摘要
随着国家新《环境保护法》的实施,越来越严格的尾气排放标准给天然气净化厂硫磺回收及尾气处理装置带来巨大的减排压力和技术升级的严峻挑战。为此,分析了国内外天然气净化厂尾气排放标准改进及国内尾气排放现状,对可用于现有装置升级改造的5种尾气处理工艺(还原吸收法、胺法SO_2吸收法、湿法制酸法、石灰石/石膏湿法和循环流化床干法)、液相氧化还原法和生物脱硫法进行了技术评价分析,并针对2种不同处理规模(原料气潜硫量大于等于1 t/d及原料气潜硫量小于1 t/d)进行了技术经济对比分析。结果表明:①现有天然气净化厂硫磺回收装置排放尾气具有SO_2排放浓度较高、总量小的特点,宜采用还原吸收法、胺法SO_2吸收法和循环流化床法用于尾气治理或采用液相氧化还原法直接处理;②对原料气中潜硫量较大的,尾气处理宜选用还原吸收类工艺,反之则宜采用液相氧化还原法直接处理;③对尾气中潜硫量为中等的,宜选用胺法SO_2吸收工艺,潜硫量较小的则宜选用循环流化床干法工艺。
As the new Law of Environmental Protection is implemented in China, sulfur recovery and tail gas treatment units in natural gas purification plants have to reduce emissions by technological upgrading in order to meet the stringent tail gas emission standards. In this paper, the improvement of tail gas emission standards on natural gas purification plants at home and abroad and the status of tail gas emission in China were analyzed. Then, five tail gas treatment methods （i.e., reduction adsorption, amine SO2 adsorption, wet acid, limestone-gypsum wet, and dry circulating fluidized bed）, liquid phase oxidation-reduction method and bio-desulfurization method were technically evaluated. Moreover, two treatment scales （potential sulfur rate of feed gas higher and equal to 1 t/d or lower than 1 t/d） were compared technically and economically. It is indicated that the tail gas emitted from the sulfur recovery units in existing natural gas pu- rification plants is characterized by a high SO2 content and a small SO2 volume. It should be treated by means of reduction adsorption method, amine SO2 adsorption method and dry circulating fluidized bed method or directly treated by means of the liquid phase oxidation-reduction method; that the tail gas of the feed gas with a higher potential sulfur rate should be treated by means of reduction adsorption technologies, and otherwise liquid phase oxidation-reduction method should be used for the direct treatment of tail gas; and that the tail gas of the feed gas with a medium potential sulfur rate should be treated by means of the amine SO2 adsorption technology and that with a lower potential sulfur rate should be treated by means of the dry circulating fluidized bed technology.
作者
宋彬
李金金
龙晓达
Song Bin Li Jinjin Long Xiaoda(Natural Gas Research Institute, PetroChina Southwest Oil ＆ Gas FieM Company, Chengdu, Sichuan 610213, China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2017年第1期137-144,共8页
Natural Gas Industry
关键词
天然气净化厂
硫磺回收
尾气处理
处理工艺对比
液相氧化还原法
生物脱硫
SO_2排放
升级改造
Natural gas purification plant
Sulfur recovery
Tail gas treatment
Treatment technology comparison
Liquid phase oxida- tion-reduction method
Bio-desulfurization
SO2 emission
Upgrading
