Potential of Using Manure in Microalgae Cultivation for Third Generation of Biofuel Production
Springer
January 01, 2023
Chemical fertilizer is the most ubiquitous nutrient source used to cultivate microalgae. However, the bottlenecks associated to its vast usage such as high cost and environmental hazards are evident, whose solution is to include a search for alternative nutrient sources. Thus, nutrient-rich wastewater has been utilized in recent years for microalgae cultivation as it is widely available and able to minimize the usage of freshwater. However, it contains a large amount of heavy metal ions and microorganisms which in turn can inhibit the growth of microalgae cells. This scenario led to the development of compost derived from animal manure as a feasible and economic substitute for existing nutrient sources to grow microalgae. It constitutes a copious amount of nutrient elements, cheap, omnipresent, and environmental-friendly, which makes it as a sustainable option for the cultivation of microalgae in the commercial stage. Nevertheless, its full-scale application is limited by several challenges such as transparency problems, variability in nutrient content, selectivity over some microalgae species, and formation of other microorganisms during the composting process as well as nitrogen leakage into the atmosphere. To overcome these limitations, pre-treatment methods such as decolourization, dilution, and zeolite addition have been incorporated and discussed to increase the potential usage of animal manure for large-scale production of microalgae biomass.
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Tags: Innovation, Renewable Energy, Sustainability
The Potential of Using Macroalgae Biomass to Harvest Microalgae for Lipid and Bioethanol Production
Nova Science Publishers, Inc.
January 01, 2021
Microalgae harvesting is identified as one of the main challenges in microalgae biofuel production. This is due to the small cell size of microalgae and appeared relatively dilute in cultivate medium. This study was aimed to investigate the harvesting process of microalgae using macroalgae (seaweed) via adsorption. The macroalgae species screened were Kappaphycus alvarezii sp (elkhorn sea moss), Undaria pinnatifida (wakame) and Saccharina angustata (kelp). From the screening process, Undaria pinnatifida (wakame) was identified as the potential seaweed as it exhibited the highest harvesting efficiency of Chlorella vulgaris. Further investigations were conducted to further study different parameters to enhance the harvesting efficiency of microalgae. Based on the studied parameters, the optimum conditions to harvest the microalgae using macroalgae were 4.0 g of macroalgae biomass, pH of the medium at 11 and harvesting duration of 18 hours. In addition, the optimized sample was found to contain 25 of lipid, which can be converted to biodiesel. The lipid extracted sample was further used to produce bioethanol with a concentration of 0.286 g/L. Overall, the study showed that both lipid and bioethanol can be simultaneously produced from microalgae harvested using macroalgae as an adsorbent.
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Tags: Innovation, Renewable Energy, Sustainability
Adsorption of Methylene Blue Onto Macroalgae Biomass: Equilibriums and Kinetics Study
Nova Science Publishers, Inc.
January 01, 2021
In the present study, removal of methylene blue (MB) through adsorption using macroalgae as alternative adsorbent to activated carbon was conducted. The influences of various experimental parameters were investigated, such as macroalgae species, initial MB concentration (50-250 mg/L), the dosage of adsorbent (0.5-1.5 g) and solution pH (3.5-7.5). Macroalgae Undaria pinnatifida attained the highest MB removal efficiency of 98.31 under the following conditions: 250 mg/L of initial MB concentration, 0.5 g of macroalgae biomass dosage and pH medium of 7.5. In addition, adsorption of MB using Undaria pinnatifida biomass was found to fit well with Langmuir isotherm, which indicated homogeneous adsorption was taking place in the process. Besides, the adsorption model in this study also followed the pseudo-second-order kinetic model. The outcomes of this study evidenced the feasibility of macroalgae as an alternative adsorbent for MB removal from the aqueous solution.
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Tags: Innovation, Renewable Energy, Sustainability
Synthesis of silver nanoparticles from microalgae for potential photocatalytic dye removal
IOP Publishing Ltd
October 01, 2022
Silver nanoparticles (AgNPs) with excellent optical and electronic properties is gaining significant attention by researchers for wastewater treatment. In recent years, the production of AgNPs has shifted towards green synthesis approach by using bio-reducing agent (e.g. plant extract). In this study, live cells Chlorella vulgaris were used as the bio-reducing agent to produce AgNPs from precursor (silver nitrate (AgNO3) solution). Two process parameters were investigated, namely incubation time and pH. The results affirmed that the optimum synthesis condition of AgNPs was at 24 hr incubation time and pH 8.4 in the mixture of live cells microalgae and 3 mM AgNO3 (3:1 v/v). The synthesized AgNPs showed Localized Surface Plasmon Resonance (LSPR) peak at 412.5 nm with absorption maxima of 0.81 a.u. as indicated using UV-Vis spectrophotometer. The synthesized AgNPs had shown 80.7% of photocatalytic dye degradation in 5 mg/L MB solution and 32.1% in 25 mg/L MB solution within 9 hr of incubation time. The dye removal rate with the addition of AgNPs was 1.2 times faster in 5 mg/L MB solution and was 3.5 times faster in 25 mg/L MB solution as compared to control set.
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Tags: Emerging Technology, Innovation, Sustainability
Utilization of solid palm kernel expeller for attached growth of Chlorella vulgaris sp.
AIP Publishing Ltd
June 09, 2022
The employment of attached microalgal cultivation in simplifying the microalgal harvesting process and reducing its associated costs has attracted much attention recently. As such, palm kernel expeller (PKE), a by-product generated from palm oil extraction process was used to grow attached microalgal biomass. Thorough characterization of PKE had suggested its potentiality in enhancing microalgal cell density. Owing to the high carbon content which improves the microalgal density and low moisture content which could prevent contamination in cultivation medium, PKE theoretically proves that it is a fit choice to be used as carbon source of growth. With regards to this, cultivation conditions such as concentrations of PKE and light intensities were varied using Response Surface Methodology (RSM) simulation software to determine these parameters influence in leveraging the dry biomass concentrations. Results obtained showed that higher dosage of PKE had significant improvement on the dry attached biomass concentration. However, the light intensity factor was found to be of least significance in this context. Correlation of these two factors in maximizing the attached microalgal biomass was obtained at PKE dosage of 2 g/L and light intensity of 60 µmol/m2s.
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Tags: Innovation, Renewable Energy, Sustainability
The potential of waste chicken feather protein hydrolysate as microalgae biostimulant using organic fertilizer as nutrients source
IOP Publishing Ltd
February 20, 2022
High costs associated with chemical triggers to promote microalgae productivity when waste-based sources are used as nutrients source has diverted the attention of microalgae growers to seek for sustainable substitute for synthetic triggers. On the other note, vast disposal of chicken feather waste cause severe environmental pollution due to its low decomposition characteristics. Following the call for rigid regulations on its disposal and in attempt to valorize this waste, chicken feathers were subjected to hydrolysis process using 1M sodium hydroxide (NaOH) and precipitated by 1M hydrochloric acid (HCL) to produce chicken feather protein hydrolysate (CFPH). The prepared CFPH was further tested for its feasibility as biostimulant for Chlorella vulgaris grown in organic fertilizer as nutrients source. From the data obtained via elemental analysis, the protein content of CFPH was determined as 73.56%. The biomass and lipid productivities of C. vulgaris cultures were significantly improved by 30.4 and 34.3 to 44.6%, respectively compared to control cultures. This research work indicated that CFPH may serve as a potential low-cost biostimulant for simultaneous augmentation of microalgae biomass and lipid. Characterization of physicochemical properties of the produced CFPH is an essential step in identifying possible avenues for its application in microalgae cultivation.
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Tags: Innovation, Renewable Energy, Sustainability
Assessing the effects of operating parameters on flocculation of Chlorella vulgaris using bioflocculants extracted from miscellaneous waste biomass
EDP Sciences
July 06, 2021
Harvesting of microalgae is one of the main challenges in the production of biodiesel due to the small cell size of microalgae cells. Chemical flocculants have been generally used in the harvesting of microalgae, but they are harmful to the environment and relatively costly. Therefore, the utilization of waste biomass in producing bioflocculants is the current research niche to introduce environmental-friendly harvesting method and to minimize the cost of biodiesel production. Thus, in the current work, flocculation Chlorella vulgaris using mild acid-extracted bioflocculants from miscellaneous waste biomass (cockle shell, peanut shell and banana peel) were conducted by varying the pH values, the dosage of bioflocculants and temperatures. Cockle shell bioflocculant demonstrated the best flocculation performance, with highest flocculation efficiency of 85.2% compared to the peanut shell bioflocculant with flocculation efficiency of 37% and banana peel bioflocculant with flocculation efficiency of 16.3%. The optimum flocculation conditions for cockle shell bioflocculant were determined as follow: pH 9, bioflocculant dosage of 140mg/L and temperature of 30oC. The findings herein presented practical applicability of bioflocculants extracted from cockle shell for safe, rapid and inexpensive microalgae harvesting.
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Tags: Innovation, Renewable Energy, Sustainability
Development of Bioflocculant from Chicken’s Eggshell Membrane to Harvest Chlorella vulgaris
IOP Publishing Ltd
June 01, 2019
As microalgae biomass is considered as the most assuring source of biodiesel,
flocculation has become a potential technology that could be able to alleviate microalgae
dewatering cost which is the cornerstone hindrance of their full-scale application. However, large
scale harvesting of microalgae biomass using commercial flocculating agents is obstructed by
economic and environmental drawbacks upon downstream discharge. Thus, in the present work,
a novel introduction of natural flocculant extracted from waste biomass, which is, chicken’s
eggshell membrane was made to harvest Chlorella vulgaris. Flocculation tests were carried out
to test the effectiveness of the natural flocculant to recover microalgae biomass. Chicken’s
eggshell membrane was proven to be one of the effective bioflocculant as it achieved above 60
% of flocculation efficiency after 1 hour of sedimentation with optimum flocculation parameters
of pH 11.8 with 80 mg/L of flocculant dosage at 40 °C.
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Tags: Innovation, Renewable Energy, Sustainability
Assessing Microalgal Protein’s Impact on Environment and Energy Footprint via Life Cycle Analysis
Springer
November 14, 2023
Conventionally, increasing the yield of microalgal biomass has been the primary focus of research, while the significant protein reserve within this biomass has remained largely unexplored. This protein reserve possesses substantial value and versatility, offering a wide range of prospective applications and presenting an enticing chance for innovation and value enhancement for various sectors. Current study employed an innovative research approach that focused solely on the LCA of protein production potential from microalgal biomass, a lesser-explored aspects within this domain. Most environmental impact categories were shown to be significantly affected by cultivation phase because of the electrical obligation, followed by the harvesting and protein extraction phase. Still, the environmental aspect was seen to yield a minimal impact on global warming potential, i.e., 4 × 10–3 kg CO2, underscoring the ecologically favorable nature of the process. Conversely, the overall energy impact was seen to intensify with NEB of − 39.33 MJ and NER of 0.49, drawing attention to the importance of addressing the energy aspect to harness the full potential of microalgal protein production.
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Tags: Innovation, Renewable Energy, Sustainability
Abiotic stress as a dynamic strategy for enhancing high value phytochemicals in microalgae: Critical insights, challenges and future prospects
Elsevier
November 07, 2023
Microalgae showcase an extraordinary capacity for synthesizing high-value phytochemicals (HVPCs), offering substantial potential for diverse applications across various industries. Emerging research suggests that subjecting microalgae to abiotic stress during cultivation and the harvesting stages can further enhance the accumulation of valuable metabolites within their cells, including carotenoids, antioxidants, and vitamins. This study delves into the pivotal impacts of manipulating abiotic stress on microalgae yields, with a particular focus on biomass and selected HVPCs that have received limited attention in the existing literature. Moreover, approaches to utilising abiotic stress to increase HVPCs production while minimising adverse effects on biomass productivity were discussed. The present study also encompasses a techno-economic assessment (TEA) aimed at pinpointing significant bottlenecks in the conversion of microalgae biomass into high-value products and evaluating the desirability of various conversion pathways. The TEA methodology serves as a valuable tool for both researchers and practitioners in the quest to identify sustainable strategies for transforming microalgae biomass into high-value products and goods. Overall, this comprehensive review sheds light on the pivotal role of abiotic stress in microalgae cultivation, promising insights that could lead to more efficient and sustainable approaches for HVPCs production.
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Tags: Innovation, Renewable Energy, Sustainability
Fundamental alteration of cellular biochemicals from attached microalgae onto palm kernel expeller waste upon optimizing the growth environment in forming adhesion complex
Elsevier
September 15, 2023
Changing the growth environment for microalgae can overall lead to the fundamental alteration in cellular biochemicals whilst attaching onto palm kernel expeller (PKE) waste to form adhesion complex in easing harvesting at stationary growth phase. This study had initially optimized the PKE dosage, light intensity and photoperiod in maximizing the attached microalgal productivity being attained at 0.72 g/g day. Lipid content increased progressively from pH 3 to pH 11, with the highest value observed at pH 11. Meanwhile, in terms of protein and carbohydrate contents, the highest values were obtained by cultivation medium of pH 5 with 9.92 g and 17.72 g, respectively followed by pH 7 with 9.16 g and 16.36 g, respectively. Moreover, the findings also suggested that the low pH mediums utilized polar interactions in the formation of complexes between PKE and microalgae, whereas at higher pH levels, the non-polar interactions became more significant. The work of attachment was thermodynamically favourable towards the attachment formation with values greater than zero which was also aligned with the microscopic surface topography, i.e., revealing a clustering pattern of microalgae colonizing the PKE surface. These findings contribute to comprehensive understanding of optimizing growth condition and harvesting strategy of attached microalgae in attaining the cellular biochemical components, facilitating the development of efficient and sustainable bioresource utilization.
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Tags: Innovation, Renewable Energy, Sustainability
Optimizing extraction of antioxidative biostimulant from waste onion peels for microalgae cultivation via response surface model
Elsevier
June 15, 2023
In this study, a novel and cost-effective method for using onion peel as a biostimulant is presented to overcome the challenge of low microalgae biomass productivity. The study successfully optimized and modelled the extraction parameters, including solid-to-solvent (SS) ratio, temperature, and time, using the response surface methodology (RSM) tool. The results indicated a strong correlation between the extraction parameters and microalgae biomass concentration (BC) and lipid content (LC), with R2 values of 0.9440 and 0.9638, respectively. The optimum biostimulant extraction conditions were SS ratio of 0.006 g/mL, temperature of 90 °C at 1.00 h, attaining BC and LC of 1.76 g/L and 19.42 %, respectively, without any negative impact on LC. Findings on bioactivities of biostimulant recovered at optimal extraction conditions supported its biostimulation capacity on microalgae, with reasonable total phenolic content (TPC) of 9.1094 ± 0.748 mg GAE/g dry weight, total flavonoid content (TFC) of 3.1307 ± 0.210 mg RE/g dry weight, and antioxidant activity (AA) of 78.65 ± 3.421 % and 73.68 ± 9.608 % for DPPH and ABTS inhibition, respectively. The results of this study suggest that biostimulant derived from onion waste has great potential for promoting rapid proliferation of microalgae even with extremely low inoculum cells. These findings present a promising roadmap for high-density microalgae farming, and the developed RSM model can be utilized for process optimization while improving the efficiency, quality, and cost-effectiveness of microalgae industry.
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Tags: Innovation, Renewable Energy, Sustainability
Mechanistic behaviour of Chlorella vulgaris biofilm formation onto waste organic solid support used to treat palm kernel expeller in the recent Anthropocene
Elsevier
April 01, 2023
The capacity to maximize the proliferation of microalgal cells by means of topologically textured organic solid surfaces under various pH gave rise to the fundamental biophysical analysis of cell-surface attachment in this study. The substrate used in analysis was palm kernel expeller (PKE) in which the microalgal cells had adhered onto its surface. The findings elucidated the relevance of surface properties in terms of surface wettability and surface energy in relation to the attached microalgal growth with pH as the limiting factor. The increase in hydrophobicity of PKE-microalgae attachment was able to facilitate the formation of biofilm better. The pH 5 and pH 11 were found to be the conditions with highest and lowest microalgal growths, respectively, which were in tandem with the highest contact angle value at pH 5 and conversely for pH 11. The work of attachment (Wcs) had supported the derived model with positive values being attained for all the pH conditions, corroborating the thermodynamic feasibility. Finally, this study had unveiled the mechanism of microalgal attachment onto the surface of PKE using the aid of extracellular polymeric surfaces (EPS) from microalgae. Also, the hydrophobic nature of PKE enabled excellent attachment alongside with nutrients for microalgae to grow and from layer-by-layer (LbL) assembly. This assembly was then isolated using organosolv method by means of biphasic solvents, namely, methanol and chloroform, to induce detachment.
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Tags: Innovation, Renewable Energy, Sustainability
Residual palm kernel expeller as the support material and alimentation provider in enhancing attached microalgal growth for quality biodiesel production
Elsevier
August 15, 2022
Albeit the biodiesel production from suspended microalgal system has gained immense interests in recent years, the domineering limitation of being economically infeasible has hindered this technology from partaking into a large-scale operation. To curtail this issue, attached growth system had been introduced by various studies; however, those were still unable to alleviate the socio-economic challenges faced in commercializing the microalgal biomass production. Thus, this study had developed a novel approach in cultivating-cum-harvesting attached Chlorella vulgaris sp. microalgae, whilst using solid organic waste of palm kernel expeller (PKE) as the supporting and alimentation material for microalgal biofilm formation. The effects of three variables, namely, PKE dosage, light intensity, and photoperiod, were initially modelled and later optimized using Response Surface Methodology tool. The derived statistical models could predict the growth performances of attached microalgal biomass and lipid productivity. The optimum growing condition was attained at PKE dosage of 5.67 g/L, light intensity of 197 μmol/m2 s and photoperiod of 8 light and 16 dark hours/cycle, achieving the microalgal density and lipid content of 9.87 ± 0.05 g/g and 3.39 ± 0.28 g/g, respectively, with lipid productivity of 29.6 mg/L day. This optimum condition had led to the intensification of biodiesel quality with a high percentage of monounsaturated fatty acid, i.e., oleic acid (C18:1), encompassing 81.86% of total fatty acid methyl ester components. Given that the positive acquisition of PKE as an excellent supporting material in enhancing the microalgal density and lipid productivity that had resulted in the commercially viable biodiesel quality, this study served as a novel revolution in augmenting the microalgae and solid waste utilities for sustainable energy generation.
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Tags: Innovation, Renewable Energy, Sustainability
Valorization of fish bone waste as novel bioflocculant for rapid microalgae harvesting: Experimental evaluation and modelling using back propagation artificial neural network
Elsevier
June 01, 2022
Harvesting of microalgae biomass is identified as one of the bottlenecks in microalgae biofuel industry due to expensive and energy-intensive dewatering technologies. Alternatively, flocculation process using bioflocculants have given much attention in recent years as green substitutes over chemical flocculants. In this study, bioflocculant was extracted from waste fish bone using mild acid to harvest the freshwater microalgae, Chlorella vulgaris. The optimum flocculation occurred at pH of 9.8 and 50 °C using fish bone bioflocculant which led to flocculation efficiency of 97.65%. To predict complex processes such as microalgae flocculation, artificial neural network (ANN) was employed. Bayesian regularization model with a topology of 2-10-1 showed high correlation coefficients, R2 of more than 0.98, which indicated that the model was significant and robust in identification of the optimum conditions. Characterizations of fish bone bioflocculant and biofloc confirmed the involvement of potassium and other cations as well as carbohydrate and protein substances to flocculate C. vulgaris cells, employing sweeping and charge neutralization as key mechanisms. This finding proposed a valuable reference for practical and rapid harvesting of microalgae using low-cost bioflocculant and the ANN algorithm can be applied in microalgae processing industries for making crucial assessments regarding the process operating conditions.
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Tags: Innovation, Renewable Energy, Sustainability
Influence of environmental stress on microalgae growth and lipid profile: a systematic review
Springer
March 20, 2022
Microalgae biomass has attracted great interest from researchers as a promising feedstock for biodiesel production. Although enormous research works have been carried out to identify microalgae species with high biomass and lipid productivities, genetic modification of strains as well as optimization of cultivation conditions, however, the progress is yet to be fully satisfied. Based on the present lipid yield and extraction methods, it is still not feasible to commercialize the microalgae biodiesel. One of the promising approaches to elevate lipid accumulation by microalgae is through tuning the cellular mechanisms and metabolic pathway by exposing microalgae cells to various abiotic stress environments such as nutrient starvation, high salinity level and strong light intensity. Nevertheless, a comprehensive analysis of quantitative influences of critical abiotic stress on both microalgae biomass and lipid profile is still limited in the literature. Hence, the present paper aims to deliver insights into selections of single and multiple abiotic stress factors for simultaneous enhancement of microalgae biomass and lipids (polar and non-polar) which could improve the techno-economic viability in the microalgae processing chains and biorefinery industries.
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Tags: Innovation, Renewable Energy, Sustainability
The effect of stress environment towards lipid accumulation in microalgae after harvesting
Elsevier
July 01, 2020
Microalgae have been recognized as a potential feedstock for biodiesel production due to their fast growth rate and ability to accumulate lipid within their cells. However, high lipid content and biomass productivity are usually difficult to achieve simultaneously. Instead of stressing the microalgae during cultivation stage, the stress environment such as nutrient starvation, salinity and light effect were introduced to Chlorella vulgaris after harvesting to study the effect on their lipid content. From the results attained, one day of nutrient starvation with 6.0 g/L of salinity stress under dark room condition had shown the highest lipid content of 38.8% (dry weight basis). The lipid content was recorded at 40.28% (dry weight basis) when the working volume was scaled up. In addition, the fatty acids identified in the extracted microalgae lipid were mainly consisted of linoleic, linolenic and palmitic acid, which were commonly found in corn oil, soybean oil and sunflower oil.
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Tags: Innovation, Renewable Energy, Sustainability
Flocculation of Chlorella vulgaris by shell waste-derived bioflocculants for biodiesel production: process optimization, characterization and kinetic studies
Elsevier
February 01, 2020
Flocculants are foreign particles that aggregate suspended microalgae cells and due to cost factor and toxicity, harvesting of microalgae biomass has shifted towards the use of bioflocculants. In this study, mild acid-extracted bioflocculants from waste chicken’s eggshell and clam shell were used to harvest Chlorella vulgaris that was cultivated using chicken compost as nutrient source. It was found that a maximum of 99% flocculation efficiency can be attained at pH medium of 9.8 using 60 mg/L of hydrochloric acid-extracted chicken’s eggshell bioflocculant at 50 °C of reaction temperature. On the other hand, 80 mg/L of hydrochloric acid-extracted clam shell bioflocculant was sufficient to recover C. vulgaris biomass at pH 9.8 and optimum temperature of 40 °C. The bioflocculants and bioflocs were characterized using microscopic, zeta potential, XRD, AAS and FT-IR analysis. The result revealed that calcium ions in the bioflocculants are the main contributor towards the flocculation of C. vulgaris, employing charge neutralization and sweeping as possible flocculation mechanisms. The kinetic parameters were best fitted pseudo-second order which resulted in R2 of 0.99 under optimal flocculation temperature. The results herein, disclosed the applicability of shell waste-derived bioflocculants for up-scaled microalgae harvesting for biodiesel production.
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Tags: Innovation, Renewable Energy, Sustainability
Insights into the microalgae cultivation technology and harvesting process for biofuel production: A review
Elsevier
November 01, 2019
Derivation of biofuel from microalgae biomass has been widely researched in the past few decades. Microalgae is capable of producing 58,700 litres oil per hectare that can generate 121,104 litres biodiesel per hectare, which seemingly a promising transition over conventional fossil fuels. Nevertheless, economic sustainability of commercial scale production of microalgae biomass is still in shadows of doubt, especially the cultivation and harvesting process. Apparently, the microalgae cultivation system has evolved from traditional open pond to various modern photobioreactor (PBR) designs. However, with regards to tubular and flat panel PBRs as the most ubiquitous systems for biofuel production at commercial level, extensive discussion on reactor configurations and design betterment was presented in this review, along with precise technical comparison on cost and energy requirements for the cultivation systems. This review intended to serve as guideline for long term adoption of these well-established cultivation technologies in biofuel plants given the numerous economic benefits. Besides that, in attempt to lower the harvesting cost, potential use of various waste biomass as bioflocculants to recover microalgae biomass was introduced in this review. This article also deliberates direction on potential policy interventions to produce microalgae biofuel in a more sustainable and cost-effective manners in near future.
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Tags: Innovation, Renewable Energy, Sustainability
Harvesting of Chlorella Vulgaris Biomass by Using Different Bio-Flocculants: A Comparison Study
UTP Press
December 18, 2018
In the present study, several natural flocculants were extracted from natural resources to harvest Chlorella vulgaris. Jar tests were carried out to evaluate the flocculation efficiencies of the extracted flocculants in harvesting C. vulgaris cells. Chitosan and maize seeds were proven to be effective flocculants as they achieved more than 80% efficiency after one (1) hour and four (4) hours of sedimentation time, respectively. Under the optimum flocculation conditions of pH 7, 2 mg/L dosage, 120 rpm of stirring speed for chitosan; and pH 3, 450 mg/L of dosage, 15 rpm of stirring speed for maize seeds flocculant; the flocculation efficiencies up to 97.9% and 84.7% are able to achieved, respectively. A scale-up study was done to test the flocculation ability of chitosan and maize seeds extracts to harvest 1 L of C. vulgaris. Approximately 97% and 82% of flocculation efficiencies were achieved by chitosan and maize seeds flocculants, respectively, under their optimum flocculation conditions. Comparatively, chitosan offer superiority in flocculating C. vulgaris than maize seeds extract in terms of floc size, dosage and sedimentation time.
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Tags: Innovation, Renewable Energy, Sustainability
Assessing Microalgal Protein’s Impact on Environment and Energy Footprint via Life Cycle Analysis
