卢巍, 王涛, 董文达, 于婷婷, 赵子昂, 朱何俊, 吕元, 丁云杰. 煤基高碳醇粗产品的加氢精制研究[J]. 煤炭学报, 2020, 45(4). DOI: 10.13225/j.cnki.jccs.YH20.0146
引用本文: 卢巍, 王涛, 董文达, 于婷婷, 赵子昂, 朱何俊, 吕元, 丁云杰. 煤基高碳醇粗产品的加氢精制研究[J]. 煤炭学报, 2020, 45(4). DOI: 10.13225/j.cnki.jccs.YH20.0146
LU Wei, WANG Tao, DONG Wenda, YU Tingting, ZHAO Ziang, ZHU Hejun, LÜ Yuan, DING Yunjie. Investigations on the hydrofining of Fischer-Tropsch long chain alcohol crude product[J]. Journal of China Coal Society, 2020, 45(4). DOI: 10.13225/j.cnki.jccs.YH20.0146
Citation: LU Wei, WANG Tao, DONG Wenda, YU Tingting, ZHAO Ziang, ZHU Hejun, LÜ Yuan, DING Yunjie. Investigations on the hydrofining of Fischer-Tropsch long chain alcohol crude product[J]. Journal of China Coal Society, 2020, 45(4). DOI: 10.13225/j.cnki.jccs.YH20.0146

煤基高碳醇粗产品的加氢精制研究

Investigations on the hydrofining of Fischer-Tropsch long chain alcohol crude product

  • 摘要: 高碳醇(C+6混合醇)是重要的精细化工原料,广泛应用于合成增塑剂,洗涤剂和分散剂等。以合成气为原料,经费托合成途径一步制得高碳醇的方法,近年来得到密切关注。但是,费托合成高碳醇的粗产品中,除了醇和烷烃外,还有较多的烯烃、醛等不饱和化合物,以及少量的有机酸,因此需要通过加氢精制将其脱除,以简化后续精馏分离工序。针对该体系开发了活性炭负载的Pd基催化剂,在液体空速6 h-1,氢油比100~300,温度100~310 ℃,压力8 MPa条件下,在实验室微型反应装置上对催化剂的性能进行了评价,考察其活性、选择性和稳定性。试验表明,不饱和组分的转化率随温度升高而增加,在温度高于250 ℃后,不饱和组分转化率可以达到99%以上,且能够将原料中大部分的酸加氢转化,转化率高于90%。但是当温度高于270 ℃后,醇收率开始显著降低,说明高温条件下醇在催化剂上发生了一定程度的氢解反应。因此,为了尽可能提高加氢产物中醇的收率,较优的反应温度应在250 ℃左右。采用X射线衍射(XRD)技术表征了反应前后催化剂活性位的晶相和粒径,证明催化剂的活性位是金属Pd纳米粒子,粒径约为20 nm,且在反应前后基本保持不变,催化剂在反应过程中活性位结构稳定。在实验室开发的基础上,该催化剂经历1 000 h寿命实验和规模化制备等环节,成功应用于陕西榆林合成气制高碳醇万吨级工业试验的粗产品加氢精制工序,在反应温度约250 ℃,8.4 MPa下,不饱和组分转化率100%,酸转化率90.4%,生产出只含有醇和烷烃的混合油品,为后续醇油分离技术的开发奠定基础。

     

    Abstract: Long chain alcohols (C+ mixed-alcohols) are recognized as important feedstocks for the production of fine chemicals such as detergents,lubricants and dispersants. Synthesis of long chain alcohols directly from syngas via Fis- cher-Tropsch synthesis (FTS) route has attracted a great attention at present. In the crude product of FTS,unsaturated compounds involving alkenes and aldehydes coexist with alcohols and paraffins accompanying with some organic acids, and a hydrofining of which is necessary for the subsequent separation process. A Pd-based catalyst supported by acti- vated carbon (AC) was prepared and evaluated in a packed-bed reactor under the conditions of 6 h-1 liquid-hourly speed velocity (LHSV),100-300 hydrogen-oil ratio,100-310 ℃ and 8 MPa. At temperatures higher than 250 ℃ ,the conversion of unsaturated compounds exceeded 99% and most of the acids ( >90% ) were removed. Whereas a further increase of temperature (higher than 270 ℃ ) resulted in the decrease of alcohol yield due to the hydrogenolysis of al- cohols. Accordingly,the most suitable reaction temperature should be kept at about 250 ℃ for the highest alcohol yield. Active site structure involving crystalline phase and particle size of the catalyst before and after reaction was characterized by X-ray radical diffraction (XRD) method,and the Pd nanoparticles were identified as the active site which remained almost unchanged after reaction,indicating that the structure of active site stayed stable in the run. Based on the lab-scale results,the catalyst was successfully utilized in the hydrofining plant of the 10 kt / a grade in- dustrial demonstration of long chain alcohol synthesis from syngas in Yulin,China after the procedures including a 1 000 hour life test and a large scale preparation. Hydrofining product composed by alcohols and paraffins was synthe- sized under the conditions of 250 ℃ and 8. 4 MPa,in which the conversions of unsaturated components and acid reached 100% and 90. 4% ,respectively. The study paves the way for the designation and construction of an alcohol- paraffin separation unit.

     

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