Waste Edible Research Articles

Modified banana peel biochar-based green nanocatalyst for biodiesel production and its utilization to improve diesel engine performance and emission

This study introduces the integration of catalyst green, waste oil, and ultrasonication procedure for biodiesel synthesis, thereby addressing existing gaps in the present paper. In this scientific research, an efficient modified banana peel green catalyst was prepared via the pyrolysis procedure and utilized for biodiesel production from waste edible oil (WEO). Various analyses, including XRD, FTIR, FESEM, EDX/mapping, CO2-TPD, TEM, and BET-BJH were conducted to evaluate the catalyst structure. The results reveled that modified banana peel have spherical shaped particles with surface area of 127.56 m2g−1 and the size of the particle is <50 nm with basic sites of 206.4 µmol/g indicating suitable as catalyst for transesterification process. The highest biodiesel yield of 97.13 % was achieved under optimum conditions (ultrasonication time of 32.53 min, catalyst dosage of 3.23 wt%, methanol to WEO molar ratio of 11.51 and reaction temperature of 63.41 °C). Besides, the reusability of the modified banana peel nanocatalysts was demonstrated through multiple reuse stages, indicating high stability and consistent biodiesel yield over seven cycles (87.65 %) with biodiesel yield reduction of 9.48 %. Furthermore, the study investigated the effects of incorporating 20 % biodiesel into diesel (B20) and the presence of modified banana biochar in B20 on a compression-ignition diesel engine. The results revealed positive impacts on reducing CO (26.08 %) and UHC (25 %) emissions compared to diesel fuel and enhancing engine parameters using B20 with 80 ppm banana peel biochar. Moreover, the activation energy and exponential factor for the conversion of WEO to biodiesel are reported as 45.58 kJ/mol and 7.97×105 min−1, respectively. In summary, the modified banana peel nanocatalyst emerges as a standout option for biodiesel production, offering outstanding reusability, rapid reaction rates, and significant biodiesel efficiency attained within a quick reaction time.

Recycling of waste edible oil derivatives as phase change materials for building energy conservation

A novel phase change microcapsule with waste edible oil derivatives core shelled by silica was prepared for building energy conservation. The substance composition, phase change parameters, and functional group of the derivatives were characterized. The phase change temperature, phase change enthalpy, and particle size of phase change microcapsules were determined. The effect of microcapsules on foamed concrete was evaluated, including mechanical and thermal properties. The results indicate that the waste edible oil derivatives with a phase change temperature of around 18 °C and a phase change enthalpy of about 140J/g are mainly composed of 73.8% methyl palmitate and 16.2% methyl oleate. The phase change temperature and enthalpy of the microcapsules with a 1:1 shell-to-core ratio are 20 °C and 73J/g, respectively. Additionally, the Dv (50) and Dv (90) of the microcapsules are 139 μm and 380 μm, respectively. Furthermore, the recommended dosage of microcapsules in foamed concrete should not exceed 6.0 wt% considering the mechanical properties of foamed concrete. During the heating process, the temperature of foamed concrete containing 6.0 wt% microcapsules is up to 4.3 °C lower than that of conventional concrete. On the other hand, the cooling rate of foamed concrete containing 6.0 wt% microcapsules is 51.5% lower than that of conventional concrete. This work realizes both building energy conservation and resource utilization of waste edible oil.

Effects of surface functional groups on the wettability of biodiesel combustion particulate matter

This paper investigates the impact of particle surface functional groups on the wettability of particulate matter (PM) emitted from biodiesel engines. Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectrometry (XPS), and Contact Angle Measurement techniques were employed to detect and analyze PM generated from combustion of diesel, soybean oil methyl ester (SME), palm oil methyl ester (PME), and waste edible oil methyl ester (WME) biodiesels. The results showed that PM derived from biodiesel exhibited a higher content of aromatic nuclei compared to that from diesel. The surface of the PM displayed significantly elevated levels of C–OH functional groups in comparison to CO functional groups, and the relative proportion of C–OH and CO functional groups on the biodiesel-derived PM surface decreased with an increase in biodiesel iodine value. The contact angles of the PM to the diesel droplets were less than 20°, and the PM is highly lipophilic. The wettability of the PM with both water and diesel droplets increased as the relative content of C–OH and CO functional groups rose. Moreover, it was observed that biodiesel-derived PM exhibited superior wettability towards water and diesel droplets when compared to its diesel counterpart, thereby enhancing its susceptibility to wetting by diesel droplets.

Ultrasound irradiation-assisted biodiesel synthesis from waste oils employing a retrievable and strong CoFe2O4/GO/SrO nanocatalyst

A novel heterogeneous CoFe2O4/GO/SrO nanocatalyst was synthesized using ultrasonic irradiation, and employed for synthesizing biodiesel from waste edible oil (WEO). To this end, a 2-step esterification-transesterification reaction utilizing ultrasound was applied. The surface attributes of CoFe2O4/GO/SrO was specified by XRD, FTIR, FESEM, EDX/Map, BET, DLS, CO2-TPD, and VSM analyses. CO2-TPD analysis indicated that the CoFe2O4/GO/SrO nanocatalyst has favorable catalytic activity for transesterification. CCD-based RSM approach was employed to examine the influence of parameters and ascertain optimal conditions under ultrasonic irradiation (24 KHz, 200 W, 70 % duty cycles and 60 % amplitude). Also, the utmost biodiesel yield (98.63 %) was achieved using CoFe2O4/GO/SrO under optimum conditions (i.e., time = 53.76 min, temperature = about 69 °C, CH3OH/oil proportion = 16.3:1, and nanocatalyst dosage = 5 wt%), which is the highest biodiesel performance ever attained using WEO. However, the highest biodiesel yield under optimal conditions by magnetic-stirrer at 600 rpm was 72.9 %, which is much lower than utilizing ultrasonic irradiation. Further, the stability investigation indicated that the CoFe2O4/GO/SrO nanocatalyst has a yield of over 90 % after five reuse stages, which reveals its remarkable stability. Besides, the kinetics of biodiesel production displayed that the reaction between methanol and WEO utilizing CoFe2O4/GO/SrO nanocatalyst is endothermic and the reaction rate enhances with temperature. On account of its high biodiesel yield, favorable catalytic activity, short reaction time, and remarkable stability, the CoFe2O4/GO/SrO nanocatalyst is strongly recommended for biodiesel generation from WEO in the presence of ultrasonic irradiation for industrial applications.

Energy and economic aspects of efficient radiative heating for biodiesel production: Prospects and challenges of using solid magnetic CaO/CoFe2O4 nano-catalyst

Direct radiative heating using an infrared (IR) source is experimentally investigated in the production of biodiesel from waste edible oil using CaO and self-synthetized CaO/CoFe2O4 as heterogeneous solid catalysts. The nano-sized CaO/CoFe2O4 particles show 30 % lower specific energy (i.e. the required energy to produce 1-L biodiesel) than that of CaO for the case of radiative (IR) heating. Meanwhile, comparing the radiative and conventional heating methods shows that the specific energy and the reaction time are reduced by 75 % and up to 50 %. However, the specific cost (i.e. the cost required to produce 1-L biodiesel) corresponding to CaO/CoFe2O4 is higher than that of CaO by 36–56 %. The strong magnetic characteristic of CaO/CoFe2O4 makes the separation process easy and has a good potential for recycling purposes. Overall, CaO/CoFe2O4 under radiative heating showed the advantages of having a high yield efficiency, shorter reaction time, low specific energy, and ease of separation which make it a good candidate for large-scale productions, while the specific cost and cyclic performance are the present challenges and still require further studies.

Sequential processing of nitrogen-rich, biowaste-derived carbon quantum dots combined with strontium cobaltite for enhanced supercapacitive performance

Disposal of waste edible oil is a major concern for government regulatory bodies worldwide, with improper disposal leading to the blocking of sewer lines, polluting water bodies, and degrading the environment. In the present work, waste soybean oil is converted into soot and hydrothermally processed to produce nitrogen-rich carbon quantum dots (N-CQDs). The N-CQDs are further treated with strontium cobaltite (SC) prepared via the sol-gel method. A significant difference is observed in the morphology, surface area, and electrochemical performance of the N-CQDs (124 Fg−1), SC particles (106.7 Fg−1), and the combined SC@N-CQDs material (386.5 Fg−1). The bio derived SC@N-CQD sample is used as an electrode in a symmetrical supercapacitor, and the device shows EDLC behavior with co-contribution of minor pseudocapacitance due to the nitrogen functional groups and Co2+/Co3+ states of the SC. The SC@N-CQDs deliver an exceptionally high specific capacitance of 180.24 Fg−1 at 0.5 Ag−1 due to the enhanced surface area offered by the combined material, good conductivity imparted by the N-CQDs, and oxygen vacancies in the SC. The synergy leads to fast ion diffusion between the electrode and the electrolyte interface, and an additional boost is achieved by the pyrrolic-N and pyridinic-N present in the electrode material. The capacitance retention is 80.8% of the initial capacitance after 5000 cycles. The SC@N-CQD supercapacitor provides a high energy density of 7.51 Whkg−1 and can operate a red LED, thus demonstrating the efficient utilization of waste edible oils to yield high-performance material for supercapacitor applications. This study can have a broad environmental impact on the reduction and reuse of biowaste.

Feasibility assessment of palmitamide derived from waste edible oil as a warm mix asphalt additive

The disposal of waste edible oil (WEO) has become a global challenge with both environmental and economic issues. To provide a novel strategy for the refinement recycling of WEO, this work investigated the feasibility of palmitamide derived from WEO as a warm mix asphalt (WMA) additive. The molecular structure and thermodynamic characteristics of palmitamide were first determined. Following, WMA binders with different palmitamide contents were prepared and their temperature sensitivity and rheological properties were evaluated. Additionally, the engineering performance of WMA mixtures was explored and the environmental benefits of WEO-derived palmitamide were assessed using the gas chromatography-mass spectrometry. The results demonstrate that the phase transition temperature of WEO-derived palmitamide is 98.87 °C, which shows great potential as a WMA additive. Palmitamide provides asphalt workability suitable for construction at relatively low temperatures through reducing the flow activation energy of asphalt. In addition, the moisture damage resistance and deformation resistance of WMA is also improved due to the hydrophobicity and filling effect of palmitamide, respectively. While it is inevitable that palmitamide slightly weakens the fatigue and low-temperature performance of WMA. Moreover, the application of WEO-derived palmitamide can reduce the volatile organic compounds of asphalt in the mixing stage and compaction stage by 40.3% and 30.8%, respectively. The findings contribute to the sustainable development of road engineering and the circular of waste resources.

Enhanced performance of activated carbon-based supercapacitor derived from waste soybean oil with coffee ground additives

Waste edible oil is discarded in enormous amounts worldwide and poses a serious threat to the environment. The work presented in this paper focuses on the synthesis and fabrication of an electrochemical electrode using waste soybean oil and waste coffee ground to provide enhanced supercapacitive characteristics. We demonstrate a novel method of synthesizing activated carbon (AC) using soot collection, wherein two distinct approaches of mixing coffee ground to waste soybean oil via ultrasonication and hydrothermal treatment have been presented. The two methods lead to different and unique properties in terms of the material porosity, particle size, surface area, carbon and nitrogen content, and the hybridization states of the materials. These properties are correlated with the performance of different supercapacitors. A twofold increase in the highest specific capacitance is observed for the sample prepared using ultrasonication mixing of coffee ground (70.97 Fg-1 at 0.5 mA cm−2) compared to the sample prepared using hydrothermal technique (36.79 Fg-1 at 0.5 mA cm−2). The ultrasonicated sample has a surface area of 684.71 m2g-1. A capacitance retention of ∼90% is observed after 1010 cycles showing good device stability.

Microwave-assisted catalytic co-pyrolysis of waste edible oil and low-density polyethylene: Synergistic enhancement of co-melt feeding

In this study, a new delayed feeding process for blending waste edible oil (WEO) as cosolvent with molten low-density polyethylene (LDPE) applied in microwave-assisted fixed bed pyrolysis was proposed. The experiment was carried out at the melting temperature of 250 ℃, the pyrolysis temperature of 550 ℃, and the catalytic temperature of 450 ℃. The co-feeding of the WEO and molten LDPE effectively promoted the formation of light aromatics, with the content of monocyclic aromatic hydrocarbons as high as 82.69 % (LDPE/WEO = 1:3) and the relative content of BTEX (benzene, toluene, ethylbenzene, xylenes) as high as 65.96 %. The proportion of feedstocks affects the distribution of pyrolysis products by adjusting the content of hydrogen radicals in the pyrolysis system. Hydrogen radicals derived from LDPE can combine with oxygen-containing intermediate from triglycerides, to promote the removal of oxygen in the form of H2O, and inhibit the decarboxylation and decarbonylation reactions. Compared with the pre-feeding process, the relative content of BTEX increased by 14.43 % and the relative content of PAHs decreased by 10.86 %. The application of downdraft reactors further improved the relative content of BTEX in pyrolysis oil. When the mass of SiC was 500 g, the peak relative content of BTEX was 69.79 %. This study provides a new process for the effective production of light aromatic hydrocarbons.

Enhanced Biodiesel Synthesis via a Homogenizer-Assisted Two-Stage Conversion Process Using Waste Edible Oil as Feedstock

In this study, a homogenizer in conjunction with a two-stage process was utilized to facilitate biodiesel production from waste edible oil (WEO). This paper contributes to the improvement of the yield and the shortening of the reaction time for biodiesel synthesis. Sulfuric acid was used in the first stage which was the esterification of the free fatty acids (FFA) of the WEO; then the transesterification reaction of triglycerides took place in the second stage with an alkaline catalysis. The present investigation aimed to explore the parameters affecting the reactions, including homogenizer speed, alcohol/oil molar ratio, catalyst dosage, reaction temperature, and reaction time. Under the operating conditions of the first stage (the reaction temperature was 65 °C, the homogenizer speed was 8000 rpm, the methanol/oil molar ratio was 15:1, and the amount of sulfuric acid was 4 wt%), the acid value fell to below 2 mg KOH/g after 10 min. The best base-catalyzed conditions in the second stage were: homogenizer speed of 8000 rpm, NaOH catalyst concentration of 1 wt%, methanol/oil molar ratio of 9:1 (mol/mol), reaction temperature of 65 °C, and reaction time 10 min. Consequently, the conversion rate from WEO to biodiesel achieved 97% after only 20 min, in line with the EU EN14214 standard, which requires a biodiesel production rate of at least 96.5%.

Effect of carbonaceous components of biodiesel combustion particles on optical properties

This paper studies the influence of carbonaceous components on the optical properties of particulate matter (PM) in biodiesel combustion by conducting a bench test on an electronically controlled high-pressure common-rail diesel engine. In addition, the PM produced by the combustion of diesel oil, soybean oil methyl ester (SME), waste edible oil methyl ester (WME), and palm oil methyl ester (PME) was collected. The carbonaceous composition and optical properties of diesel and three biodiesel particulates were then analyzed. The obtained results showed that the ratio of organic carbon (OC) to total carbon (TC) in diesel PM was 0.25 and the ratio of OC/EC was 0.33. The OC to TC ratio of biodiesel PM was significantly greater than that of diesel PM, ranging between 0.59 and 0.65, with OC/EC values in the range of 1.44–1.86. The mass absorption cross-section (MAC) values of three kinds of biodiesel particles were all higher than those of diesel particles. When the incident laser wavelength increased, the difference of MAC values among four kinds of fuel particles gradually decreased. The MAC values of all the three biodiesel particles were higher than those of the diesel particles, and the difference between the MAC values of the four fuel particles gradually decreased with the increase of the incident laser wavelength. Afterwards, the “shell-core” model of particles was developed with 80 nm EC sphere as the core. At the two refractive indices, the scattering cross section, absorption cross section, and extinction cross section of the particles decrease with the increase of the incident light wavelength, and the scattering cross section, absorption cross section, and extinction cross section of the particles increase with the increase of the OC coating thickness.

Nanocatalysts for biodiesel production

Biofuels are a class of clean fuels and promising for energy demand. Biodiesel is relatively costly, which limits the commercialization of the product. The waste edible oil and animal fats are raw materials for biodiesel production. This paper focuses on the catalytic production of biofuels and reviews the application of different catalysts to produce biodiesel from waste oils by using esterification and transesterification reactions. The reaction in the presence of nanocatalysts is carried out under mild operating conditions. Nowadays, magnetic nanocatalysts are preferred to bulk catalysts due to the absence of mass transfer resistance and fast deactivation as well as high recovery rate during the separation. Functionalized magnetic nanocatalysts are more attractive for biodiesel production. Further studies should do to develop highly active and selective nanocatalysts for industrial scale.

Ultrasound-assisted biodiesel generation from waste edible oil using CoFe2O4@GO as a superior and reclaimable nanocatalyst: Optimization of two-step transesterification by RSM

In current study, CoFe2O4@graphene oxide (GO) and CoFe2O4 heterogeneous nanocatalysts were successfully synthesized using the ultrasonic method and then used to generate biodiesel from waste edible oil (WEO) in a two-step transesterification process. To do so, the catalysts surface was characterized using CO2-TPD, SEM, EDX/Map, XRD, VSM, BET, FTIR, and DLS analyses. Also, central composite design (CCD) was utilized to optimize the impact of various factors on biodiesel generation. With the help of ultrasonication, the highest biodiesel yield using CoFe2O4 (91.64%) and CoFe2O4@GO (98.17%) was achieved at time of 55.75 min, temperature of 64.75 °C, methanol/oil ratio of 16.05:1 and catalyst concentration of 5.22 wt%. Also, the highest biodiesel yield without ultrasonication using CoFe2O4 and CoFe2O4@GO were gained as 58.96 and 67.13%, respectively. Moreover, the highest predicted biodiesel yield in the presence of CoFe2O4@GO by the RSM-CCD method is 98.95%, which is the maximum biodiesel yield ever achieved from WEO. The outcomes show that ultrasound-assisted transesterification is an efficient method for biodiesel generation, which can reduce costs and production time. After 5 reuse cycles, the CoFe2O4@GO nanocatalyst showed a yield of about 90%, which is due to its desirable magnetic attributes and easy separation. According to international standards and using FT-IR and HNMR analyses, the biodiesel produced can be used in diesel engines without further modification. Besides, kinetic and thermodynamics studies indicated that the generation reaction of biodiesel using both nanocatalysts is endothermic and non-spontaneous.

Molecular design of environmental friendly green plasticizers

<p indent="0mm">Plasticizers are substances that can increase the plasticity and processibility of the polymer materials. Plasticizer is one of the largest chemical additives for plastic processing industry, which can effectively improve its processing performance and has great economic and social significance. Ideal plasticizer should have good compatibility with the polymer. It should have high plasticization efficiency and light, heat, weather resistance. Low volatility, slow migration rate, excellent electrical insulation, non-toxicity, being odorless, tasteless and colorless, excellent stain resistance as well as being cheap and easily available are desirable properties ideal plasticizer would have. Among thousands of compounds that being able to be taken as plasticizers, there are only less than 100 kinds that subjecting to wide application. Phthalic acid esters plasticizers (such as dibutyl phthalate, dioctyl phthalate) are used in the largest amount. The advantages and disadvantages of the main commercial plasticizers are analyzed, especially phthalate plasticizers. However, recently phthalate plasticizers have been restricted in many countries and regions due to their toxic side effects and impacts on human health and environment. Some phthalate plasticizers can kill soil and aquatic organisms when they degrade into relatively persistent toxic metabolites. By designing green plasticizers, researchers are finding alternatives to conventional plasticizers that may alleviate health concerns. In this review, the research progress of environmental friendly green plasticizers is summarized from the molecular design perspective. Firstly, the working principle of plasticizer is elucidated and the lubrication theory, gel theory and free volume theory are discussed. The basic working mechanism is the insertion of the plasticizer molecules between the chains of polymers, making the interaction between polymer chains weakened, and thus decrease the aggregation of molecular chains, and increase the movement property, softness of molecular chains, making the plastic materials more easily to be processed. Polar plasticizer can weak the polarization effect between polar polymer chains and the non-polar plasticizer can increase the space volume between polymer chains. Environmental friendly green plasticizers are alternative solution to gradually replace traditional petroleum based plasticizers in the future. Bio-based plasticizers with renewable resources have attracted significant attention. These plasticizers have the advantages of renewable, easily degradable, non-toxic, and migration resistance, and are promising substitutes for phthalate plasticizers. This review summarizes the latest research progress of plant oil based plasticizers such as soybean oil and castor oil. The distinctive structure and property features of hyperbranched polyester plasticizers (such as adipic acid type and ε-caprolactone type polyester plasticizers) are described. In addition, due to the unique structure, hyperbranched polyester plasticizers have strong anti-migration ability and play an important role in applications that require high migration resistance, such as children’s products, food packaging and medicine. Specific examples of design and application of plasticizers based on cashew phenol, waste edible oil, lactic acid, rosin and tartaric acid are highlighted. Finally, the relationship between chemical structure and properties of plasticizer is analyzed. It is proposed that molecular design will be promising approach for novel plasticizer design. The replacement of petroleum-based plasticizers with bio-based environmental friendly green plasticizers is the future direction in plastic industrial. This review analyzes the relationship between the characteristic molecular motifs and properties and performances of plasticizer. The approach and perspectives of designing next generation of plasticizers are proposed and future trend and outlook are predicted.

Review on technology of making biofuel from food waste

The disposal of food waste has become an environmental issue of great concern with the increasing consumption of materials. The conversion of food waste into biofuels using biotechnology is a very promising approach. Food waste can be converted into fuels such as bio-methane, bio-hydrogen, bio-ethanol, and bio-diesel by different biotechnologies. Food wastes as raw materials for biofuel preparation are mainly classified into protein, fat, starch, sugar, and cellulose. Carbohydrate-rich wastes such as straw, bagasse, grape and apple pomace, and kitchen garbage can produce biofuels, which can be converted into biofuels through anaerobic digestion, aerobic digestion, and microbial fermentation processes. Co-substrates are increasingly used to increase biofuel production and to overcome the shortcomings of a single substrate. The main raw materials for each biofuel are different. Anaerobic digestion technology can be utilized for the production of biomethane, and the digestion efficiency can be changed by the adjustment of the substrate combination, and reactor configuration. The process of methane production by anaerobic digestion mainly includes hydrolysis, acid production, acetic acid production, and methane production. The main raw materials used for methane preparation are livestock manure (pig manure, chicken manure, cow manure, etc.), straw and kitchen waste. Each raw material has a different methane yield and environmental friendliness. Fermentation technology of Saccharomyces cerevisiae can be used to produce bio-ethanol, which consists mainly of raw material pretreatment, enzymatic digestion (saccharification), fermentation, and ethanol production. Cellulosic raw materials (including hemicellulose) are the most promising raw materials for ethanol production on earth, mainly straw, wood chips, peanut shells, and corn. Coupled biomass dark and photo-fermentation technologies can be utilized to produce bio-hydrogen, which includes degradation, dark fermentation, photo-fermentation, and hydrogen production. Food waste containing lipids, proteins, and complex carbohydrates is a good substrate for the dark fermentation stage. The main raw materials for hydrogen production are kitchen wastewater, sugars (glucose), starch (cassava), and cellulose (water hyacinth and rice straw). Hydrothermal liquefaction, hydrothermal gasification, and hydrothermal carbonization technologies can be utilized to produce bio-oil or bio-char. The raw materials for bio-oil/biochar are mainly Edible vegetable oil, nonedible vegetable oil, animal oil, waste edible oil, coffee residue, peanut shell, brewer's grains, grape pomace, sugarcane peel, straw, and wood chips, etc. The industrialization of biofuel technologies is limited by the lack of relevant research and needs to be extensively and thoroughly evaluated. In this paper, the respective advantages and disadvantages of each biofuel technology are clarified and the effects of culture conditions, pretreatment technologies, and reactors on biofuel production are discussed from a technological perspective. In the future, the technology of producing biofuels from various food wastes needs more research in waste conversion rate, product yield, treatment cycle, and cost effectiveness.

MgO@CNT@K2CO3 as a superior catalyst for biodiesel production from waste edible oil using two-step transesterification process

Due to limited fossil fuel resources and greenhouse gas emissions, the use of biodiesel is increasing. In this study, biodiesel was produced from waste edible oil (WEO), as a low-cost oil, using MgO and MgO@CNT@K2CO3 catalysts. The MgO@CNT@K2CO3 catalyst was first synthesized in this study and used to produce biodiesel. To this end, the features of these catalysts were studied using FTIR, BET, XRD, EDX, SEM, and Map analyses. The results indicated that both catalysts have high catalytic activity with mesoporous structures. Due to the high content of free fatty acid (2.43 wt%) in WEO, a two-step transesterification process was used to convert WEO to biodiesel. In the first step, hydrochloric acid homogeneous catalyst was employed to reduce the FFA content and then in the second step, MgO and MgO@CNT@K2CO3 heterogeneous catalysts were used to generate biodiesel. The highest biodiesel yields using MgO and MgO@CNT@K2CO3 were 94.26% and 98.25%, respectively, which were achieved at a catalyst concentration of 4%, temperature of 65 °C, and methanol/oil ratio of 24:1 and 20:1 after 5 and 4 h for MgO and MgO@CNT@K2CO3, respectively. The MgO@CNT@K2CO3 showed the highest biodiesel yield ever achieved from WEO. Also, the physical features of biodiesel were investigated and the results demonstrated that the biodiesel produced are in accordance with ASTM D6751 and EN14214 standards. Moreover, kinetic and thermodynamic studies showed that the transesterification reaction is endothermic and non-spontaneous. Therefore, MgO@CNT@K2CO3 is proposed as a strong and cost-effective catalyst for biodiesel generation from WEO on an industrial scale.

Preparation of zinc oxide graphted nickel incorporated mesoporous SBA-16 doped graphene oxide: An efficient catalyst for transesterification of waste edible oil to biodiesel and photocatalytic degradation of organic dyes

Graphene-based composite materials a wide range of applications, including the production of electronic components and capacitors, as well as adsorption and catalysis. In this work, the ZnO/Ni-SBA-16@GO nanocatalyst was applied to synthesized biodiesel from waste edible oil (WEO) as an efficient and easily available source. The said nanomaterial was applied for the degradation of methylene blue (MB) and methyl orange (MO). The catalyst was characterized by HRTEM, XRD (small angle and wide angle), SEM, EDX, BET, N2 adsorption/desorption isotherm, and TGA. The findings illustrated that the nanostructure has well-controlled pore diameter (4.0 nm) and prominent surface area (735 m2/g). Furthermore, it was possible to reuse the catalyst up to five times; with the results indicating that the catalyst's catalytic activity was sufficient for the synthesis of WEO biodiesel for up to three cycles before diminishing. The present study used a centralized composite approach to look at the influence of numerous features on biodiesel synthesis in order to discover the optimal conditions for biodiesel production. According to the findings, the maximum biodiesel conversion yields 98% had been obtained during a 7-hour reaction time at a temperature of 70 °C. The nanostructure has also been worked as a photocatalyst to degrade MB and MO. According to the statistics, more than 90% of both dyes were degraded in less than 40 min.

Highly Active and Recyclable CoFe2O4/GO/SrO as a Novel Nanocatalyst for Biodiesel Generation From Waste Edible Oil Using Ultrasound Irradiation: Optimization by RSM-CCD Method

Highly Active and Recyclable CoFe2O4/GO/SrO as a Novel Nanocatalyst for Biodiesel Generation From Waste Edible Oil Using Ultrasound Irradiation: Optimization by RSM-CCD Method

Possibility of using waste edible oil for biogas production

Anaerobic digestion is a process by which energy from organically degradable waste can be recovered in the form of biogas. The uncontrolled disposal of such organic waste is very burdensome to the environment. In Slovenia, large quantities of waste edible oils are produced every year, which could be used for biogas production. In this study, we investigated the methane potential of waste edible oil in a batch reactor. Further in the pilot scale in a semi-continuous experiment we evaluated the use of waste edible oil in anaerobic digesters of wastewater treatment plant. The results show that the quantity of oil per day that is fed into the anaerobic reactor is limited due to the process's instability and lower biogas production. The optimal daily organic loading of waste edible oil was between 1.6 and 2.4 g VS/L inoculum. During these conditions, the process of anaerobic digestion was stable and methane production was highest. At higher organic loading, the process became unstable, pH was reduced, volatile fatty acids increased, COD at the outflow of reactor increased, and biogas production was significantly reduced.

Pyrolytic conversion of waste edible oil into biofuel using sulphonated modified alumina

Bioenergy generated from vegetable oils is an interesting alternative energy source to fossil fuel in terms of reducing carbon footprint and realizing a circular economy. The catalytic cracking route is a promising method due to its capability to process a variety of feedstocks and its ability to produce a wide range of fuels. Catalytic pyrolysis of waste edible oil was performed using heterogeneous acidic catalyst synthesized through sulphonation of modified alumina. The optimum ratio of the catalyst was 0.8 wt%, relative to the used oil, to produce 88% of liquid biofuel. The acidity of the catalyst was determined, and the analysis showed high activity compared to the recently documented heterogeneous acidic catalysts. The physical properties of the obtained biofuel including viscosity, density, acid value, cloud, pour, flash points, and cetane number were in accordance with ASTM values. Furthermore, these values were better than those recently reported. The most effective process limitation was the deposition of coke during the process, which was in its minimal value at the selected catalyst ratio. The process mechanism was discussed based on oil fatty acid composition. Engine test investigated the obtained biofuel properties, and engine performance of biofuel-diesel blends showed the suitability of the B30 blend.