LCA OF WASTE MANAGEMENT SYSTEMS

Life cycle assessment of waste strategies for used lubricating oil

Eslam M. Hassanain1& Dalia M. M. Yacout2 & M. A. Metwally3 & M. S. Hassouna2

Received: 24 January 2016 /Accepted: 20 December 2016 /Published online: 29 December 2016# Springer-Verlag Berlin Heidelberg 2016

AbstractPurpose The study aimed to evaluate the environmental im-pacts of used lubricating oil (ULO) recovery in the largest oilconsumer country in Africa, Egypt. The main questions were:What are the impacts of the different waste management strat-egies for the recovery of used lubricating oil and which wastemanagement strategy is more eco-friendly?Methods Life cycle assessment (LCA) was employed to mod-el the environmental impacts of the two waste managementapproaches for used lubricating oil recovery in Egypt:recycling by re-firing and recovery by co-firing. The modelwas applied to assess the impacts of one of the largest ULOrecovery units in the Middle East and North Africa (MENA)region and the only operating unit in Egypt. The followingimpact categories were included: global warming potential(GWP), acidification potential (AP), eutrophication potential(EP), carcinogens potential (CP), ecotoxicity potential (ETP),respiratory inorganic formation potential (RIFP), respiratoryorganic formation potential (ROFP), radiation potential (RP),ozone layer depletion (OLD), mineral depletion (MD), landuse (LU) and fossil fuel depletion (FFD).Results and discussion Results indicated that recycling by re-refining strategy is more environment-friendly. De-asphalting,

de-aromatization and de-waxing processes are the main pro-cesses that affect the environmental impacts of lubricating oilproduction in both strategies, due to the use of hazard mate-rials and toxic solvents in these processes. Fuel gas and fuel oilused as a fuel in the refinery and power units are the maincontributors affecting the environmental impacts in case ofrecycling by re-refining strategy. The highest impacts weredetected on FFD, followed by RIFP, GWP, AP, EP, ETP andCP in both strategies; no impacts were detected on RP, OLDand MD.Conclusions It can be concluded that recycling by re-refiningof ULO is the more eco-friendly approach. This strategy ismore energy conservative, saves a diminishing fossil fuel re-source and reduces burdens on the environment. ULO con-taining high percentages of additive remnants such as viscos-ity index improvers and pour point depressants which repre-sents a valuable resource and its proper management shouldbe given the most attention.

Keywords Egypt . Environmental impacts . Used lubricatingoil .Waste recovery

1 Lubricating oil production and study sitedescription

Lubricating oil is a valuable constituent in crude oil; it is usedfor the reduction of friction and wear in machines, with manymechanical applications. By time and continued operation, thelubricant degrades and comes out of service. These used lu-bricants constitute a serious pollution problem since the illegaldumping or improper disposal may contaminate groundwater,surface water and soils. If they are directly combusted as low-grade fuels without pretreatment for removing contaminants,toxic pollutants may be released into the atmosphere. Proper

Responsible editor: Shabbir Gheewala

* Dalia M. M. Yacoutdalia.yacout@gmail.com

1 Department of Distillation, Alexandria Petroleum Company (APC),Ministry of Petroleum and Mineral Resources, Alexandria, Egypt

2 Environmental Studies Department, Institute of Graduate Studies &Research, Alexandria University, Alexandria, Egypt

3 Middle East Oil Refinery (MIDOR), Ministry of Petroleum andMineral Resources, Cairo, Egypt

Int J Life Cycle Assess (2017) 22:1232–1240DOI 10.1007/s11367-016-1255-x

collection and treatment for utilizing used lubricating oil(ULO) reduces its environmental impacts and preserves valu-able resources with great economic value (John 2005; Tsai2011). ULO produced from the recovery process is about80% of the feed (less cost), while the main lubricating oil fromcrude distillation is (10–15%) (more cost). The manufacturingof 1 ton of mineral base oil by conventional processing re-quires 4–6 ton oil equivalent (TOE), while the manufacturingof the same amount of base oil from recovered oil requires1.1–1.2 TOE. That is a considerable amount of energy con-servation (Kajdas 1994). The power used for oil recovery isabout 40% less than the power used in the refining of the crudeoil to obtain main lubricating oils (APC 2015). Several wastemanagement practices of lubricating oil are available; howev-er, it was estimated that more than 35 million tons of ULO areglobally generated annually from the industrial sector. Lessthan 45% of it is being collected and the remaining 55% iseither misused or discarded by the end user to the environment(Norrby 2003).

The Middle East and North Africa (MENA) region is thelargest contributor in the worldwide crude oil production mar-ket, accounting for more than 55% of global crude oil reser-voir (Lubes‘n’Greases 2014 and Eni Spa 2014). The Egyptiancrude oil reserve accounts for 3.9 billion barrels, with a dailyproduction of about 478,000 barrels of oil equivalent and500,000 tons of generated ULO per year (US EIA 2015;APC 2015). Alexandria Governorate is the top producer oflubricating oil in Egypt and one of the top consumers as well.The annual consumption of lubricant oils in Alexandria isestimated to be 200,000 tons, while its production reaches150,000 tons. This production represents 30% of the totalproduced lubricating oils in Egypt (APC 2015). At the sametime, Alexandria is the top generator of ULO, about 30% ofthe produced lubricating oil is locally consumed by industrialmotors and vehicle engines; the remaining 70%, an amount ofalmost 140,000 tons/year, is considered ULO. From that gen-erated ULO, only 50,000 tons/year is recovered and re-re-fined, the rest 90,000 tons/year of ULO (an estimated valueof 49.5 million USD) are discharged into both municipal andeffluent wastewaters which eventually sinks into the environ-ment. These numbers reflect the seriousness of ULO genera-tion and recycling in Alexandria.

The present investigation studies the different waste han-dling scenarios for used lubricating oil in Egypt, in order toidentify the more eco-friendly one. Egypt is the largest oilconsumer in Africa, accounting for about 20% of petroleumconsumption in Africa in 2013 (US EIA 2015). Life cycleassessment was used to model the environmental impacts ofULO recovery: recycling by re-refining and recovery by co-firing with heat. Themodel represents in a great deal the actualenvironmental burdens of ULO recovery in Egypt as it wasapplied to the only operating unit in the country. The results ofthe study will support decision makers by suggesting the more

eco-friendly strategy for ULO and at the same time uncover anopportunity for energy conservation. Furthermore, the study isan addition to current LCA studies in ULO (Kanokkantaponget al. 2009; Liu et al. 2011). In spite of the large share ofMENA countries in the global crude oil market, to the author’sknowledge to date, no similar studies for LCA of ULO wereconducted neither in Middle East nor in Africa.

At the present time in Egypt, there is only one operatingunit for ULO recovery, which is represented by the casestudy company Alexandria Petroleum Company (APC).APC is one of the Egyptian General PetroleumCorporation companies which produces about 4.8 milliontons/year of crude oil. It produces 30% of the national con-sumption of basic lubricating oils with a total productioncapacity of 150,000 tons lubricating oil per year and re-covers 50,000 ton ULO/year. ULO collected from the dif-ferent fuel stations, garages, workshops and different indus-trial sites is received at APC to be fed to the ULO recoveryplant. Then, it is sent to a de-watering unit to remove itswater content, gas oil removal unit to remove gas oil con-tent, thin film evaporator system to remove the heavy resinpresent in it, then it is treated with hydrogen to improve itscolour characteristics before fractionated into light, mediumand heavy neutral oil. The output of all the steam ejectors ofthe unit (vacuum system) is condensed using barometriccondensers and accumulated, with the water coming fromthe de-watering unit and the wash water, into a surge drum.After that, oil is separated from the water and the oil-freewater is routed to the water stripper where it undergoesstripping by steam from volatile compounds such as hydro-gen sulfides and ammonia. The unit wastewater is routed tosour water sewer before being sent to the API gravity sep-arator. The stripped vapours from the stripper are routed tothe incinerator. Figure 1 presents the steps of lube oil pro-duction and used oil re-refining at the case study plant.

2 Life cycle assessment

2.1 Goal, scope and system boundaries

The whole LCAwas based on the International Standards forLCA, ISO 14040:1998 (1998) and ISO 14044:2006 (2006).The goal of the present study was to evaluate the environmen-tal impacts of two waste management strategies for the recov-ery of ULO in order to recommend the more environment-friendly strategy. The two waste management strategies wererecycling by re-refining and co-firing. The comparative lifecycle assessment was based on three phases: (a) the environ-mental evaluating of the first strategy for ULO re-refining, (b)the environmental evaluating of the second strategy for ULOco-firing and (c) the comparison between the two strategies.The process of quantifying energy, raw materials

Int J Life Cycle Assess (2017) 22:1232–1240 1233

requirements, transportation, atmospheric emissions, water-borne emissions and solid wastes for the entire life cycle of

lubricating oils was applied starting from crude oil transporta-tion till the recovery process.

ATMOSPHERIC DISTILLATION

UNIT

GASOLINENAPHTHAKEROSENE

VACUUM DISTILLATION

UNIT

LWDMWDHWDSPINDLE

PROPANE DE-ASPHALTING

UNITPD TAR

FUEL OIL

VACUUM RESIDUE

DEASPHALTED OIL

FURFURAL DE-g at UNIT AROMATIC

DEAROMATIZED OIL

MEK & TOLUENE DE-WAXING UNIT

AROMATIC

LUBE OIL

(BRIGHT STOCK)

DE-WATERING UNIT

WATER

CRUDE OIL USED OIL

GAS OIL REMOVAL

DE-WATERED OIL

GAS OIL

IMPROVED OIL

THIN FILM EVAPORATORS

HEAVY IMPURITIES

LUBE OIL

HYDRO-FINISHING

LUBE OIL

DEGRADATION PRODUCTS

Fig. 1 Steps of lube oilproduction and used oil re-finingat APC

Fig. 2 System boundariesconsidered in this study

1234 Int J Life Cycle Assess (2017) 22:1232–1240

Table 1 Inventory summary for waste strategies of 1000 kg lubrication used oil

Unit process

Atmosphericfractionaldistillation

Vacuumdistillation

Propane de-asphaltingunit

Aromaticsremovalunit

Oil de-waxingunit

Recyclingunit

Inputs

Resources Unit Amount

Balyiem crude oil kg 11,250

Cooling water (sea water) m3 2.25 2.63 7.47 8.00 2.56 25.00

Pumps coolingwater (surface water) m3 0.53 0.39 1.21 0.92 0.59 2.40

Material/fuel

De-ionized water m3 0.2

Light fuel oil kg 85

Natural gas m3 0.05 0.30 0.28 0.28 0.23 0.17

Ammonia kg 0.41 0.92

Sodium hydroxide kg 0.82 0.02

Dimethylamine kg 0.82 0.34 9.33

Fuel oil kg 7550

Vacuum residue kg 4120

Di-methyl sulfate kg 0.23

Propane kg 6 1.2

De-Asphalted oil kg 1570

Ammonium bicarbonate kg 5

N-methyl-2-pyrrolidone kg 1.9

Rafinated oil kg 11.9

Methyl ethyl ketone kg 3.8

Toluene kg 3.4

Oil waste kg 10

Soft water kg 30.66

Hydrogen kg 3.47

Electricity/heat

Crude oil pumping to refinery units tkm 3937.5

Steam kg 270 625 730 785 760 4000

Electricity MWh 103 23.43 68.66 10.47 91.95 16.13

Hot oil (heat source) MJ 98.92

Outputs

Products and co-products

Fuel oil kg 7550

Gas oil kg 1350 92.5

Kerosene kg 840

Naphtha kg 1350

Gases + gasoline kg 160

Vacuum residue kg 4120

Black oil kg 100

Wax distillate kg 1700

Spindle oil kg 130

Vacuum gas oil kg 1500

De-asphalted oil kg 1570

PD Tar kg 2630

Rafinated oil kg 1190

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LCAwas evaluated based on the impact assessment meth-odology Eco-Indicator 99. The following impact categorieswere considered: global warming potential (GWP), acidifica-tion potential (AP), eutrophication potential (EP), carcinogenspotential (CP), ecotoxicity potential (ETP), respiratory inor-ganic formation potential (RIFP), respiratory organic forma-tion potential (ROFP), radiation potential (RP), ozone layerdepletion (OLD), mineral depletion (MD), land use (LU) andfossil fuel depletion (FFD). According to Kanokkantaponget al. (2009) and Liu et al. (2011), the process inputs to ULOrecovery process were evaluated in a single score analysis inorder to allocate the impacts of each input to the correspond-ing impact category. The evaluation of the impact categorieswere expressed in mega points (mPt) to evaluate the impact ofa product or process, more points mean worst environmentalburden (Goedkoop et al. 2008). In compliance with ISO14044: 2006, a cut-off criteria of 1% was used.

LCAwas applied for the production of 1000 kg lubricatingoil in APC from marine Balyiem crude oil. Pumping of crudeoil from the extraction units to the refinery units in APC wasassumed to be 350 km. The production processes included thefollowing: (a) atmospheric distillation of crude for productionof fuel oil as a main product, (b) vacuum distillation for theproduction of vacuum residue, (c) propane de-asphalting unitfor production of de-asphalted oil, (d) solvent extraction unitto remove aromatics for production of refined oil and (e) de-waxing unit for production of bright stock (de-waxed oil).This bright stock (de-waxed oil) is being blended with addi-tives such as antioxidants, pour point depressants, viscosity

index improvers, detergents and dispersants to produce thefinal product. Following the study by Kanokkantapong et al.(2009), transportation was assumed to be insignificant whenbeing distributed throughout the life span of such plant; con-sequently, transportation of lubricating oil to end user andconsumption by users were not included in the study.Figure 2 shows the system boundaries considered in thisstudy.

2.2 Data collection, uncertainty and life cycle inventory

Life cycle inventory analysis (LCI) was conducted usingSimaPro 7.1. Foreground data for the analysis was deliveredfrom literature review including US EPA standards for ULO,onsite measurements and collected data from APC during theperiod of 2012–2015. Background data was created utilizingeco-profiles from the Eco-Invent database for all of the neces-sary input materials and processes. Inventory summery for therecovery of 1000 kg of used lubricating oil is presented inTable 1.

This study started by modeling the impacts of EgyptianULO re-refining process. These impacts were then comparedto the impacts of co-firing in space heater as a substitute for theprimary energy sources of either fuel oil or natural gas. Co-firing of ULO in space heater (atomizing burner) generatesdifferent amounts of environmental air pollution components,e.g. CO, CO2, SOx, NOx, PM < 10 μg and heavy metals.

It was noted that the data presented in this case study issubject to several uncertainties. The available data in the LCA

Table 1 (continued)

Unit process

Atmosphericfractionaldistillation

Vacuumdistillation

Propane de-asphaltingunit

Aromaticsremovalunit

Oil de-waxingunit

Recyclingunit

Extract kg 380

De-waxed oil kg 800

Wax kg 390

Lubricating oil kg 762

Emissions to air

Carbon dioxide kg 13 30 176 105 164 590

Sulfur dioxide kg 0.02 0.01

Nitrogen dioxide kg 2.00 0.05 0.23 0.32 0.27 2.16

Particulates <10 μm kg 6.13 2.36 1.90 1.10 2.06 9.50

Liquid discharge

Wastewater to effluent treatmentplant

m3 2 1.9 5.91 4.45 2.88 10.27

Wastewater to stripping andincineration

m3 0.09

Solid waste

Oil sludge (recycled) kg 92.27

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database may not exactly represent the quantity being studieddue to the geographical/regional location of the case studyarea in Egypt. To date, no available databases representEgypt or the MENA region (Ali et al. 2014; Yacout et al.2016). Data for basic materials used in the study is consideredfor the region of Europe (Ecoinvent v2 Database), which willrepresent the case study only if all the used raw materials areimported from Europe. Energy data for both electricity andsteam generationmay vary as well based on the used database.The electrical data used in this case study was the generatedelectricity in Africa (IDEMAT 2001 database). This data rep-resents the average fuel use and emissions for total energygeneration for the whole continent. As for steam, on-sitesteam source average was used (Industry Data 2.0Database). This steam source is suitable for the current casestudy as it represents the produced steam on site.

A further reason for the large uncertainties is the natureof the lubricating oil production system which is charac-terized by diverse practices (Van der Velden et al. 2014).An example for the diversity in practices is the usage ofKinetics Technology International (KTI) process for re-refining of ULO in the current case study. Other processesmay be used for the same purpose such as the BartlesvilleEnergy Research Center (BERC) process, Institut FrancaisDu Pétrol (IFP) process or the Phillips Used Oil Re-Refining Process.

3 Results of life cycle analysis

LCA results are presented in Table 2 and Figs. 3 and 4. It canbe noticed that recycling by re-firing of ULO is the more eco-friendly strategy. Consumption of fusel fuels was the maincontributor to overall environmental impacts of both strate-gies. Second highest impact was on the human respiratoryeffect due to inorganic substances. The processes of de-asphalting, de-aromatization and de-waxing are the main con-tributors to the previous categories due to the consumption offusel fuels in these processes and use of hazard materials andtoxic solvents such as methyl ethyl ketone (MEK), tolueneand furfural. These solvents have a very high toxicity potentialto both human health and the environment. On the other hand,the processes of atmospheric and vacuum distillation do notseem to exert significant effect to life cycle. Almost no im-pacts were detected on the following categories: radiation po-tential, ozone layer depletion, mineral depletion or humanrespiratory effect due to organic substances. The reason fornot detecting any impacts on the previous categories is thatboth waste strategies do not generate any substances that mayaffect the ozone layer or cause radiation. Neither organic sub-stances nor minerals are used in both waste handlingapproaches.

4 Discussion of life cycle analysis

4.1 Global warming potential

The calculated GWP of each scenario, expressed as ton CO2

equivalents, was shown in Table 2 and Figs. 3 and 4. When

Table 2 Life cycle inventory of different scenarios for management of1000 kg used oil

Unit Recyclingby re-firing

Co-firing inspace heater

Air emissions

CO2 kg 660 2930

CH4 kg 0.0176 0.0658

N2O kg 0.165 0.674

SO2 kg 97.7 425

NOx kg 33.9 141

HCl kg 0.226 0.936

HF kg 0.0267 0.11

CO kg 0 0.252

NMVOC kg 9.24 38.5

H2S kg 0.0117 0.0154

NH3 kg 0.0483 0.166

As gm 1.71 7.86

Cd kg 0.00405 0.0171

Cr kg 0.00259 0.0322

Hg gm 0.501 2.06

Ni kg 0.0405 0.185

Pb kg 0.00754 0.0314

PAH gm 0.369 1.08

Furan gm 0.00771 0.0319

PCBs mg 0.846 3.4

Dioxins (measuredas 2, 3, 7, 8-TCDD)

μg 0.616 2.48

Particulates <10 μm kg 10.7 10.2

Liquid effluents

P kg 0.00494 0.0205

N kg 0.025 0.104

S kg 0.0811 0.343

COD kg 97 414

BOD kg 95.5 405

Phenol kg 0.0631 0.266

PAH kg 0.00258 0.011

As gm 1 4.04

Cd gm 0.154 0.629

Cr gm 1.32 5.57

Hg gm 0.0358 0.138

Ni kg 0.0127 0.051

Pb kg 0.00272 0.0112

Resources consumption

Energy GJ eq. 0.182 0.711

Int J Life Cycle Assess (2017) 22:1232–1240 1237

used oil re-refining was replaced by its co-firing, largeamounts of CO2 (293 ton CO2 equivalents/100 ton ULO)and NOx (14.1 ton CO2 equivalents/100 ton ULO) were gen-erated. These gases were generated as a result of burning oilwaste containing large amounts of pollutants including PAHs,PCBs and heavy metals. Raising the ratio of recycling from 50to 90% against the co-firing scenario reduced the amount ofcarbon dioxide and carbon monoxide from 180 ton CO2

equivalents/100 ton ULO to 88 ton CO2 equivalents/100 tonULO and from 12.6 ton CO2 equivalents/100 ton ULO to2.52 ton CO2 equivalents/100 ton ULO, respectively.Carbon monoxide emission from the refinery units indicatesthe presence of uncompleted combustion in the heaters orincinerators of the units. As a result, huge amount of heatwas evolved into air resulting in a high GWP. From the lifecycle consideration, it can be seen that the co-firing of usedlube oil completely in space heaters of APC contributes tohigh GWP compared to the other scenario. Also, it shouldbe remarked that used oil contains a high calorific value; if itis used, it will save a significant amount of energy instead ofusing other energy sources such as natural gas or fuel oil.

It has been believed that all re-refining scenarios generatehigh pollution into the environment because of the high con-taminants present in air or wastewater of the recovery plant;surprisingly, it produced the lowest GWP. The refining scenar-ios emitted only 66 ton CO2 equivalents/100 ton ULO in com-parison to 293 ton CO2 equivalents/100 ton ULO evolved

during the co-firing of used oil in space heater. This can beattributed to the presence of the incinerator in the recovery plantwhich destructs all the pollutants emitted converting them intowater vapour and carbon dioxide. It was unexpected to find thatthe recycling by re-refining process produced the largest amountof particulates <10 μm in comparison to the co-firing scenarios.As a consequence, it is suggested to use a more conventionalgas cleaning systems such as cyclones to capture these particles.Thus, it has been concluded that the ratio of 90% recycling byre-refining to 10% co-firing of used oil was the best option forAPC in terms of both GWP and energy resources.

4.2 Acidification potential

Acidification potential of different scenarios, expressed asSO2 equivalent, was shown in Table 2 and Figs. 3 and 4.When used oil re-refining is replaced by its co-firing, loweracidification potential was achieved. This may be due to thehigh acidity present in ULO. This acidity can be attributed tothe high sulfur components which arise during the process ofco-firing. Another acidification substance related to sulfur ishydrogen sulfide (H2S), which showed a great rising duringULO co-firing although its share in acidification potential wasbelow 1%. The same observations were reported byKanokkantapong et al. (2009). Acidification could also resultfrom the presence of HCL and HF as reported by Liu et al.(2011). Hydrogen sulfide emission was related to the sulfate

Fig. 3 Comparison between the different scenarios of oil waste management using Eco-Indicator method

1238 Int J Life Cycle Assess (2017) 22:1232–1240

content in the used oil; usually, it is released in the process ofanaerobic decomposition of used oil by specific bacteria.Hydrogen sulfide is extremely toxic gas that has the potentialfor bringing injury to the central nervous system even at lowdose exposure. Also, high content of chlorine in used oilbrings concerns of HCl release during its combustion.

4.3 Eutrophication potential

It should be noted that both the NOx discharge and levels ofnitrogen and phosphorous, which contribute to eutrophication,increased with the rising in the substituted ratio of re-refiningby co-firing. Table 2 and Figs. 3 and 4 illustrate that ULOburning seems to have higher potential for eutrophication thanULO recycling due to the presence of high levels of ammonia,nitrates and phosphorous emissions to water. Eutrophicationpotential was detected due to the emissions of nitrogen.

Considering these facts, NOx control should be a crucialproblem for reducing the environmental impacts from eutro-phication in the proposed industrial process. Besides, the re-lease of phosphorous and ammonia should be paid attentionalthough their contribution was not remarkable.

4.4 Ecotoxicity potential

Results of life cycle analysis revealed a significant impact onthe ecotoxicity potential as well. The ecotoxicity potential canbe attributed to the discharge of heavy metals, when the ULOwas used as a fuel, the generated amounts of Cd, As and Hgwere four times more than of those in the recycling strategy.Although the amounts of heavy metals are only in trace levels,they share a decisive contribution to human toxicity and eco-toxicity due to their relatively high values of characterizationfactors. Both Ni and Pb gave the greatest contribution (rangedfrom 67 to 71% and from 11 to 13%, respectively). The lowerpotential of heavy metals in wastewater of the oil recoveryunit can be attributed due to their accumulation in the sludgethat is drained from the bottom of the thin film evaporator.

4.5 Carcinogenic potential

Results of life cycle analysis revealed that the substitution ofULO re-refining with its co-firing raised the amount of carci-nogenic compounds emitted to air where PCBs increased from84mg/100 ton ULO to 340 mg/100 ton ULO, PAHs increased

Fig. 4 Environmental impacts for different scenarios of oil waste management

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from 36 g/100 ton ULO to 108 g/100 ton ULO, dioxin in-creased from 61 μg/100 ton ULO to 248 μg/100 ton ULO andfuran increased from 0.77 g/100 ton ULO to 3.19 g/100 tonULO. Also, the wastewater contains a variety of pollutantsincluding PAHs which increased from 0.25 kg/100 ton ULOto 1.1 kg/100 ton ULO and phenol from 6 kg/100 ton ULO to26 kg/100 ton ULO. After removing the impurities from theULO during the re-refining process, parts of these impuritieswere out with the wastewater; the other parts were incineratedat a high temperature (1200 °C). These impurities includePAHs, PCBs, dioxin and furan; their incineration at a hightemperature reduced their levels in air in comparison of theirconcentration in case of burning used oil as a fuel in a spaceheater (Figs. 3 and 4).

4.6 Respiratory inorganic formation potential

The potential emission of the respiratory in-organic particulatematter was another factor highly affected due to particulatesemission from the industrial processes. Results indicated ma-jor differences between the two strategies. The co-firing strat-egy had more than double the impact of the recycling strategyon this category. This can be attributed to the release of largeamounts of emissions from uncompleted combustion inheaters or incinerators of the units. It is recommended to useconventional gas cleaning systems such as cyclones in orderto capture these emissions and prevent their potential impacts.

4.7 Fossil fuel depletion

Fossil fuel depletion was an important impact category takeninto consideration in this study. Results indicate that it is thecategory with major impact. Fuel gas and fuel oil are used asfuels in the refinery and power units during the production oflubricating oils. FFD could be attributed to the fact that sig-nificant amounts of fuel oil are saved as a result of the efficientwaste management of ULO. Results regarding the impact ofthis category for ULO burning strategy were three timeshigher, respectively, in comparison with the ULO recyclingstrategy (Figs. 3 and 4). The waste management strategy ofULO recycling not only has a lower impact on the differentenvironmental categories but also saves a significant amountof fossil fuels.

5 Conclusions

Two waste handling strategies for recovery of ULO in Egyptwere assessed in order to identify the more eco-friendly strat-egy. Recycling by re-firing strategy was proved to be the bestchoice in terms of eco-friendly basis. Fossil fuel depletion wasthe highest category impacted as significant amounts of oil are

saved as a result of the efficient waste management of used oilrecovery. The potential emission of the respiratory inorganicparticulate matter and GWP was highly affected due to partic-ulate emissions from the industrial processes. In order to re-duce the overall the environmental impacts of ULO recoverystrategies, special attention should be given in order to controland reduce the NOx, phosphorous and ammonia emissionsfrom the different processes.

Recovery of ULO is an excellent waste to energy approachfor both energy conservation and reduction of negative envi-ronmental impacts, in addition to the high economic value.Further investigations are recommended in order to assessthe implementation of waste strategies in the different indus-tries in the MENA region.

References

Ali AAM, Negm AM, Bady AF, Ibrahim AG (2014) Moving towards anEgyptian national life cycle inventory database. Int J Life CycleAssess 19:1551–1558

APC (2015) Alexandria Petroleum Company, one of the EgyptianGeneral Petroleum Authority’s (EGPA) Companies, Mex,Alexandria, Egypt

Goedkoop M, Schryver A, Oele M (2008). Introduction to LCA withSimaPro 7: PRé Consultants. The Netherlands

ISO14041 (1998) International Organization for Standardizations:Environmental management—life cycle assessment—goal andscope. Geneva, Switzerland

ISO14044 (2006) International Organization for Standardizations:Environmental management—life cycle assessment—requirementsand guidelines. Geneva, Switzerland

John P (2005) Waste management practices: municipal, hazardous, andindustrial. CRC Press, New York

Kajdas C (1994) Modern Waste Oil Recycling Technologies - AnOverview. Esslingen Conference 1994. Lubricants and RelatedProducts

Kanokkantapong V, Kiatkittipong W, Panyapinyopol B, Wongsuchoto P,Pavasant P (2009) Used lubricating oil management options basedon life cycle thinking. J Res Con Rec 53:294–299

Liu Q, Jiang P, Zhao J, Zhang B, Bian H, Qian G (2011) Life cycleassessment of an industrial symbiosis based on energy recoveryfrom dried sludge and used oil. J Clean Prod 19:1700–1708

Lubes‘n’Greases (2014) Lubes‘n’Greases Europe-Middle East-Africa.LNG publishing INC–UK

Norrby B (2003) Environmentally adapted lubricants—where are theopportunities? Ind Lubr Tribol 55(6):268–274

Eni Spa (2014) World oil and gas review. Eni Spa, Rome-ItalyTsai WT (2011) An analysis of used lubricant recycling, energy utiliza-

tion and its environmental benefit in Taiwan. J Energy 36:4333–4339

US EIA (2015) U.S. Energy Information Administration. Egypt, interna-tional energy data and analysis report

Van der Velden NM, Patel MK, Vogtländer JG (2014) LCAbenchmarking study on textiles made of cotton, polyester, nylon,acryl, or elastane. Int J Life Cycle Assess 19:331–356

Yacout DMM, Abdel Kawi MA, Hassouna MS (2016) Cradle to gateenvironmental impact assessment of acrylic fiber manufacturing.Int J Life Cycle Assess 21:326–336

1240 Int J Life Cycle Assess (2017) 22:1232–1240