专一脱硫菌催化氧化原油脱硫的研究

Study on Biodesulfurization of Crude Oil by Desulphurized Bacteria

燃烧石油所产生的SO2可导致环境污染,为了有效地脱去原油中的硫,采用实验室驯化、富集得到的微生物作为专一脱硫菌株,对原油中含硫化合物二苯并噻吩(DBT)进行了脱硫研究。着重探讨了微生物驯化、富集培养体系,培养温度,摇床转数和微生物初始浓度等因素对生物催化脱硫效率的影响,并结合气相色谱-质谱联用仪(GC-MS)分析方法对氧化脱硫机理进行了探讨。结果表明:以甘油作为碳源、DBT作为唯一硫源的培养体系来驯化、富集得到的微生物,能够有效地将DBT上的硫脱下来。DBT的脱硫率随培养温度、摇床转速、生物接种量的变化而不同;随着培养温度、摇床转速的增加,脱硫效率先增加后降低;生物接种量越大,脱硫效率越高,直至平缓。生物催化脱硫反应条件优化为:温度25℃,摇床转速180 rpm,生物接种量3 m L,使DBT的脱硫率达到了95. 01%。微生物催化脱硫反应是通过4S途径将DBT转化成油溶性的2-羟基联苯(2-HBP)并释放出硫来,同时DBT原有的碳骨架得以保存完好,使得原油的热值不受影响。

The SO2 produced by burning oil can lead to environmental pollution.In order to remove the sulfur from the crude oil effectively,laboratory domestication and enrichment of microbes are used as specific desulfurization strain.The effects of various parameters for the desulfurization procedure such as temperature,rotating speed of rocking bed and biocatalyst initial concentration are discussed,and the mechanism of biodesulfurization is studied by gas chromatography-mass spectrometry(GC-MS)analysis method.The results show that the sulfur on DBT can be removed by the native microbial cells through the 4S pathway and the oil soluble 2-hydroxy biphenyl(2-HBP)is formed without resulting in a loss in the fuel value or energy loss.The desulfurization rate varies with the temperature of culture,rotating speed of rocking bed and the initial amount of biocatalyst.The desulfurization rate increased first and then decreased with the increase of culture temperature and rotating speed.The greater the amount of biocatalyst,the higher the desulfurization rate until to a certain degree.The optimum conditions of biocatalytic desulfurization are as follows:temperature 25℃,shaking speed 180 rpm,inoculation rate 3 ml,and the desulfurization rate of DBT reaches 95.01%.Microbial catalytic desulfurization is to transform DBT into oil-soluble 2-hydroxy biphenyls(2-HBP)and release sulfur through 4S process.Meanwhile,the original carbon skeleton of DBT is well preserved,so that the calorific value of crude oil is not affected.