有机硫水解催化剂研究进展

Research Progress of Organic Sulfur Hydrolysis Catalyst

有机硫是焦炉煤气、天然气、黄磷尾气、合成氨等气体净化的重点和难点,其中羰基硫(COS)和CS_(2)占主要部分。催化水解法被认为是净化工业气体中有机硫的有效途径之一,是一种低成本高效净化技术,能够在较低温度下将COS和CS_(2)催化水解为H_(2)S,进而对H_(2)S进行高效脱除。催化水解法应用于工业精脱硫中具有两大优势:(1)转化率高,反应温度低,不消耗氢源;(2)水解产物H_(2)S的净化工艺成熟,可进行硫资源的回收。催化水解法已有较成熟的研究和工业应用,然而水解过程中的氧化反应是导致水解剂效率降低和寿命缩短的重要原因。因此,开发出廉价高效的水解催化剂成为本领域的研究热点,H_(2)S的高选择性是有机硫催化水解的重要指标。以γ-Al_(2)O_(3)、活性炭作为载体制备的水解催化剂是目前应用效果较好的催化剂,且γ-Al_(2)O_(3)的应用最早、最广泛,但其抗氧能力较差、催化剂易中毒等特点使其在应用过程中受到一定限制。TiO_(2)、ZrO_(2)等载体在近几年的研究工作受到关注,不同活性组分的添加为突破水解催化剂对H_(2)S的低选择性和抗毒性提供了可能。此外有机硫水解机理的探究也为水解催化剂的开发提供了理论依据,在此基础上调控反应路径,改善水解过程中多种影响因素,也有助于有机硫水解催化剂活性和寿命的双提升。本文介绍了COS和CS_(2)催化水解的主要载体和活性组分的研究和应用情况,分别对有机硫水解机理和水解催化剂失活原因进行了总结和归纳,分析了催化水解法在应用中面临的问题并展望其前景,以期为新型高效水解催化材料的设计提供参考。

Organic sulfur is the key and difficult point in the purification of coke oven gas,natural gas,yellow phosphorus tail gas,synthetic ammonia and other gases,among which COS and CS_(2) account for the main part.Catalytic hydrolysis is considered to be one of the most effective ways to purify organic sulfur in industrial gases,which is a low-cost and high-efficiency purification technology.COS and CS_(2) can be converted to H_(2)S by catalytic hydrolysis at lower temperature,and H_(2)S can be then removed efficiently.There are two major advantages for refined desulfurization by catalytic hydrolysis:(i)high conversion rate,low reaction temperature,and no hydrogen source consumption;(ii)mature purification process of the hydrolysate H_(2)S,which can be used for the recovery of sulfur resources.Catalytic hydrolysis has been well studied and applied in industry,but the oxidation reaction in the hydrolysis process is an important reason for the reduction of the efficiency and life of the hydrolysis catalyst.Therefore,the development of cheap and efficient hydrolysis catalysts has become a research hotspot in this field.Moreover,high selectivity of H_(2)S is a core indicator of organic sulfur hydrolysis catalysis.The hydrolysis catalysts prepared withγ-Al_(2)O_(3) and activated carbon as support are the catalysts with a better application effect at present.Besides,the application ofγ-Al_(2)O_(3) is the earliest and most extensive,but its poor antioxidant capacity and catalyst poisoning characteristics make it limited in the application process.Supports such as TiO_(2) and ZrO_(2) have been followed with interest in recent years,and the addition of different active components provides the possibility to break through the low selectivity of H_(2)S and anti-toxicity.In addition,the study on the mechanism of organic sulfur hydrolysis also provides a theoretical basis for the development of hydrolytic catalysts.On this basis,the activity and life of organic sulfur hydrolysis catalysts can be improved by adjusting the reaction path and improving influencing factors in the hydrolysis process.This review introduces the research and application of the main supports and active components on COS and CS_(2) catalytic hydrolysis.The hydrolysis mechanism of organic sulfur and hydrolysis catalyst deactivation reason has also been summarized,and the problems faced and future prospect of the catalytic hydrolysis method are analyzed.It is hoped that this paper can provide reference for the design of new high efficiency hydrolytic catalytic materials.