塔河油田高含硫混烃分馏脱硫工艺探讨

塔河油田为高含硫油田,生产过程中产生的混烃中H_2S质量分数为0.68%,有机硫质量分数为0.22%,目前采用碱洗工艺,存在处理成本高、废碱液处理困难的问题。通过对现场生产流程、混烃中的硫形态及物理性质进行分析,提出了混烃分馏处理新思路。经分馏处理,混烃中的H_2S与部分硫醇随塔顶气进入天然气处理系统,依托天然气脱硫系统进行处理;塔底轻烃总硫质量分数由0.90%降至0.15%,进一步进行碱洗处理后,轻烃中总硫质量分数满足GB 9053-2013《稳定轻烃》的要求。此工艺碱耗量可由目前的2t/d降至0.22t/d,碱(NaOH)用量仅为目前的约1/10,可降低处理费用190.1万元/年。

Discussion on fractionation desulfurization process of high hydrogen sulfide mixed hydrocarbon in Tahe Oilfield

Tahe Oilfield is a high hydrogen sulfide oilfield, the H₂S mass fraction in mixed hydrocarbon is 0.68% and the organic sulfur mass fraction is 0.22%. Current desulfurization process adopting the caustic washing process which has high treatment cost and the waste caustic washing water was difficult to treat. A novel idea of mixed hydrocarbon fractionation desulfurization process was put forward by analyzing the on-site process, the sulfur form and the physical properties in mixed hydrocarbon were analyzed. After fractional treatment, the H₂S and part mercaptan in mixed hydrocarbon entered into the natural gas processing system followed with the overhead gas. The total sulfur content in light hydrocarbons in the bottom of the tower was reduced from 0.90% to 0.15%. For further caustic washing treatment, the total sulfur content meets the requirement of GB 9053-2013 Stable Light Hydrocarbon. The alkali consumption of fractionation desulfurization process was reduced from 2 t/d to 0.22 t/d compared to caustic washing process, the dosage of alkali(NaOH) were only about one tenth of the present. The processing cost will be reduced by 1.901 million RMB per year.