Advantages of LNG

Compared to LPG and CNG, the advantages of LNG as a substitute automotive fuel are as follows:

(1) Clean and environmentally friendly. As an automotive fuel, LNG must be vaporized by a vaporizer before it is introduced into the engine in a gaseous state for complete combustion, resulting in minimal harmful substances in the exhaust, making it highly clean and environmentally friendly.

(2) High calorific value per unit price. Compared to other fuels, LNG offers a lower price and higher calorific value per unit. The low-temperature characteristics of LNG can reduce the temperature of the mixed gas and the combustion temperature, thereby improving the engine's thermal efficiency. Consequently, LNG boasts strong economic and applicability advantages.

(3) High safety. LNG fuel tanks typically allow for a working pressure of 1.586 MPa. Automotive LNG storage tanks commonly use double-layered metal vacuum powder insulation or double-layered metal vacuum spiral insulation structures, which offer high thermal insulation efficiency and can maintain a longer period without releasing gas.

(4) Easy to install. Compared to CNG refueling stations, LNG refueling stations have smaller land requirements, no noise, and lower operating costs. The initial investment for setting up an LNG station is more than 30% less than that for a CNG station, and it can reduce daily operation and maintenance costs by over 50%. As LNG refueling stations are not restricted by natural gas sources and pipelines, they can be designed as fixed stations for natural gas or mobile skid-mounted units, offering strong mobility.

(5) High Efficiency of Cold Energy Recovery. LNG is transported and stored at atmospheric pressure and low temperatures, releasing a large amount of cold energy during gasification to normal conditions. Currently, the recovery rate of LNG cold energy can reach 50%, with 1 cubic meter of LNG capable of recovering and utilizing 960 to 1095 MJ of cold energy. For instance, an average refrigerated truck absorbs 56.16 MJ of heat daily during operation. To absorb this heat, a standard diesel refrigeration system would require about 15 liters of diesel. However, in an LNG vehicle, the cold energy released by vaporizing 143 liters of liquefied natural gas can completely absorb 56.16 MJ of heat, significantly improving economic benefits. Utilizing LNG cold energy for automotive air conditioning or refrigerated trucks eliminates the need for a dedicated refrigeration system, saving energy and reducing noise pollution from mechanical refrigeration.

(6) Wide Application Range. By adding high-pressure pumps and high-pressure gasifiers to the LNG refueling system, an LNG/CNG refueling station can be established, enabling direct conversion of LNG to CNG. The refueling station can service both LNG and CNG vehicles, thereby avoiding the need for fuel system modifications in CNG vehicles and eliminating the limitations of CNG refueling stations due to natural gas sources and pipelines. The scalability of the LNG refueling system further expands the applicability of LNG.