一、引言从1812年世界上成立第一个煤气公司到现在已超过一个半世纪了。我国第一个煤气公司(上海)1865年投产到现在也已一个多世纪过去了。在这一百多年中,国外城市煤气发生了巨大的变化。开始,城市煤气是作为公用事业的一个组成部分出现的,随着天然气的大量开采和长输 I. INTRODUCTION It has been over a century and a half since the establishment of the first gas company in the world in 1812. It has been more than a century since the first gas company in our country (Shanghai) was put into operation in 1865. In the past 100 years, the city gas in foreign countries has undergone tremendous changes. At the beginning, city gas appeared as an integral part of the public utilities, with the massive exploitation and long loss of natural gas.