Current scenario and potential of biodiesel production from waste cooking oil in Pakistan: An overview

Biodiesel utilization has been rapidly growing worldwide as the prime alternative to petrodiesel due to a global rise in diesel fuel demand along with hazardous emissions during its thermochemical conversion.Although,several debatable issues including feedstock availability and price,fuel and food competition,changes in land use and greenhouse gas emission have been raised by using edible as well as inedible feedstocks for the production of biodiesel.However,non-crop feedstocks could be a promising alternative.In this article,waste cooking oils have been recommended as a suitable option for biodiesel production bearing in mind the current national situation.The important factors such as the quantity of waste cooking oil produced,crude oil and vegetable oil import expenses,high-speed diesel imports,waste management issues and environmental hazards are considered.Moreover,process simulation and operating cost evaluation of an acid catalyzed biodiesel production unit are also conducted.The simulation results show that the production cost of waste cooking oil-based biodiesel is about 0.66 USD·L-1.We believe that the present overview would open new pathways and ideas for the development of biofuels from waste to energy approach in Pakistan.

Biodiesel Production from Waste Cooking Oil Using Sulfuric Acid and Microwave Irradiation Processes

A comparative study of biodiesel production from waste cooking oil using sulfuric acid (Two-step) and microwave-assisted transesterification (One-step) was carried out. A two-step transesterification process was used to produce biodiesel (alkyl ester) from high free fatty acid (FFA) waste cooking oil. Microwave-assisted catalytic transesterification using BaO and KOH was evaluated for the efficacy of microwave irradiation in biodiesel production from waste cooking oil. On the basis of energy consumptions for waste cooking oil (WCO) transesterification by both conventional heating and microwave-heating methods evaluated in this study, it was estimated that the microwave-heating method consumes less than 10% of the energy to achieve the same yield as the conventional heating method for given experimental conditions. The thermal stability of waste cooking oil and biodiesel was assessed by thermogravimetric analysis (TGA). The analysis of different oil properties, fuel properties and process parametric evaluative studies of waste cooking oil are presented in detail. The fuel properties of biodiesel produced were compared with American Society for Testing and Materials (ASTM) standards for biodiesel and regular diesel.

Investigation of performance and emission characteristics of waste cooking oil as biodiesel in a diesel engine

Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific technical treatments are required to improve certain fuel properties such as viscosity and calorific value of the biodiesel being obtained from waste cooking oil methyl ester （WCOME）. Various treatments are applied depending on the source and therefore the composition of the cooking oil. This research investigated the performance of WCOME as an alternative biofuel in a four-stroke direct injection diesel engine. An 8-mode test was undertaken with diesel fuel and five WCOME blends. The best compromise blend in terms of performance and emissions was identified. Results showed that energy utilization factors of the blends were similar within the range of the operational parameters （speed, load and WCOME content）. Increasing biodiesel content produced slightly more smoke and NOx for a great majority of test points, while the CO and THC emissions were lower.

Supercritical Synthesis of Ethyl Esters via Transesterification from Waste Cooking Oil Using a Co-Solvent

Biofuels became more promising alternative to the fossil fuels because of the depletion of fossil resources, renewability, environmental benefits, and energy security. Ethanolysis of waste cooking oil with hexane as co-solvent was carried out for the production of fatty acid ethyl ester (FAEE). This process reduced the severity of process parameters with high purity biodiesel yield. Process variables such as co-solvent ratio, ethanol to oil molar ratio, reaction temperature and reaction time were optimized. The maximum biodiesel yield of 88% was obtained at ethanol/oil molar ratio of 40:1, co-solvent (hexane) to oil ratio of 0.2% (v/v), reaction temperature of 300°C in 20 min of reaction time. Fatty acid ethyl ester (biodiesel) samples produced from this process were measured and evaluated using GC-MS analytical instrument. Thermo gravimetric analysis (TGA) was also performed to examine the thermal stability of waste cooking oil, ethyl esters and fuel blends. Fuel properties of ethyl esters were determined and compared with the ASTM standards for biodiesel, regular diesel and ethyl esters from different feedstock.

Diester Derivatives from Chemically Modified Waste Cooking Oil as Substitute for Petroleum Based Lubricating Oils

In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.

Ultrasound-assisted Biodiesel Production from Waste Cooking Oil at Room Temperature

Waste cooking oil(WCO) is considered to be a promising alternative for vegetable oils that have been traditionally used for biodiesel production. In this study, WCO with a fairly high free fatty acid content was transesterified into biodiesel in a one-step procedureat room temperature(25℃) under ultrasound irradiation and in the presence of potassium hydroxide(KOH) as catalysts. Response surface methodology(RSM) was used to investigate the effects of the methanol/oil molar ratio, reaction time,and catalyst loading on the fatty acid methyl ester(FAME) yield and the biodiesel yield. The optimal reaction conditions for the production of WCO biodiesel were found to be a methanol/oil molar ratio of 8.6:1, a reaction time of 25 min, and a catalyst loading of 2.43 wt%. Under these optimal settings,the FAME and biodiesel yields were 96.4% and 92.7%, respectively. The properties of the resultant WCO biodiesel, including kinetic viscosity, acid number, water content, and flash point, were measured according to ASTM D6751 standards. The obtained results provide useful information for the large-scale production of WCO biodiesel.

Rheological properties and microscopic mechanism of waste cooking oil activated waste crumb rubber modified asphalt

In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface performance.The rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test,multiple stress creep recovery(MSCR)test,BBR test and infrared spectroscopy.The results show that the dissolution degree of waste crumb rubber is improved after WCO activation,and the compatibility with asphalt components is enhanced,and the stable cross-linking structure is formed,which improves the asphalt performance.The several new absorption peaks,which were obvious,were all caused by the composition of WCO,that is,there was no significant chemical change during the interaction between the activated crumb rubber and base asphalt.Compared with the common waste crumb rubber modified asphalt(CRMA),activation with WCO can significantly reduce the viscosity of CRMA,decrease the difference of segregation softening point by 27%,and enhance the low temperature performance by 30%.The aging degree is greatly reduced,and the anti-aging performance of OCRMA is increased by about 20%with the same dosage.The high temperature performance,though higher than that of base asphalt,decreases to some extent.After comprehensive analysis,the optimal dosage of crumb rubber for OCRMA is 30%.

Engine performance and combustion characteristics of a direct injection compression ignition engine fueled waste cooking oil synthetic diesel

Biodiesels produced from various feedstocks have been considered as alternative fuels used in internal combustion engines without major modifications.This research focuses on producing biodiesel from waste cooking oil(WCOSD)by the catalytic cracking method using MgO as the catalyst and comparing the engine operating characteristics of the test engine when using WCOSD and traditional diesel(CD)as test fuels.As a result,the brake power of the test engine fueled WCOSD,and traditional diesel is similar.However,the engine fuel consumption in the case of using WCOSD is slight increases in some operating conditions.Also,the nitrogen oxides emissions of the test engine fueled WCOSD are higher than those of CD at all tested conditions.The trend is opposite for hydrocarbon emission as the HC emission of the engine fueled by WCOSD reduces 26.3%on average.The smoke emission of the test engine in case of using WCOSD is lower 17%on average than that of CD.However,the carbon monoxide emissions are lower at the low and medium loads and higher at the full loads.These results show that the new biodiesel has the same characteristics as those of commercial biodiesel and can be used as fuel for diesel engines.

Esterification of Free Fatty Acids in Waste Cooking Oil by Heterogeneous Catalysts

Waste cooking oil(WCO) is becoming the most promising alternative feedstock to produce biodiesel due to its low cost in China. In this study, NKC-9 ion-exchange resin and H-beta zeolite were selected as heterogeneous catalysts in the WCO esterification process and their esterification characteristics were compared by orthogonal experiments. NKC-9 resin showed higher activity and achieved a higher final conversion compared with H-beta zeolite under the same reaction conditions. Reusability experiments showed that NKC-9 resin still exhibited high activity after 5 runs. The effects of the mole ratio of alcohol to oil, reaction time, reaction temperature and the catalyst dose were investigated by multifactor orthogonal analysis. The influence of the free fatty acid(FFA) content was also investigated, and the result showed that the esterification rate could be as high as 98.4% when the FFA content was 6.3wt%.

Biodiesel Production from Waste Cooking Oil over Mesoporous SO42-/Zr-SBA-15

从在 SO4 2/Zr-SBA-15 催化剂上的浪费食用油的 Biodiesel 生产成功地被执行并且调查。SO4 2/Zr-SBA-15 催化剂被一步舞过程作为锆资源用无水的锆硝酸盐准备，并且赋予了以强壮的路易斯酸地点由支持锆种类到 SBA-15 表面上形成了。同样准备的 SO4 2/Zr-SBA-15 在优化反应条件下面与甲醇为浪费食用油的 transesterification 显示出 92.3% 的优秀 triglyceride 变换效率和 91.7% 的丰满的酸甲基酉旨(名声) 产量：甲醇 / 油 30 的臼齿的比率， 160 的反应温度提高甘蔗甘蔗渣 saccharification。与90.1%葡萄糖选择减少糖产量中的超过65%个在 50 摯椠?桷捩?被完成?眠獡甠敳?獡愠獳獩楴杮映畬?湡??慬杲?整灭牥瑡牵?牧摡敩瑮???鰠??釦?鳛???鴿鮘???微鴿钤??颞酋?鱎?隝????龜?徬?疞?螮趬鐿?????????吗????？？

The Kinetics of the Esterification of Free Fatty Acids in Waste Cook- ing Oil Using Fe2（SO4）3/C Catalyst

The esterification of free fatty acids(FFA) in waste cooking oil with methanol in the presence of Fe2(SO4)3/C(ferric sulfate/active carbon) catalyst was studied.The effects of different temperature,methanol/FFA mole ratio and amount of catalyst on the conversion of FFA were investigated.The results demonstrated that under optimal esterification conditions the final acid value of the resultant system can be reduced to ～1(mg KOH)·g-1,which met fully the requirements in post-treatment for efficient separation of glycerin and biodiesel.The kinetics of the esterification were also investigated under different temperatures.The results indicated that the rate-control step could be attributed to the surface reaction and the esterification processes can be well-depicted by the as-calculated kinetic formula in the range of the experimental conditions.

Diffusion and Regeneration Mechanism of Waste Composite Oils Rejuvenator in Aged Asphalt

The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,the diffusion degree of the rejuvenator under different temperatures and time process was analyzed,and the diffusion efficiency of the rejuvenator was evaluated from the macro and micro perspective.The regeneration mechanism of the rejuvenator in the aged asphalt was also analyzed using the Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and chemical composition tests.The research results showed that the optimum rejuvenator content was about 3%.Higher temperature and longer time were beneficial to improving the permeability and diffusion of the rejuvenator.During the aging process,the light components were reduced,and more macromolecular asphaltenes were generated as well as a large number of carbonyl and sulfoxide.After diffusion and regeneration,the light components in the asphalt were supplemented,the wrinkles and gullies of the aged asphalt were almost improved to the surface state of the matrix asphalt.

不同生物油再生沥青性能比选

为确定生物油对老化沥青性能的恢复能力,比选出再生能力较强的一种生物油并确定其最佳掺量,采用植物沥青、餐厨废弃油脂和工业用动物油3种生物油作为再生剂,分别对老化SBS改性沥青进行再生,通过测定生物油再生沥青的针入度、延度、软化点和布氏黏度并进行薄膜加热试验,研究生物油种类和掺量对老化沥青各项性能的影响规律。结果表明,3种生物油对老化SBS改性沥青的基础性能和耐老化性均有一定的恢复能力,其中餐厨废弃油脂对老化沥青再生能力较强,并且社会和经济效益较高,植物沥青和工业用动物油次之;餐厨废弃油脂被选为最佳再生生物油,掺量为4%时能够使老化SBS改性沥青的黏滞性和高温性能得到完全恢复,因此被确定为最佳掺量。

Metakaolinite as a catalyst for biodiesel production from waste cooking oil

The use of metakaolinite as a Catalyst in the transesterification reaction of waste cooking oil with methanol to obtain fatty acid methyl esters （biodiesel） was studied. Kaolinite was thermally activated by dehydroxylation to obtain the metakaolinite phase. Metakaolinite samples were characterized using X-ray diffraction, Nz adsorption-desorption, simultaneous thermogravimetric analyse/differential scanning calorimetry （TGA/DSC） experiments on the thermal decomposition of kaolinite and Fourier-transform infrared spectrometer （FTIR） analysis. Parameters related to the transesterificaion reaction, including temperature, time, the amount of catalyst and the molar ratio of waste cooking oil to methanol, were also investigated. The transesterification reaction produced biodiesel in a maximum yield of 95% under the following conditions： metakaolinite, 5 wt-% （relative to oil）; molar ratio of oil to methanol, 1：23; reaction temperature, 160℃; reaction time, 4 h. After eight consecutive reaction cycles, the metakaolinite can be recovered and reused after being washed and dried. The biodiesel thus obtained exhibited a viscosity of 5.4 mm2＂ s-1 and a density of 900.1 kg-m-3. The results showed that metakaolinite is a prominent, inexpensive, reusable and thermally stable catalyst for the transesterification of waste cooking oil.

Emissions of intermediate volatility organic compound from waste cooking oil biodiesel and marine gas oil on a ship auxiliary engine

Ship auxiliary engines contribute large amounts of air pollutants when at berth.Biodiesel,including that from waste cooking oil(WCO),can favor a reduction in the emission of primary pollutant when used with internal combustion engines.This study investigated the emissions of gaseous intermediate-volatile organic compounds(IVOCs)between WCO biodiesel and marine gas oil(MGO)to further understand the differences in secondary organic aerosol(SOA)production of exhausts.Results revealed that WCO exhaust exhibited similar IVOC composition and volatility distribution to MGO exhaust,despite the differences between fuel contents.While WCO biodiesel could reduce IVOC emissions by 50%as compared to MGO,and thus reduced the SOA production from IVOCs.The compositions and volatility distributions of exhaust IVOCs varied to those of their fuels,implying that fuel-component-based SOA predicting model should be used with more cautions when assessing SOA production of WCO and MGO exhausts.WCO biodiesel is a cleaner fuel comparing to conventional MGO on ship auxiliary engines with regard to the reductions in gaseous IVOC emissions and corresponding SOA productions.Although the tests were conducted on test bench,the results could be considered as representative due to the widely applications of the test engine and MGO fuel on real-world ships.

Molecular dynamics simulation on the rejuvenation effects of waste cooking oil on aged asphalt binder

Waste cooking oil(WCO)has received attention on rejuvenating aged asphalt binder widely in recent years.This study evaluated the rejuvenation effects of WCO on aged asphalt binder on the micro-scale using molecular dynamics(MD)simulation.First,the representative molecules of WCO and asphalt binders were selected.The molecular mixture model was then developed.The thermodynamic properties were investigated,including density,cohesive energy density,solubility parameter,and surface free energy.The results show that WCO can restore the thermodynamic properties of aged asphalt binder to some extent and WCO has different influences on electrostatic interactions and van der Waals effects.From the diffusion behavior and molecular structure of asphalt binder,WCO can improve the molecular mobility and restore the colloidal structure.Besides,the adhesion work and moisture susceptibility of asphalt binder-aggregate interfaces(calcite and quartz)were evaluated.The results show that WCO can improve adhesion work between asphalt binder and aggregates since WCO can change molecular structure of asphalt binders and certain adhesion work exists between WCO and aggregates.Also,it can mitigate the moisture susceptibility of asphalt binder-aggregate interfaces(calcite and quartz).The study demonstrates that the MD simulation can help to understand the rejuvenation effects of WCO on aged asphalt binder on the micro-scale.

Impact of different nano additives on performance, combustion, emissions and exergetic analysis of a diesel engine using waste cooking oil biodiesel

Biodiesel is derived from waste cooking oil (WCO) by transesterification. Methylester was prepared by mixing diesel and biodiesel oils as 20% by volume. Nano particles asTiO2, Al2O3 and CNTs were blended with biodiesel blend at different concentrations of 25,50, and 100 mg/l to enhance the physicochemical fuel characteristics to obtain clean and effi-cient combustion performance. An experimental setup was incorporated into a diesel engine toinvestigate the influence of these nano-materials on engine performance, exergy analysis, combustion characteristics and emissions using WCO biodiesel-diesel mixture. Enriching methylester mixture with 100 ppm titanium, alumina and CNTs (B20T100, B20A100 andB20C100) increased the thermal efficiency by 4%, 6% and 11.5%, respectively compared toB20. Biodiesel blending with nano additives B20T100, B20A100 and B20C100 decreasedthe emissions of CO (11%, 24% and 30%, respectively), HC (8%, 17% and 25%, respectively)and smoke (10%, 13% and 19%, respectively) compared to B20. However, the noticeable increase of NOx was estimated by 5%, 12% and 27% for B20T100, B20A100 and B20C100,respectively. Finally, the results showed the rise in peak cylinder pressure by 5%, 9% and 11% and increase in heat release rate by 4%, 8% and 13% for B20T100, B20A100 andB20C100, respectively. The fuel exergy of B20T100, B20A100 and B20C100 are lower thanbiodiesel blend B20 by 6.5%, 16% and 23% but the exergetic efficiency are increased by 7%,19% and 30% at full load about B20.