Plastic asphalts produced from residua of West Siberian crudes

Summary A study has been made of the physicochemical and rheological properties of oxidized asphalts obtained from residua of West Siberian crudes.It has been shown that the nature of the feedstock has a decisive influence on the properties of the oxidized asphalts. The asphalts produced from a straight-run long residuum from West Siberian crudes have wide ranges of plasticity (91 and 111°C), low brittle points (–20 and –30°C), and better heat resistance than do the oxidized asphalts produced from a solvent-precipitated asphalt obtained in Stage II deasphalting.It has been established that, as the degree of oxidation is increased, the asphaltene content of the asphalts increases sharply, and the amount of the most reactive bicyclic and polycyclic aromatic compounds decreases through conversion into resins and then asphaltenes; the amount of oxygen-containing groups increases, as evidenced by the IR spectra of the component groups of the asphalt.The oxidized asphalts produced from residua of West Siberian crudes are highly structured systems within the interval of temperatures that was investigated (from 60 to 180°C); for a given penetration, the asphalt produced from the straight-run long residuum is more highly structured than that produced from the solvent-precipitated Stage II asphalt, as a consequence of the higher asphaltene content of the former.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 5, pp. 26–29, May, 1973.     

Production of paving asphalts from high-wax crude oils

High-quality BND 40/60 and BND 60/90 asphalts were made from high-wax Kotur-Tepe crudes with additives — heavy catalytic gasoil, hard asphalt from propane deasphalting, and extracts from selective treatment of oil feedstock — were manufactured in pilot conditions. Production of such asphalts by direct oxidation of vacuum resid is not possible. Optimum feedstock compositions are proposed.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 6, pp. 23 – 26, November– December, 2004     

Modification of Feedstock for Productino of Oxidized Asphalts

Production of oxidized asphalts with improved quality characteristics an be increased by modifying the initial feedstock, for example, with cationic surfactants (CSF). The use of a quaternary ammonium compound with a C₁₇ – C₁₉; hydrocarbon radical in the optimum concentration of 0.06 wt. % increases the proportion of heavier components in the asphalt, that is, causes a greater degree of oxidation of the feedstock. A decrease in consumption rates in production of asphalt is possible as a result. The quality of the asphalt obtained either with a 30% decrease in air consumption or a 10–15°C decrease in the temperature or with a 30% reduction in the oxidation time is as good as the baseline sample.     

Manufacture of Special Asphalt Varnish with Improved Properties

Technology was developed for manufacturing special asphalt varnish with improved properties directly in the stage of oxidation of the feedstock by addition of modifiers. Oxidation is intensified and the yield of target product increases. The asphalt obtained satisfies the requirements in GOST 21822–87 for brittle petroleum asphalts for paints and varnishes. The performance characteristics of coatings made from this asphalt are significantly improved.     

Paving Asphalts with Modifying Additives

The possibility of increasing the quality of paving asphalts by modifying them with an inexpensive, nontraditional additive — Kashpir slate softener with a significant content of resins and asphaltenes — is demonstrated. In the concentration of under 7 wt. %, this additive gives asphalt elasticity on the level of expensive polymeric asphalt binders (PAB), decreases the brittleness temperature by 2–3° and also causes a more stable and plastic colloidal sol system. When the softener and BP–3M adhesive additive are incorporated in asphalt together, the thermal stability of the additive increases and the asphalt acquires high adhesion to mineral materials for a long period.     

Improved technology for utilizing spent sulfuric acid in refineries

Summary The utilization of spent sulfuric acid to produce sulfur dioxide can be accomplished by continuous mixing of the spent sulfuric acid (or acid tar) with a straight-run residuum in amounts to give a ratio of organic mass to sulfuric acid between 20 and 40, with an SR resid temperature of 200–250°C and a contact time of 3–5 min. The resulting semiasphalt is used in mixture with more SR resid as a feedstock for asphalt manufacture.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 7, pp. 24–27, July, 1975.     

Increasing the thermal stability of paving asphalts

A comparative analysis of domestic and foreign standards and technical specifications for paving asphalts is reported. A LUKOIL — Nizhegorodnefteorgsintez OAO draft corporate standard (DCS) for viscous paving asphalts which totally agrees with the foreign specifications was developed. Data from a pilot-industrial run on manufacture of commercial BND asphalt that satisfies the requirements of the DCS and is characterized by elevated plasticity and thermal stability are reported. The compositions of the feedstock and commercial asphalt and the process conditions of oxidation of vacuum resid were refined. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 7–16, May–June, 2008.     

Exhaustive Processing of Low-viscosity Raffinate

In exhaustive dewaxing of raffinate from the 300 – 400°C cut, the yield of MS–8 lube stock with a solid point of –55°C does not exceed 40%. The slack wax obtained contains 30 – 40% oils. As a result of deoiling the slack wax at a temperature of –24°C, soft wax with a melting point of +43°C and dewaxed oil with a solid point of –2°C were obtained. The first product is used as a component of the feedstock for production of synthetic fatty acids and the second is used for production of cooling fluids. The scheme for exhaustive refining of raffinate and the material balance of the process are reported.     

Production of Better–Quality Oxidized Asphalts. Process Implementation

The method is based on use of fluidics — an injection system for feed of feedstock and air. Introduction in asphalt production at Ryazan' Oil Refining Co. showed: equipping the oxidizing reactor with an injection system allowed obtaining viscous paving asphalts for which all parameters exceeded the requirements of GOST 22245–90, TU 38.1011356–91, and Neste specifications; stable operation of the reactor was attained in all output ranges; the injection feed system is distinguished by simplicity and reliability, and coking problems are totally eliminated; the investments are insignificant, the output of the oxidizing reactors is increased, and specific air consumption is reduced.     

Effect of sulfur-containing acids on the penetration and softening point of asphalts obtained from acid sludge

The dependence of the penetration and the softening point of asphalts produced from acid sludge on the concentration of sulfuric and sulfonic acids that were present in the sludge, as well as on the total acidity of the initial sample, was studied. It was found that the asphalt viscosity decreases with a decrease in the concentration of sulfur-containing acids. The dependence of the asphalt softening point and on the acidity of the feedstock sludge is a logarithmic function, and the penetration is related to this parameter by a power law.     

Cost calculation methods for petroleum products in catalytic cracking

Conclusions For a correct valuation of savings in converting cat cracking units to highly active zeolite-containing catalysts with the aim of increasing the gasoline yields, it is desirable to reexamine the current procedure for costing petroleum products and to consider the target products in cat cracking to be only the gasoline and the light ends, whether the unit is operating in the fuel regime or in the petrochemical regime.The diesel fraction (fuel variant) or the 270–420°C (petrochemical variant) used as a source of carbon black feedstock should be considered as a byproduct, valued at the cost of original feedstock for the cat cracking process.In the extraction process, the target products should be considered to be the feedstock for carbon black production (extract) and the 270–420°C diesel fraction (raffinate).Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 7, pp. 26–29, July, 1973.     

Modification of Asphalts with Phosphazenes

Phosphazenes - triphosphonitrile chloride and polyphosphonitrile chloride - are effective asphalt modifiers that expand the temperature range of its elastic-plastic state. The modulus of elasticity of asphalts modified with them allow recommending them for obtaining high-quality incombustible coatings.__________Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 46 – 48, July – August, 2005.     

Effect of a modifying additive on the blown-asphalt manufacture process

The effect of a modifying additive (brown-coal pyrolysis tar) on the asphalt oxidation process has been investigated. The dependences of the softening temperature and the dynamic viscosity of the product asphalts upon the duration of oxidation and the amount of the additive have been determined, and the oxidation rate constants and the viscous-flow activation energies have been calculated for the oxidized asphalts. On the basis of experimental data, it has been shown that the introduction of the modifying additive into vacuum residue leads to a decrease in dynamic viscosity and softening temperature of the blown asphalts owing to its inhibitory effect on the oxidation process. Asphalts derived from the modified feedstock are characterized by a more ordered structural organization compared with those obtained from the unmodified feedstock.     

Production of high-quality catalytic reforming feed stock by deep hydrogenation of secondary-process gasolines

Conclusions As a result of experiments on the deep hydrogenation of thermally cracked gasoline from the visbreaking and delayed coking of tar from high-sulfur Arlan crude on an industrial alumo-cobalt-molybdenum catalyst it was established that to obtain a high-quality feedstock for catalytic reforming from these gasolines the purification must be done in two stages.With purification of the feedstock in Stages I and II it is recommended to maintain, correspondingly, the following parameters: pressure 50 and 30 atm, temperature 380–420 and 380–400°C, space velocity of feed of feed-stock 2 and 5–6 h^–1, circulation of hydrogen containing gas 500 and 100 liter/liter feedstock.After two-stage purification, the catalytic reforming feedstock contains not more than 0.003 wt. % sulfur and 0.0002 wt. % nitrogen; the iodine number does not exceed l g I₂/100 g product.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 1–5, April, 1969.     

Carcinogenicity and Toxicity of Petroleum Asphalts with Coal Tar Additives

Coal binders — tars — are materials traditionally used in road construction, in particular, as additives to petroleum asphalts. However, the existing technology for mixing them with asphalts has many drawbacks. To eliminate these drawbacks, the Voronezh Engineering and Construction Institute (VECI) has developed new technology for manufacturing paving asphalts with coal tar additives. It is based on incorporation of the coal tars in oxidized petroleum feedstock by portions.     

Catalytic cracking of heavy crude on a zeolite catalyst

Conclusions The authors study catalytic cracking of the 280–460°C fraction of Upper Cretaceous Chechen-Ingush oil on CaHX zeolite without a binder. The zeolite was 6.6–7.5% more active and 8.4–9.4% more selective than a commercial aluminosilicate catalyst under moderate cracking conditions.The catalytic cracking gases obtained on a zeolite catalyst contain 1.72–3.35 wt. % propylene, 1.76–3.50 wt. % butylenes, and 3.51–5.82 wt. % isobutane (all these contents being percentages of the feedstock).The naphtha fractions contain 45 wt. % of isoparaffins and 26 wt. % of aromatic hydrocarbons.The wide-cut 200–360°C diesel fractions contain (on average) 46.5 wt, % of methanic, 12.5 wt. % of naphthenic, 34 wt. % of aromatic, and 7 wt. % of unsaturated hydrocarbons.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 7, pp. 9–11, July, 1969.     

A STUDY OF RHEOLOGICAL PROPERTIES OF LIME TREATED PAVING ASPHALTS AGED AT 60°C IN A PRESSURE AGING VESSEL

Abstract

The oxidation and age-hardening propensities of eight widely varying petroleum asphalts used for paving were studied with and without hydrated lime, and with inert particulate matter in place of lime. The results show that oxidation of sulfides to sulfoxides and benzyl carbon to ketone is affected very little by the presence of lime. However, the addition of lime does inhibit age-hardening in asphalt whereas the inert particulate matter in the same amount and particle size has little effect other than the filler effect exhibited by the lime and the inert particulate.

The principal inhibition of age-hardening of asphalt by hydrated time occurs at high pavement temperatures (> 60°C). At low and moderate temperatures (<50°C), age-hardening is very slow and typically not a major problem in pavement.

It is speculated elsewhere in detailed aging studies that the high temperature age-hardening of paving asphalts results from formation of multimolecular, three dimensional matrices in asphalt formed among polar molecules. Hydrated lime appears to interfere with this type of matrix formation, probably by chemical reaction with carboxylic and other acids, to reduce the sizes and/or strengths of the matrices. As a practical result, lime reduces the rate of hardening of asphalt hence prolonging the expected lifetime of a roadway.     

FRACTIONATION OF ASPHALT MATERIALS BY USING SUPERCRITICAL CYCLOHEXANE AND PENTANE

ABSTRACT

Fractionation of asphalt materials by using supercritical cyclohexane and pentane has been successfully conducted. Each of three asphalts was fractionated into ten fractions. These asphalts and their fractions were then characterized by a variety of analyses including Corbett chromatographic separation, infrared analysis, refractive index- and intrinsic viscosity-size exclusion chromatography (gel permeation chromatography), and elemental analysis by atomic absorption. The fractions were then reblended to produce materials of typical asphalt consistency. These blends were then subjected to oxidative aging in a pressure oxidation vessel and were found, in some cases, to have improved aging characteristics in the sense that they did not harden in response to a given carbonyl formation (oxidation) as much as normal asphalt materials. Hence, the supercritical fractionation technique is considered to have great potential for producing improved asphalt materials.     

Universal system for injection feed of feedstock and air into a vacuum resid oxidation reactor

A universal system was developed for injection feed of feedstock and air into an oxidation reactor which ensures its efficient operation in a wide range (15–40 m³/h) of output in feedstock: production of oxidized asphalts of improved quality, reduced specific air flow and oxygen content in oxidation gases. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 13–16, July–August, 2008.     

The influence of different minerals on the mechanical resistance of asphalt mixtures

The adsorption of five asphalts processed in Brazilian refineries and designated as A, B, C, D and E, and their asphaltenes and maltenes constituents, from toluene solutions, onto quartz, feldspar and biotite and the relationship between this tendency and the mechanical properties of the asphalt pavement have been investigated. For all minerals asphalts A and C strongly absorbed the others. Their respective curves levelling off between 3.5 and 4.0 mg g^− 1 for gneiss and quartz, increasing to 5 and 6 mg g^− 1 for feldspar and biotite. The eletrophoretic mobility of quartz was not modified by the adsorption of asphaltenes in contrast to that observed for feldspar and biotite, indicating that the sites liable for the surface charge of the latter minerals were affected by the presence of the adsorbed organic species. Regarding the mechanical resistance tests for asphalt mixtures, only asphalts A and C gave that would be considered values acceptable by the Brazilian National Department of Terrestrial Infra-structure (DNIT) (> 80%). Those results indicate that the chemical interaction among minerals and asphalts should affect for good or bad the mechanical resistance of the asphalt mixture.