Dairy Waste Scum Research Articles

Valorization of dairy waste scum oil and rice husk ash-supported CuO nanocatalyst towards cleaner production of biodiesel: A waste-to-energy approach

This study surveys the valorization of dairy waste scum oils (DWSO) to synthesis biodiesel using a novel rice husk ash-supported CuO nanocatalyst. The rice husk ash-supported CuO nanocatalyst was synthesized through a facile impregnation method and characterized by BET, XRD, FTIR, EDX, CO2/TPD, TEM, and FESEM to confirm its structural and morphological features. Transesterification of DWSO was conducted under optimized conditions, achieving a maximum biodiesel yield of 97.42% at temperature of 62.36°C, methanol/DWSO proportion of 11:12, and nanocatalyst loading of 2.76wt.% within 2.85h. Kinetic studies revealed that the transesterification reaction follows a pseudo-first-order model with an activation energy of 100.34kJ/mol. Thermodynamic analysis indicated that the reaction is endothermic (ΔH = 100.26kJ/mol) and non-spontaneous (ΔG = -11043.6kJ/mol) at the studied temperature range, suggesting the requirement of external heat to drive the process. Reusability tests demonstrated that the rice husk ash-supported CuO nanocatalyst retains over 86% of its initial activity after seven cycles, highlighting its potential for practical applications. This study highlights the dual benefits of utilizing agro-industrial waste for both feedstock and catalyst support, promoting a cleaner and economically viable approach for biodiesel generation.

Production of Bio-Diesel from Dairy Waste Scum

Abstract-Dairy factory waste scums are increasingly being considered a valuable resource. However, these wastes may also contain contaminants, natural or artificial, that may adversely affect the land or water to which they are discharged. The study investigates the potential of using dairy waste scum as a feed stock for bio-diesel production. Present study optimized the parameters involved in the alkali catalysed Trans esterification process of dairy waste scum oil. The effects of methanol to oil ratio, temperature and amount of KOH were investigated. A study was conducted to evaluate the capability of production of biodiesel from consortium of native microalgae culture in dairy farm treated waste water. Native algal strains were isolated from dairy farm waste waters collection tank (untreated wastewater) as well as from holding tank (treated wastewater). The consortium members were selected on the basis of fluorescence response after treating with Nile red reagent. Preliminary studies of two commercial and consortium often native strains of algae showed good growth in waste waters. A consortium of native strains was found capable to remove more than 98% nutrients from treated waste water. The biomass production and lipid content of consortium cultivated in treated waste water were 153.54t ha-1 year-1 and 16.89%, respectively. 72.70% of algal lipid obtained from consortium could be converted into biodiesel. The present study found that bio- diesel from dairy waste scum is quite suitable as an alternative to petroleum diesel with recommended fuel properties as per ASTM standards. By using dairy waste scum as a feed stock for bio diesel and the environmental impact related to the disposal of dairy scum Keywords: Environment,Bio-Diesel,Dairy Waste Scum, Extraction of Lipids

Demonstrating photocatalytic esterification as a potential strategy to improve the properties of feedstock oil derived from dairy waste scum for biodiesel production

The availability of quality feedstock for biodiesel production is challenging; and therefore, techniques to improve the quality of feedstock are highly desired, as they could be utilized to modify any feedstock and enhance the biodiesel production. Dairy waste scum oil (DWSO) is recently known to be a valuable feedstock for producing biodiesel. However, DWSO needs to go through an esterification process to reduce its high free fatty acid (FFA) content. To do this, herein, we have treated the DWSO using photocatalytic tin oxide (SnO2) particles under UV light irradiation and reduced the FFA content significantly compared to the conventional cumbersome acid-mediated esterification process. The synthesized catalyst is characterized for its structural, morphological, optical and surface properties using various characterization techniques. Parameters such as catalysts dosage, methanol to oil ratio, reaction time, and temperature involved in the photo-assisted esterification processes are optimized, and a mechanism for the photocatalytic esterification reaction is also proposed. Importantly, SnO2 particles also showed excellent reusability in the photo-assisted esterification process. Overall, the physiochemical and fuel properties of the photo-esterified DWSO-derived biodiesel are found to be improved compared to the biodiesel synthesized via conventional acid-esterified oil.

Synthesis of biodiesel from the composite oil and process parameters optimization using artificial neural network

This study aims to investigate the effect of catalyst utilization (wt%), methanol to composite oil molar ratio (mole) and reaction thermal state (°C) on the biodiesel yield percentage of transesterification of novel composite oil (equal volume % of Castor oil, Mahua oil and dairy waste scum oil). Artificial neural network (ANN) based on central composite design was implemented to investigate the influence of catalyst utilization (1–3 wt%), methanol to composite oil molar ratio (6–12 molar) and reaction thermal state (55–65 °C) as the independent variables. Levenberg-Marquardt algorithm was used to predict the responses, biodiesel yield %. The fairness of the ANN prediction of biodiesel yield % is tested by means of coefficients of determination of training phase, validation set, test set and combined training, validation and test. The results revealed that the optimum catalyst utilization, methanol to composite oil molar ratio and reaction thermal state were determined as 3 wt%, 9 molar, and 65 °C for the maximum biodiesel yield of 94 ± 1% from the composite oil. The ASTM D6751 standard is employed to assess the quality of biodiesel derived from a blend of oils. The findings of this study indicate that the newly developed mixed oil is a viable feedstock for the production of biodiesel.

Syntheses and characterization of lithium modified cao from eggshell and cow bone and its performance in biodiesel production from dairy waste scum oil (DWSO)

Syntheses and characterization of lithium modified cao from eggshell and cow bone and its performance in biodiesel production from dairy waste scum oil (DWSO)

Utilization of Dairy Waste Scum Oil for Microwave-Assisted Biodiesel Production over KOH-Waste Eggshell based Calcium Oxide Catalyst

The sustainability can be maintained by utilizing the available waste as feedstock and catalysts such as dairy and eggshell waste respectively for biodiesel production. In this study, the calcium oxide (CaO) synthesized from calcined eggshell was doped with potassium hydroxide (KOH-ECaO) via wet impregnation method and analyzed the catalyst performance on biodiesel production from dairy waste scum oil (DWSO) via microwave-assisted transesterification. The catalyst was characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy equipped with Energy Dispersive X-ray (SEM-EDX), Brunauer-Emmett-Teller (BET) and Thermogravimetric analysis (TGA). The fatty acid methyl ester (FAME) contents were deduced by Gas Chromatography-Mass Spectrometry (GC-MS). The KOH-ECaO catalyst shows good potential based on the characterization analysis such as high pore size (25.5 nm) which is supported by SEM pattern analysis. The highest biodiesel production (75%) was obtained at optimum reaction parameters conditions. The optimized conditions were discovered to be 3 wt.% of catalyst, 16:1 of methanol to oil molar ratio, reaction temperature of 65°C and 15 minutes of reaction time as microwave provided faster reaction for the transesterification. These innovative results showed that KOH-ECaO could enhance the biodiesel production from DWSO which encourage the usage of waste for wealth product.

Optimization and kinetic studies for biodiesel production from dairy waste scum oil via microwave assisted transesterification

This study presents an investigation of the optimization and kinetic aspects of the microwave (MW) heating transesterification process for converting dairy waste scum oil (DWSO) into biodiesel using lithium impregnated calcium oxide from eggshell (Li-ECaO) as a catalyst. The transesterification was done via microwave heating while varying catalyst loading (1 – 5 wt%), methanol to oil molar ratio (6 – 18:1), temperature (55 – 75⁰C), and reaction time in the range of 5 – 25 min. Response Surface Methodology (RSM) optimized the process parameters, yielding an impressive 90.5% biodiesel yield. The optimal operating conditions were determined 3 wt% catalyst loading, 18:1 methanol to oil molar ratio, a reaction temperature of 65ºC, and a reaction time of 25 minutes. A thorough kinetic analysis of the transesterification reaction for the MW heating transesterification of DWSO by Li-ECaO was performed at various temperatures (45 – 75ºC). The pseudo-first order kinetic study of the reaction revealed a moderately low activation energy of 38.86 kJ/mol and a high pre-exponential factor of 1141.27 s−1, which is consistent with previous studies. Importantly, the observed activation energy was lower than that of conventional methods, highlighting the potential of MW heating as a viable technique for future biodiesel production, and using wastes such as DWSO and eggshell could contribute to being greener and environmentally friendly.

A novel biomass derived activated carbon mediated AC@ZnO/NiO bifunctional nanocatalyst to produce high-quality biodiesel from dairy industry waste oil: CI engine performance and emission

In the current study, biomass-derived activated carbon (AC) with zinc oxide/nickel oxide (AC@ZnO/NiO) bifunctional nanocatalyst with enhanced surface area is utilized for the generation of biodiesel from dairy waste scum oil (DWSO). The synthesized AC and AC@ZnO/NiO catalysts are characterized through XRD, BET, CO2-TPD, NH3-TPD, FTIR, FESEM with EDX, and TEM. Besides, the response surface methodology (RSM) of computational modelling with the central composite design (CCD) algorithm is used to optimize the reaction conditions of ultrasonication-assisted biodiesel production. A maximum 97.81% yield of dairy waste scum oil methyl ester (DWSOME)/biodiesel was attained at optimum reaction parameters of a methanol to oil molar ratio of 11.24:1, an AC@ZnO/NiO loading of 2.41 wt%, an ultrasonic time of 36.62 min, and an ultrasonic power of 240.45 W. The AC@ZnO/NiO nanocatalyst demonstrated noble catalytic strength up to seven cycles with a minor decrement in biodiesel yield. The kinetic study for the conversion of DWSO to DWSOME fits well with a pseudo-first-order reaction. The activation energy (Ea) of 50.88 kJ/mol and frequency factor (A) of 33.1105were found from a kinetic study. Moreover, the thermodynamic analysis shows that the enthalpy and entropy of the activation process are found to be 48.14 kJ/mol and −0.129 kJ/mol.K, respectively. In addition, HNMR and FTIR analyses were conducted for DWSOME. The fuel properties of DWSOME were found in the range of ASTM 6751 standards. Furthermore, the influence of adding DWSOME to diesel at various engine loads on engine performance and emissions of a CI diesel engine indicated acceptable results of diesel engine performance. Finally, the economic feasibility study also conducted in the present study.

Enhanced conversion of dairy waste oil to biodiesel via novel and highly reactive UiO-66-NH2/ZnO/TiO2 nano-catalyst: Optimization, kinetic, thermodynamic and diesel engine studies

This study focuses on developing a novel UiO-66-NH2/ZnO/TiO2 nano-catalyst for efficient biodiesel generation from dairy waste scum oil (DWSO). UiO-66-NH2, UiO-66-NH2/TiO2, and UiO-66-NH2/ZnO/TiO2 nano-catalysts were prepared via the sol–gel approach and their structural features were analyzed by XRD, FT-IR, BET, ED/Map, SEM, TEM, and CO2-TPD approaches. The UiO-66-NH2/ZnO/TiO2 nano-catalyst demonstrated a mesoporous surface with a specific surface area and an average particle size of 568.1 m2/g and 28.35 nm, respectively. The central composite design (CCD) was also utilized to optimize crucial variables. Biodiesel conversion of 98.7 % was achieved under the optimized process circumstances such as the methanol to DWSO ratio of 9.8:1, reaction temperature of 61 °C, and nano-catalyst concentration of 2 wt%. As a novelty, biodiesel conversion is the highest methyl ester achieved from DWSO so far. The survey of the reaction kinetics employing UiO-66-NH2/ZnO/TiO2 indicated that the rate constant, activation energy and Arrhenius factor are 0.1325 min−1, 48.73 kJ mol−1, and 39.6 × 105 min−1, respectively. Besides, the thermodynamic scrutiny implicates that the process is nonspontaneous (ΔG = 88.94 kJ/mol at 338 K) and endothermic (ΔH = 46.01 kJ/mol). Moreover, the impact of adding DWSO-derived biodiesel to diesel on the diesel engine parameters and viscosity alterations was scrutinized. Fuel rheological behaviour appraisal exhibited that biodiesel follows the Newtonian model. The stability of the UiO-66-NH2/ZnO/TiO2 nano-catalyst was assessed in transesterification successive processes. The nano-catalyst could be reused multiple times, and a conversion of 90.14 % was obtained during the 7th consecutive run. It can be concluded that UiO-66-NH2/ZnO/TiO2 nanoparticles can be employed as a highly retrievable nano-catalyst for efficient transesterification of DWSO.

A MILP approach of optimal design of a sustainable combined dairy and biodiesel supply chain using dairy waste scum generated from dairy production

The present study proposes a mixed integer linear programming (MILP) approach for optimal design of a sustainable combined supply chain for the production of biodiesel using as a feedstock dairy waste scum generated from the implementation of optimal product portfolio of dairy supply chain. The latter includes models of economic and environmental impacts of the combined supply, constraints and an optimization criterion in terms of capital and operation costs. Тhe environmental impact is assessed through greenhouse gas emissions obtained through whole life cycle of the products. The proposed approach is implemented on a real case study from Bulgaria. As a result, optimal operating conditions of the considered supply chain, which includes: dairy farms portfolios, dairy plants portfolios, production capacity and location of biorefineries that should be built, performance of biorefineries and transportation routes are obtained. It can be used as a tool for decision-making.

Utilization of Dairy Scum Waste as a Feedstock for Biodiesel Production via Different Heating Sources for Catalytic Transesterification

AbstractThe increasing demand of the world energy consumption has made it necessary to shift energy technologies toward renewable energy sources. The sustainability of feedstock can be maintained when utilizing feedstock from waste sources, such as dairy waste, food waste, and others. Dairy waste is one of the cheapest sources available. The compositions of dairy waste scum, including free fatty acids (8–10 %), triglycerides (more than 80 % in dry bases), and fats around 60 %, which have the potential to be used as the feedstock for biodiesel production in the presence of certain catalysts. To ensure more sustainability, the catalyst should be derived from waste (e.g., eggshells and cow bones) that consists of calcium oxide, which can then be used to catalyze the transesterification of dairy waste. This review emphasizes the current production of dairy waste globally and the potential of the waste and other types of organic waste as feedstock for biodiesel production, as well as determines the optimum reaction conditions for high‐quality biodiesel production.

Dairy waste scum as a potential feedstock for bio-diesel production: optimisation, quality and reliability studies

ABSTRACT Dairy waste scum obtained from the downstream milk production process is a potential source to produce biodiesel. It’s a less dense floating solid mass that primarily consists of triglycerides and fatty acids, which are important constituents for fuel. The present study aims to produce biodiesel using dairy waste scum by a transesterification process using NaOH/KOH catalysts. The present work identifies the better catalyst between two alkaline catalysts NaOH and KOH, using low-cost methodologies. The preliminary confirmation characteristics, such as density, calorific value, Kinematic Viscosity, Specific Gravity, Flash Point, and Fire Point will support the formation of synthesised biodiesel via the proposed methodology. The experimental results lead to a yield of 89.02% of biodiesel using NaOH catalyst with optimised process parameters of the temperature of 55°C, the reaction time of 120 min, and catalyst loading of 1 wt./wt.%. Finally, biodiesel was tested for emission and combustion characteristics in a CI engine. To optimise the process parameters, the response surface methodology (RSM) along with Bootstrap estimation has been performed using MINITAB19. Furthermore, the experimental and predicted yields obtained from ANOVA were reported.

Optimal Design of Sustainable Biodiesel Supply Chain Using Dairy Waste Scum as a Feedstock Generated from Dairy Supply Chain

The rapid depletion of fossil fuels and the increased environmental impact of their combustion make it necessary to find cleaner and more sustainable energy resources. Over the last decades, biodiesel has been introduced as an alternative because of its advantages over fossil fuels. However, the high production cost of biodiesel is one of the main obstacles to achieving its commercial viability. One way to improve the efficiency and sustainability of this process is to use Dairy Waste Scum (DWS), which is a waste product from the dairy industry as a feedstock. Selection of the feedstock used is only a part of the strategy to increase the sustainability of this type of production. The most effective way to achieve this is by optimising the activities across the supply chains (SCs). In addition, the sustainability of the biodiesel production process using DWS may be influenced by design of optimal product portfolio of the considered dairy SC. This study proposes an approach for optimal design of a sustainable combined dairy and biodiesel/diesel SC using dairy waste scum as a feedstock, generated from dairy SC. It is based on defining mixed integer linear programming (MILP) model of the optimal design of the considered combined SC. The latter includes economic and environmental assessments. The first one is defined as an optimization criterion while the second one is defined as a constraint. The model takes into account key SC activities such as infrastructure compatibility; the production of the dairy products; milk, dairy products and DWS transportation between the regions, carbon taxes, related with all SC activities. The environmental and economic performance of the combined dairy and biodiesel/diesel SC is assessed by the annual operating costs for the combined SC design and greenhouse gas (GHG) emissions of pollutants associated with its operation. The developed approach was implemented on a real case study from Bulgaria. The analysis of the environmental results shown that the total GHG emissions generated by the operation of the SC for all time intervals are mainly due to the production of the products in dairies and utilization of unused DWS for production of biodiesel.

Process Optimisation and Kinetics Study of Biodiesel Production from Dairy Waste Scum Using ZnO Heterogeneous Nanocatalyst

The present paper describes about the biodiesel production from diary waste using zinc oxide as a heterogeneous catalysts. The bio-oil from dairy waste scum was collected and used for biodiesel production. Zinc oxide nanostructures was synthesised by sol-gel method and characterised using particle size analyser, X-ray diffractometer and thermogravimetric analyser. The synthesised heterogeneous ZnO nanocatalyst was used for transesterification of dairy waste scum. The maximum biodiesel yield of 94.8% was obtained at the optimised reaction conditions, 0.8 wt. %, and methanol to oil molar ratio 9:1, reaction time 40 min, reaction temperature 65 °C, and mixing speed 300 rpm. The fatty acid methyl ester production reaction follows a first order reaction rate. This research work shows that synthesised ZnO nanocatalyst was an effective catalyst to produce biodiesel from dairy waste scum.

Parametric studies on the storage stability and aging effect of biodiesel treated with Eucalyptus oil as a cost‐effective green‐antioxidant additive

Oxidation stability is one of the most significant fuel quality standards for biodiesel and mainly distresses the stability of biodiesel. Therefore, the present work aims to report the Eucalyptus oil (EO) as a natural green antioxidant additive to evaluate the oxidation stability of biodiesel produced from dairy waste scum, Bauhinia variegata and Butea monosperma oil. The obtained results have also been compared with the conventional synthetic antioxidant, butylated hydroxy toluene (BHT). The oxidation stability of the biodiesel treated with these additives was evaluated using the professional biodiesel Rancimat instrument. Further, the fuel properties kinematic viscosity and acid value were measured during the storage period. The obtained results showed an increase in the induction period in the biodiesel sample treated with EO, indicating a protective effect and inhibiting the oxidation initiation step. As a result, the oxidation stability of dairy waste scum methyl ester (DWSME), B variegata methyl ester (BVME) and B monosperma methyl ester (BMME) was found to be ~10, ~8 and ~8 hours, respectively, during 90 days storage when the natural antioxidant EO with a concentration of 4000 ppm was used and these obtained values were in the limit of EN 14214 standard. Interestingly, these values were found to be on par with the oxidation stability of DWSME (~11 hours), BVME (~9 hours) and BMME (~9 hours), when the synthetic antioxidant BHT was used with a concentration of 3000 ppm during the 90 days storage. Although the addition of EO as antioxidant resulted in increase in kinematic viscosity and acid value of the biodiesel samples, those values well-fall in the ASTM 6751 standard limit. On the other hand, synthetic antioxidant BHT showed enhanced results as compared to the EO. However, the effectiveness of the proposed natural antioxidant additive (EO) is on par with the synthetic antioxidant (BHT), which can be replaced for cost-effectiveness, non-toxic and safer consumption of biodiesel as compared to synthetic antioxidant-treated biodiesel.

Biodiesel production from dairy waste scum by using a efficient nano-biocatalyst

In the present paper, magnetic nanoparticles (Fe3O4 NPs) covered with tartaric acid (TA) have been synthesized through an eco-friendly approach and subsequently used for direct physical immobilization of the lipase from Thermomyces lanuginous (TLL). The immobilized lipase was used for the biodiesel production from dairy waste scum oil in a solvent-free system. The maximum yield to biodiesel of the immobilized lipase is about 90%, at the alcohol/oil molar ratio of 6:1, in the same operating conditions free lipase exhibits, after 24 h, a maximum yield of 76% with a molar ratio of 3:1. The immobilized lipase showed excellent reusability. The biodiesel properties evidence the feasibility of the dairy waste scum oil as raw material for biodiesel production.

Ochrocarpus longifolius assisted green synthesis of CaTiO3 nanoparticle for biodiesel production and its kinetic study

In this study, calcium titanate nano-particles (CaTiO3 NPs) were synthesized through solution combustion synthesis (SCS) by using Ochrocarpus longifolius leaves extract as a novel fuel. The CaTiO3 NPs were successfully utilized in the biodiesel synthesis from dairy waste scum oil (DWSO) as a heterogeneous base catalyst. The synthesized CaTiO3 NPs were characterized by SEM, XRD, TEM, BET, FT-IR and CO2-TPD. Response surface methodology (RSM) in arrangement with central composite design (CCD) was utilized to determine the optimum conditions for biodiesel production by varying catalyst loading, molar ratio and reaction time. The maximum 97.7% yield of dairy waste scum oil methyl ester (DWSOME/biodiesel) was obtained for a molar ratio (methanol to DWSO) of 9:1, 1.80 wt% catalyst loading and 45 min reaction time with constant temperature (65 °C) and stirring speed (650 rpm). The CaTiO3 NPs shows a good catalytic stability up to five cycles with a low loss of yield. The kinetic study of biodiesel production fit well to pseudo-first order reaction. For transesterification reaction, the 35.56 kJ/mol of activation energy (Ea) was found. Finally, the DWSOME was characterized by 1H NMR and the fuel properties were also determined and were in the range of ASTM standards.

Optimization and kinetic study of biodiesel production from Hydnocarpus wightiana oil and dairy waste scum using snail shell CaO nano catalyst

The present study is an effort to optimize the production of biodiesel from dairy scum and Hydnocarpus wightiana oil using Snail shell CaO nanocatalyst for transesterification. Response surface methodology is used to optimize the reaction parameter that affects the transesterification process for the biodiesel yield. The CaO nanocatalyst was characterized by powder X-ray diffraction, Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, Brunauer-Emmett-Teller, Fourier Transformer Infrared Spectroscopy, Thermo Gravimetric/Differential Thermal Analysis and Atomic Force Microscopy. The maximum biodiesel yield for Scum Oil Methyl Ester and Hydnocarpus wightiana Oil Methyl Ester was (96.929%) and (98.93%) at the optimized condition: Methanol to oil molar ratio 12.7:1 and 12.4:1, catalyst dosage of 0.866 wt.% and 0.892 wt.%, reaction temperature 58.56°C and 61.6°C and reaction time 119.684 min and 145.154 min respectively. A comprehensive kinetic study for the transesterification reaction was performed at different temperatures (50-65°C) for the methanolysis of SO and HWO catalyzed by CaO nanoparticles. A pseudo-first order kinetic reaction was established and the activation energy (Ea) and frequency factor (A) for SO and HWO to be 67.21kJmol-1 & 5.182×108 min-1 & 73.15 kJmol-1 & 4.59×109 min-1 respectively. Recovered CaO nanocatalyst is reused for 5 times with substantial loss in biodiesel yield.

Production of Biodiesel from Dairy Waste Scum

Production of Biodiesel from Dairy Waste Scum

Combustion, performance, and emission characteristics of dairy-washed milk scum biodiesel in a dual cylinder compression ignition engine

ABSTRACT The present work has been carried out to study the suitability of milk dairy waste scum (MDWS) biodiesel as a fuel for diesel engine. The investigations were carried out on performance, emission and combustion characteristics of a direct injection dual cylinder diesel engine fueled with MDWS methyl ester, and their blends. Two-step transesterification process was used to synthesize the MDWS biodiesel, characterization according to specified ASTM D6751-15C standards. The performance characteristics studies showed an increased brake thermal efficiency of B20 (3%) and B30 (0.94%) blends in comparison to fossil diesel. However, the increased brake specific fuel consumption (BSFC) was also found with all the fuel blends and an higher (9%) BSFC was obtained with B50 compared to diesel fuel at full load condition. The emissions of blends were found to be lower in comparison with diesel fuel, except for nitrogen oxides. A 32% increase in NOx emission was found with B50 blend compared to diesel fuel at maximum load condition. However, improved combustion characteristics would found with MDWS blends with respect to in-cylinder pressure, ignition delay, and heat release rate compared to fossil diesel.