Used Lubricating Oil Research Articles

Assessment of overall remaining useful life of lubricants by integrating oil quality and performance

Effective lubricant health monitoring programs are essential for extending the lifespan of both the lubricant and machinery. An accurate and reliable remaining useful life (RUL) prediction is necessary for maintenance decision support. The degradation of used lubricating oil information trends evaluated using used oil analysis results is necessary. This study addresses the need for a comprehensive tool to consolidate oil analysis parameters and determine the remaining useful life (RUL) of used lubricating oil (ULO). A Performance Rating Index (PRI) was developed by integrating various oil degradation testing parameters, including membrane patch colorimetry for varnish and sludge potential, along with viscosity, foaming stability, water separability, air release properties, oxidation stability, rust prevention, and copper strip corrosion. The integration of routine and performance test results of a turbine oil at 25,480 operating hours exhibited a PRI of 48.5. Correlating with the ASTM degradation alarm limits of 50 %, the PRI results provide clear maintenance actions before the original equipment manufacturer's recommended overhaul. The PRI approach supports proactive maintenance by facilitating early oil replenishment, extending RUL, and reducing waste oil.

Purification of Used Lubricating Oils Using Vacuum Distillation

Engine oil (EO) is produced by mixing base oil derivatives from crude oil with chemical additives to the lubricity of moving parts and reduce the friction inside the engine. Used lubricating oil (ULO) is one of the hazardous materials that consists of pollution harmful to the environment, it needs to be managed properly. In this work, vacuum distillation technique is used to recycle used lubricating oil. Used lubricating oil samples from two different brands of diesel engine oil (20w-50) and gasoline engine oil (10W-30) are used in this study. Various properties of ULO and recycled oil were characterized such as kinematic viscosity, viscosity index, density, pour point, flash point, Sulphur content, and Fourier transform Infrared spectroscopy FTIR. The yield recycles for ULO of gasoline engines, diesel engines, and mix (gasoline and diesel) by vacuum process were 85%, 74%, and 75% respectively, it was discovered that the sulfur component decreased from 9792.3 ppm of ULO to 405 ppm of yield distillates. The pour point results show an increase from -30 °C of used lubricating oil to -18 and -6 for distillates cut for vacuum distillation, compared to the pour point of Iraqi base oil 40 and 60 Stook (SN150 and SN200) -18 °C and -6 °C

EXPERIMENTAL AND REGRESSION ANALYSIS OF COMPRESSION IGNITION ENGINE POWERED BY DIESEL SURROGATE FUEL FROM USED LUBRICATING OIL USING MICROWAVE PYROLYSIS

Fossil fuels are depleting rapidly, and the search for alternative fuels has become inevitable. The researchers investigated the usage of surrogate fuels for internal combustion engines due to the high demand for diesel fuel in all sectors. Diesel surrogate fuels (DSFs) from used lubricating oil seem to be a solution for the future. The disposal of used lube oils poses a major environmental issue that affects the entire planet. This study aims to anticipate the exhaust emissions, brake-specific fuel consumption (BSFC), and brake thermal efficiency (BTE) of a compression ignition engine powered by blends. The blends used are B10 (DSF10% + diesel 90%), B20 (DSF20% + diesel 80%), B30 (DSF30% + diesel 70%), and B50 (DSF50% + diesel 50%) of DSF with diesel through microwave-assisted pyrolysis of used lubricating oil as fuel. Experimental findings were applied to predict each condition's performance characteristics. To estimate the performance characteristics, regression analysis was employed using experimental data in Microsoft Excel and Design Expert-12 software. The experimental data were compared to the simulated data. It was observed that fuel obtained from used lubricating oil using microwave-assisted pyrolysis could be used to power diesel engines without making any changes to the existing engines because the chemical characteristics of the diesel surrogate fuel were almost identical to those of diesel. The BTE of a compression ignition engine with DSF was close when compared to diesel up to full loading condition. At 1.924 kW brake power, the DSF30% has a higher efficiency than the other three blends. It was also observed that the rise in brake power also raises BSFC, thereby lowering thermal efficiency.

Handling of used lubricating oil in Tabasco, Mexico

The improper handling of used lubricating oil (ULO) in Tabasco, Mexico, and worldwide is a serious problem posing a high risk of soil and water pollution. Therefore, this study evaluated the handling of ULO in 10 municipalities in the state of Tabasco. Collection sites were chosen by simple random sampling. The ULO collected was assessed for solids, water, oil and density. The results show that small generators have the greatest potential to generate ULO in Tabasco. Huimanguillo, Comalcalco and Cardenas were the municipalities with the highest ULO generation. The ULO with the highest quality for its low water and solids content was collected in Jalpa de Mendez, Comalcalco and Car Dealerships. 1,287 automotive repair shops were tested in the 10 municipalities that were included

RECOVERY OF USED LUBRICATING OIL BY GLACIAL ACETIC ACID WITH TWO DIFFERENT ACTIVATED CARBONS

Recovery of used lubricating oil (ULO) generally comprises cleaning, drying, and adsorption in order to eliminate water, sludge, and impurities. As the ULO is one of the hazardous wastes generated in various industrial and automotive industries, it should not be used or disposed of in ways that are harmful to the environment. The main purpose of this study was to investigate the effectiveness of two different types of activated carbons (ACs) which are coconut AC (CAC) and rice husk AC (RHAC) in recovering the ULO. Glacial acetic acid was used in the acid treatment as it does not react with the base oils, and the ACs were substituted with the clay used in the clay treatment. The recovered oil was analysed through analytical characterizations, which are Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis) spectroscopy and atomic absorption spectrometry (AAS). FTIR analysis revealed that the properties of the untreated ULO samples improved by removing the carbonyl compounds. In terms of metal removal, RHAC had shown better performance than CAC as it gave low metal contents in AAS. The response surface methodology (RSM) was used to study the optimum process parameters that would maximise the efficiency of the process. There are two factors that were manipulated, which are the weight of adsorbent (A) and speed of mixing (B). For CAC, the optimum value of factors A was 4.00 g while the B was set to 524.89 rpm. Meanwhile, for RHAC, the optimum value of factors A was 2.29 g while the B was set to 4000 rpm. CAC has higher desirability with 0.83 compared to RHAC with 0.69.

Used lubricating oil recovery process and treatment methods: A review

Used lubricating oil (ULO) is considered hazardous as it is able to cause pollution and affect the environment. The presence of degraded additives, contaminants, and by-products of degradation render ULO more toxic and harmful to health and environment than virgin base oils. Recovery of ULO generally comprises cleaning, drying, and adsorption in order to eliminate water, sludge, and impurities. As the ULO is one of the hazardous wastes generated in various industries, such as industrial and automotive, it should not be used or disposed of in ways that are harmful for the environment. Recovery of ULO carries out many advantages which includes lower environmental impact, higher energy saving and lower risks. The main objective of this paper was to thoroughly review various recovery process principles and treatment methods for ULO. Importance of ULO recycling and various techniques along with their limitations were also discussed. The significance of this study lies in reviewing the roles of adsorbent and adsorption reclamation processes of ULO and few promising adsorbents were earmarked for further study.

Evaporation and combustion characteristics for a droplet of lubricating oil and gasoline

The droplet suspension technology is used to study the effects of ambient temperatures (from 673 to 873 K) and gasoline blending ratios (from 0% to 20%) on evaporation and combustion characteristics of lubricating oil (LO), used lubricating oil (ULO) and the mixture of lubricating oil and gasoline (LO/gasoline and ULO/gasoline). The experimental results show that the evaporation process of LO80G20 (the blend of 80% LO and 20% gasoline by volume fraction) contains a transient heating period, a fluctuation evaporation period and a slow evaporation period at 673 K. The combustion process at high temperatures (from 723 to 873 K) includes an auto-ignition delay period, a combustion period and an extinction period. At the same ambient temperature, both the auto-ignition delay and lifetime of ULO are shorter than those of new LO. The occurrence time and intensity of puffing for ULO are earlier and stronger than those of new LO. For the mixture of lubricating oil and gasoline (LO/gasoline and ULO/gasoline), the auto-ignition delay, droplet lifetime and the occurrence time of puffing decrease with the increase of gasoline component.

Nanomaterial-assisted pyrolysis of used lubricating oil and fuel recovery

ABSTRACT Used lubricating oil (ULO) is a heavy mixture of various hydrocarbons and needs to be treated before discharging. Considering ULO nature, it is more favorable to recover lighter hydrocarbon cuts from ULO, which not only improves the whole process economically, but also prevents the emission of hardly decomposable hydrocarbons into the environment. In this research, the potential of pyrolysis method for ULO recovery was studied. Furthermore, graphene nanoplatelets (GNP), γ- Fe2O3 and ZnO nanoparticles were used to improve the kinetics of the process and their impacts on the final product quality were evaluated. Based on the results, adding nanomaterials increased the tendency to produce gas product during pyrolysis. This tendency increased with enhancing the temperature. Among the three studied nanomaterials, γ- Fe2O3 incorporation was associated with the most satisfactory outcomes and resulted in liquid products with 81% and 83% of C-8 to C-15 at final temperatures of 400°C and 450°C, respectively. GNP and ZnO nanoparticles led to similar results and about 75% of their products were composed of C-8 to C-15 hydrocarbon cuts. Furthermore, according to the outcomes of GC, atmospheric distillation, density and flash point analyses, γ- Fe2O3 nanoparticles can produce hydrocarbon cuts that are lighter than diesel and close to kerosene.

Recycling of used lubricating oil by solvent extraction: experimental results, Aspen Plus simulation and feasibility study

This study investigates the recycling of used lubricating oil (ULO) by solvent extraction using a ternary solvent consisting of 2-propanol, 1-butanol and methyl ethyl ketone (MEK) followed by a vacuum distillation unit. In order to select the best combination of solvents for the liquid–liquid extraction process, many parameters were first evaluated on a laboratory scale such as the effect of the solvent composition, the solvent-to-oil ratio and the temperature. The oil recovery efficiency and the physicochemical properties of the oil obtained from the extraction process were measured, and the results showed that a ternary system consisting of 50% 1-butanol/25% isopropanol/25% MEK is the best mixture for effectively reducing the contaminants in ULO with a good sludge separation prior to the fractionation. Also, a solvent-to-oil ratio of 3:1 and a temperature of 25 °C are the optimal parameters for the extraction when the aforementioned solvent mixture is used. The whole re-refining process including the vacuum distillation unit was then simulated for a plant capacity of 2125 kg/h using Aspen Plus™. Four pseudo-components (saturate, monoaromatic, diaromatic and polyaromatic) together with the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) were used to describe the liquid–liquid equilibrium (LLE) in the system solvent/lubricating oils during the extraction phase. The calculated yields on the extraction unit performed for different solvent composition, solvent-to-oil ratio and temperature showed a good agreement with the experimental data performed at the laboratory scale which verifies the right choice of the solvent mixture. The investigation of the amount and composition of oil loss inside the sludge obtained from the simulation showed that the contaminant reduction and the oil recovery depend on the percentage of 1-butanol in the solvent mixture. Also, the results confirmed that the amount of MEK and 2-propanol in the solvent mixture should not exceed 25% and the best results were obtained when 1-butanol was used as a base solvent with an amount of 50%. Finally, to check the feasibility of the process, the investment payback time and the return on investment of the re-refining process were evaluated. Based on the economic study results, the production process was found to be highly profitable with a return on investment equal to 55% and a payout period of 1.9 years in the worst-case scenario where the price of lubricating oil is 2.5 $/L.

Non-isothermal pyrolysis of used lubricating oil and the catalytic effect of carbon-based nanomaterials on the process performance

Pyrolysis is a commonly used method for the recovery of used lubricating oil (ULO), which should be kinetically improved by a catalyst, due to its high level of energy consumption. In this research, the catalytic effects of carbon nanotube (CNT) and graphene nanoplatelets on the pyrolysis of ULO were studied through thermogravimetric analysis. First, the kinetic parameters of ULO pyrolysis including activation energy were calculated to be 170.12 and 167.01 kJ mol−1 by FWO and KAS methods, respectively. Then, the catalytic effects of CNT and graphene nanoplatelets on pyrolysis kinetics were studied. While CNT had a negligible effect on the pyrolysis process, graphene nanoplatelets significantly reduced the temperature of maximum conversion during pyrolysis from 400 to 350 °C, due to high thermal conductivity and homogenous heat transfer in the pyrolysis process. On the other hand, graphene nanoplatelets maximized the rate of conversion of highly volatile components at lower temperatures (< 100 °C), which was mainly due to the high affinity of these components toward graphene nanoplatelets and also the effect of nanoplatelets’ edges which have free tails and can bond with other molecules. Moreover, graphene nanoplatelets decreased the activation energy of the conversion to 154.48 and 152.13 kJ mol−1 by FWO and KAS methods, respectively.

Combustion performance of the premixed and diffusion burners with used lubricating oil and used cooking oil as fuel

This work investigated combustion performance of the premixed and diffusion burners by measuring flame temperature and gas emissions with used lubricating oil (ULO) and used cooking oil (UCO). Air–fuel ratio (AFR) is an important parameter to investigate combustion performance. Flame temperatures and gas emissions of the burners were examined to know the combustion behavior. The results found were that the flame temperatures in the premixed burner were higher than the diffusion burner at all the AFRs. The maximum flame temperature was obtained at AFR = 16 at all types of burners and fuel blending ratios. The highest flame temperature was [Formula: see text], which occurred when using 100% ULO with premixed burner at AFR = 16. By adding UCO into ULO, the flame temperatures can be decreased. The premixed burner produced 86.67% and 71.23% less CO and HC emissions, respectively, than the diffusion burner, in contrast, the premixed burner formed 26.31% and 54.7% higher [Formula: see text] and [Formula: see text] emissions, respectively, than the diffusion burner.

A Review of Methods for Removal of Contaminants in Used Lubricating Oil

Management and disposing of used lubricating oil (ULO) poses deleterious effects to air, land and water pollution. These contaminants not only causes environmental problems, they also have bio-accumulation effects on living organisms, reduces the inhabitants lifespan as a result of the diseases spread, poisoning and fouling of catalyst as well as corrode processing equipment. The contaminants removal in used lubricating oil is a major step to avoid pollution as discussed thoroughly by many researchers in literature. In addition, to curbing pollution, another advantage is converting waste to wealth. This review paper presents insight into various methods for removal of contaminants in used lubricating oil. The advantages and drawbacks of each method were earmarked for further study.

Low sulfur fuel oil from blends of microalgae pyrolysis oil and used lubricating oil: Properties and economic evaluation

Microalgae pyrolysis oil (MPO) is one of the most promising alternative renewable fuels to replace fossil fuel oil due to its high heating value, low sulfur content and environmentally sustainable production. Used lubricating oil (ULO) is another attractive alternative fuel with a relatively low cost. It is classified as a hazardous waste that is encouraged to be recycled. The International Maritime Organization (IMO) has mandated the use of low sulfur fuel oil (LSFO) (sulfur < 0.5% m/m) for marine transportation in the year 2020. Blends of MPO and ULO have an opportunity to satisfy the growing LSFO demand while the world is still facing challenges of LSFO production from fossil sources, due to cost and processing. MPO was derived from the Spirulina platensis specie due to its ease of harvesting and high yield of pyrolysis oil. The dried algae were fed into a continuous pyrolysis reactor to produce pyrolysis oil, from which MPO was extracted. ULO from vehicle engine was obtained from a vehicle service center and treated by flocculating and filtering. The blends were prepared to 100:0, 80:20, 50:50, 20:80 and 0:100 of MPO and ULO ratios, and tested for properties in accordance to ISO 8217, residual marine fuels. The results of the testing demonstrate that the blend of 20% MPO and 80% ULO, termed Microalgae Lubricant Blend (MLB20), can be a promising low sulfur marine fuel. The property tested and their results for MLB20, are as follows: 910.9 kg/m3density at 15 °C, 87.26 mm2/s kinematic viscosity at 50 °C, 0.461 %wt sulfur content, 0.515 %wt ash, 4.1 %vol. water content, and a total acid number of 5.4 mg KOH/g. MLB20 meets the majority of ISO 8217 specifications except for relatively high ash, acidity and water content. The pyrolysis process produced a yield of 41.37% liquid phase with MPO yield of 18.65%. The total cost of MPO production was 953.23 THB/liter, of which 73% is attributed to the algae nutrient cost. From the blending calculation, it was determined that the MLB20 cost is 198.65 THB/liter which is approximately 171 THB/liter higher than the LSFO market price. The barriers to MLB20 viability as LSFO are mainly the ISO 8217 standard’s strict ash, acidity and moisture requirements and MPO cost; specifically the nutrient cost.

Performance of used lubricating oil as flotation collector for the recovery of clean low-rank coal

In this study, the possibility of used lubricating oil (ULO) as a collector to float low-rank coal was explored; a traditional coal collector, diesel oil (DO), was used for possible comparisons. Experimental measurements including Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and zeta potential were used to determine the chemical constituents of the collectors. Flotation tests were conducted to investigate the flotability, flotation rate, and flotation selectivity. The coal-water, coal-collector, and coal-bubble interactions were emphatically analyzed using X-ray photoelectron spectroscopy, water contact angle, coal-water-collector contact angle, and the designed particle-bubble wrap angle experiment. The results indicate that ULO contains more oxygenated functional groups, aromatic groups, and long-chain hydrocarbons than DO, leading to its strong interaction with low-rank coal. A significant increase in zeta potential was also observed in the ULO environment, which could decrease the repulsion between particles. Flotation results confirm that ULO can significantly enhance the clean coal yield and flotation rate, and present high flotation selectivity. Furthermore, the mechanism of ULO as a flotation collector was examined. The adsorption of ULO increased the carbon content and decreased the oxygen content on the low-rank coal surface. This is beneficial as it helps to decrease coal-water interaction. Meanwhile, ULO showed stronger interaction with the coal, and coal particles pretreated with ULO more easily adhere to the bubble surface. The application of ULO can promote low-rank coal flotation, and has an important role in saving coal resources and alleviating the impact of used oil on the environment.

Effect of Used Lubricating Oil Contaminated Soil on Seed Germination and Early Growth Performance of Wild -Type Legume, Crotalaria retusa L.

Contamination of soil due to used lubricating oil (ULO) has become a common environmental issue, especially in major cities worldwide. This may affect negatively on overall soil quality and may pose a risk to biota. Phytoremediation is a novel green technological approach, which uses plants to remove organic and inorganic pollutants from contaminated soil, air and water and can be usefully used to clean up ULO contaminated soil. Screening of plant species with tolerance to ULO contamination is the most critical initial step in phytoremediation. The aim of the present study is to evaluate tolerance of Crotalaria retusa L. to ULO-contaminated soil. Germination of C. retusa seeds in soils with 1-5% w/w ULO contamination levels was tested according to the ISO method, with five replicates per treatment and ten seeds per replicate. Percentage inhibition of seed germination, root growth and biomass were measured at 48 and 72 hours of incubation. Results showed 100% seed germination in the control (uncontaminated soil) and all treatments indicating high tolerance of tested seeds to germinate in ULO-contaminated soil. However, there was a significant (p<0.05) reduction in root length of seedlings in all treatments above 3% w/w ULO. Therefore, a further pot experiment was carried out using ULO contamination levels of 0.5%, 1%, 1.5%, 2%, 2.5% and 3% w/w ULO. A fully randomized block design (RBD) was employed with 4 replicates per treatment and control. Percentage biodegradation of ULO and shoot height were measured monthly and at the end of a three month exposure chlorophyll a, b, total chlorophyll content, shoot height, root length, shoot system biomass and root system biomass were all measured. Results indicated time-dependent increases in percentage biodegradation of different treatments. At three months, percentage biodegradation was 52.2%, 43.8%, 35.6%, 32.2%, 25.2% and 22.0% for the 0.5-3.0% w/w ULO treatments, respectively. A decrease in growth parameters was observed with an increase in ULO contamination levels. However, the calculated IC50values inferred that the substantial negative effects resulted only on plants grown in soil with contamination levels greater than 2% w/w. There were no significant differences in chlorophyll contents of seedlings under any treatments. Therefore, from the present study we can conclude that C. retusa is able to grow in soils contaminated with ULO up to a level of 2% w/w without showing any negative effects. This result highlights the potential of C. retusa for the phytoremediation of ULO contaminated soil. Keywords: Crotalaria retusa, Phytoremediation, Used lubricant oil Acknowledgements: National Research Council, Sri Lanka (Grant No. 16-144) for financial assistance

Markers of oil exposure in cold-water benthic environments: Insights and challenges from a study with echinoderms

In spite of increasing naval activities and petroleum exploration in cold environments, there is currently a paucity of tools available to monitor oil contamination in boreal marine life, especially in sedentary (non-fish) species that dominate benthic communities. This research aimed to identify biotic sources of variation in biomarkers using subarctic echinoderms, and to identify suitable biomarkers of their exposure to hydrocarbons. The focal species included the sea star Asterias rubens, the brittle star Ophiopholis aculeata, the sea urchin Strongylocentrotus droebachiensis, and the sea cucumber Cucumaria frondosa, which are among the most abundant echinoderms in the North Atlantic and Arctic Oceans. The latter two species are also commercially exploited. A series of 96-h acute exposures of the water-accommodating fraction (WAF) of used lubricating oil (ULO) were performed in different seasons (i.e. distinct reproductive stages). Digestive and reproductive tissues were analyzed for baseline and response levels of glutathione peroxidase (GPx) and ethoxyresorufin-O-deethylase (EROD). GPx activity was detected in the pyloric caecum, stomach, and gonad of sea stars, the intestine and gonad of sea cucumbers, and the gonad of brittle stars and sea urchins. No seasonal variation in baseline GPx activity occurred. Upon exposure to the ULO WAF, sex-based differences were elicited in the GPx activity of sea star stomachs (lower in females than males). EROD activity was present in the pyloric caeca of sea stars, and the gonads of brittle stars and sea urchins. An interaction between season and sex on baseline EROD activity was measured in the gonads of sea urchins. Ovaries exhibited significant seasonal variation in EROD activity and had greater activity than testes during the spawning and post-spawning seasons. Seasonal variation in EROD activity also occurred in sea star pyloric caeca and brittle star gonads. Furthermore, testes of sea urchins exposed to the ULO WAF exhibited suppressed EROD activity compared to baseline levels. The nearly universal presence of GPx activity highlights its potential as a useful biomarker, while EROD activity was much more limited. Findings suggest a complex relationship between temporal and biotic factors on both the baseline and response levels of enzymatic activity, emphasizing the need to consider sex and sampling season in studies of biomarkers of hydrocarbon exposure in boreal indicator species that display annual reproductive cycles.

Changes in bacterial diversity associated with bioremediation of used lubricating oil in tropical soils.

Used lubricating oil (ULO) is a widespread contaminant, particularly throughout tropical regions, and may be a candidate for bioremediation. However, little is known about the biodegradation potential or basic microbial ecology of ULO-contaminated soils. This study aims to determine the effects of used ULO on bacterial community structure and diversity. Using a combination of culture-based (agar plate counts) and molecular techniques (16S rRNA gene sequencing and DGGE), we investigated changes in soil bacterial communities from three different ULO-contaminated soils collected from motorcycle mechanical workshops (soil A, B, and C). We further explored the relationship between bacterial community structure, physiochemical soil parameters, and ULO composition in three ULO-contaminated soils. Results indicated that the three investigated soils had different community structures, which may be a result of the different ULO characteristics and physiochemical soil parameters of each site. Soil C had the highest ULO concentration and also the greatest diversity and richness of bacteria, which may be a result of higher nutrient retention, organic matter and cation exchange capacity, as well as freshness of oil compared to the other soils. In soils A and B, Proteobacteria (esp. Gammaproteobacteria) dominated the bacterial community, and in soil C, Actinobacteria and Firmicutes dominated. The genus Enterobacter, a member of the class Gammaproteobacteria, is known to include ULO-degraders, and this genus was the only one found in all three soils, suggesting that it could play a key role in the in situ degradation of ULO-contaminated tropical Thai soils. This study provides insights into our understanding of soil microbial richness, diversity, composition, and structure in tropical ULO-contaminated soils, and may be useful for the development of strategies to improve bioremediation.

Life cycle assessment of waste strategies for used lubricating oil

The study aimed to evaluate the environmental impacts of used lubricating oil (ULO) recovery in the largest oil consumer country in Africa, Egypt. The main questions were: What are the impacts of the different waste management strategies for the recovery of used lubricating oil and which waste management strategy is more eco-friendly? Life cycle assessment (LCA) was employed to model the environmental impacts of the two waste management approaches for used lubricating oil recovery in Egypt: recycling by re-firing and recovery by co-firing. The model was applied to assess the impacts of one of the largest ULO recovery units in the Middle East and North Africa (MENA) region and the only operating unit in Egypt. The following impact categories were included: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), carcinogens potential (CP), ecotoxicity potential (ETP), respiratory inorganic formation potential (RIFP), respiratory organic formation potential (ROFP), radiation potential (RP), ozone layer depletion (OLD), mineral depletion (MD), land use (LU) and fossil fuel depletion (FFD). Results indicated that recycling by re-refining strategy is more environment-friendly. De-asphalting, de-aromatization and de-waxing processes are the main processes that affect the environmental impacts of lubricating oil production in both strategies, due to the use of hazard materials and toxic solvents in these processes. Fuel gas and fuel oil used as a fuel in the refinery and power units are the main contributors affecting the environmental impacts in case of recycling by re-refining strategy. The highest impacts were detected on FFD, followed by RIFP, GWP, AP, EP, ETP and CP in both strategies; no impacts were detected on RP, OLD and MD. It can be concluded that recycling by re-refining of ULO is the more eco-friendly approach. This strategy is more energy conservative, saves a diminishing fossil fuel resource and reduces burdens on the environment. ULO containing high percentages of additive remnants such as viscosity index improvers and pour point depressants which represents a valuable resource and its proper management should be given the most attention.

Application of Biosurfactant from Sphingobacterium spiritivorum AS43 in the Biodegradation of Used Lubricating Oil

This study aimed at investigating the application of biosurfactant from Sphingobacterium spiritivorum AS43 using molasses as a substrate and fertilizer to enhance the biodegradation of used lubricating oil (ULO). The cell surface hydrophobicity of bacteria, the emulsification activity, and the biodegradation efficiency of ULO were measured. The bacterial adhesion in the hydrocarbon test was used to denote the cell surface hydrophobicity of the used bacterial species. The results indicate a strong correlation between cell surface hydrophobicity, emulsification activity, and the degree of ULO biodegradation. The maximum degradation of ULO (62 %) was observed when either 1.5 % (w/v) of biosurfactant or fertilizer was added. The results also revealed that biosurfactants alone are capable of promoting biodegradation to a large extent without added fertilizer. The data indicate the potential for biosurfactant production by using low-cost substrate for application in the bioremediation of soils contaminated with petroleum hydrocarbons or oils.

Catalytic Steam and Autothermal Reforming of Used Lubricating Oil (ULO) over Rh- and Ni-Based Catalysts

The steam reforming of used lubricating oil (ULO) over Ni- and Rh-based catalysts supported by Ce-ZrO2 and Al2O3 is studied in the present work. Among all catalysts, Rh/Ce-ZrO2 (5 wt % Rh) provides relatively higher reforming reactivity (in terms of ULO conversion and H2 yield) with excellent resistance toward carbon deposition compared to the other three catalysts. At 850 °C after exposure in the steam reforming condition for 72 h, H2 yield of 78.1% can be achieved from the reaction over Rh/Ce-ZrO2. For Ni/Ce-ZrO2 and Ni/Al2O3, significant deactivations with time are detected and H2 yields of 55.3−58.7% are achieved after exposure for 72 h; in addition, considerable amounts of C2H4, C2H6 and C3H6 are also found in the product along with H2, CO, CO2, and CH4. The effect of O2 addition was further studied over Ni/Ce-ZrO2 and Ni/Al2O3. It was found that this addition significantly reduces the degree of carbon deposition as well as promoting the conversion of hydrocarbons to CO and H2. At a suitable amount o...