Determination of Metastable Zone Width and Nucleation Induction Period of Palm Oil and its Olein/Stearin in Melting Layer Crystallization

Measurement methods of metastable zone width (MZW) and nucleation induction time for melting layer crystallization of palm oil (PO) and its olein/stearin (POL/PST) were established, and the effects of cooling rate (corresponding to various supercoolings) on MZWs and induction time for melting layer crystallization of PO, POL, and PST were determined. The results indicated that the MZW coherently rose with increasing cooling rates with respect to PO and POL, while it declined with higher cooling rates for PST. The induction period results demonstrated that the nucleation induction periods of PO, PST, and POL decreased with increasing supercoolings, and the lag time for nucleation negatively correlated to the melting point of oils at the same supercooling. These data could offer significant instruction in designing and controlling the melting layer crystallization process for palm oil.     

Study on wax precipitation characteristics of wax deposit in pipes

Wax deposit properties are a significant concern in pipeline pigging during waxy crude oil transportation. In the present work, the impacts of flow conditions and oil properties on the wax precipitation characteristics of wax deposits are investigated. A flow loop apparatus was developed to conduct wax deposition experiments using four crude oils collected from different field pipes. The differential scanning calorimetry (DSC) technique was employed to observe the wax precipitation characteristics of crude oil and wax deposit. The results show that the wax content and the wax appearance temperature (WAT) of the deposits increase with shear stress and radial temperature gradient, and decrease with radial wax molecule concentration gradient near the pipe wall. The DSC tests on the wax deposits revealed that the deposit wax content is strongly correlated to the oil wax content. Furthermore, an empirical correlation was developed to predict the wax content and the WAT of the wax deposit. Verification of the empirical correlation using the different oils indicated that the average relative error of the wax content prediction and average absolute error of WAT prediction were 13.2% and 3.6°C, respectively.     

Amine-impregnated natural zeolite as filler in mixed matrix membranes for CO2/CH4 separation

Flat mixed matrix membranes (MMMs) comprising polysulfone and clinoptilolite-type natural zeolite were prepared by casting. Zeolite was modified with three alkylamines: ethanolamine (EA), bis(2-hydroxypropyl)amine (BHPA), and polyethylenimine (PEI) by the impregnation method. Impregnated zeolite samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and N₂ adsorption–desorption. The alkylamine loading extent determined by thermogravimetric analysis was 5.2, 4.8, and 8.5% for EA, BHPA, and PEI, respectively. Analyses of MMMs showed that the incorporation of impregnated zeolite affected the glass-transition temperature (T_g) and mixed-gas transport properties. In this regard, a decreasing trend of the T_g values from 185.5 °C for the polymeric membrane up to 176.6 °C for Clino-EA-based MMM was recorded. In addition, the gas separation performance was evaluated at two different feed pressures. At 50 psi, MMMs showed an enhancement up to 30% on the CO₂ permeability (22.79 Barrer) and 55% on the CO₂/CH₄ selectivity (45.78) in comparison with the polymeric membrane (CO₂ permeability 17.34 Barrer; CO₂/CH₄ selectivity 29.38). These values varied depending on the alkylamine, BHPA being the most selective. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48286.     

润滑油基础油的生产工艺及发展趋势

本文主要分析"老三套"生产工艺、异构脱蜡和加氢生产工艺,并探讨我国润滑油基础油生产工艺的发展方向。     

海面油膜的偏振反射特性仿真实验

为了给海面溢油污染识别检测提供理论基础,根据菲涅尔反射公式的偏振反射系数,结合偏振双向反射率因子和粗糙海面的概率密度分布函数,建立了完善的pBRDF模型,仿真在不同太阳入射角度、不同探测器观测角度以及不同海面风速风向等条件下海水和油膜的偏振反射分布函数。结果表明:海水和油膜太阳天顶角为53°和56°时P偏振反射率分别为1.0×10^-5和2.5×10^-5,S偏振反射率随着太阳天顶角的增加而增加;海面风速越大偏振反射率峰值越小;海面风向只改变pBRDF的空间位置;海水和油膜线偏振度空间分布有明显差异。搭建实验平台相机以40°拍摄时,得出海水和油膜的线偏振度分别在0.2~0.4, 0.5~0.7之间,同时表明利用偏振探测获取目标场景的偏振度和偏振角图可提高图像质量。     

中压加氢裂化生产合格喷气燃料技术开发与应用

为满足市场对喷气燃料的需求并与企业现有装置相契合，中国石化石油化工科学研究院（简称石科院）开发了生产合格喷气燃料的中压加氢裂化技术。通过考察反应压力、裂化催化剂、原料油、转化深度及体积空速对喷气燃料性质的影响规律，提出了中压条件生产合格喷气燃料的加氢裂化技术方案。中压加氢裂化生产合格喷气燃料技术在中国石化上海石油化工股份有限公司1.5 Mt/a中压加氢裂化装置得到工业应用，在国内首次实现了中压条件下蜡油生产合格喷气燃料。装置工业标定结果表明，采用该技术加工高硫减压蜡油（VGO）馏分，在氢分压约10 MPa的条件下，喷气燃料馏分收率达到20%以上，且满足3号喷气燃料质量要求，尾油馏分BMCI值约为10，是优质的裂解制乙烯原料。     

悬浮于润滑油中的颗粒运动分析及其对油膜压力的影响

对含有固体颗粒的局部润滑流域建立格子Boltzmann(LBM)离散模型,分析固体颗粒在润滑油中的动力学特性;考虑颗粒形状的影响,推导计入单个固体颗粒运动的润滑方程,并分析得到油膜压力;将油膜流动特性与颗粒动力学计算相结合,分析不同形状的颗粒运动对于油膜压力的影响。分析发现,当颗粒进入润滑油后,经过很短的瞬时颗粒就会达到一个瞬态稳定的状态,无论颗粒在油膜厚度方向的初始位置位于两壁面之间的中线上侧还是下侧,颗粒都会向中线位置移动;当颗粒速度为0时对于油膜压力的影响较大,随着颗粒速度逐渐增大,颗粒对于油膜压力的影响逐渐减小;当颗粒的宽度在油膜厚度方向相同时,长宽比越大的颗粒对于油膜压力的影响也越大;当颗粒长轴相等时,颗粒在油膜厚度方向的宽度越大,则其对于油膜压力的影响也越大,即颗粒形状对于油膜流动的阻碍能力越强,则其对于油膜压力的影响越大。     

高温泵轴承失效分析及润滑可靠性监测系统的应用

某重油催化装置油浆泵采用集中油雾润滑方式,油液监测发现轴承润滑油中的金属元素含量高,并且呈急剧增加的趋势,拆机检查发现油浆泵轴承出现了严重磨损。分析该油浆泵轴承磨损原因,提出了采用稀油润滑和油雾润滑组合方式来改善轴承润滑。同时,采用了大型炼化企业机泵群油液监测平台对关键动设备进行状态监测,有效保证了设备长周期安全运行。     

Flame spectroscopy of waste tire oils and waste cooking oils blends using coaxial burner

Waste tires and cooking oil pose a serious danger to human health and environment. Self-reacting pyrolysis system for waste tires is designed and constructed for converting waste tires into oil that could be used as a sustainable fuel. This study aims to analyze the thermal microstructure of conventional fuels like light diesel oil (LDO) and heavy diesel oil (HDO) as well as blended with waste cooking oil (WCO) and tires pyrolysis oil (TPO) using a co-axial burner via flame spectroscopy analysis. The first Blend 1 (B1) consists of 20% WCO + 80% LDO, the second one (B2) consist of 20% WCO+80%HDO and the last one (B3) was 20%TPO and 80% LDO by mass. This percentage was chosen carefully and according to previous combustion characteristics results. The experimental results showed that B1 will shrink C2 radicals by nearly 61% and 64.5% at Ф = 0.63 and 0.96 respectively. B2 will decrease C2 radicals by nearly 19% and 82% at Ф = 0.63 and 0.96 respectively. Finally, B3 will reduce C2 radical's intensity by nearly 39% and 58% at Ф = 0.63 and 0.96 respectively. TPO produced CH emission radicals lower than that of LDO by nearly 5.9%. LDO droplets absorbed more radiation energy needed for excitation than that of WCO due to droplet size and fuel physic-chemical properties. B2 fuel is recommended to replace LDO at Ф = 0.63 and 0.96.