel – the components that can evaporate are those that are relatively light in nature, not the components found in heavier oils. Low temperatures have little effect on these light components. As for heavy oil and paraffin, etc., their boiling points are very high, so they basically do not evaporate

Thank you for sharing your personal experience; I have learned a great deal from it

After much consideration, the challenge in current cryogenic technologies is VOC emissions, while water is the issue to be addressed regarding clogging.

Cooling is intended for gas-liquid mixtures with a low freezing point, and it is not suitable for wax oils, heavy oils, and similar substances that exist in a liquid-solid phase. For your reference only.

1) For the recovery of benzene and benzene derivatives, the condensation adsorption method may require a low temperature of -75°C, as the saturated vapor pressure of benzene derivatives at -75°C is 0.010133 kPa, corresponding to a concentration of 0.348 g/m3; this allows only for basic removal of these substances. At such low temperatures, the main goal is to prevent water from freezing and causing blockages. Since it is not possible to ensure 100% nitrogen sealing at the VOCs vaporization sources, unorganized VOCs exhaust gases will inevitably contain moist air; there is also a certain amount of moisture in the desorbed gas (when the temperature of the oil and gas drops to 6–8°C, the saturated water content in them is about 3–5 g/m3). This moisture enters the low-temperature condensation chamber, where it attaches to the heat exchange tubes or plates in the form of ice. As time goes by, more and more ice accumulates, eventually blocking the channels through which the oil and gas flow. Therefore, it is necessary to remove this ice regularly. 2) For the recovery of aromatic compounds, due to their high freezing points, a large amount of these compounds will condense within the heat exchange tubes or plates. At 5°C, the saturated concentration of aromatics is 159 g/m3, while it drops to 348 mg/m3 at -75°C; in other words, nearly 159 g/m3 of this material condenses, which can quickly block the oil and gas channels. Therefore, it is necessary to melt this condensed material on a regular basis. 3) To ensure the continuous operation of the equipment, the common approach used in current \"condensation adsorption\" oil and gas recovery systems is to employ a single refrigeration system that controls two oil and gas flow paths; an electronic expansion valve is used for the distribution of the refrigerant, while special control valves designed for low temperatures ensure zero leakage in such conditions. When the pressure difference across a gas path reaches a set value (as detected by a pressure difference sensor), the system automatically switches to another standby gas path for operation. At the same time, the channel blocked by ice enters the thawing process; this thawing is achieved using the superheated refrigerant vapor discharged by the compressor, which results in high efficiency and no need for an additional heat source. The thawing time is short, usually between 20 and 30 minutes. Once thawing is complete, the refrigerant can be distributed via an electronic expansion valve as per instructions, allowing the low-temperature cooling environment to be restored quickly and maintained at a constant temperature for use in the next switching cycle, thereby ensuring continuous recovery of the excess gas over an extended period.