During the period of1920s, the output of liquefied petroleum gas surged. The earliest existing record shows that1922 * * produced 223,000 gallons a year. 1927, the annual sales volume is close to 1 10,000 gallons. By 1935, the annual sales volume has reached 5.6 million gallons. The major industrial developments in the1930s included the use of rail transit, the increase of malodorous gases and the increase of propane filling stations. 1945, the annual sales volume of liquefied petroleum gas reached10 billion gallons. By the end of 1947, more than 62% American families had used natural gas or propane as cooking fuel.
1950, Chicago Transportation Authority ordered 1000 propane fuel vehicles. By the end of 1958, the annual sales in the United States had reached 7 billion gallons. In 2004, it was reported that the whole propane industry was worth $8 billion to 100 billion, and the annual consumption exceeded1500 million gallons.
Xiangyun, the torch of Beijing Olympic Games, uses propane as fuel, which is cheap and has a wide temperature range. When burning, only water vapor and carbon dioxide are formed, and there are no other substances, which will not pollute the environment. It is a clean fuel and conforms to the concept of "Green Olympics". The flame color of propane gas combustion is bright yellow, which can meet the needs of convenient identification, TV broadcast and news photography.