1. Adsorption method
Activated carbon adsorption devices represented by Jordan Company of the United States and Kuso Shen Company of Denmark, silica gel activated carbon adsorption devices and silica gel adsorption devices of Japan Systems Engineering Services Co., Ltd. device. Tokyo Metropolitan Regulations in Japan stipulate that if the oil and gas concentration is ≥1vol, the use of flammable activated carbon adsorbents is prohibited, and the use of membrane separation and activated carbon adsorption oil and gas recovery technologies is prohibited in Japan.
At present, there are 6 sets of activated carbon adsorption oil and gas recovery devices built in China, 5 of which are imported products, except for the oil and gas recovery device used for railway loading in a refinery in North China, which is in acceptable condition. There are 3 sets of devices used in oil depots. Due to problems with the crane pipe sealing and oil and gas collection systems, the actual operating results of the devices did not reach the expected results. One unit of a refinery in northwest China has been idle for more than five years. The only set of domestic adsorption devices has not been put into use for a long time. Since activated carbon is frequently replaced, several tons are required at one time. The operating cost is too high, and it is now out of operation.
2. Absorption method
Because the absorption method has its fatal flaws, it is rarely used alone now. The application of absorption oil and gas recovery equipment is rarely seen in Europe and the United States. There are three sets of absorption method oil and gas recovery devices built in China, two sets of special absorbent methods and one set of diesel absorbent. Judging from the operating results of the devices already in use, the recovery rate of the absorption method is the lowest among several oil and gas recovery technologies. The first independently developed oil and gas recovery equipment in China adopts the "absorption method". From 2004 to 2005, under the direct leadership of the Ministry of Science and Technology of Sinopec, Professor Huang Weiqiu of Jiangsu Institute of Technology led his team at the Jiangsu Institute of Technology Industry-Academic-Research Base. The "absorption method" oil and gas recovery equipment was successfully developed using the special absorbent AbsFov-97, which was installed in Jiujiang Petrochemical Company and is operating normally. However, with the implementation of the national "Air Pollutant Emission Standards for Oil Storage Depots", this device can no longer meet the standards.
3. Condensation method
The advantages of the condensation method are very obvious and it is widely used around the world. As early as 1997, Edwards Company of the United States had installed more than 400 "condensation method" oil and gas recovery equipment in major oil companies around the world, and has now transferred the patent to the Australian Shirenwei Company. In 1989, my country also introduced a "condensation method" oil and gas recovery equipment from Edwards Company and installed it in the Zhenhai Refinery. The equipment is still in operation. All 24 oil depots in Taiwan, my country, use "condensation method" oil and gas recovery equipment.
Nowadays, the oil and gas emission devices of general gas stations adopt the relatively mature method of "condensation adsorption". The oil and gas are first condensed to about -40 degrees to liquefy most of the oil and gas, and the remaining oil and gas are adsorbed through the adsorption tank. Due to the adsorption, a high recovery rate can be achieved, and the emission concentration is low, fully meeting national standards.
4. Direct combustion method
The oxidation incineration method has been eliminated because it cannot recover valuable hydrocarbon components.
5. Membrane separation method
The process is relatively simple and the investment cost is in the low to medium range. Liquid ring compressors and membrane modules are the core equipment of this technology. Compressor explosion-proof performance requirements are extremely high, and only a few companies in Germany and the United States can produce them. However, due to the maturity of explosion-proof technology, the safety hazards of compressors have been controlled to a minimum, and safe operation can be said to be achieved. As another core equipment, the membrane module has initially achieved localization after more than 20 years of development, and the price will be reasonable in the future.