世界上许多工业发达国家都经历了从煤制气、油制气而最终选用天然气的过程。如加拿大是从50年代,英国、法国、荷兰则是在60年代初开始进行人工煤气向天然气的转换。日本大阪是在70年代初开始引进液化天然气以替代原来的油制气,到80年代末才完成转换工作。 Many industrialized countries in the world have gone through the process of choosing natural gas from coal gas and oil gas. For example, in Canada from the 1950s, the United Kingdom, France, and the Netherlands began to convert artificial gas to natural gas in the early 1960s. Osaka, Japan, began to introduce liquefied natural gas in the early 1970s to replace the original oil gas. It was not until the end of the 1980s that the conversion was completed.