scholarly journals Development and optimization of technology for the extraction and conversion of micro algal lipids to biodiesel

2015 ◽  
Author(s):  
◽  
Krishan Ramluckan

Fossil fuel reserves have been diminishing worldwide thus making them very scarce in the long term. These fuel sources and their by-products which are used commercially tend to produce large quantities of emissions. Some of them are believed to be toxic to flora and fauna. It is primarily for this reason that researchers worldwide have begun to seek out alternative sources of environmentally safe fuel. Biodiesel from algae is one of these sources that have been examined over the last few decades. Biodiesel has been produced from other plant-based material and waste oils in countries like America and Japan. However, the use of food based crops for biodiesel production has been challenged as it has an impact on food production on an international scale. Algae have only recently been investigated for their feasibility for biodiesel production on a large scale. The aim of this study was to investigate and develop technologies for biodiesel production from algae. The species of algae chosen were chlorella sp and scenedesmus sp., since they are indigeneous to Kwazulu Natal in South Africa. Samples were obtained from a local raceway pond and prepared for analysis. Drying protocols used freeze, oven and sun drying for initial preparation of the samples for analysis. Sun drying was the least energy intensive but most time consuming. At laboratory scale, oven drying was chosen as the best alternative. Lipid extraction methods investigated were the separating funnel method, the soxhlet method, microwave assisted extraction (MAE) and the expeller press. Thirteen solvents covering a range of polarities were used with the extraction methods to determine the efficiency of the solvent with these methods. Optimization of the MAE method was conducted using both the one factor at a time (OFAT) method and a design of experiment (DOE) statistical method. The shelf life of algal biomass was determined by ageing the samples for approximately three months. Direct and in-situ transesterification of lipid extracts to produce biodiesel was investigated using both acid and base catalysis. Qualitative and quantitative analyses were conducted using Fourier transform infra-red (FTIR) and gas chromatography (GC). Chemical and physical characterization of the biodiesel produced from the algal lipid extracts were compared to both local and international standard specifications for biodiesel. In terms of extraction efficiency, it was found that soxhlet and microwave assisted extraction methods were almost equally good. This was proved by the MAE method yielding an average of 10.0% lipids for chloroform, ethanol and hexane after 30 mL of solvent was used in an extraction time of 10 minutes, while the soxhlet method yielded 10.36% lipids using an extraction volume of 100 mL of solvent with an extraction time of 3 hours. Chloroform, ethanol and hexane were more efficient than the other ten solvents used. This was shown by these three solvents producing lipid quantities between 10% to 11% while all the other solvents produced lipid quantities between 2 and 10 %. The best extraction efficiency was achieved by the binary solvent mixture made up of chloroform and ethanol in a 1:1 ratio. Under the conditions optimized, this solvent ratio yielded a lipid content of 11.76%. The methods chosen and optimized for extraction are very efficient, but the actual cost of production of biodiesel need to be determined. Physical methods like the expeller press are not feasible for extraction of the type of biomass produced unless algae are pelletized to improve extraction. This will impact on the cost of producing biodiesel. The transesterification protocols investigated show that the base catalysis produced biodiesel with a ratio of saturates to unsaturates conducive to a good fuel product. The direct esterification method in this study proved to be better than the in-situ method for biodiesel production. The in-situ method was also more labour intensive. Chromatography was found to be a fast and efficient method for qualitative and quantitative determination of biodiesel. Characterization tests showed that the quality of biodiesel produced was satisfactory. It also showed that the methods used in this study were feasible for the satisfactory production of biodiesel which meets local and international specifications.

Technologies ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 45
Author(s):  
Marilena Radoiu ◽  
Harmandeep Kaur ◽  
Anna Bakowska-Barczak ◽  
Steven Splinter

Cannabis is a flowering plant that has long been used for medicinal, therapeutic, and recreational purposes. Cannabis contains more than 500 different compounds, including a unique class of terpeno-phenolic compounds known as cannabinoids. Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most extensively studied cannabinoids. They have been associated with the therapeutic and medicinal properties of the cannabis plant and also with its popularity as a recreational drug. In this paper, an industrial method for cannabis extraction using 915 MHz microwaves coupled with continuous flow operation is presented. The main advantages of the microwave-assisted extraction (MAE) are associated to the continuous-flow operation at atmospheric pressure which allows for higher volumes of biomass to be processed in less time than existing extraction methods, with improved extraction efficiency leading to increased final product yields, improved extract consistency and quality because the process does not require stopping and restarting material flows, and ease of scale-up to industrial scale without the use of pressurised batch vessels. Moreover, due to the flexibility of changing the operation conditions, MAE eliminates additional steps required in most extraction methods, such as biomass decarboxylation or winterisation, which typically adds at least a half day to the extraction process. Another factor that sets MAE apart is the ability to achieve high extraction efficiency, i.e., up to 95% of the active compounds from cannabis biomass can be recovered at industrial scale.


Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 285 ◽  
Author(s):  
Ching-Chi Yen ◽  
Chun-Wei Tung ◽  
Chih-Wei Chang ◽  
Chin-Chuan Tsai ◽  
Mei-Chich Hsu ◽  
...  

Since 2017, higenamine has been added to the World Anti-Doping Agency (WADA) prohibited list as a β2-agonist prohibited at all times for sportspersons. According to WADA’s report, positive cases of higenamine misuse have been increasing yearly. However, higenamine occurs naturally in the Chinese herb lotus plumule—the green embryo of lotus (Nelumbo nucifera Gaertn) seeds—commercially available as concentrated powder on the Asian market. This study evaluated the major phytochemical components of lotus plumule products using an appropriate extraction method, followed by a human study in which the products were orally administered in multiple doses to investigate the risk of doping violations. Comparing various extraction methods revealed that optimized microwave-assisted extraction exhibited the highest extraction efficiency (extraction time, 26 min; power, 1046 W; and temperature, 120 °C). Subsequently, the alkaloids in lotus plumule products were quantitatively confirmed and compared. Human study participants (n = 6) consumed 0.8 g of lotus plumule (equivalent to 679.6 μg of higenamine) three times daily for three consecutive days. All participants’ urinary higenamine concentrations exceeded the WADA reporting cut-off of 10.0 ng/mL. Accordingly, lotus plumule consumption may engender adverse analytical findings regarding higenamine. Athletes should avoid consuming lotus plumule-containing products during in- and out-of-competition periods.


2020 ◽  
Vol 7 (1) ◽  
pp. 17-23
Author(s):  
Khadiza Fitri Shafira ◽  
Abul Kalam Azad ◽  
Zubair Khalid Labu ◽  
Abul Bashar Mohammed Helal Uddin

Background: Eugenol is the main constituent of clove essential oil. Past studies have found that clove oil has diverse uses in the pharmaceutical field due to its antioxidant, antibacterial and anesthetic properties. Objective: This work compares the performance of different extraction methods and factors and identifies the effect of the treatments on oil yields and eugenol content. Materials and Methods: Maceration, Hydro distillation, microwave-assisted extraction (MAE), and Soxhlet were performed. The best technique was identified according to yield and content. Further studies were conducted to examine the effects of different factors, such as solvent types (ethanol and methanol) and sample-to-solvent ratio (1:10 and 1:15). HPLC UV-Vis was utilized in the analysis of eugenol concentration. Results and Discussion: Soxhlet extraction provided the highest yield (39.98%) and eugenol content (15.83%), compared to other methods. The results observed from several Soxhlet extraction factors showed that there is no significant difference between the different factors. In the meantime, methanol 1:15 provided the greatest amount of yields (57.83%) and eugenol content (22.21%). In this regard, the higher ratio resulted in higher eugenol content. Conclusion: The results obtained are less comparable because the processing time, the working solvent, and the separation technique were carried out differently for each method. In the meantime, as there is no past study that compared the selected methods and factors, this study’s findings will contribute substantially to fill the gap in this field.


2016 ◽  
Vol 70 (6) ◽  
Author(s):  
Van T. Nguyen ◽  
Michael C. Bowyer ◽  
Ian A. van Altena ◽  
Christopher J. Scarlett

Abstractis known as a healing herb which has traditionally been used in the treatment of various diseases such as hepatitis, diabetes and cancer. The extraction parameters have great effects on the extraction efficiency of bioactive compounds and pharmacological activity of the extracts. This study sought to optimise the microwave-assisted extraction parameters for phenolic compounds-enriched extracts and antioxidant capacity from


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2879
Author(s):  
Aleksandar Radivojac ◽  
Oskar Bera ◽  
Zoran Zeković ◽  
Nemanja Teslić ◽  
Živan Mrkonjić ◽  
...  

Consumers are becoming more mindful of their well-being. Increasing awareness of the many beneficial properties of peppermint essential oil (EO) has significantly increased product sales in recent years. Hydrodistillation (HD), a proven conventional method, and a possible alternative in the form of microwave-assisted hydrodistillation (MWHD) have been used to isolate peppermint EO. Standard Soxhlet and alternatively supercritical fluid (SFE), microwave-assisted, and ultrasound-assisted extraction separated the lipid extracts. The distillations employed various power settings, and the EO yield varied from 0.15 to 0.80%. The estimated environmental impact in terms of electricity consumption and CO2 emissions suggested that MWHD is an energy efficient way to reduce CO2 emissions. Different extraction methods and solvent properties affected the lipid extract yield, which ranged from 2.55 to 5.36%. According to the corresponding values of statistical parameters, empiric mathematical models were successfully applied to model the kinetics of MWHD and SFE processes.


2008 ◽  
Vol 91 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Mercedes Barriada-Pereira ◽  
Iván Iglesias-García ◽  
María J Gonzlez-Castro ◽  
Soledad Muniategui-Lorenzo ◽  
Purificación López-Maha ◽  
...  

Abstract This paper describes a comparative study of 2 extraction methods, pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), for the determination of organochlorine pesticides (OCPs) in fish muscle samples. In both cases, samples were extracted with hexaneacetone (50 + 50), and the extracts were purified by solid-phase extraction using a carbon cartridge as the adsorbent. Pesticides were eluted with hexaneethyl acetate (80 + 20) and determined by gas chromatography with electron-capture detection. Both methods demonstrated good linearity over the range studied (0.0050.100 g/mL). Detection limits ranged from 0.029 to 0.295 mg/kg for PLE and from 0.003 to 0.054 mg/kg for MAE. For most of the pesticides, analytical recoveries with both methods were between 80 and 120, and the relative standard deviations were <10. The proposed methods were shown to be powerful techniques for the extraction of OCPs from fish muscle samples. Although good recovery rates were obtained with both extraction methods, MAE provided advantages with regard to sample handling, cost, analysis time, and solvent consumption. Acceptable validation parameters were obtained although MAE was shown to be more sensitive than PLE.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 456 ◽  
Author(s):  
Ding-Tao Wu ◽  
Wen Liu ◽  
Mei-Lin Xian ◽  
Gang Du ◽  
Xin Liu ◽  
...  

Seven extraction methods, including hot water extraction (HWE), pressurized water extraction (PWE), ultrasound-assisted extraction, microwave-assisted extraction, ultrasound-assisted enzymatic extraction, high-speed shearing homogenization extraction, and ultrasound-microwave-assisted extraction, were utilized to extract polyphenolic-protein-polysaccharide complexes (PPPs) from Hovenia dulcis. Next, their physicochemical properties and in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were studied and compared. The findings from this study indicate that various extraction processes exhibit notable influences on the physicochemical properties and in vitro bioactivities of PPPs. Extraction yields, contents of polyphenolics and flavonoids, apparent viscosities, molecular weights, molar ratios of monosaccharide compositions, and ratios of amino acid compositions in PPPs varied in different extraction methods. Furthermore, 13 phenolic compounds in PPPs, including rutin, myricitrin, myricetin, quercetin, kaempferol, protocatechuic acid, gallocatechin, p-hydroxybenzoic acid, ampelopsin, quercetin-7,4′-diglucoside, dihydroquercetin, 5-methylmyricetin, and naringenin, were identified. The relatively strong in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were determined in both PPP-W and PPP-P obtained by HWE and PWE, respectively. The high content of total polyphenolics may be one of the main contributors to their in vitro bioactivities. The findings have shown that the PWE method can be an appropriate method to prepare PPPs with strong bioactivities for application in the functional food industry.


Author(s):  
Marilena Radoiu ◽  
Harmandeep Kaur ◽  
Anna Bakowska-Barczak ◽  
Steven Splinter

Cannabis is a flowering plant that has long been used for medicinal, therapeutic, and recreational purposes. Cannabis contains more than 500 different compounds, including a unique class of terpeno-phenolic compounds known as cannabinoids; Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most prevalent cannabinoids and have been associated with the therapeutic and medicinal properties of the cannabis plant. In this paper, continuous flow microwave assisted extraction (MAE) is presented and compared with other methods for commercial cannabis extraction. The practical issues of each extraction method are discussed. The main advantages of MAE are: continuous-flow method which allows for higher volumes of biomass to be processed in less time than existing extraction methods, improved extraction efficiency leading to increased final product yields, improved extract consistency and quality because the process does not require stopping and restarting material flows, and ease of scale-up to industrial scale without the use of pressurised batch vessels. Moreover, due to the flexibility of changing the operation conditions, MAE eliminates additional steps required in most extraction methods, such as biomass decarboxylation, winterisation, which typically adds at least a half day to the extraction process. Another factor that sets MAE apart is the ability to achieve high extraction efficiency even at the industrial scale. Whereas the typical recovery of active compounds using supercritical CO¬2 remains around 70-80%, via MAE up to 95% of the active compounds from cannabis biomass can be recovered at the industrial scale.


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