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Building off of the work of Kervaire and Milnor, and Hill, Hopkins, and Ravenel, Xu and Wang showed that the only odd dimensions n for which S^n has a unique differentiable structure are 1, 3, 5, and 61. We show that the only even dimensions below 140 for which S^n has a unique differentiable structure are 2, 6, 12, 56, and perhaps 4., Comment: 52 pages. Revised version includes some additional recommendations of referee

In fluidized bed reactors such as Fluid CokersTM, liquid injections are used. Good contact between liquid and bed solids is required to maximize product yields and quality, and gas-atomized nozzles are, therefore, used in all these processes. The spray nozzle technology is known to affect the liquid distribution. Therefore, the objective of this study is to assess the effect on liquid distribution of a draft tube located downstream of the spray nozzle, inside the fluidized bed. Experiments were conducted at a relevant scale, using a commercial-scale nozzle with a liquid flow rate of about 100 L/min in a large-scale pilot fluid bed containing about 7 tonnes of silica sand. Liquid injected into a fluidized bed either forms liquid-solid agglomerates or free moisture, consisting of individual particles coated with a thin layer of liquid. Several electrodes were used to map the free moisture distribution throughout the bed. A draft tube greatly improves the contact efficiency throughout the bed. It also increases the penetration of the gas-liquid jet formed by spray inside the fluidized bed. This article is protected by copyright. All rights reserved

In collaboration with Total E&P Canada (TEPCA), CanmetENERGY conducted an extensive research program to investigate possible alternatives for TSRU tailings disposal. We have reported on alternative methods for TSRU tailings disposal without recovery of asphaltenes in an earlier publication.[1] Because the asphaltenes are high-molecular-weight hydrocarbons and may have potential for use as fuel or paving material, in this work, we investigate possible approaches for recovery of the asphaltenes from TSRU tailings. Two methods were tested, solvent extraction and aggregation. In the first method aromatic solvent is mixed with TSRU tailings to dissolve the asphaltenes followed by centrifugation to remove mineral solids and water. The experimental results demonstrated that more than 90% of the asphaltenes in the tailings can be recovered from the tailings. The recovered asphaltenes contained only a small fraction of mineral solids and may be useable as coker feed. In the second method, TSRU tailings are agitated at elevated temperature (80°C) at which the asphaltene particles form large aggregates and separate from the tailings, giving an asphaltene-rich phase and almost asphaltene-free tailings. The recovered asphaltene aggregates still contain significant amounts of mineral solids and water, and would require further treatment. Several coking tests were conducted using the recovered asphaltenes and the asphaltene aggregates. The results demonstrated that about 40 wt% of the recovered asphaltenes can be converted to lighter oil fractions under the coking conditions used in this work.

An explosion in an atmospheric storage tank initiated additional tank explosions and a pool fire at a tank facility in Norway. The tank farm had been operated as a purification plant for a petroleum product called coker gasoline. The process entailed extraction of malodorous sulfur containing components, in particular thiols (mercaptans). After several tanker loads of coker gasoline had been treated with a solution of sodium hydroxide and water, the efficiency of the sweetening process declined as precipitated waste accumulated in the tanks and the alkaline solution became increasingly saturated with impurities. The approach adopted for handling the accumulated waste included the addition of hydrochloric acid to neutralize the spent caustic. The explosion occurred when about 80% of the scheduled amount of acid had been added to the solution in the tank. There were no fatalities in the accident, but at least two people received medical treatment for injuries sustained during the course of events. The investigation concluded that the accident was caused by a chemical explosion in the tank. Several factors point toward thiols as the predominant constituents in the fuel–air mixture, but vapors from other volatile substances may also have played a decisive role. The ignition source was most likely a hot surface, resulting from adsorption of volatile organic compounds on activated carbon in the air filter and subsequent self-heating and glowing combustion in the carbon bed. The article summarizes the main results from the accident investigation and lists various measures that can be taken to prevent similar accidents in the future. © 2013 American Institute of Chemical Engineers Process Saf Prog 32: 268–276, 2013

The stripper section of a fluid-coker consists of a system of baffles (sheds) that enhances the removal efficiency of entrained and adsorbed hydrocarbons from the fluidised coke-particles. If the particles contain a thin liquid film layer of heavy hydrocarbons, making them excessively ‘wet’ or ‘sticky’, and if they stay in contact with sheds for too long, solid deposits are formed that lead to stripper fouling. Extensive fouling decreases stripping efficiency and liquid product yield and can shorten run-times between shutdowns. Because of the fouling, the shape of sheds mostly changes by increasing their surfaces thickness. An early indication of that fouling and the ability to follow its development are essential for choosing optimal parameters of the process. The radioactive particle tracking (RPT) method has been tested to determine its applicability to indicate the change in the shape of internals within a fluidised bed reactor when direct observation is impossible. A single radioactive tracer-particle has been traced in experiments lasting from 2 to 6 h. The experiments were conducted in a lab-scale, cold-flow fluidised bed into which a single shed with walls of different thickness was incorporated. This experimental fluidised bed provides intensive solid phase mixing that allows a single tracer-particle to be located in any place within the reactor. By registering the frequency of the tracer-particle appearance within a defined internal space surrounding the shed, the shape of shed was reconstructed. The conducted experiments suggest that RPT technique allows for tracking internals' fouling within a fluidised bed reactor. © 2012 Canadian Society for Chemical Engineering

Carbonaceous deposits in automotive engines are the major problems associated with oil aging. Efficient detergents and dispersants have been used for several decades to solve this problem particularly in petroleum oils. But future lubricants and new engine hardware require development of new nontoxic detergent/dispersant additive technologies. Environmental concerns limit the formulation of the future lubricants. It requires not only the base oil to be ecofriendly but the additives also. In the present work, some of the potential ecofriendly chemical’s molecules were identified. Specific detergents applications along with effects of chemical modifications were evaluated by Blotters Spot and Panel Coker Tests. Among the studied compounds, the PIB (polyisobutylene) succinimides are showing promising results at lower temperature, while at higher temperature piperazine derivatives citrate and oleate have the best potential to be develop as ecofriendly detergent/dispersant additives.

The hydrodesulfurization of Athabasca oil sands coker gas oil has been compared over Ni-Mo and Co-Mo catalysts on the basis of rate constants at 400°C, 10.3 MPa (H2) and at an LHSV of 12.0 h−1. Both catalysts were cylindrical extrudates of 3.5 mm × 1.6 mm. A Berty Continuous Stirred Tank Reactor (CSTR) was used for the hydroprocessing. Although the Ni-Mo catalyst had higher activity per gram of catalyst, on the basis of the rate constant per gram of molybdenum, the Co-Mo catalyst was slightly more active with lower activation energy than the Ni-Mo catalyst for HDS.

Summary: Host range of Achlya caroliniana Coker has been extended to include Puntius Sophore, P. conchonius, P. ticto, Colisa fasciata, Chanda ranga, Labeo rohita (fingerlings), L. bata (fingerlings), Notopterus notopterus, Anabas testudineus, and Channa punctatus by artificial inoculation studies under controlled laboratory conditions. Zusammenfassung: Durch kunstliche Infektion unter kontrollierten Laborbedingun-gen konnte die Zahl der Wirtsorganismen, auf denen der Pilz Achlya caroliniana para-sitieren kann, auf folgende Fischarten ausgedehnt werden: Puntius Sophore (Barbe), P. conchonius (Prachtbarbe), P. ticto (Fleckbarbe), Colisa fasciata (gestreifter Fadenfisch), Chanda ranga (indischer Glasbarsch), Labeo rohita (Fransenlipper), L. bata (Fransen-lipper), Notopterus notopterus (sudasiatischer Messerfisdi), Anabas testudineus (Kletter-fisch) und Channa punctatus (Schlangenkopf).

During plant start-up, a critical interface exists at block valves located at battery limits of process units. A relatively small leak at a battery-limit isolation point was established as the source of gas that caused an explosion in a 26-foot diameter fractionator on a Fluid Coker nearing the end of a maintenance turn a round. This incident could easily have occurred in any modern oil refinery or chemical plant. This paper shares the technology and learning associated with small release scenarios that are often overlooked in large-scale plant operations. The explosion event did not damage the fractionator shell, but displaced all but two of the sieve trays in the column, and produced minor damage in the overhead condensers and receiver drum. Importantly, the consequent down-time resulted in a major production loss. Damage analysis supports the proposition that a deflagration occurred in the top portion of the fractionator involving under 50 lbs. of fuel. It is believed that relatively small leaks, persisting over a period of a few hours, supplied the required amount of fuel. The accident investigation identified multiple potential pathways whereby natural gas leaking past battery limit block valves could have reached the fractionator. This incident highlights the importance of securing leak tight connections between active and inactive sections of process systems. As a result of this experience, several procedural and organizational reforms have been instituted.

The cyclone sections of fluid coking reactors at oil sand upgrading facilities have been observed to undergo severe coke fouling during each operational cycle. This work was conducted to determine if vapour phase deposition mechanisms could be responsible for the formations observed in the cyclones. The effects of vapour phase temperature (from 490°C to 560°C) and residence time (from 0.4 to 4.4 s) were studied. Raising the vapour phase temperature above the temperature at which the vapours were derived was found to significantly increase both the yield and rate of production of vapour phase coke. On a observe que les sections de cyclonage de reacteurs de cokefaction de fluides dans des installations de valorisation. On a realise ce travail dans le but de determiner si les mecanismes de deposition de la phase vapeur pouvaient ctre la cause de cet encrasse-ment. L'effet de la temperature de la phase vapeur (de 490°C a 560°C) et le temps de sejour (de O a 4.4 s) a ete etudie. On a trouve que le fait d'augmenter la temperature de la phase vapeur au-dessus de la temperature a laquelle ont ete obtenues les vapeurs augmentait de maniere significative a la fois le rende-ment et la vitesse de production de coke en phase vapeur.

The vapours derived from thermally cracked Athabasca bitumen were exposed to temperatures phase 490°C and 560°C in order to investigate the effects of vapour phase thermal cracking on product yields and campositiom. Raising the vapour phase temperature above the temperature at which the vapours were derived increased both the yield of non-condensable vapours and the amount of olefins in the produced gas. In addition, the liquid yield decreased with increasing vapour phase temperature and changes in liquid product composition were also observed. The H/C ratio of the liquid product decreased with increasing vapour phase temperature. Les vapeurs provenant de bitumes d'Athabasca ayant subl un craquage thermique ont ete exposees a des temperatures comprises entre 490°C et 560°C dans le but d'etudier les effets du craquage thermique en phase vapeur sur les rendements et compositions de produits. Le fait d'elever la temperature de la phase vapeur au-dessus de la temperature a laquelle les vapeurs ont ete obtenues augmente a la fois la production de vapeur non condensable et la quantite d'olefins dans le gas produit. En outre, la rendement du liquide diminue avec l'augmentation de la temperature en phase vapeur et des changements dans la composition du produit liquide ont egalement ete observes. Le rapport H/C du produit liquide diminue avec l'augmentation de la temperature en phase vapeur.

Farmers in the Southeast are interested in growing cotton (Gossypium hirsutum L.) following a winter cash crop or a legume cover crop. This results in a relatively late planting date. Late planting of cotton is now possible because eradication of the boll weevil in some locations has extended the effective period for boll production. Additionally, modern cotton cultivars are earlier in maturity than those previously available. Our objective was to determine the effect of five planting dates on yield, height, and fiber properties of six cotton cultivars: Coker 130 and DES 119 (early), Coker 320 and PD-3 (medium), and Deltapine 5415 and Deltapine Acala 90 (late maturing). Cotton was planted in mid-April, early- and mid-May, and early- and mid-June in 1991, 1992, and 1993. As planting date was delayed, yields decreased 2 of 3 yr, but were unaffected the third year when drought conditions limited yields. As planting date was delayed, lint percentage declined, plant height increased, fiber strength increased, fiber elongation increased, and micronaire declined. Over all years and planting dates, DES 119, Coker 130, and Deltapine 5415 had the highest yield. Deltapine 5415, a longer maturing cultivar, yielded less than the two other cultivars when planted on the later planting dates. Coker 130 had the highest lint percentage and lowest fiber strength, whereas Deltapine Acala 90, the tallest cultivar, had the lowest lint percentage and highest fiber strength. DES 119 had a lint percentage equal to that of Coker 130, as well as the highest fiber uniformity. Fiber elongation and micronaire were highest for Deltapine 5415 and DES 119. These data indicate cultivar selection is an important consideration when planting at a later than optimum date.

Experiments were conducted to examine the growth responses of cotton (Gossypium hirsutum L. cv. Coker 315) to CO 2 enrichment under different light regimes. Plants were exposed to 350 or 700 μl l -1 CO 2 and six light treatments differing in photosynthetic period length (8 or 16 h) and in photosynthetic photon flux density (PPFD) for 32 days of vegetative growth. Higher PPFD (1 100 μmol m -2 s -1 ) was provided by a combination of high intensity discharge and incandescent lamps

Several pitch materials and a petroleum coke were added to coke oven charges in an attempt to make good metallurgical coke from Canadian coal of poor coking quality. Coal and petroleum pitches were added to a low fluid western Canadian coal of medium volatile bituminous rank, and the blends coked in a technical-scale moveable wall test oven having a 230-kg charge capacity. Pitches improved coke tumble test indices, the principal coke quality parameter related to blast furnace performance. Varying levels of petroleum coke were added to an eastern Canadian coal of high volatile bituminous rank, and the blends, some partially briquetted, were carbonized in a test oven. Tumble indices of coke from the partially briquetted charges approached an acceptable level. These investigations confirm that petroleum products as well as coal derivative can play a useful part in the production of a metallurgical strength coke from poor or non-coking coals.

A method of Structural Group Analysis (SGA) was used to characterize feed and liquid products from catalytic hydroprocessing using a commercial Ni-Mo catalyst. Comparison of the structural profiles revealed significant changes in the concentration of various structural groups. SGA is a promising tool for investigating chemical changes in complex reacting systems. On a utilise la methode d'analyse de groupes fonctionnels (SGA) pour mesurer l'alimentation et les produits liquides d'un procede d'hydrotraitement catalytique utilisant un catalyseur commercial Ni-Mo. La comparaison des profils de groupes fonctionnels revele des changements importants dans la concentration de divers groupes fonctionnels. La technique SGA est un outil prometteur pour etudier les changements chimiques dans les systemes reactionnels complexes.

A coker distillate of Athabasca bitumen was hydrogenated over a fixed bed of cobalt molybdate on alumina catalyst. The effect of reaction pressure on the rate of catalyst deactivation was investigated at 896°F., an hourly space velocity of 2.0 and pressures from 1,000 to 3,000 p.s.i. The following expression was derived from the results of these experiments which relates reaction pressures and the hourly increase of the oil product specific gravity at these conditions. The yield and quality of the hydrogenated oil products and the relative hydrogen consumptions were determined at the following operating conditions: 1. Pressure—1,000–10,000 p.s.i.; Temperature—797–896°F. Space velocity—2.0 hr.−1. 2. Pressure—3,000 p.s.i.; Temperature—797–896°F. Space velocity—1.0–4.0 hr.−1. On a hydrogene le distillat provenant de la cokefaction du bitume d'Athabasca au moyen d'un lit fixe de molybdate de cobalt sur L'alumine. L'influence de la pression entre 1000 et 3000 psi sur le taux de desactivation du catalyseur a ete etudiee pour une temperature de 896°F. et une vitesse volumetrique horaire de 2 volumes de distillat par unite de volume de reacteur par heure. A L'aide des valeurs experimentales obtenues on derive une correlation entre la pression de reaction et L'augmentation horaire de la densite du produit. Le rendement et la qualite des produits hydrogenes ainsi qui la consommation d'hydrogene ont determines aux conditions suivantes: 1. Pression—1,000–10,000 psi; Temperature—797–896°F.; Vitesse volumetrique—2.0 hr−1. 2. Pression—3,000 psi; Temperature—797–896°F; Vitesse volumetrique—1.0–4.0 hr−2.