对天然气干法脱硫技术(分子筛法,氧化铁法及活性炭法)及所用脱硫剂作了综合分析。在相应的室内脱硫装置上,在单一空速、温度等条件下,测定了5种氧化铁脱硫剂和5种活性炭脱硫剂用于含3mg/LH2S的N2气脱硫时的硫容。在扩大的空速(500-20001/h)、温度(20~120℃)、H2S浓度(2-11mg/L,氧化铁)或粒度(0.2~1.0mm,活性炭)条件下,对初选氧化铁脱硫剂EF-2和活性炭脱硫剂3018作了进一步考察,通过脱硫效果和工艺条件对比,选择3108为大庆油田天然气脱硫剂。在3108基础上,改用Na2CCh为浸渍用碱,浸渍量6%,改用商品TLC为催化剂,制得了一种高效煤制活性炭脱硫剂。将这种脱硫剂用于大庆油田喇二注气站天然气脱硫,日处理天然气72×10^4m^3,空气需求量24m^3/h,原料气含H2S0.0445~0.213mg/L,净化气含H2S0~0.0017mg/L,满足有关国家标准的要求(≤0.02mg/L)。图1表6参9。
The dry methods of desulfurizing natural gas (NG) and the desulfurizers(DSs) used of molecular sieve, ferric oxide (FO) and activated carbon(AC) type are summarized. 5 FO DSs and 5 AC DSs are tested for their sulfur capacities on laboratory desulfurizing apparatus with gaseous N2 containing 3 mg HaS per liter under conditions of single space speed and temperature. The chosen FO desulfurizer, EF-2, and AC desulfurizer, 3108, are further tested under conditions of widened space speed, 500-2000 h^-1, temperature, 20-120℃, and H2S content, 2- 11 mg/L, for EF-2 or particle size, 0.2-1.0 mm, for 3108 and, as a result of comparison of desulfurizing efficiency and technologic parameters, 3108 is chosen as basic desulfurizer for Daqing. A high efficiency activated charcoal desulfurizer is prepared on the basis of 3108 with following modification in its processing; to impregnate activated charcoal with Na2CO3 solution to a percentage impregnation of 6% ; to use commercial catalyst TLC instead. This desulfurizer is now used in NG injection station La-2 in Daqing, where 7.2×10^5 m^3 NG containing 0.0445-0.213mg/L H2S per liter is treated daily with an air demand of 24 m^3/h and the treated NG contains 0-0.0017 mg H2S per liter, fully meeting the norm of State Standard, ≤0.02 mg/L.