Preface

City gas can be classified into three categories: natural gas, manufactured gas and liquefied petroleum gas according to the source or production method of the gas. Among them, natural gas is naturally generated; manufactured gas is converted from other energy sources or a by-product of the production process; and liquefied petroleum gas mainly comes from by-product gas in petroleum processing process.
         In recent years, China’s urban natural gas energy development and utilization have made great achievements, however due to late beginning and lower popularization rate, we are still confronted with a big gap compared with developed countries in terms of safe gas supply, safe operation, and effective management. In particular, the gas supply technology and service levels of our country cannot meet the growing needs of residents, so we need to work hard to catch up. With the rapid growth of China’s explored onshore and offshore gas reserves and the continuous discoveries of world-class large gas fields, as well as the accelerated construction and preparation of West-East natural gas transmission project, air-sea landing, and Russia gas southbound project, a natural gas framework blueprint that stretching east to west across the mainland, connecting the coastland, and running through the north and south has been presented. This will inevitably provide a reliable security and rare opportunities for the development of urban gas in China. The use of green energy is bound to become a major trend in the development of the future world. Especially in such a context that green and environmentally friendly environment is gradually recognized by more and more people, vigorously developing city gas has extraordinary economic and social significance.

前 言

城市燃气根据燃气的来源或生产方式可以归纳为天然气、人工燃气和液化石油气三大类。其中，天然气是自然生成的，人工燃气或是由其他能源转化而成或是生产工艺的副产品，液化石油气主要来自石油加工过程中的副产气。
       近年来，尽管我国城市天然气能源发展和利用取得了很大的成绩，但是由于我们起步晚、普及率低，在安全供气、安全运行、有效管理等方面与发达国家相比还有很大差距，特别是供气技术水平和服务水平还满足不了居民不断增长的需求，需要我们在努力追赶，随着我国陆上和海上天然气探明储量的快速增长和世界级大气田的不断发现，以及西气东输、海气登陆、俄气南下等项目正在加速建设和筹备，一幅横跨大陆东西、连接沿海、纵贯南北的天然气框架蓝图已经呈现出来，这必然为我国城市燃气的发展提供可靠的保障和难得的机遇。绿色能源的使用必将成为未来世界发展的一大趋势，尤其在这个绿色、环保逐渐被更多人所认可的环境下，大力发展城市燃气有着非同寻常的经济与社会意义。