从失活的油脂加氢催化剂中回收镍

采用酸浸后再氨络合的方法从废油脂加氢催化剂中回收镍，镍的回收率最高可达99%以上。酸浸前先在适当温度下焙烧废催化剂样品有利于镍的溶出。使用由盐酸与硫酸以适当比例构成的混酸比使用单一盐酸或硫酸更有利于镍的溶出。加氨时，采用反加方式比正加和并流方式所得镍的回收率高。     

油脂氢化后废催化剂中金属镍的回收

考察了酸的种类及其浓度对废催化剂中镍回收率的影响。结果表明，在废催化剂和混酸（ＨＣｌ：ＨＮＯ＿３为３：１）的比例为１：６（ｇ：ｍｌ）、反应时间为３ｈ的条件下，镍的回收率可达９０％以上。     

含铜废催化剂中金属的回收方法

介绍了各种含铜催化剂中金属的多种回收方法,并综述了各种回收方法的工艺特点及可行性。     

Reclamation of nickel from spent nickel catalyst

Spent nickel catalyst containing an average 9.6% nickel was obtained locally from an oil hydrogenation industry. It was digested with 1–3N HCl, HNO₃, H₂SO₄ and mixtures thereof in one to three stages of durations ranging from one to three hr at 100°C using spent nickel catalyst to acid proportions of 1:3 to 1:8 (w/v). Nickel recoveries of over 94% were obtained when one part of spent catalyst was digested for three hr with six or more parts of 3N mixture of HCl and HNO₃ (3:1, v/v). Acid extracts of spent nickel catalyst obtained using HCl, H₂SO₄ and mixtures thereof were treated with NaOCl to convert their content of iron in the ferric form. The iron from the nickel extract was precipitated out in the form of ferric hydroxide at pH 6.0. Nickel from the iron-freed acid extracts was recovered at pH 8.5±0.5 as nickel hydroxide. Nickel formate was prepared by refluxing nickel hydroxide with 10% formic acid in about 6% excess to stoichiometric requirements for 30 min. The dried nickel formate was reduced in peanut oil at 230°C to 270°C for 0.25 to 2.75 hr. The reduction at 260°C on kieselguhr support, employing nickel formate:oil:support in ratio of 50:43:7, for two hr provided catalyst of maximum activity. The hydrogenation activity of the reclaimed catalyst, assessed by standard AOCS procedure, was greater than that of the parent catalyst. Presented at the AOCS Meeting in New Orleans, LA, in May 1987.     

Industrial hydrogenation of rapeseed oil with nickel catalyst

Refined and deodorized rapeseed oil was hydrogenated using Girdler nickel catalyst at a starting temperature of 140 C and at 25 and 30 psig hydrogen gas pressures. The studies revealed that the hydrogenation was more effective, as determined by rate of decrease in iodine value (Wi js) and increase in the melting point, at 25 psig than at 30 psig. The rate of effectiveness was, however, not significant. The rate of hydrogenation was compared to cottonseed oil subjected to hydrogenation under identical conditions. Cottonseed oil showed a better, though insignificant, rate of increase in melting point per unit increase in time.     

模拟酸性气预硫化加氢催化剂工艺研究

在常压下采用固定床反应器,研究了以H2S,H2,N2,CO2气体模拟炼油厂酸性气为硫化介质,对加氢催化剂进行器外预硫化;考察了硫化温度、硫化时间、空速、模拟气组成等因素对催化剂硫化效果的影响.用裂解汽油一段加氢油为原料,对催化剂进行高压微反活性评价.实验结果表明:以模拟酸性气为硫化介质对加氢催化剂进行器外预硫化是可行的...     

Recovery of carotenoids from palm oil

The carotenoids from palm oil were recovered through a two-stage process involving transesterification of palm oil followed by molecular distillation of the ester. The carotenoid fraction contained more than 80,000 ppm carotenoids. α- and β-Carotenes were the major components. Vitamin E and sterols were also present.     

用电去离子过程从稀溶液中回收镍离子并制备纯水

利用基于EDI工艺的单个过程实现了低浓度废水中镍的回收并同时制备纯水.研究表明:当原水镍含量为55ppm时,镍去除率可达99.9%以上,淡水产水中镍的浓度低于0.05mg·L-1,其电阻率稳定在2.02～2.59MΩ•cm,浓水中镍浓度则可高达1263mg·L-1.该研究充分证明了EDI可用于回收低浓度含镍废水中的镍离子且同时产生优质纯水,从而可实现如电镀等行业的清洁生产和闭路循环。     

Recovery of nickel from spent catalysts using ultrasonication‐assisted leaching

BACKGROUND: Solid catalysts containing metals or metal oxides play a key role in the chemical process industries to produce valuable products and fuels and consequently are left as solid wastes after a certain period of use. Disposal of these spent catalysts requires compliance with stringent environmental regulations because of their hazardous nature and content of toxic chemicals. Therefore recovery of the metals by various methods has been explored. In the present study recovery of nickel from spent nickel catalysts using ultrasonication‐assisted leaching has been investigated. RESULT: The effect on nickel recovery of acid concentration, temperature, solid to liquid (S:L) ratio, and time of digestion were studied in detail and optimized for the ultrasonication route. The results obtained are compared with the chelation route and conventional acid leaching technique. Using ultrasonication‐assisted leaching 95% extraction of nickel was achieved at 90 °C, 40% nitric acid concentration and S:L ratio 1:10 (g:mL) in 50 min from the spent nickel–alumina catalysts. CONCLUSION: Using an ultrasonication technique 95% recovery of nickel was significantly faster (50 min) than the chelation route (7 h), while with conventional acid leaching a maximum of 93% nickel recovery was obtained in 9 h. Compared with conventional acid leaching the purity of leached nickel salts was good and they could be recycled for the preparation of fresh catalysts after removing Al impurities. Copyright © 2011 Society of Chemical Industry     

Trisaturates in the hydrogenation of canola oil with a commercial nickel catalyst

Refined and bleached Canola oil was hydrogenated with Pricat 9906 catalyst to an iodine value of 65 using various temperatures, pressures and catalyst concentrations. Hydrogenation with this catalyst resulted in great differences in SFI curves of fats with the same IV. Hydrogenation rate, dropping point, trisaturate content and linoleate selectivity were determined. All of the oils hydrogenated to IV 65 contained almost the same amount of solid fat at 20 C. For this reason, the crystal structure of the fats was examined by X-ray diffraction at 20 C. The catalyst was found to be non-selective. Increased selectivity can be obtained by careful temperature and pressure control. Reactivity also is temperature and pressure dependent. High trisaturate content increased instability by promoting formation of β crystals. The catalyst had excellent filterability characteristics.     

Recovery of useful chemicals from oil palm shell-derived oil using zirconia supporting iron oxide catalysts

The possibility for recovering methanol, acetic acid and phenol from oil palm shell-derived oil was investigated. Thermal cracking mainly produced a solid residue and was not a suitable method for recovering these three target chemicals. When zirconia supporting iron based catalyst (Zr/FeOx, Zr-FeOx or Zr-Al-FeOx) was applied, the “others”—unidentified hydrocarbons—were satisfactorily removed without formation of a solid residue while these target compounds were considerably stable over these catalysts. Zr-Al-FeOx showed the highest activity for oxidation of the oil to CO₂. Effect of operating parameters (steam to oil ratio, temperature and time factor) on its performance was further investigated. In order to gain insight into the reaction path, the reaction using model compounds (methanol, acetic acid, acetone, ethyl acetate and phenol) was performed. This paper was presented at the 11th Korea-Japan Symposium on Catatysis held at Seoul, Korea, May 21–24, 2007.     

Recovery of zinc chloride catalyst from coal hydrogenation char

In the catalytic liquefaction of coal using zinc chloride, the recovery of the various spent zinc products is a prime requirement if the process is to be economically feasible. After hydrogenation, depending on the extent of coal conversion to liquid and gaseous products, about one third of the applied zinc is found with the liquids and two thirds remain with the char. The zinc associated with the liquid product is readily recovered with a water wash. The zinc associated with the char can be recovered by means of water and hydrochloric acid leaches to the extent of 70% of that present. The remaining char associated zinc (15–20% of that originally applied to the coal) is incorporated within the organic matrix of the char. A room temperature concentrated nitric acid leach is required to liberate the remaining zinc from the char. Ultimate recoveries of 98.5–99.7% are possible with the combined water, hydrochloric acid and nitric acid leach sequence.     

Production of biodiesel from palm oil (Elaeis guineensis) using heterogeneous catalyst: An optimized process

Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the three important reaction variables — methanol/oil molar ratio (x₁), reaction time (x₂) and amount of catalyst (x₃) for production of biodiesel from palm oil using KF/ZnO catalyst. Based on the CCD, a quadratic model was developed to correlate the reaction variables to the biodiesel yield. From the analysis of variance (ANOVA), the most influential factor on the experimental design response was identified. The predicted yield after process optimization was found to agree satisfactory with the experimental value. The optimum conditions for biodiesel production were found as follows: methanol/oil ratio of 11.43, reaction time of 9.72 h and catalyst amount of 5.52 wt%. The optimum biodiesel yield was 89.23%.     

超声强化浸出废加氢催化剂中的有价金属研究

采用超声波强化硫酸浸出回收废加氢催化剂中的有价金属铝、钼、钴,考察了超声功率、浸出剂浓度、液固比、反应温度和反应时间对有价金属浸出率的影响,并进行了动力学研究。结果表明,超声强化全面提高了有价金属铝、钼、钴的浸出率,最佳反应条件为超声功率400 W,浸出剂浓度为2mol/L,液固比为50∶1 mL/g,反应温度为90℃,反应时间为60 min,在此条件下,超声强化可以实现有价金属钼、钴的高效浸出(Co 99.1%,Mo 98.3%,Al 46.8%)。     

Homogeneous catalytic hydrogenation of canola oil using a ruthenium catalyst

Dichlorodicarbonylbis (triphenylphosphine) ruthenium (II), RuCl₂ (CO)₂ (PPh₃)₂, was investigated as a catalyst for edible oil hydrogenation in a preliminary screening of potential catalysts for producing partially hydrogenated fats with lowtrans-isomer content. Refined, bleached and deodorized canola oil was hydrogenated using 1.77 × 10⁻⁵ − 6.64 × 10⁻⁴ mol/kg-oil of ruthenium catalyst equivalent to 1.79 × 10⁻⁴ − 6.71 × 10⁻³ wt% Ru. The effects of temperature (50–180 C) and pressure (50–750 psig) on reaction rate,trans-isomer content and fatty acid composition were examined. The activities of RuCl₂ (CO)₂ (PPh₃)₂ and nickel (Nysel HK-4 and AOCS standard nickel catalyst) were compared on a molar basis. At 4.40 × 10⁻⁴ mol/kg-oil (0.0026 wt/Ni or 0.0044 wt% Ru), 140 C and 50 psig, the nickel catalysts were completely inactive, but the ruthenium catalyst produced an IV drop of 40 units in 60 min. At 110 C, 750 psig and 1.34 × 10⁻⁴ mol/kg-oil (1.35 × 10⁻³ wt% Ru), a hydrogenation rate of 0.89 ΔIV/min and a maximumtrans-isomer content of 10.4% (IV=45.0) was obtained with the ruthenium catalyst.     

Kinetics of methyl ester production from mixed crude palm oil by using acid-alkali catalyst

The production of biodiesel from high free fatty acid mixed crude palm oil using a two-stage process was investigated. The kinetics of the reactions was determined in a batch reactor at various reaction temperatures. It was found that the optimum conditions for reducing high free fatty acid (FFA) in MCPO (8-12 wt.%/wt oil) using esterification was a 10:1 molar ratio of methanol to FFA and using 10 wt.%/wt of sulfuric acid (based on FFA) as catalyst. The subsequent transesterification reaction to convert triglycerides to the methyl ester was found to be optimal using 6:1 molar ratio of methanol to the triglyceride (TG) in MCPO and using 0.6 wt.%/vol_TG sodium hydroxide as catalyst. Both reactions were carried out in a stirred batch reactor over a period of 20 min at 55, 60 and 65 °C. The concentration of compounds in each sample was analyzed by Thin Layer Chromatography/Flame Ionization Detector (TLC/FID), Karl Fischer, and titration techniques. The results were used for calculating the rate coefficients by using the curve-fitting tool of MATLAB. Optimal reaction rate coefficients for the forward and reverse esterification reactions of FFA were 1.340 and 0.682 l mol⁻¹ min⁻¹, respectively. The corresponding optimal transesterification, rate coefficients for the forward reactions of TG, diglyceride (DG), and monoglyceride (MG) of transesterification were 2.600, 1.186, and 2.303 l mol⁻¹ min⁻¹, and for the reverse reactions were 0.248, 0.227, and 0.022 l mol⁻¹ min⁻¹, respectively.     

Alteration of long chain fatty acids of herring oil during hydrogenation on nickel catalyst

During hydrogenation of a refined herring(Clupea harengus) oil iodine value (IV) 119, on a commercial nickel catalyst, samples were collected at IV 108, 101, 88 and 79. In the early stages of the process, IV 119 to IV 101, the positional and geometrical isomerization of the long chain monoenoic fatty acids (20:1 and 22:1) was hindered by the stronger absorption on the catalyst surface of the polyenes with 4, 5 and 6 double bonds. Consequently at IV 101, 70% of these polyenes had been converted to dienoic and trienoic fatty acids, but only 3-4%trans 20:1 and 22:1 accumulated. As the hydrogenation proceeded, IV 101 to IV 79, the originaleis 20:1 and 22:1 isomers (mainly Δ11 with some ΔA9 and Δ13) decreased and new positional and geometrical isomers (both cis andtrans in positions Δ6 to Δ15) were formed. The majortrans isomers were Δ11 accompanied by important proportions of Δ10 and Δ12. At IV 79, moretrans 20:1 (ca. 36%) thantrans 22:1 (ca. 29%) was detected. Monoethylenic fatty acids newly formed from polyethylenic fatty acids made only minor contributions to the total 20:1 and 22:1 at these levels of hydrogenation, but a “memory effect” which skews the proportions of minorcis andtrans isomers can be attributed to the proportions of minorcis 22:1 isomers (Δ9, Δ13 and Δ15) orginally present. Presented in part at AOCS Annual Conference, San Francisco, May 1979.     

棕榈油碱催化制备生物柴油实验研究

用氢氧化钾作催化剂,考察了反应温度、催化剂用量、醇油摩尔比、反应时间对棕榈油和甲醇制备生物柴油产率的影响。结果表明,最佳反应条件为:反应温度40℃,催化剂用量0.6%,醇油摩尔比6∶1,反应时间2.0 h。此时,生物柴油产率可达97.82%。     

棕榈油碱催化制备生物柴油实验研究

用氢氧化钾作催化剂,考察了反应温度、催化剂用量、醇油摩尔比、反应时间对棕榈油和甲醇制备生物柴油产率的影响。结果表明,最佳反应条件为:反应温度40℃,催化剂用量0.6%,醇油摩尔比6∶1,反应时间2.0 h。此时,生物柴油产率可达97.82%。     

镍系SBS加氢反应机理及加氢催化剂制备研究

对镍系SBS催化加氢机理进行了探讨,对催化剂制备工艺进行了优化。当催化剂组分质量浓度为2～4 g/L,陈化温度为50～70℃,n(Al)/n(Ni)为3～6时催化剂活性最高。向待加氢胶液中加入一定量破杂剂A可使催化剂活性及稳定性有一定程度提高。用该法制备的催化剂有较好的稳定性,常温下放置一个月其催化活性几乎没有变化。