Due to insufficient research on the detachment of bubbles and sub-bubbles caused by contact angle hysteresis, the paper focuses on accurately describing the bubble-particle detachment evolution. Based on a two-dimensional extended phase-field lattice Boltzmann (LB) model, the improved unidirectional interpolation algorithm and corresponding contact angle hysteresis scheme ensure to simulate the bubble-particle detachment with contact angle hysteresis on curved boundaries. Two benchmark cases are conducted to validate the phase-field LB model. Then, we simulate that the bubble is detached from the particle under the condition of different hysteresis windows, initial contact angles, and detachment forces. The effects of contact angle hysteresis on the bubble-particle detachment process and trapped sub-bubble are explored. The advancing angle in the hysteresis window inhibits bubble detachment, and the volume of the trapped sub-bubbles becomes larger. The contact angle hysteresis may weaken the effects of the receding angle and initial contact angle. The detachment force accelerates the process of bubble detachment, and the volume of the sub-bubble shows a tendency to first expand and then shrink. Large bubbles are easily detached, but the role works in a small range. The results provide guidance to control the sub-bubble size and bubble-particle detachment process.

The CoMo/Al2O3 catalysts with varying Co/(Co+Mo) ratios were employed to probe sulfur compound transformation in two decant oils with distinct molecular structures, using Fourier transform ion cyclotron resonance mass spectrometry for molecular characterization. Results show that increasing the Co/(Co+Mo) ratio enhanced both the fraction of Mo atoms at edge and corner sites. S-edge/Mo-edge ratio in the CoMoS phase reached its maximum at 0.10 of Co/(Co+Mo) atomic ratio. Both sulfur removal and aromatic saturation increase with Co loading, but the catalyst with a Co/(Co+Mo) atomic ratio of 0.10 prioritizes selectivity. Thiophenic sulfur compounds with double bond equivalent (DBE) of 9 are the most refractory species in both oils. In DO-JL (decant oil from Jinling ), these sulfur compounds with DBE of 9 show increasing conversion with carbon number due to easily removable naphthenic-benzothiophene structures with long side chains. At low Co loadings, S-edge predominance favors direct desulfurization, leading to high selectivity for sulfur removal relative to aromatic hydrogenation. With increasing Co loading, the greater exposure of Mo-edges enhances hydrogenation, which may contribute to overall HDS conversion but also boosts aromatic saturation, thereby compromising sulfur removal selectivity. To maximize both the efficiency and selectivity of sulfur removal from decant oils, future catalyst design should focus on optimizing the distribution of these active edges through promoter incorporation.

Autocatalysis from the by-product metal sulfides plays a critical role in the residual oil hydrotreating (RHT) process. However, it has not been considered to build the catalyst deactivation models, which probably is one important reason that the widely used S-type deactivation models are inaccurate in predicting some RHT processes' deactivation profiles. A three-stage catalyst deactivation model was first developed to fill this gap based on the mechanism inferred from the experimental and literature data. This model accounts for active site formation from by-product metal sulfides, deactivation due to active site coverage by coke formation and metal deposition, active site poisoning by highly-adsorbed species, active phase sintering, and diffusion resistance from the pore blockage at the same time, resulting in a function of dimensionless metals-on-catalyst. Then, the effectiveness of the proposed model was evaluated using the industrial data of an RHT unit and the experimental data from the literature, either in combination with reaction kinetics or independently. Results showed that RHT processes with clear autocatalytic effects may display different types of deactivation profiles from the traditional "S" shape. However, the proposed model was able to accurately track the entire deactivation curve of the RHT process and well predict the product properties. This approach yields valuable insights into the intricate autocatalytic effect that remarkably contributes to the performance modification of RHT catalysts. It is highly recommended that further research should be conducted on this topic, as it shows great potential to significantly advance catalyst and process development.

A comprehensive insight into the evolution and molecular structure of basic and neutral nitrogen compounds during the residue hydrotreating(RHT) process was gained through ESI(+)/ESI(-) FT-ICR MS analysis of the feedstock and its hydrogenated samples, with hydrodenitrogenation(HDN) ratios of 15.9%-70.1%. This study revealed that carbazoles, characterized by a double bond equivalent(DBE) of 9-11,were the refractory neutral nitrogen compounds during the RHT process. Their recalcitrant nature was primarily due to their low aromaticity and high steric hindrance. Conversely, quinolines(DBEs 7 to 9)were the most abundant basic nitrogen compounds. Through a meticulous analysis of DBE evolution, we revealed the intricate reaction mechanisms of benzocarbazoles and dibenzocarbazoles in residual oil,highlighting the crucial role of quinolines as key intermediates in eliminating these compounds. Interestingly, nitrogen compounds with either low or high carbon numbers(for a given DBE) exhibited higher reactivity than those with medium carbon numbers, which can be attributed to the low steric hindrance resulting from short alkyl chains and more naphthenic-aromatic structures, respectively. After hydrotreatment, the molecular structures of the most refractory or abundant nitrogen compounds could consist of two main types: those with multiple naphthenic-aromatic rings and those with long side chains near the nitrogen atom. This research has revealed nitrogen compounds' evolutionary mechanisms and refractory nature, and the molecular structure of the most resistant or abundant basic and neutral nitrogen compounds, providing a deeper understanding of the HDN process and ultimately paving the way for the rational RHT catalyst design and process development.

高硫渣油深度加氢脱硫过程中,最难脱除的含硫化合物因有侧链取代、空间位阻效应强而最难转化,深度脱硫过程中,催化剂上金属(镍+钒)沉积及积炭均会加快.针对加氢脱金属剂及加氢脱硫降残炭剂分别开展级配比例的研究,结果表明:脱金属率随反应物流在脱金属催化剂上停留时间的增加而增加,脱硫率随反应物流在脱硫降残炭剂上停留时间的增加而增加,但在达到一定停留时间后的增加趋势均明显变缓;所开发的新型渣油加氢脱硫降残炭剂初始加氢脱硫活性不高,随着运行时间的延长活性有所提升并保持稳定.基于级配研究结果及加氢脱金属脱硫剂的特性,开发了新型高硫渣油深度加氢脱硫催化剂级配技术,并在高硫渣油固定床加氢装置上进行了工业应用.结果表明,新型级配催化剂具有良好的加氢脱硫活性及优异的稳定性,该固定床渣油加氢装置在确保催化裂化装置原料供应的前提下能够稳定生产低硫重质船用燃料油调合组分.

考察了不同再生方法对柴油加氢废催化剂物化性质及其渣油加氢脱硫活性的影响.首先,对柴油加氢废催化剂进行常规再生处理,再生后催化剂孔道得到疏通,聚集态活性金属重新分散,但梯级应用于渣油加氢脱硫反应的活性明显低于标准剂.其次,分别从扩孔和强化活性金属-载体相互作用的角度对催化剂进行改性处理,扩孔后催化剂中聚集态低活性金属被脱除,催化剂孔道结构得到进一步优化,活性金属利用率提高;强化活性金属-载体相互作用后,催化剂的渣油加氢脱硫性能明显提升.最终,耦合以上两种改性方法,得到优化后的再生催化剂,将其梯级应用于渣油加氢脱硫反应的活性接近标准剂水平.

采用中东高硫渣油考察了工艺条件对渣油加氢反应的影响,并将该数据对创建的渣油加氢反应器模型进行求解.实验和计算结果表明:反应温度对杂质脱除率的影响最大,体积空速的影响次之,氢分压的影响最小.在反应温度365～395 ℃、氢分压14～17 MPa、体积空速0.15～0.25h-1、氢/油体积比800条件下,创建的渣油加氢反应器模型计算的脱杂质率和实验的脱杂质率最大相对误差为6.9％,可以较好地模拟实际反应情况.以实验室装置工况下的气-液传质速率为基准,气-液传质速率提高10倍时,残炭加氢转化率和加氢脱氮率分别提高2.6和6.3百分点;但以渣油加氢工业装置工况下的气-液传质速率为基准,气-液传质速率提高10倍时,残炭加氢转化率和加氢脱氮率仅分别提高0.2和0.6百分点,即气-液传质速率不是反应过程的速控步骤.

在固定床渣油加氢试验装置上研究了催化裂化柴油(催化柴油)、煤油和催化裂化油浆在线清洗对渣油加氢催化剂活性和反应器压降的影响.首先采用催化柴油对运转中期的渣油加氢试验装置进行 72h在线清洗,结果表明,清洗后再通入渣油时加氢渣油的密度、残炭、硫含量和金属含量都显著降低,金属含量可长时间保持在较低水平.通过大幅提高反应温度模拟后部反应器压降升高现象,再分别采用煤油和催化裂化油浆对装置进行在线清洗,结果表明,使用煤油清洗后再通入渣油时反应器压降会很快再次升高,而使用催化裂化油浆清洗后再通入渣油运行 500 h后反应器压降未见上升,说明催化剂结焦导致反应器压降上升的问题可采用高芳香性催化裂化油浆间歇清洗的方式解决.

A deep insight into the molecular structure of the refractory sulfur compounds during residue hydrotreating process was realized by controlling the hydrodesulfurization (HDS) rate from 91.7% to 99.2%. The reactivity and the molecular-level evolution of the sulfur compounds were characterized by APPI FT-ICR MS and CID FT-ICR MS combined with HDS kinetic analysis. It was found that during deep RHT process, the increased reactivity order of sulfur families is mainly determined by the increased order of aromaticity and the decreased order of alkyl-substituted carbon number. Furthermore, the most refractory sulfur compounds have dominate double bond equivalent (DBE) of 10–12, followed by 9, and carbon number range of 36–38, and their skeleton typically include 2–3 aromatic rings and 0–1 naphthenic/cyclohexene ring, whose substitution positions near the sulfur atom may possibly be occupied by alkyl side chains with carbon number 4–9. This work reveals the reactivity order of individual sulfur compounds and its key influencing factors, and especially the molecular structure of the most refractory sulfur compounds, which may provide a deep understanding about the sulfur evolution.

将大孔最可几孔径和大孔孔体积占比呈梯度分布的3种双峰孔载体制备成催化剂,考察双峰孔对催化剂物化性质和性能的影响.结果表明,与单峰孔载体制备的渣油加氢降残炭催化剂相比,由于双峰孔载体比表面积的降低以及单位质量羟基数量的降低,催化剂上金属分散度较低,金属与载体间作用力较弱,硫化态活性相平均长度和平均堆积层数均较高.随催化剂中大孔孔体积占总孔体积比例的降低,催化剂的脱硫和降残炭活性增加.

Hydrodesulfurization (HDS) is a widely used technology to reduce the sulfur content of heavy oils, and the HDS reactivities of sulfur compounds are closely related to their structures. In this work, the tandem mass spectra of sulfur-containing model compounds were measured by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled with collision-induced dissociation. The influences of naphthenic rings, size of aromatic rings, number of heteroatoms, and number of alkyl side chains to the fragmentation behaviors of sulfur-containing model compounds were studied. Finally, the structure differences of sulfur compounds in heavy oils before and after hydrogenation were compared by tandem mass spectra of FT-ICR MS. The most refractory sulfur compounds in the heavy oil were those with fully conjugated aromatic rings attached with fewer and longer side chains. These results would be helpful for the development of a HDS catalyst/process for heavy oils. For example, developing a new HDS catalyst with high alkyl side-chain cracking activity may be conducive to HDS of heavy oils.

中国石化石油化工科学研究院建立了新型高性价比渣油加氢催化剂NATURE制备技术平台,在此基础上根据渣油中残炭前躯物分子结构和反应特点,通过对催化剂孔结构、表面性质以及活性相结构进行设计,开发出高性价比RCS-202催化剂.中型加氢装置评价结果表明,与上一代工业剂相比,新开发的RCS-202催化剂堆密度降低20％,降残炭和脱硫的活性及稳定性明显提升.表征结果表明:与上一代催化剂相比,RCS-202催化剂孔体积和比表面积更高,硫化态催化剂中NiMoS相所占比例更高,反应后催化剂上积炭量更低,具有更高的性价比.

对中国石化海南炼油化工有限公司渣油加氢装置改造前后两个周期的失活催化剂进行了对比分析,结果表明:沿反应物流方向,(镍+钒)沉积量呈先增大后减小的趋势,且钒在反应物流方向上游的沉积比例更大;铁沉积量呈前高后低的趋势且有催化剂床层结盖的现象;积炭量呈逐渐降低的趋势且高温操作会导致催化剂的积炭量显著增加.根据杂质沉积分布的不同特点及其影响因素提出了渣油加氢催化剂级配的改进方向.

以5种不同的渣油为原料,从催化剂开发、催化剂级配、工艺条件优化、原料适应性考察等角度深入研究并开发了渣油深度加氢技术.结果表明:新开发的渣油深度加氢系列催化剂活性显著高于常规催化剂;反应温度是影响加氢深度最关键的因素;在优化的催化剂级配方案和工艺条件下,渣油深度加氢技术不仅可以显著提高原料中杂原子的脱除率,提高生成油的氢含量,还可以实现烃类定向转化多产化学品;高硫、低氮常压渣油更适宜采用渣油深度加氢技术生产优质催化裂解原料.

选取炼油厂卸载的典型废渣油加氢脱硫脱残炭催化剂(简称废剂),采用氧化预处理和再分散剂浸渍后处理对废剂进行再生,考察氧化预处理和后处理条件对废剂物化性质以及活性恢复的影响.结果表明,420℃氧化预处理后,催化剂物化性质和活性的恢复率都较高,并且在中型装置上运转800 h过程中,氧化预处理剂的相对脱硫和脱残炭活性均能达到并超过新鲜剂的85％以上.与后处理过程相比,氧化预处理过程对废剂活性恢复的影响更大,说明沉积金属所引起的不可恢复孔体积,尤其是金属钒沉积在催化剂孔口所带来的孔口堵塞,是造成废剂活性不能完全恢复的主要原因.

Residue deep hydrotreating (RDHT) process was developed by the Research Institute of Petroleum Processing (RIPP) to provide high quality feedstock for deep catalytic cracking (DCC) process. In this research work, the effects of RDHT process and reaction severity on heteroatom removal, hydrogen content increase, hydrocarbon composition improvement, and DCC product yields were studied. It was showed that the RDHT process can effectively reduce heteroatoms, increase hydrogen content and improve the hydrocarbon compositions, which can contribute to an increase of light olefins yield in DCC unit.

分别以石蜡基青海原油渣油(简称青海渣油)和中间基沙特阿拉伯轻质原油渣油(简称沙轻渣油)为原料,采用RHT系列渣油加氢催化剂进行了1500 h稳定性试验,采用傅里叶变换离子回旋共振质谱仪和核磁共振波谱仪分析原料和加氢生成油的分子结构差异及试验后催化剂(简称试验旧剂)上积炭组成.结果表明:青海渣油分子芳烃侧链多且长,通过初期快速升温可使其侧链断裂,改善其内扩散性能,且生焦倾向降低;沙轻渣油分子芳烃含量高,侧链较短,低温时即可达到较高杂质脱除率,高温则易生成结焦前身物,造成催化剂快速失活;与青海渣油相比,沙轻渣油加氢试验旧剂的积炭量更大,硬炭比例更高.对青海渣油加氢反应的温度分布进行优化,快速升高脱金属催化剂床层温度,降低脱硫剂反应温度,形成前高后低的温度分布,结果表明优化后方案的加氢生成油性质更优.

SO42− anchors to a NiMo/γ-Al2O3 catalyst, weakening the metal–support interactions, inhibiting MoS2 aggregation, increasing the number of Ni–Mo–S sites, and thus improving its activity and stability.

基于Ni-Mo活性体系,通过设计新的活性相结构及合成工艺路线,中国石化石油化工科学研究院(RIPP)开发了具有活性缓释功能的渣油加氢催化剂RDM-203.以茂名常压渣油为原料,催化剂RDM-203稳定运转的脱硫率比上一代催化剂RDM-33C提高了5百分点,催化剂的活性稳定性明显提升.表征结果表明:催化剂RDM-203中活性组分与载体的相互作用力有所增强,四面体钼物种的比例明显增加,催化剂中易还原及难还原组分大幅度减少,活性组分的分散度明显改善;催化剂硫化后,在反应初期,活性组分的硫化度以及NiMoS活性相结构的数量随着反应进行呈现不断增加的趋势,以上结构特征使催化剂具有活性缓释的技术特征.