Kazem M. Sadeghi

Sonication method and reagent for treatment of carbonaceous materials

Hydrocarbon liquids are recovered from carbonaceous materials such as tar sands utilizing a separation reagent formed in situ by reacting polar resin components of tar sands with an inorganic base such as sodium silicate in sonicated aqueous solution in absence of an organic solvent to form a surfactant. When tar sands are added to the sonicated separation reagent, the surfactant penetrates the bitumen which aids in removing the bitumen from the sand particles. The lighter, non-polar hydrocarbon oil fraction separate from the emulsion and rise to the top and are recovered by skimming. The heavier asphaltenes and preasphaltenes complex with the polyvalent metals to form charcoal-like agglomerates which settle to the bottom of the treatment tank. The separation reagent forms during the reaction and can reach a concentration capable of dissolving bitumen. The separation reagent can be recovered and used in other processes after removal and recovery of the clay. The separation reagent must be substantially diluted after being recycled and reused to reduce solvation properties.

Fractionation of various heavy oils and bitumen for characterization based on polarity

Abstract Shale oil, coal liquid, heavy petroleum oil, and oil sand bitumen were separated into four fractions through a silica gel column, with good recovery and repeatability. Structural characterization was performed using elemental analysis i.r., and 1 H n.m.r. by the modified Brown-Ladner equations as well as the five-regions method. The structural parameters revealed that coal liquid contained the most polar material while crude oil contained the least. Shale oil had the highest nitrogen content, while oil sand bitumen had the highest sulphur content, and coal liquid had the highest oxygen content. The molecular weight of crude oil was the highest and that of coal liquid was the lowest. The degree of condensation of the aromatic system was as follows: oil sand bitumen > crude oil > coal liquid > shale oil. Coal liquid contained mainly internal olefins while shale oil contained mainly α-olefins. The distribution pattern of the four fractions was different for each fossil fuel studied. This suggests a separation scheme that is a simple, efficient, and rapid technique to fractionate heavy oil and bitumen samples.

Asphalt colloidal types differentiated by Korcak distribution

Abstract Asphalt in a colloidal context can be considered as a sol, sol-gel or gel type where in all three cases the asphaltene particle plays an important role. Usually the three colloidal types can be differentiated by refinery processes or by rheological properties. The aggregation or clustering of the asphaltene particles (or micelles) from sol to sol-gel and finally to the gel state with a fixed lattice can follow the stochastic process of fractal Brownian motion which can fit a hyperbolic (or Korcak) distribution. A test was carried out using the same mass of various asphalts of different colloidal types for floc formation with a series of n-alkanes (dispersion media) of increasing characteristic lengths. Results from floc formation studies indicate that the value of the size distribution for the gel type is small, is higher for the sol-gel type, and is highest for the sol type. On the other hand, the surface irregularities for all three types of asphalt do not have any correlation. These observed facts are consistent with principles based on the fractal approach.

Sonochemical treatment of fossil fuels

Abstract A new method has been developed to recover upgraded lighter-hydrocarbon liquid oil from an asphaltene-containing oil material (tar sand, asphalt, heavy oil, shale oil, coal liquids, etc.). The process describes dispersing particles of the carbonaceous material in an aqueous solution containing an inorganic base (NaOH, Na2SiO3, etc.) and / or surfactant at ambient temperatures and pressures. With the aid of sonication energy, the inorganic base and / or surfactant will combine with the polar components of the fuel to speed the recovery of upgraded oil material. The reaction process essentially removes and / or converts the asphaltene fraction in the bituminous material to lighter fractions. The process is highly efficient, and the reaction time in minutes for the samples is examined. The reaction mechanisms are related to principles of sonochemistry as well as membrane mimetic chemistry.

A New Tar Sand Recovery Process: Recovery Methods and Characterization of Products

Abstract A novel approach to bitumen recovery from tar sands using sodium silicate solution and low-power ultrasound was successfully demonstrated (U.S. Patent 4,765,885; 4,891,131) in this laboratory. Elemental analysis indicated that the quality of the bitumen recovered was upgraded by this treatment (the hexane soluble fraction of the recovered bitumen was higher than the raw bitumen). The active compounds responsible for the enhanced oil recovery rate were identified as long-chain fatty acids by GC and FT-IR analyses. Further improvement of this novel approach is possible by introducing reagents that accelerate the degradation reaction of bitumen in the microenvironment of membrane mimetic agents (i.e., the surfactants formed by long-chain fatty acids and sodium silicates).

A new process for tar sand recovery

An extraction process for bitumen recovery from tar sand has been developed using an alkaline solution (e.g., NaOH, Na2SiO3) and sonication at a low temperature and ambient atmosphere. The bitumen recovered thus far is extraordinarily low in ash content and virtually free of metal and asphaltene, with an average gravity of 15° API for 95% cumulative recovery (based on carbon content) in a continuous operation. The heavier components, asphaltene and preasphaltene, were separated as solids, which contained many highly-enriched strategic metals. Clean sand and intact clay can be recovered simultaneously, easily, and essentially in full. It is demonstrated here that (1) the addition of radicals (H2O2, benzoyl peroxide, AIBN) reduces the reaction time from hours to minutes, and (2) hydroquinone (radical inhibitor) slows the reaction rate tremendously. This process utilizes the principle of membrane-mimetic chemistry. By applying sonication simultaneously, the multi-lamellar vesicles dissociate into individual ...

Determination of optimum rate constants for autocatalytic reaction of tar sand recovery process

ABSTRACT In this paper a parameter optimization technique is introduced involving a minimization algorithm. The technique is applicable to a wide range of problems involving data analysis. In particular, it is applied to the first-order initial-value problem describing the autocatalytic reaction of tar sand recovery process, as a result of which, the optimal reaction rate constants for a given set of experimental data are obtained. The analytical solution to the governing differential equation corresponding to these optimal parameter values is then shown to fit the experimental data. Numerical results are presented in graphical form for three different sets of data, and discussion and conclusions are provided subsequently.

Fourier transform infrared analysis of partially oxidized kerogen concentrates

In an attempt to obtain a greater insight into the structure of Monterey kerogen, partially oxidized kerogen concentrates obtained from Na2Cr2O7glacial CH3COOH stepwise oxidation were examined by Fourier transform infrared (FT-i.r.) analysis. The results show that the kerogen samples contain condensed aromatic systems to which are attached OH and Oalkyl functional groups, and also indicate that the majority of N and S atoms are within the ring structure. It was found that the carbonyl, aromatic and ether groups are not affected while CH2 groups are lost upon oxidation. Furthermore, it was concluded that in kerogen oxidation, organic sulphur can be fixed as inorganic sulphate in the presence of COO− in a manner similar to coal oxidation.

Effects of oxygen on mesophase microstructure and pyrolysis yield in coal liquid asphaltene

Abstract Asphaltene derived from the Catalytic Incorporated coal liquefaction process was oxidized by two methods; 1. (a) heat treatment in air at high temperature for several hours and 2. (b) oxidation over chromyl chloride using the Law and Perkin method. The oxygen contents of the oxidized asphaltenes were analyzed both quantitatively by direct Unterzaucher method and semi-quantitatively by FT-IR spectroscopy. Subsequently the asphaltenes were pyrolyzed under nitrogen. The pyrolysis products were examined both for their microstructures and percent yields. It was found that the addition of oxygen could increase the pyrolysis yield without suppressing mesophase growth as long as the total weight percent of oxygen remained below six percent. Since the coal asphaltenes derived from other known processes are shown to have similar characteristics, the results of this study implies that the optimum products from those asphaltene samples could be obtained as long as the oxygen content for the mesophase formation is kept below the maximum amount of six percent by weight.

A new bitumen recovery technology and its potential application to remediation of oil spills

Abstract A new process of bitumen recovery from tar sand has been developed which utilizes the saponification reaction between the long-chain acids in the raw bitumen and the fresh alkaline solution with the aid of ultrasound. The bitumen recovered was found to be upgraded as evidenced by its extremely low contents of asphaltene and pre-asphaltene. The time required for separation can be greatly reduced if the spent alkaline solution (which contained a substantial amount of surfactants and still had high alkalinity) from the first phase of this work was re-used in subsequent experiments. Furthermore, a high efficiency of bitumen recovery can be achieved within minutes if a trace amount of a free radical reagent (such as H2O2) was added to the spent alkaline solution. The feasibility of applying this innovative technology to the separation of hydrocarbons from beach sands and soils contaminated by oil spills was also demonstrated in this work. The mechanism for such efficient recovery (or separation) and upgrading of hydrocarbons is discussed from the viewpoints of membrane mimetic chemistry and sonochemistry.