The Processing of Pyrolysis Fuel Oil by Dielectric Barrier Discharge Plasma Torch

In present paper, an atmospheric-pressure low-temperature plasma treatment of pyrolysis fuel oil (PFO) was investigated in dielectric barrier discharge plasma torch reactor. The effect of the applied voltage and the volume of feedstock, as the main parameters, on the cracking of PFO were studied. By increasing the applied voltage from 10 to 16 kV, the production rate of hydrocarbons containing methane, ethylene, acetylene, propane, propylene, and C₄ rise 18 times. In this case, the production rate of hydrogen increases by approximately 14 times and reaches 7.27 × 10^?3 mol/min for 16 kV. In the feedstock volume investigation, based on limitation of reactor volume, the production rate of hydrocarbons decreased from 0.44 × 10^?3 to 0.15 × 10^?3 mol/min by increasing volume of feedstock from 1 to 5 cc.     

费谢尔判别法鉴别原油/燃料油

以多环芳烃作为变量,建立了原油、燃料油属性鉴别的费谢尔判别法。分别测定了来自不同国家和地区的26个原油样品和25个燃料油样品中8种多环芳烃的含量,并将它们作为判别变量。借助SPSS 16.0进行费谢尔判别分析,建立费谢尔判别函数。将未知样品的判别变量值代入后,可以快速地得知样品的类别。结果表明,以多环芳烃作为判别变量进行原油、燃料油费谢尔判别快速而准确。     

Entrained Flow Gasification of Polypropylene Pyrolysis Oil

Petrochemical products could be produced from circular feedstock, such as waste plastics. Most plants that utilize syngas in their production are today equipped with entrained flow gasifiers, as this type of gasifier generates the highest syngas quality. However, feeding of circular feedstocks to an entrained flow gasifier can be problematic. Therefore, in this work, a two-step process was studied, in which polypropylene was pre-treated by pyrolysis to produce a liquid intermediate that was easily fed to the gasifier. The products from both pyrolysis and gasification were thoroughly characterized. Moreover, the product yields from the individual steps, as well as from the entire process chain, are reported. It was estimated that the yields of CO and H₂ from the two-step process were at least 0.95 and 0.06 kg per kg of polypropylene, respectively, assuming that the pyrolysis liquid and wax can be combined as feedstock to an entrained flow gasifier. On an energy basis, the energy content of CO and H₂ in the produced syngas corresponded to approximately 40% of the energy content of the polypropylene raw material. This is, however, expected to be significantly improved on a larger scale where losses are proportionally smaller.     

基于费谢尔判别法的原油、燃料油鉴别技术研究

对原油、燃料油的鉴别方法进行了研究.以来自不同国家和地区的30个原油样品以及不同产地、不同种类的24个燃料油样品中的正构烷烃(n-C7～30)、植烷(Ph)、姥鲛烷(Pr)的含量构成训练集.借助SPSS 16.0进行费谢尔(Fisher)判别分析,建立Fisher判别函数.将判别变量值代入后,得到样本的空间位置,再计算样本至各组重心的距离,据此判断分类情况.结果表明,Fisher判别法可以很好地用于原油和燃料油的鉴别,具有快速、准确等特点.     

Non-Isothermal Pyrolysis and Kinetics of Oil Shales

In this research, non-isothermal pyrolysis behavior and kinetics of three oil shales were studied by thermal analysis methods. All the thermal effects were endothermic and no exothermic region was observed in DSC curves. When oil shales are heated in nitrogen atmosphere in TG/DTG, two different mechanisms causing loss of mass were observed. The region between ambient temperature and 500 K was distillation. The second mechanism was visbreaking and cracking and it was observed between the region 500 and 800 K. Kinetic parameters of all the samples are determined by Coats and Redfern method and the results are discussed with regard to their accuracy and the ease of interpretation. This revised version was published online in August 2006 with corrections to the Cover Date.     

低温燃料化学特性对湍流预混火焰传播的影响

大分子碳氢燃料的低温化学反应及两阶段点火特性会显著影响火焰的分区及燃烧情况。本文采用数值模拟的方法探究了正庚烷/空气预混混合气在RATS燃具上的湍流火焰传播,与试验结果具有一致性。模拟使用的是44种物质,112步的正庚烷简化动力学机理。使用Open FOAM的reacting Foam求解器建立了简化模拟流道及出口的三维模型,模拟了在大气环境下,初始反应温度450–700 K、入口速度6 m·s~(-1)与10 m·s~(-1)、焰前流动滞留时间100 ms及60 ms、当量比φ=0.6的正庚烷/空气混合气湍流火焰燃烧情况。结果发现,标准化湍流燃烧速度与混合气初始温度以及流动滞留时间有关。在低温点火阶段,正庚烷氧化程度受到初始温度与速度的影响,燃料分解并在预热区中产生大量中间物质如CH_2O,继而会影响湍流火焰燃烧速度。随着初始反应温度的升高,湍流燃烧火焰逐渐由化学反应冻结区过渡到低温点火区;温度超过一定数值后,燃料不再发生低温反应,此时燃烧位于高温点火区域。     

Flame retarding of wood by impregnation with boric acid - Pyrolysis products and char oxidation rates

The pyrolysis of fir wood impregnated with boric acid (0-5.4%) has been investigated for heating temperatures of 650 and 800 K by examining the yields of char, water, permanent gases (CO₂, CO, CH₄) and total organic products (together with 32 compounds). The yields of the last product class continuously decrease to the advantage of char and water, but the most significant modifications occur for acid contents below 2%. The formation of levoglucosan (with 2-acetylfuran, 5-methyl-2-furaldehyde and other minor species) first and levoglucosenone (with 2-furaldehyde) afterwards is favoured, whereas other compounds generated from the holocellulosic (hydroxyacetaldehyde, hydroxypropanone, acetic acid and minor carbohydrates) and lignin (phenols, cresols) fractions generally decline. Conversion times become longer and volatilization rates are reduced. The oxidation characteristics of char have been studied by means of thermogravimetric analysis and interpreted according to a three-step reaction mechanism. The boric acid treatment lowers the activation energy and reaction order of the most important step (145 versus 226 kJ/mol and 1.2 versus 0.86, respectively) which also shows lower rates and is slightly delayed.     

Volatile Products of Temperature-Programmed Pyrolysis of Oil Shales

Temperature-programmed pyrolysis of oil shales was studied. The composition of pyrolysis products was analyzed by the chromatographic technique.     

用Dawson型聚氧钨酸乳液催化氧化燃油超深度脱硫

合成了Dawson型聚氧钨酸乳液催化剂Q18P2W18,Q18P2W17,和Q18P2W12.采用红外光谱和固体核磁技术对其进行了表征,并用于温和条件下H2O2氧化4,6-二甲基二苯并噻吩(4,6-DMDBT)、二苯并噻吩(DBT)、苯并噻吩(BT)和2,5-二甲基噻吩(2,5-DMT)等含硫化合物的反应中.结果表明,...     

在线热裂解/气相色谱-质谱联用技术研究八角茴香油的热裂解行为

采用在线热裂解/气相色谱-质谱(Py/GC-MS)联用技术分析研究了八角茴香油的主要成分和裂解产物,探讨了氦气氛围中八角茴香油在300,400,500,600,700,800℃下的热裂解行为。结果从八角茴香油中检测出13种组分,其中反式茴香脑占94.848%;从裂解产物中检测出28种物质;八角茴香油组分在低温下(300~500℃)大部分发生转移;高温下(600~800℃)裂解相对比较剧烈,生成一些香味物质及甲苯、乙苯等有害物质;反式茴香脑在500℃时具有最大的转移率。上述结果为八角茴香油在食品中的应用提供了参考。     

Vinyl Polymerization Initiated by Peroxydiphosphate. IV. Polymerization of Acrylonitrile Initiated by Peroxydiphosphate-Thioacetamide Redox System

Abstract

The kinetics of the aqueous polymerization of acrylonitrile initiated by the peroxydiphosphate-thioacetamide redox system was investigated at 35, 40, and 50°C. The rates of polymerization were measured at different concentrations of oxidant, activator, and monomer. Peroxydiphosphate alone did not initiate polymerization under deaerated and undeaerated conditions. Addition of certain water-miscible organic solvents and neutral salts depress the rate and conversion. On the basis of experimental observations of the dependence of the rate of polymerization on various variables, a suitable kinetic scheme has been proposed.     

Flash Pyrolysis and Kinetic Parameters of Decomposition of Oil Shales

Flash pyrolysis of oil shales, distribution of the organic matter in the volatile products, solidresidue at various pyrolysis temperatures were studied. The concentrations of aliphatic hydrocarbons andnaphthenes + arenes in the volatile products were determined.     

Polymerization Initiated by Organic Electron Donors

Polymerization reactions with organic electron donors (OED) as initiators are presented herein. The metal‐free polymerization of various activated alkene and cyclic ester monomers was performed in short reaction times, under mild conditions, with small amounts of organic reducing agents, and without the need for co‐initiators or activation by photochemical, electrochemical, or other methods. Hence, OED initiators enabled the development of an efficient, rapid, room‐temperature process that meets the technical standards expected for industrial processes, such as energy savings, cost‐effectiveness and safety. Mechanistic investigations support an electron‐transfer initiation pathway that leads to the reduction of the monomer.     

Vinyl Polymerization Initiated by Sulfur Dioxide

Abstract

A number of monomers have been polymerized in the presence of catalytic and higher concentrations of SO₂. The addition of t-butyl hydroperoxide greatly accelerates the rate of polymerization. The use of ³⁵SO₂ indicates that at catalytic concentrations of SO₂ (10^?2 mole/liter), only one or two molecules of SO₂ are incorporated in the chain, but, at high SO₂ concentrations, copolymerization of SO₂ with vinyl monomers occurs.     

光敏引发合成聚丙烯酰胺

采用紫外光照射下光敏引发聚合技术,以丙烯酰胺(AM)为单体,以水溶性光敏剂为引发剂,合成了分子量较高的聚丙烯酰胺(PAM)。探讨了光敏引发剂浓度、单体浓度、Na2CO3浓度、pH、络合剂乙二胺四乙酸二钠盐(EDTA)浓度等因素对PAM分子量的影响,通过红外光谱对产物结构进行了表征。结果表明:光敏引发合成的PAM黏均分子量可以达到1.7×107,溶解性能良好,纯度较高。     

一种含氢燃料火焰降温观色筒的设计和应用*

针对酒精灯火焰呈黄色的解释争议进行研究,以降低环境温度和减少氧气浓度为方向,设计了可观察环境温度变化对含氢燃料火焰颜色影响的仪器。对乙醇、丁烷、蜡烛等燃烧火焰进行降温测试,发现含氢燃料正常燃烧火焰颜色一般为黄色、降低环境温度后变为极淡的蓝色(光亮条件下)的规律,证明了燃烧过程中水分子处于激发态是导致火焰颜色由蓝色变为黄色的重要原因,钠元素的焰色反应不是酒精灯火焰呈黄色的唯一原因。对丁烷喷枪火焰颜色的降温测试,意外观察到4种疑似氢原子光谱的可见光谱线,为今后寻找该谱线提供了可借鉴的方向。研究过程可作为基于真实情境的研究素材,通过问题的发现、仪器的改进和规律的总结,提高学生运用化学知识解决真实问题的能力,培养学生的核心素养。     

N-羟基邻苯二甲酰亚胺引发的聚乙烯熔融接枝反应

研究了N-羟基邻苯二甲酰亚胺(NOP)用于引发4种卤胺类前驱单体包括甲基丙烯酰胺(MA)、N-叔丁基丙烯酰胺(N-t-BuA)、马来酰亚胺(MI)和N,N-二烯丙基三聚氰胺(NDAM)与线性低密度聚乙烯(LLDPE)的熔融接枝聚合反应,并将其与工业上普遍应用的有机过氧化物(过氧化二异丙苯,DCP)引发法作对比。在接枝效率方面,NOP的引发效率与单体的分子结构和投料量密切相关。这4种单体中,N-t-BuA的接枝效率最高,与DCP法的差异在2.5%~16.0%之间;MI的接枝效率最低,比DCP法低55%。在副反应控制方面,实时扭矩、凝胶含量和熔融指数测试证实NOP引发体系中聚乙烯交联副反应程度明显低于DCP,接枝反应更加可控。     

纳米颗粒结合ZIF-67衍生的PtCo-NC催化剂用于醇类燃料电氧化

Alcohols fuel electro-oxidation is significant to the development of direct alcohols fuel cells, that are considered as a promising power source for portable electronic devices. Currently, the catalyst was restricted by the serious poisoning effect and high cost of noble metals. Developing low-cost Pt alloy with high performance and anti-CO poisoning ability was highly desired. In this work, PtCo-NC catalyst was synthesized by combining Pt nanoparticles with ZIF-67 after annealing in the tube furnace and the in situ generated N-doped carbon from ZIF-67 was functionalized to support the PtCo alloy nanoparticle. The structure and morphology were probed by X-ray diffraction, scanning electron microscope and transmission electron microscope, and the electrochemical performance was evaluated for alcohols of methanol and ethanol oxidation in the acid electrolyte. Compared with the reference sample of Pt/C, several times performance enhancement for alcohols fuel oxidation was found on PtCo-NC catalyst as well as the good catalytic stability. Specifically, the peak current density of PtCo-NC was 79.61 mA∙cm⁻² for methanol oxidation, about 2.2 times higher than that of the Pt/C electrode (36.97 mA∙cm⁻²) and 2.5 times higher than that of the commercial Pt/C electrode (31.23 mA∙cm⁻²); it was 62.69 mA∙cm^–2 for ethanol oxidation, about 1.65 times higher than that of Pt/C catalyst (37.99 mA∙cm⁻²) and commercial Pt/C electrode (37.77 mA∙cm⁻²). These catalytic performances were also much higher than some analogous catalysts developed for alcohols fuel oxidation. A much higher anti-CO poisoning ability was demonstrated by the CO stripping voltammetry experiment, in which the CO_ad oxidation peak potential for PtCo-NC was 0.46 V, ca. 110 mV negative shift compared with Pt/C catalyst at 0.57 V. A strong electronic effect was indicated by the peak position shifting to the lower binding energy direction by 0.3 eV on PtCo-NC compared with Pt/C reference catalyst. According to the d-band center theory, the electron-enriched state of Pt will decrease the interaction strength of poisoning intermediates adsorbed on its surface; Moreover, according to the bifunctional catalytic mechanism, the presence of Co can form the adsorbed oxygen-containing species (―OH) more easily than Pt at low potentials, and this oxygen-species were helpful in the oxidation of CO_ad at neighboring Pt sites. The high catalytic performance for alcohols fuel oxidation could be due to the largely improved anti-CO poisoning ability and the synergistic effect between the in situ formed PtCo nanoparticles and the N-doped carbon support.     

Vinyl Polymerization Initiated by Peroxydiphosphate. XI. Polymerization of Methyl Methacrylate Initiated by Peroxydiphosphate-Tartaric Acid Redox System

The polymerization of methyl methacrylate was studied using the peroxydiphosphate and tartaric acid redox system as the initiator. The rate of polymerization increases with increasing peroxydiphosphate concentration and the initiator exponent was computed to be 0.5. The rate of polymerization increases with increasing monomer concentration and the monomer exponent was computed to be unity. The reaction was carried out at three different temperatures, and the overall activation energy was computed to be 3.80 kcal/mol. The effect of certain surfactants on the rate of polymerization has been investigated and a suitable kinetic scheme has been proposed.