Showing papers in "Energy & Fuels in 2002"

Novel Polyethylenimine-Modified Mesoporous Molecular Sieve of MCM-41 Type as High-Capacity Adsorbent for CO2 Capture

Abstract: The objective of the work presented here is to develop a nanoporous solid adsorbent which can serve as a “molecular basket” for CO2 in the condensed form Polyethylenimine (PEI)-modified mesoporous molecular sieve of MCM-41 type (MCM-41-PEI) has been prepared and tested as a CO2 adsorbent The physical properties of the adsorbents were characterized by X-ray powder diffraction (XRD), N2 adsorption/desorption, and thermogravimetric analysis (TGA) The characterizations indicated that the structure of the MCM-41 was preserved after loading the PEI, and the PEI was uniformly dispersed into the channels of the molecular sieve The CO2 adsorption/desorption performance was tested in a flow system using a microbalance to track the weight change The mesoporous molecular sieve had a synergetic effect on the adsorption of CO2 by PEI A CO2 adsorption capacity as high as 215 mg-CO2/g-PEI was obtained with MCM-41-PEI-50 at 75 °C, which is 24 times higher than that of the MCM-41 and is even 2 times that of the pure

Biodiesel Fuels from Vegetable Oils: Transesterification of Cynara cardunculus L. Oils with Ethanol

Abstract: A study was made of the transesterification reaction of Cynara cardunculus L. oil by means of ethanol, using sodium hydroxide and potassium hydroxide as catalysts. The objective of the work was to ...

Pyrolysis of Lignins: Experimental and Kinetics Studies

Abstract: Lignins are generally used as a low grade fuel in the pulp and paper industry. In this work, pyrolysis of Alcell and Kraft lignins obtained from the Alcell process and Westvaco, respectively, was carried out in a fixed-bed reactor and in a thermogravimetric analyzer (TGA) using helium (13.4 mL/min/g of lignin) and nitrogen (50 mL/min/g of lignin), respectively. The reaction temperature was increased from 300 to 1073 K, while the heating rates were varied from 5 to 15 K/min. The gaseous products mainly consisted of H2, CO, CO2, CH4, and C2+. With increase in heating rate from 5 to 15 K/min both lignin conversion and hydrogen production increased from 56 to 65 wt % and from 25 to 31 mol %, respectively for fixed-bed pyrolysis reaction of Alcell lignin at 1073 K, whereas at the same condition the conversion and hydrogen production increased from 52 to 57 wt % and from 30 to 43 mol % for Kraft lignin. The distributed activation energy model (DAEM) was used to analyze complex reactions involved in the lignin p...

Review of PM2.5 and PM10 Apportionment for Fossil Fuel Combustion and Other Sources by the Chemical Mass Balance Receptor Model

Abstract: This review examines how the Chemical Mass Balance (CMB) receptor model has been used to quantify source contributions from fossil fuel combustion and other sources to ambient concentrations of PM2.5 and PM10 for urban and regional scales. Nonfossil fuel sources, such as fugitive dust, cooking, vegetative burning, and natural or human-caused biogenics must be considered together with fossil-fuel sources in a CMB analysis to obtain closure for PM2.5 and PM10 mass. CMB analyses in 22 different studies have found fossil fuel combustion to be a large contributor to PM2.5 and PM10 concentrations, with most of the primary contributions originating form diesel- and gasoline-powered vehicle exhaust. Primary contributions from ducted sources, such as coal- and oil-fired power stations, are negligible when these facilities have been modernized with effective pollution controls, but they have been shown to be large contributors without these controls. Secondary sulfates and nitrates from fossil fuel combustion are r...

Petroleum AsphalteneProperties, Characterization, and Issues

Abstract: Importance of asphaltene characteristics, the characterization techniques, and the practical issues regarding industrial operations are briefly reviewed. The properties are viewed from macroscopic and microscopic length scales. Techniques used for characterizing such properties and their relevance to upstream and downstream operations are introduced. Finally, a conceptual approach for predicting asphaltene miscibility with lighter components is proposed.

Rapid and accurate SARA analysis of medium gravity crude oils

Abstract: Crude oils can be described compositionally by a number of methods. SARA analysis is widely used to divide crude oil components according to their polarizability and polarity using a family of related analytical techniques. Problems arise because the analytical techniques do not necessarily produce identical results. Users of the data, however, rarely distinguish between the different techniques, assuming that SARA fraction values generated by any of the commonly used methods are essentially interchangeable. We examine this assumption for medium gravity crude oils and three SARA analysis methods: gravity-driven chromatographic separation, thin-layer chromatography (TLC), and high-pressure liquid chromatography (HPLC). Results for a suite of six crude oil samples show that a significant volume of volatile material that contains both saturates and aromatics is lost in the TLC analysis. An improved HPLC method is introduced that gives analyses comparable to the ASTM-recommended chromatographic method in les...

About the Colloidal Nature of Asphaltenes and the MW of Covalent Monomeric Units

Abstract: Problems surrounding molecular aggregation, covalent molecular weight, and their experimental investigation in asphaltene chemistry are reviewed. Chromatographic, fluorescence spectroscopic, and mass spectroscopic (MS) methods for the investigation of these problems are surveyed and their merits and limitations discussed. Dissociation of asphaltene in dilute solution can be followed in time by monitoring the gel permeation retention time variation with the age of the solution. This way, Athabasca asphaltene was reported to dissociate from several thousand to less than about 1000 g mol-1 molecular weight (MW) species in CH2Cl2 solution to an extent of at least 80% in 14 days' time. The dissociation products represent the monomeric covalent molecules of asphaltene, and the remaining undissociated 20% could be slowly dissociating aggregates or high-MW covalent asphaltenes. The vapor pressure osmometry (VPO) determined number average MW of the same asphaltene was of the order of 4000 g mol-1, manifesting the ...

Sensitivity of Asphaltene Properties to Separation Techniques

Abstract: Asphaltene properties vary with separation method and sometimes with individual technique. Factors such as contact time, solvent-to-crude oil ratio, and temperature influence asphaltene precipitation and are somewhat standardized. However, the final step in most separations, washing the asphaltene filter cake with solvent, is not standardized. Asphaltene properties can be very sensitive to small amounts of resins and therefore may be sensitive to the amount of washing. Asphaltenes were extracted with three different levels of washing from four source oils (Athabasca, Cold Lake, Lloydminster, and Peace River). In all cases, increased washing decreased asphaltene yield and slightly increased asphaltene density. Increased washing significantly increased molar mass and decreased the solubility of the extracted asphaltenes. A new washing method using a Soxhlet apparatus removed the largest amount of resinous material and yielded asphaltenes with significantly different properties from conventionally washed asp...

An Evaluation of Spontaneous Imbibition of Water into Oil-Wet Carbonate Reservoir Cores Using a Nonionic and a Cationic Surfactant

Abstract: Some surface-active chemicals are able to improve the spontaneous imbibition of water into oil-wet carbonates. In this work, the oil recovery from oil-wet reservoir cores was compared using aqueous solutions of an ethoxylated alcohol (EA) and a cationic surfactant (C12TAB). The experiments were conducted at room temperature using short (∼5 cm) and long (∼30 cm) cores with initial water saturation in the range of 17−33%. Due to wide variation in porous structure, the cores were characterized into two groups, i.e., moldic and sucrosic. The former cores had more than 25% of the pore volume (PV) related to vugs, and the latter appeared more homogeneous. The permeability of the moldic and sucrosic cores varied between 20 and 180 and 80−350 mD, respectively. In general, the efficiency of C12TAB was superior to EA regarding spontaneous oil expulsion from the cores. For the short core experiments, about 40−45% of original oil in place (OOIP) was recovered using C12TAB, while only 10% was the average recovery usin...

XPS and 15N NMR study of nitrogen forms in carbonaceous solids

Abstract: A combination of XPS and solid-state 15N NMR have been used to characterize the nitrogen forms in a variety of different carbonaceous samples having high natural nitrogen abundance. It is currently difficult to unequivocally interpret and quantify individual 15N NMR and XPS spectra. The advantages of using a multiple technique approach for nitrogen speciation as well as the limitation of XPS nitrogen (1s) and 15N NMR spectroscopy are discussed. XPS and 15N NMR results show that pyridinic and pyrrolic nitrogen are present in quinoline and isoquinoline pyrolysis chars. Pyridinic nitrogen is the most abundant form in quinoline pitch while isoquinoline pitch produced the most pyrrolic nitrogen. A small amount of quaternary nitrogen (∼10 mol %) appeared in the XPS spectrum of the chars, however, no additional nitrogen forms were identified above the noise level in the 15N NMR spectra. The 15N NMR spectrum of Green River kerogen shows a single broad feature centered around −245 ppm in the 15N NMR, consistent wi...

Extraction and characterization of asphaltenes from different crude oils and solvents

Abstract: Three crude oils were employed for precipitation of asphaltenes using two solvents, n-pentane and n-heptane. Crude oils were analyzed by API gravity, elemental composition and metals content. Asphaltenes were characterized by VPO molecular weight, liquid State 1H and 13C NMR, elemental composition, and metals content. Spectra were divided in three and two different regions for 1H and 13C NMR, respectively, to determine the most important structural parameters of asphaltenes. To avoid errors when determining asphaltene content and characterization, a solvent-to-oil (S/O) ratio of 60:1 was used. This optimal ratio was defined after conducting various experiments with different values of S/O in the range of 5:1 to 100:1. It was found that solvent type has a very important influence in composition of asphaltenes, which were also very different for the three crude oils studied. Aromaticity of asphaltenes was higher when n-heptane was employed.

Pilot-Scale Investigation of the Influence of Coal−Biomass Cofiring on Ash Deposition

Abstract: Cofiring biomass with coal is a promising short-term option for reducing the net CO2 emissions from existing coal-fired power plants. This paper examines the effects of cofiring biomass and coal on ash deposition under conditions representative of those found in the superheater region of pulverized-coal boilers. Experiments were conducted with blends of eight different fuelsthree types of bituminous coal, sub-bituminous coal, two types of straw, switchgrass, and wood. For each fuel, reference tests of unblended fuel establish a baseline against which to compare the results from the cofiring tests. The deposition rates for the cofire blends are between the measured deposition rates of the unblended fuels. Therefore, blending straw with coal reduces the high deposition rates observed while firing unblended straw, and cofiring coal with wood results in slightly lower deposition rates than those that occur while firing unblended coal. The primary interaction between the biomass and coal during cofiring is the...

Time-Dependent Microstructure of Bitumen and Its Fractions by Modulated Differential Scanning Calorimetry

Abstract: Bitumen fractions were analyzed by modulated differential scanning calorimetry (MDSC) before and after annealing at room temperature. MDSC allowed for separating glass transitions (Tg's) from order−disorder transitions. All fractions showed at least two Tg's and different states of order. Saturates were semicrystalline, aromatics were amorphous, resins, and asphaltenes were mesophasic. In bitumen, the fractions order in four stages upon cooling from the melt. In the first stage, all fractions order rapidly into a weakly organized phase. In the second stage, low molecular weight saturated segments crystallize. In the third stage, high molecular weight saturated segments crystallize. In the fourth stage, resins and asphaltenes order into a mesophase. The third and fourth stages are responsible for the room-temperature (steric) hardening of bitumen.

Characterization of Organically Bound Oxygen Forms in Lignites, Peats, and Pyrolyzed Peats by X-ray Photoelectron Spectroscopy (XPS) and Solid-State 13C NMR Methods

Abstract: A combination of XPS and solid-state 13C NMR techniques have been used to characterize organic oxygen species and carbon chemical/structural features in peats, pyrolyzed peats, lignites, and other coals. Both the 13C NMR and XPS results show the same ordering for the amount of aromatic carbon, higher ranking coals > lignites > peats. In general the value for H/C decreases as the percent of aromatic carbon increases. For pyrolyzed peats, the H/C level is higher than lignites and other coals of comparable levels of aromatic carbon. This is likely due to significant differences in the carbon structural framework of these materials. A van Krevelen plot, based on elemental H/C data and XPS derived O/C data, shows the well-established pattern for peats, lignites, and other coals. In general, O/C decreases as the percent of aromatic carbon increases, with the expected magnitude ordering, peats > lignites > higher ranking coals. Most of the H/C values of pyrolyzed peats are higher than coals at comparable O/C. A ...

Powdered Activated Carbons and Activated Carbon Fibers for Methane Storage: A Comparative Study

Abstract: During this study different raw materials, activating agents, and preparation variables were used to compare the behavior of carbon materials with different morphologies in methane storage applications. Two different types of carbon materials have been prepared: (i) chemically activated carbons prepared from an anthracite and a bituminous coal using KOH as activating agent, and (ii) physically activated carbon fibers prepared from petroleum pitch and coal tar pitch-based carbon fibers, by activation with CO2 and steam. Both type of materials have been prepared in order to cover a wide range of surface area. The effects of different properties of the adsorbents (porous texture, packing density, and pore size distribution) in their performance in methane storage applications (methane uptake and delivery) were analyzed. The comparison of both types of materials (powder and carbon fibers) has shown that activated carbon fibers have the advantage of a higher packing density than powdered activated carbons. On...

Probing Order in Asphaltenes and Aromatic Ring Systems by HRTEM

Abstract: Recent findings regarding the controversy surrounding asphaltene molecular weight coupled with increasing understanding of their molecular structure has enabled the understanding of asphaltene properties. It has been shown previously that larger ring systems require more alkane substituents to maintain a balance between ring stacking propensity vs steric repulsion. Here, stacking and its disruption in asphaltenes and aromatic ring systems are explored using high-resolution transmission electron microscopy (HRTEM). It is shown that molecularly disparate asphaltenes exhibit stacking invariants. Solubility data herein suggests these stacking invariants naturally follow from the solubility classification of asphaltenes.

Role of Chain Reactions and Olefin Formation in Cracking, Hydroconversion, and Coking of Petroleum and Bitumen Fractions

Abstract: Although the mechanism of cracking of distillate fractions is well-known, the reactions that underlay conversion of the residue fractions of petroleum and bitumen are not well defined. Despite the difficulties in analyzing residue fractions in detail, the chemistry of these materials must follow the same elementary reactions as distillates. This paper presents a consistent mechanism for cracking of residues based on the known chemistry of free-radical chain reactions and model compounds. The roles of hydrogen, donor solvents, and added catalysts are then interpreted in this context. The formation of olefin groups from cracking of aliphatic groups gives the potential for addition reactions in the liquid phase. Removal of olefin groups, by reactions with donor solvents or hydrogenation, controls addition reactions and thereby suppresses coke formation. This mechanism suggests that innovative methods to remove or react olefinic groups may allow higher conversion of residues to desirable liquid products.

Wax Formation in the Pyrolysis of Polyolefins in a Conical Spouted Bed Reactor

Abstract: The pyrolysis of polyolefins (low-density and high-density polyethylene and polypropylene) in a new kind of reactor, a conical spouted bed, has been studied in the 450−600 °C range and the kinetics of the formation of wax and individual gaseous products and significant groups of components have been determined. The activation energy of wax formation is similar for both polyethylenes (214 kJ mol-1 for that of low density and 225 kJ mol-1 for that of high density) and lower for polypropylene (176 kJ mol-1). The characteristic gas−solid contact of this reactor is especially suitable for selectively obtaining wax (92 wt % from polypropylene and 80 wt % from both polyethylenes) due to the high gas linear-velocity. Wax composition determined by Fourier transform infrared spectrophotometry indicates that it is a less branched and that its olefinic content is higher than that of commercial waxes.

Effect of Oxygenated Fuel on Combustion and Emissions in a Light-Duty Turbo Diesel Engine

Abstract: In previous studies on a single-cylinder IDI diesel engine and a V-8 DI turbo diesel engine, significant reductions in particulate matter emissions were observed with the blends of glycol ethers in diesel fuel. In this study, experiments on the effects of oxygenated fuels on emissions and combustion were performed in a 4-cylinder TDI diesel engine. A blend of 20 wt % monoglyme and 80 wt % diglyme, referred to as CETANER, has been examined as a diesel reformulating agent. Blend ratios were considered to provide approximately 2, 4, and 6 wt % oxygen to low-sulfur diesel fuel. Gaseous and particulate emission measurements, as well as heat release rate analysis, have been used to address how emissions and combustion scale with increasing weight percent oxygen in the fuel. The results demonstrate that the oxygenated fuel provides significant reduction in particulate matter with a small penalty on NOx emission, especially at high load. This oxygenated fuel effect may result from an enhanced concentration of oxy...

Structure-I and Structure-H Hydrate Formation Using Water Spraying

Abstract: An attempt has been made to form continuously either a structure-I or a structure-H hydrate using methane as the common guest substance and methylcyclohexane as the second guest for the structure-H hydrate. The experimental technique we tested was to spray water into a high-pressure chamber charged with methane gas. In the experiments to form the structure-I hydrate, water droplets sprayed from a single nozzle at the top of the chamber coalesced into a water pool underlying the methane gas phase. In the experiments to form the structure-H hydrate, the water droplets fell onto a methylcyclohexane layer superposed on a pool of water then merged with the pool. Water was continuously drained from the bottom of the chamber and circulated back through the spray nozzle. During this circulation, the water passed through a heat exchanger outside the chamber to release the heat generated by hydrate formation. The pressure in the chamber was maintained at a prescribed level (typically 2.5−3.7 MPa) by supplying metha...

Asphaltene Aggregation from Crude Oils and Model Systems Studied by High-Pressure NIR Spectroscopy

Abstract: The aggregation of asphaltenes by pressure depletion both in a live crude oil and model systems of asphaltenes in toluene/pentane solvents is studied. Near-infrared spectroscopy utilizing a high-pressure NIR cell with a maximum operating pressure of 325 bar is used to study the onset of asphaltene aggregation. The NIR spectra are subject to a principal component analysis (PCA) in order to detect the asphaltene aggregation onset pressure. The effect of fluid compressibility on the NIR spectra is also demonstrated. The aggregation behavior of asphaltenes in model systems is shown to resemble the aggregation behavior for the crude oil. However, while the asphaltene aggregation in the crude oil is more or less completely reversible with repressurization, indications of only a partial redissolution are seen in the model systems. The kinetics of the redissolution is quite slow. A time of 72 h to equilibrate at the original pressure of 300 bar was required to redissolve the asphaltene aggregates formed within th...

Solubility/Molecular Structure Relationships of Asphaltenes in Polar and Nonpolar Media

Abstract: Asphaltenes separated from a Maya type of crude oil were suspended in toluene and later fractionated by solubility in a polar (acetone) and a nonpolar (n-heptane) precipitating solvent. The two sets of derived fractions were characterized using size exclusion chromatography (SEC), elemental analysis, Fourier transform infrared spectroscopy (FTIR), and synchronous fluorescence spectroscopy and proton nuclear magnetic resonance (1H NMR) spectroscopy. The results show that the acetone-precipitated asphaltene fractions have larger structural differences compared with those of n-heptane. The average size of the aromatic and aliphatic-substitutions regions of each fraction was also found to correlate with asphaltene solubility in such a way that the smaller the aromatic region and the larger the aliphatic substitutions, the greater the solubility. These correlations may provide further explanations as to the role of structural properties on the solubility of asphaltenes in polar and nonpolar media.

Study of the Low Temperature Pyrolysis of PVC

Abstract: The characteristics of PVC pyrolysis dechlorination has been studied in a fixed bed reactor under different operating conditions such as temperature, time, heating rate. It is found that about 90% chlorine in PVC can be effectively removed within 3 h with heating rate of 5 μ/min at temperature 300 °C, with 10% chlorine remaining in volatile gas and residue. The yield of combustible gas increases and the yield of tar as well as residue decreases with the increasing of the pyrolysis temperature. Thermogravimetric technique was used to investigate the weight-loss curves of PVC pyrolysis process; elemental analysis and FTIR were conducted to analyze the functional-group composition of products. The results showed that the PVC pyrolysis is a two-step process. The first step is mainly a dechlorination process which, accompanied by depolymerization and this reaction, can be seen as a first-order reaction: apparent energy activation is about 130 kJ/mol. The second step is a further cracking process of the residu...

Hydrogen production by steam gasification of biomass using Ni-Al coprecipitated catalysts promoted with magnesium

Abstract: Ni−Al coprecipitated catalysts promoted with magnesium have been prepared using the rising and the constant pH techniques, two precipitant agents [(1) KOH and K2CO3, and (2) NH4OH)] and different metal contents. Catalyst characterization by temperature-programmed reduction and CO2 reforming of methane as a test reaction served to select the appropriate catalysts for use in the steam gasification of biomass. The catalysts selected were NiMgAl2O5, prepared at constant pH and precipitated with KOH and K2CO3; NiMgAl4O8 and NiMgAl1.24O3.86, both prepared at increasing pH with NH4OH. Biomass steam gasification experiments were carried out at 700 °C and at atmospheric pressure using different steam/biomass (S/B) and catalyst weight/biomass flow rate (W/B) ratios. From an analysis of the results obtained, the initial activity and stability of the catalysts have been studied. The NiMgAl2O5 catalyst presents the best performance showing the highest initial activity and stability. This work evidences an improvement ...

Tandem Mass Spectrometric Characterization of Commercial Naphthenic Acids and a Maya Crude Oil

Abstract: Elemental analysis, Fourier transform infrared, C13 nuclear magnetic resonance, and electrospray ionization/mass spectrometry (ESI/MS) experiments were performed on two commercial naphthenic acid m...

Production of Diethyl Carbonate from Ethanol and Carbon Monoxide over a Heterogeneous Catalyst

Abstract: Diethyl carbonate (DEC) has been produced by the oxidative carbonylation of ethanol in the gas phase over a heterogeneous CuCl2/PdCl2 catalyst supported on activated carbon. Yields of DEC with this catalyst are approximately 10 wt % with the byproducts diethoxymethane, ethyl formate, and acetaldehyde also formed in significantly lower yields. Treatment of the catalyst immediately after preparation with potassium hydroxide enhances the production of DEC almost 2-fold without increasing the amount of byproducts formed. The reactions that form DEC and the byproducts occur in a parallel, rather than a sequential, manner indicating that it should be possible to identify a catalyst which is more selective for DEC.

Effect of Large Aspect Ratio of Biomass Particles on Carbon Burnout in a Utility Boiler

Abstract: This paper reports on the development and validation of comprehensive combustion sub models that include the effect of large aspect ratio of biomass (switchgrass) particles on carbon burnout and temperature distribution inside the particles. Temperature and carbon burnout data are compared from two different models that are formulated by assuming (i) the particles are cylindrical and conduct heat internally, and (ii) the particles are spherical without internal heat conduction, i.e., no temperature gradient exists inside the particle. It was inferred that the latter model significantly underpredicted the temperature of the particle and, consequently, the burnout. Additionally, some results from cofiring biomass (10% heat input) with pulverized coal (90% heat input) are compared with the pulverized coal (100% heat input) simulations and coal experiments in a tangentially fired 150 MWe utility boiler.

Alkali emission from birchwood particles during rapid pyrolysis

Abstract: The emission of potassium- and sodium-containing compounds during rapid birchwood pyrolysis was studied. Birchwood particles (2−130 mg) were inserted into a preheated furnace at constant temperature (350−850 °C) and the alkali emission was measured. Particle mass, furnace temperature, and moisture were varied. At temperatures ≤ 500 °C, the alkali emission from birchwood particles took place solely during the pyrolysis phase. At temperatures ≥ 600 °C, alkali evaporation from the ash increased. The total alkali release increased with temperature in the range studied and the release during the pyrolysis was larger or equal to the release from the ash phase. Small particles (2−10 mg) emitted more alkali per unit mass than large ones (60−130 mg) and this tendency increased with temperature. At 800 °C the emission per unit mass from small particles was 10 times the one for large particles. Wet particles went through a drying phase, which delays the heating, and thereby the alkali emission. The present findings ...

Fly ash penetration through electrostatic precipitator and flue gas condenser in a 6 MW biomass fired boiler

Abstract: The effects of an electrostatic precipitator and a flue gas condenser on size resolved fly ash particle concentration and composition were studied in a 6 MW biomass combustion unit, fired with moist forest residue. The boiler was of moving grate type. The fly ash particles were sampled upstream and downstream of the electrostatic precipitator and flue gas condenser, respectively. Fine particle number size distributions were measured using an electric mobility spectrometer (SMPS) and coarse particle number size distributions were measured using a time-of-flight instrument (APS). The mass size distributions were measured using a multi-jet low pressure cascade impactor (DLPI). For chemical analyses of the impactor substrates particle induced X-ray emission analysis (PIXE) was used. After the flue gas passed the electrostatic precipitator (ESP), the fly ash particle concentration was reduced by approximately 96% by number and 83% by mass. After the particles passed the flue gas condenser, particle number concentration was only marginally altered, whereas the mass concentration was reduced by half. Both the ESP and the condenser showed, size dependent particle separation efficiency. The main elements (Z > 12) in the fine fly ash fraction were K, S, and Cl, whereas the main elements in the coarse fraction were Ca, K, S, and Cl. After passing the ESP the mass ratio of Ca decreased in the coarse fraction, while the ratios of K, S, and Cl increased, indicating transference of fly ash material from the fine to the coarse particle fraction. There was no significant difference in the elemental composition for any particle size fraction sampled upstream or downstream of the condenser.

Use of Inexpensive Additives in Pyrolysis of Oil Sludge

Abstract: Previous efforts were made to convert the oil sludge into useful resources such as lower molecule organic compounds and carbonaceous residues by pyrolysis with the carrier gas of N2 The liquid products (condensates of gases at 298 K) obtained from the pyrolysis of oil sludge are close to diesel oil However, they contain a significant amount of vacuum residues of about 957 wt %, which decrease the qualities of liquid products In the present study, the oil sludge from the oil storage tank of a typical petroleum refinery plant located in the northern Taiwan is used as the raw material for the pyrolysis The influences of using inexpensive and nonharmful additives on the possible improvement of the pyrolysis of oil sludge are investigated The additives employed include two groups: (1) aluminum compounds (Al, Al2O3, and AlCl3), and (2) iron compounds (Fe, Fe2O3, FeSO4·7H2O, FeCl3, and Fe2(SO4)3·nH2O) For the increases of conversion X, the additives provide the offers on the order of Fe2(SO4)3·nH2O > Fe2