VOCS full-process recovery equipment for oil and gas storage and transportation: detailed explanation of key components and working principles

Oil and gas storage and transportation VOCs full-process recovery equipment: detailed explanation of key components and working principles

In the process of oil and gas storage and transportation, the emission of volatile organic compounds (VOCs) not only causes waste of resources, but also has a negative impact on the environment and human health. In order to effectively control the emission of VOCs, the whole process recovery equipment has become an important technical means of oil and gas storage and transportation. This paper will introduce the key components of the equipment and its working principle in detail, in order to provide reference for the technical application in related fields.

1. key components

1 Adsorption system

The adsorption system is the core component of VOCs recovery, usually using activated carbon, zeolite molecular sieve or polymer adsorbent as the medium. Its function is to enrich the VOCs components in the gas on the surface of the adsorbent through the principle of physical or chemical adsorption. Multi-tower parallel design can ensure continuous operation, one tower adsorption when the other tower desorption regeneration.

2 Condensing system

The condensing system converts the VOCs from a gaseous state to a liquid state by cryogenic cooling. Using multi-stage condensation technology, the temperature gradient is usually set from 3 ℃ to minus 70 ℃, and the temperature is reduced step by step to improve the recovery efficiency of different boiling point components. Key equipment includes compressors, evaporators and throttle valves.

3 Membrane separation unit

For high concentration VOCs gas flow, the membrane separation system uses the principle of selective permeation to achieve component separation. The polymer composite membrane material has preferential permeability to organic matter, and can effectively separate VOCs from air, and the recovery rate can reach more than 90%.

4 Catalytic oxidation unit

For low concentration or difficult to condense VOCs, the catalytic oxidation unit converts organic matter into carbon dioxide and water at 250-400°C through a catalyst (such as platinum, palladium). The unit is equipped with a heat exchanger to recover the heat of reaction and reduce energy consumption.

Detailed explanation of 2. working principle

The whole process recycling equipment adopts multi-technology coupling process. First, the gas containing VOCs is pretreated to remove particulate matter and moisture and then enters the adsorption system for preliminary enrichment; then the saturated adsorption medium is desorbed by hot nitrogen or steam to produce high concentration VOCs gas. The gas is liquefied and recovered in the condensation system, and the uncondensed part is further purified by membrane separation. The final exhaust gas is discharged to the standard by catalytic oxidation.

The system adopts PLC automatic control, real-time monitoring of pressure, temperature and concentration and other parameters, dynamic adjustment of the operating state of each unit. The design of thermal energy reuse can reduce the operating energy consumption by more than 30%, which meets the requirements of green and low carbon.

Advantage and Development Trend of 3. Technology

The current equipment has achieved modular design, to adapt to the tank area, loading and unloading stations and other different scenarios. Future research directions include the development of new adsorbent materials, low-temperature plasma coupling