Liquid Oil Products Research Articles

Co-current combustion of oil shale – Part 1: Characterization of the solid and gaseous products

Co-current combustion front propagation in a bed of crushed oil shale (OS) leads to the production of liquid oil, of a flue gas and of a solid residue. The objective of this paper was to provide a detailed chemical characterization of Timahdit oil shale and of its smoldering combustion products. The amount of fixed carbon (FC) formed during devolatilization is measured at 4.7% of the initial mass of oil shale whatever the heating rate in the range 50–900 K min −1. The combustion of oil shale was operated using a mix of 75/25 wt. of OS/sand with an air supply of 1460 l min −1 m −2. In these conditions, not all the FC is oxidized at the passage of the front, but 88% only, with a partitioning of 56.5% into CO and the rest into CO 2. A calorific gas with a lower calorific value of 54 kJ mol −1 is produced. Approximately 52% of the organic matter from OS is recovered as liquid oil. The front decarbonates 83% of carbonates.

Conversion of secondary pulp/paper sludge powder to liquid oil products for energy recovery by direct liquefaction in hot-compressed water

The present work demonstrated that secondary pulp/paper sludge powder, with a higher heating value of 18.3 MJ/kg on a dry basis, could be effectively converted into liquid oil products by direct liquefaction in hot-compressed water with and without catalyst. Treatments of secondary pulp/paper sludge in water at 250–380 °C for 15–120 min in the presence of N 2 atmosphere resulted in yields of water-soluble oils at 20–45 wt% and yields of heavy oils at 15–25 wt%, with higher heating values of 10–15 and >35 MJ/kg, respectively. The higher caloric values for the heavy oil products were accounted for by their compositions of long-chain carboxylic acids, heterocyclic nitrogen compounds and phenolic compounds and derivatives as evidenced by the gas chromatograph (GC)/MS measurements. The liquefaction product yields were significantly influenced by the liquefaction temperature, the residence time, the initial biomass concentration, catalysts and the liquefaction atmosphere (inert or reducing). Within the temperature range (250–380 °C) tested, the lowest temperature produced the highest yield of total oils (at 60 wt%), while the greatest yield of heavy oil (at about 24 wt%) was obtained at 350 °C. If the temperature was fixed at 280 °C, a greater yield of heavy oil (reaching as high as 25 wt% for 120 min) was obtained as the length of reaction time increased. Similarly, a higher initial biomass concentration produced a greater yield of heavy oil but a reduced yield of water-soluble oil. The presence of 0.1 M K 2CO 3 dramatically enhanced organic conversion, but suppressed the formation of both heavy oil and water-soluble oil. The use of the two alkaline earth metal catalysts, i.e., Ca(OH) 2 and Ba(OH) 2, did not alter organic conversion, but it catalyzed the formation of water-soluble oil and produced higher yields of total oil products. It was also demonstrated that the reducing atmosphere (i.e., H 2) in the liquefaction process promoted the heavy oil formation while suppressing the water-soluble oil formation. With the presence of 0.1 M Ca(OH) 2 and 2 MPa H 2, liquefaction of the sludge powder in water at 280 °C for 60 min produced a higher yield of heavy oil (26 wt%), almost two times as high as that in N 2 (13.6 wt%), resulting in a greater net energy efficiency. It was thus suggested that direct liquefaction of secondary pulp/paper sludge in hot-compressed water with Ca(OH) 2 catalyst and in the presence of H 2 could be an effective approach to recovering energy from the waste for production of liquid oil products.

X-ray fluorescence determination of sulfur and other elements in customs control of oil and liquid oil products

Results of an X-ray fluorescence determination of sulfur and other elements in oils and liquid oil products are presented, obtained using a Spectro-Xepos energy-dispersive spectrometer with the excitation of the fluorescence spectrum immediately in the liquid samples under investigation. It is shown that the amount of trace elements considerably varies not only in different types of oil products, but also in different samples of the same product. An experimental evaluation of the metrological characteristics of the determination of sulfur in oil products showed that they met the requirements of GOST (Russian State Standard) R 50442-92 Oil and Oil Products: X-ray Fluorescence Method for Determining Sulfur.

Pyrolysis of oil sludge with additives of catalytic solid wastes

Previous efforts have been made to convert the oil sludge into useful resources such as lower molecule organic compounds and carbonaceous residues by pyrolysis. The liquid products are close to diesel oil; however, they contain a significant amount of vacuum residues, which decrease the qualities of liquid products. For the reuse, conservation and recycling of solid wastes, the effects of using fly ash, oil sludge ash, waste DAY-zeolite and waste polymer of polyvinyl alcohol (PVA) as additives on the possible improvement of the pyrolysis of oil sludge were investigated. For the increase of conversion (X), two weight ratios of 10 and 5 wt.% additives provided the offers in the order of fly ash of 10 wt.% > PVA of 10 wt.% > oil sludge ash of 10 wt.% > DAY-zeolite of 10 wt.% > fly ash of 5 wt.% > DAY-zeolite of 5 wt.% > no additives. The addition of additives achieved the improvement of the quality (q) of pyrolysis oil (as sum of light and heavy naphtha and light gas oil) in the order of fly ash of 10 wt.% > oil sludge ash of 10 wt.% > PVA of 10 wt.% > DAY-zeolite of 10 wt.% > fly ash of 5 wt.% > DAY-zeolite of 5 wt.% > no additives. All this information is useful not only to the improvement of a pyrolysis system but also to the better utilization of liquid oil products.

Pyrolysis of oil sludge with additives of sodium and potassium compounds

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 N 2. In the present study, the oil sludge from the oil storage tank of a typical petroleum refinery plant located in the northern Taiwan was used as the raw material of pyrolysis. The influences of using sodium and potassium compounds as additives on the possible improvement of the pyrolysis of oil sludge are investigated. The additives employed include two groups: (1) sodium compounds (NaOH, NaCl and Na 2CO 3), and (2) potassium compounds (KCl, KOH and K 2CO 3). For the increases of conversion, the additives provide the offers in the order of K 2CO 3>KOH>NaOH>Na 2CO 3>KCl>NaCl>no additives. It appears that the above additives enhance the reaction rates when the temperatures are in 650–710 K, following the orders NaOH>Na 2CO 3>NaCl>no additives, and K 2CO 3>KOH>KCl>no additives. The additives achieve the improvement of the quality of pyrolysis oil (as sum of light and heavy naphtha and light gas oil) in the order of KOH>KCl>K 2CO 3>NaOH>Na 2CO 3>NaCl>no additives. Nevertheless, the additives improve the liquid yields in the order of KCl>Na 2CO 3>NaCl>no additives>NaOH>K 2CO 3>KOH. All this information is useful not only to the improvement of a pyrolysis system but also to the better utilization of liquid oil products.

Major Products Obtained from the Pyrolysis of Oil Sludge

Oil sludge, if unused, is one of the major industrial wastes that needs to be treated for the refinery or petrochemical industry. It contains a large portion of combustible components with high heating values. Obviously, the conversion of oil sludge to various useful materials such as lower molecular weight organic compounds and carbonaceous residue via pyrolysis not only solves the disposal problem but also matches the appeal of resource utilization. In this study, the oil sludge from the oil storage tank of a typical petroleum refinery plant located in northern Taiwan is used as the raw material of pyrolysis. Its heating value of dry basis and low heating value of wet basis are about 10681 and 5870 kcal/kg, respectively. The pyrolysis of oil sludge is conducted by using nitrogen as carrier gas in the temperature range 378−873 K. The pyrolytic reaction is complex and significant in the range 450−800 K. The residues of pyrolysis of oil sludge exhibit very high viscous form below 623 K (pyrolysis temperature), while low viscous or solid form above 713 K. The major gaseous products (noncondensable gases at 298 K) excluding N2 are CO2 (50.88 wt %), HCs (hydrocarbons, 25.23 wt %), H2O (17.78 wt %), and CO (6.11 wt %). The HCs mainly consist of low molecular weight paraffins and olefins (C1−C2, 51.61 wt % of HCs). The temperature corresponding to the maximum production rate of HCs is 713 K. The distillation characteristics of liquid product (condensate of gas at 298 K) from the pyrolysis of oil sludge is close to diesel oil. However, it contains a significant amount of vacuum residue of about 9.57 wt %. The heating value of liquid product is about 10840 kcal/kg. All this information is useful not only to the proper design of a pyrolysis system but also to the better utilization of liquid oil product and understanding of gaseous emission.

Thermochemical processing of rubber waste to liquid fuel

Liquid obtained from solid rubber waste via a thermochemical conversion process is expected to play an important role in the future of energy as high value energy carriers and value added chemicals. The energy density of liquid is higher than raw rubber waste because of both chemical and physical characteristics. The Association of South East Asian Nations (ASEAN) coun tries, especially Malaysia and Indonesia, generate a significant amount of solid waste in the form of natural rubber. Leading on from the elemental composition and thermal characteristics (obtained via thermogravimetric analysis) of solid rubber waste, the production of pyrolysis liquid oil by a fixed bed pyrolysis technique has been attempted. This is both energy recovery and protection of the environment. The liquid oil may be used directly as raw fuel in diesel engines. The liquid oil was characterised by Fourier transform infrared and gas chromatography–mass spectrometry techniques for its detailed chemical composition. The fuel properties of the derived oil were also analysed and compared with petroleum products.

Prioritizing Regulatory Policy in Pipeline Safety

This paper presents a regulatory priority model and its operationalization for pipeline safety. It begins with a brief discussion of pipeline systems and regulatory legislation associated with pipeline safety. The systems transport natural gas, liquid crude oil, gasoline and other liquid hazardous petroleum products. The regulations relate to technologies to be used, human factors, research requirements and environmental protection considerations. The legislative focus is on public safety, property damage and, most recently, environmental protection. Using a risk assessment approach to operationalize the model requires integration of concepts from engineering, economics and ecology. The specific measures applied include reliability, vulnerability and resiliency. Congressional, private industry and Department of Transportation (DOT) regulatory priorities are compared. The paper concludes with the risk assessment implementation strategy by the DOT Office of Pipeline Safety.

1-Alkenes as potential indicators of sediment shale oil contamination

Hydrocarbon fractions isolated from four shale oils, two petroleum oils, and one solvent-refined coal liquid product were analyzed by capillary gas chromatography/mass spectrometry for the presence of a homologous series of 1-alkenes. Of the liquid oil products examined, only the shale oils contained the 1-alkenes. 1-Alkenes were not detected in the hydrocarbon fractions of extracts from a raw oil shale or surface sediments collected in a drainage at locations above, adjacent to, and below the Department of Energy Anvil Points Oil Shale Facility, Rifle, CO. However, 1-alkenes were detected in restored shale, sediment aggregates formed after oil transport downstream of the facility, and oil discharging from a shale pile. The absence of 1-alkenes in petroleum and a coal liquid product suggests that this class of compounds may be unique to shale oils, perhaps allowing their use as diagnostic indicators of sediments in contact with shale oils or their refined products.