MCM-41-supported Co-Mo catalysts for deep hydrodesulfurization of light cycle oil

Light cycle oil (LCO), a by-product of the fluid catalytic cracking (FCC) process in a petroleum refinery, can be used as a blendstock for the production of diesel and jet fuels. Regulatory and operational issues result in need for new and more active catalysts for the deep hydrodesulfurization (HDS) of diesel feedstocks, such as LCO. This paper reports the activity of a mesoporous molecular sieve MCM-41-supported Co-Mo catalyst in comparison to a commercial γ-alumina (Al₂O₃)-supported Co-Mo catalyst for the desulfurization of a LCO with a sulfur content of 2.19 wt.%. The HDS of dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene—polyaromatic sulfur compounds present in LCO—and their relative reactivities in terms of conversion were examined as a function of time on stream in a fixed-bed flow reactor. The MCM-41-supported catalyst demonstrates consistently higher activity for the HDS of the refractory dibenzothiophenic sulfur compounds, particularly 4,6-dimethyldibenzothiophene. The presence of a large concentration of aromatics in LCO appears to inhibit the HDS of the substituted dibenzothiophenes.     

Deep hydrodesulfurization of diesel fuel: Design of reaction process and catalysts

Deep hydrodesulfurization (HDS) of diesel fuel oil was designed based on the recognition that alkyl dibenzothiophenes such as 4-methyl-and 4,6-dimethyldibenzothiophenes were the main target for deep HDS. Multi-stage and fractional HDS were very effective to achieve satisfactory HDS in terms of both sulfur level and fluorescent color of desulfurized oil. Catalysts with the selective hydrogenation of refractory sulfur species in major aromatic partners and isomerization-disproportionation of their alkyl groups prior to HDS were also designed to promote the desulfurization of such sulfur species.     

On the hydrodesulfurization of FCC gasoline: a review

The possible origins of sulfur impurities in FCC gasoline are reviewed and discussed. Their mechanism of formation during the FCC process as well as their mechanism of transformation on hydrotreating catalysts are also examined.The article focuses on the desulfurization of FCC gasoline by means of catalytic processes considering the fact that deep desulfurization must be achieved (in accordance with new regulations) while preserving octane rating of the fraction. The various parameters (presence of a promoter, nature and modification of the support, additives and poisons) which may influence the selectivity in hydrodesulfurization (HDS) versus olefin hydrogenation are also discussed. Existing and potential processes for the HDS of FCC gasoline with octane preservation are described.     

催化裂化汽油脱硫精制技术研究进展

催化裂化汽油是我国车用汽油的主要调和来源，但是硫含量远高于车用汽油质量标准的要求值；因此如何高效降低硫含量是催化裂化汽油精制处理的关键。本文综述了国内外催化裂化汽油脱硫精制生产技术。从选择性加氢脱硫技术（Prime-G⁺技术、SCANfining技术、CD Tech技术、RSDS技术、OCT-M技术和DSO技术），选择性加氢脱硫耦合辛烷值恢复技术（RIDOS技术和GARDES技术）以及吸附脱硫技术（S-Zorb技术）三方面来阐述国内外催化裂化汽油清洁化技术的原理、特点及其应用。指出深度脱硫和辛烷值保持、烯烃饱和率之间的矛盾，后续研究者仍需在工艺流程改进、工艺条件优化以及新型催化剂开发等方面做出巨大努力。     

Oxidative Desulfurization of Hydrocarbon Fuels

New requirements for very low sulfur content (10 ppm) in liquid motor fuels demand novel approaches for ultra-deep desulfurization. For production of near-zero-sulfur diesel and low-sulfur fuel oil, removal of refractory sulfur compounds, like 4,6-dimethyldibenzothiophene and other alkyl-substituted thiophene derivatives, is necessary. Elimination of these compounds by hydrodesulfurization (HDS) requires high hydrogen consumption, high pressure equipment, and new catalysts. Various oxidative desulfurization processes, including recent advances in this field for diesel fuels, and the drawbacks of this technology in comparison with HDS are examined and discussed. It is shown that the oxidation of sulfur compounds to sulfones with hydrogen peroxide allows for production of diesel fuels with a sulfur content of 10 ppmw or lower at atmospheric pressure and room temperature. The gas phase oxidative desulfurization of sulfur compounds with air or oxygen is feasible at atmospheric pressure and higher temperatures: 90–300 °С and offers better economic solutions and incentives.     

生产清洁汽油和柴油催化技术进展(续完)

为面对新世纪清洁燃料生产的新机遇和新挑战，各种生产清洁燃料的催化技术正在竞相开发之中，尤其是生产低硫、超低硫汽油和柴油技术。其中，催化裂化（FCC）降硫催化剂和助剂、选择性加氢处理新催化剂及工艺、汽柴油吸附脱硫、柴油生物催化脱硫和选择性氧化脱硫等新技术尤其引人注目。我国应加快清洁燃料生产催化新技术的开发研究，为生产更清洁的汽油和柴油燃料提供技术储备。     

油品深度加氢脱硫催化研究进展

汽油深度脱硫的关键是在脱硫同时避免辛烷值的下降和汽油收率的损失;柴油深度脱硫的关键是对反应活性最低的4,6-二甲基苯并噻吩类化合物中硫原子的脱除,并克服原料中多环芳烃和含氮物以及产物中H2S对脱硫效果的抑制作用.本文概述了汽油和柴油深度脱硫催化剂在工业应用方面的研究进展,综述了加氢脱硫催化剂基础研究方面的最新动态;强调了在分子和原子水平上认识加氢脱硫催化剂微观结构和反应机理对研发超高活性及选择性深度脱硫催化剂的指导作用.     

高硫FCC汽油加氢脱硫降烯烃DSRA技术开发

在分析催化裂化汽油硫和烯烃分布不均匀的基础上,对催化裂化汽油进行轻、重组分分馏,开发了活性高和稳定性好的重馏分辛烷值恢复催化剂及FCC汽油加氢脱硫降烯烃DSRA技术。采用DSRA技术对高硫格尔木催化裂化汽油进行轻馏分脱硫醇、重馏分加氢脱硫和辛烷值恢复等改质处理,总脱硫率为94.1%,烯烃降至20%,辛烷值不损失,汽油收率97.83%,化学氢耗0.88%,可生产符合欧Ⅲ规范的清洁汽油。     

DSO-FCC汽油加氢脱硫技术开发与应用

介绍了玉门炼油厂320 kt/a催化裂化汽油加氢脱硫装置,首次采用了中国石油石油化工研究院开发研究的DSO-FCC汽油加氢脱硫技术。结果表明:加氢后重汽油硫含量随原料硫含量波动,原料平均硫含量从451μg/g降到166μg/g,脱硫率为63.2%,RON平均损失0.35个单位,在大幅度降低硫含量的同时辛烷值损失较小,能够保证国Ⅲ清洁汽油的出厂。     

FCC汽油加氢脱硫/降烯烃工艺技术的研究

在分析催化裂化汽油硫和烯烃分布不均匀的基础上,对催化裂化汽油进行分馏,开发出了活性高和稳定性好的重馏分辛烷值改进催化剂和选择性加氢脱硫催化剂及其工艺技术。采用该工艺技术对RFCC汽油进行轻馏分碱洗抽提脱硫醇,重馏分辛烷值改进/选择性加氢脱硫等改质处理,再按分馏比例回调,产品汽油烯烃含量为24.2v%,较原料油降低了16.0v%,芳烃含量为19.2v%,较原料油提高了4.1v%,硫含量为41.5ppm,总脱硫率为85.46%,RON为87.8,较原料油提高0.4个单位,液收99.1%,可生产符合国Ⅳ规范的清洁汽油。