Ultrasound assisted biodiesel synthesis from jatropha oilseeds using in-situ reactive extraction / Tan Shiou Xuan

Utilisation of edible feedstock in biodiesel production had caused food versus fuel crisis. Mechanical stirring was found to be a cost-ineffective approach as excessive energy was needed with the requirement for external heating while consuming more catalyst. Furthermore, several intermediate steps between oilseeds harvesting and biodiesel synthesis could be integrated, thereby simplifying the process and reduced the production cost. The main aim of the present study was to produce biodiesel with satisfactory fatty acid methyl ester (FAME) purity (≥96.5%) after two-step ultrasound assisted in-situ esterification and ultrasound assisted transesterification by directly utilising non-edible Jatropha oilseeds containing high acid value (AV) as feedstock. Ultrasound assisted in-situ esterification utilising sulphuric acid (H2SO4) as catalyst and the reaction parameters affecting the extraction, esterification efficiencies and FAME purity such as ultrasonic pulse mode, Jatropha oilseed particle size, n-hexane to methanol volume ratio, H2SO4 loading, reaction time and ultrasonic amplitude were investigated in detail. For ultrasound assisted transesterification, potassium hydroxide (KOH) was utilised as catalyst and the optimum reaction parameters of KOH loading, methanol to esterified oil molar ratio, reaction time and ultrasonic amplitude were investigated. Jatropha oilseeds before and after ultrasound assisted in-situ esterification were characterized and the fuel properties of the biodiesel produced were examined. The results showed that ultrasound assisted in-situ esterification obtained extraction efficiency of 83.96%, esterification efficiency of 71.10% and FAME purity of 38.58% at optimum reaction parameters of ultrasonic pulse mode 5s on/2s off, particle size of 1−2 mm, n-hexane to methanol volume ratio of 3:1, H2SO4 loading of 5 vol.%, reaction time of 150 min and ultrasonic amplitude of 60%. It was revealed from the results that ultrasonic pulse mode had significant effects on esterification efficiency and FAME purity. On the other hand, Jatropha oilseed particle size and n-hexane to methanol volume ratio significantly affected extraction efficiency. Other reaction variables (H2SO4 loading, reaction time and ultrasonic amplitude) had considerable effects on extraction, esterification efficiencies and FAME purity. The esterified Jatropha oil produced from esterification was then subjected to transesterification in order to further improve the FAME purity and minimized the AV to acceptable limit according to American Standards for Testing Materials (ASTM D6751) and European Union Standards for Biodiesel (EN14214). In the subsequent ultrasound assisted transesterification, high FAME purity of 99.03% and biodiesel yield of 85.20% were attained at KOH loading of 1.5 wt.%, methanol to esterified oil molar ratio of 12:1, reaction time of 15 min and ultrasonic amplitude of 60%. It was revealed from ultrasound assisted transesterification that ultrasound could produce biodiesel within a short reaction time while producing high FAME purity at the same time. In conclusion, ultrasound assisted in-situ esterification and transesterification can be a feasible biodiesel production method using solid oil bearing seeds directly without pre-extraction in the future. Detailed and in-depth information of the influence of each reaction parameters in ultrasound assisted in-situ esterification of Jatropha oilseeds on extraction efficiency, esterification efficiency and FAME purity was contributed to current literatures, specific to Jatropha oilseeds. These information would be crucial for the commercialisation of the process in the future

In situ reactive extraction of Jatropha curcas L. seeds assisted by ultrasound: Preliminary studies

Esterification is required to reduce the high free fatty acid (FFA) content of crude Jatropha oil to below 3% prior to transesterification. In this study, raw decorticated Jatropha seeds were employed as the feedstock in in situ reactive extraction assisted by ultrasound in the presence of sulfuric acid (H2SO4) as a catalyst. Extraction efficiency, esterification efficiency, and fatty acid methyl ester (FAME) yield were optimized as a function of ultrasonic pulse mode, amplitude, and H2SO4 amount. The optimum extraction efficiency of 83.96%, esterification efficiency of 71.10%, and FAME yield of 38.58% were achieved at a pulse mode of 5 s on/2 s off, an ultrasonic amplitude of 60%, and an H2SO4 amount of 5 mL in reaction time of 150 min

Process intensification of biodiesel synthesis via ultrasound-assisted in situ esterification of Jatropha oil seeds

BACKGROUND: Non-edible oil such as Jatropha oil has high free fatty acids (FFAs) content. Therefore, acid esterification is a suitable route to reduce its FFA content to an acceptable limit (2 FFA%) before being subjected to further transesterification. In the present study, Jatropha seeds were utilized as the feedstock directly instead of Jatropha oil during ultrasound-assisted in situ esterification. The objective of this work is to evaluate the feasibility of in situ esterification of Jatropha oil seeds using sulphuric acid (H 2 SO 4 ) as catalyst with the aid of ultrasound. RESULTS: The reaction parameters (particle size, n-hexane to methanol volume ratio, H 2 SO 4 amount, reaction time and ultrasonic amplitude) were optimized and evaluated in term of extraction and esterification efficiencies as well as fatty acid methyl ester (FAME) yield. The highest extraction efficiency of 83.96%, esterification efficiency of 71.10% and FAME yield of 38.58% were achieved at particle size of 1–2 mm, n-hexane to methanol volume ratio of 3:1, 5 vol% of H 2 SO 4 and ultrasonic amplitude of 60% with reaction time of 150 min. CONCLUSION: Synthesis of biodiesel via ultrasound-assisted in situ esterification of Jatropha oil seeds was successful with considerable yield, which could provide improvement in terms of process intensification and more value added by-products. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industr

A Comprehensive Review on the Emerging Roles of Nanofillers and Plasticizers towards Sustainable Starch-Based Bioplastic Fabrication

Petroleum-based plastics are associated with environmental pollution problems owing to their non-biodegradable and toxic properties. In this context, renewable and biodegradable bioplastics possess great potential to replace petroleum-based plastics in mitigating these environmental issues. Fabrication of bioplastic films involves a delicate mixture of the film-forming agent, plasticizer and suitable solvent. The role of the plasticizer is to improve film flexibility, whereas the filler serves as a reinforcement medium. In recent years, much research attention has been shifted toward devising diverse methods for enhancing the performance of bioplastics, particularly in the utilization of environmentally benign nanoparticles to displace the conventional hazardous chemicals. Along this line, this paper presents the emergence of nanofillers and plasticizers utilized in bioplastic fabrication with a focus on starch-based bioplastics. This review paper not only highlights the influencing factors that affect the optical, mechanical and barrier properties of bioplastics, but also revolves around the proposed mechanism of starch-based bioplastic formation, which has rarely been reviewed in the current literature. To complete the review, prospects and challenges in bioplastic fabrication are also highlighted in order to align with the concept of the circular bioplastic economy and the United Nations’ Sustainable Development Goals

Rapid Ultrasound-Assisted Starch Extraction from Sago Pith Waste (SPW) for the Fabrication of Sustainable Bioplastic Film

The present study was conducted to optimize the extraction yield of starch from sago (Metroxylon sagu) pith waste (SPW) with the assistance of ultrasound ensued by the transformation of extracted starch into a higher value-added bioplastic film. Sago starch with extraction yield of 71.4% was successfully obtained using the ultrasound-assisted extraction, with the following conditions: particle size −8 g m−1 s−1 Pa−1 was obtained, suggesting its feasibility as bioplastic material. These findings provide a means of utilization for SPW which is in line with the contemporary trend towards greener and sustainable products and processes

Characterization and Parametric Study on Mechanical Properties Enhancement in Biodegradable Chitosan-Reinforced Starch-Based Bioplastic Film

Bioplastic has been perceived as a promising candidate to replace petroleum-based plastics due to its environment-friendly and biodegradable characteristics. This study presents the chitosan reinforced starch-based bioplastic film prepared by the solution casting and evaporation method. The effects of processing parameters, i.e., starch concentration, glycerol loading, process temperature and chitosan loading on mechanical properties were examined. Optimum tensile strength of 5.19 MPa and elongation at break of 44.6% were obtained under the combined reaction conditions of 5 wt.% starch concentration, 40 wt.% glycerol loading, 20 wt.% chitosan loading and at a process temperature of 70 °C. From the artificial neural network (ANN) modeling, the coefficient of determination (R2) for tensile strength and elongation at break were found to be 0.9955 and 0.9859, respectively, which proved the model had good fit with the experimental data. Interaction and miscibility between starch and chitosan were proven through the peaks shifting to a lower wavenumber in FTIR and a reduction of crystallinity in XRD. TGA results suggested the chitosan-reinforced starch-based bioplastic possessed reasonable thermal stability under 290 °C. Enhancement in water resistance of chitosan-incorporated starch-based bioplastic film was evidenced with a water uptake of 251% as compared to a 302% registered by the pure starch-based bioplastic film. In addition, the fact that the chitosan-reinforced starch-based bioplastic film degraded to 52.1% of its initial weight after 28 days suggests it is a more sustainable alternative than the petroleum-based plastics

Two-step catalytic reactive extraction and transesterification process via ultrasonic irradiation for biodiesel production from solid Jatropha oil seeds

A two-step catalytic reactive extraction and transesterification process was adopted to synthesize biodiesel from solid Jatropha seeds, a non-edible source with high free acid content, directly using ultrasound irradiation. From the intensification of reactive extraction process coupled with ultrasound, esterified oil with satisfactory extraction efficiency of 84.0 ± 0.5%, FAME purity of 38.6 ± 1.3% and esterification efficiency of 71.1 ± 1.3% were obtained. High acid value (AV) of 18.2 ± 0.5 mg KOH/g was successfully reduced to 5.3 ± 0.2 mg KOH/g. In the subsequent transesterification of esterified Jatropha oil, FAME purity of 99.0 ± 1.3% and biodiesel yield of 85.2 ± 1.3% were attained at KOH loading of 1.5 wt.%, methanol to oil molar ratio of 12:1 and ultrasonic amplitude of 60% after 15 min reaction time. From the artificial neural network (ANN) modelling, coefficient of determination (R2) for FAME purity and biodiesel yield were found to be 0.9926 and 0.9845, respectively, which proved that the model had good fit with the experimental data. Under the same optimized reaction conditions, this process intensification could achieve higher FAME purity (99.0% vs. 91.8%), biodiesel yield (85.2% vs. 75.6%) and AV reduction efficiency (88.5% vs. 88.2%) than conventional magnetic stirring. © 2019 Elsevier B.V

Ultrasonic assisted oil extraction and biodiesel synthesis of Spent Coffee Ground

Spent Coffee Ground (SCG) was studied as a potential source of oil feedstock for biodiesel production as an alternative waste utilisation instead of being disposed as municipal waste. This study evaluated the ultrasonic assisted oil extraction from SCG, which was followed by biodiesel conversion via transesterification. Hexane was found to be the most effective extractant for SCG oil. Soxhlet extraction could obtain maximum SCG oil yield of 12.5% within 3 h whereas the highest SCG oil yield (14.52%) using ultrasonic extraction was obtained at hexane to SCG ratio of 4 mL g−1 and at 30% ultrasonic amplitude for 30 min. The improved oil yield with shorter extraction time was due to the ultrasonic fragmentation on SCG cells, which enhanced the interactions between oil and solvents. Fourier transform infrared analysis showed that the SCG oil possessed suitable functional groups for biodiesel conversion. Then, the SCG oil was successfully converted to biodiesel via ultrasonic assisted transesterification. The optimal FAME yield (97.11%) was achieved with molar ratio of methanol to SCG oil of 30:1, 4 wt% of catalyst concentration, at 30% ultrasonic amplitude and for 3 h. The produced SCG biodiesel has promising properties which adhere to the biodiesel standards but acid value was beyond the permissible limit which could be overcome by utilising as blend feedstock with other commercially available biodiesel. The high calorific value along with low viscosity, density and corrosion properties suggested SCG biodiesel as an interesting and viable option for biodiesel blending. © 201