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Jo Shu Chang - One of the best experts on this subject based on the ideXlab platform.
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production of lactic acid from Microalgal Biomass chlorella vulgar esp 31 as a feedstock using pva immobilized bacteria l plantarum 23
Nusantara Science and Technology Proceedings, 2020Co-Authors: Atika Nandini, Dilirani Nagarajan, Jo Shu ChangAbstract:Lactic acid is a valuable industrial chemical that is mostly used in the food and non-food industries such as the pharmaceutical industry. Production of lactic acid from renewable materials can be an alternative method to reduce the high production cost associated with raw material acquirement. In this study, polyvinyl alcohol (PVA) immobilized L. plantarum 23 was used. To obtain high lactic acid productivity and yield from renewable feedstock, the optimal fermentation conditions were determined in both batch and continuous mode. The renewable feedstock used was Microalgal Biomass Chlorella vulgaris ESP-31. The optimal conditions for this fermentation are pH 5.5, temperature 30°C, PVA particle loading 12.5%, PVA concentration 5.25g cell/L, HRT: 2-4 hrs, carbon source concentration 40 g/L. The feedstock was pretreated and hydrolyzed appropriately and the reducing sugars obtained were used. With Microalgal sugars as a feedstock in continuous fermentation mode, the maximum lactic acid productivity of 12.59 g/L/h was achieved, compared to glucose (7.39 g/L/h). The highest yield achieved in this study (0,98 g/g) was obtained when using pure glucose as the feedstock. Considering high productivity as the most important parameter, Microalgal Biomass seems to be the best feedstock for lactic acid production in continuous fermentation, giving high productivity and yield of 12.59 g/L/h and 0.91 g/g, respectively.
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pretreatment of Microalgal Biomass for efficient biohydrogen production recent insights and future perspectives
Bioresource Technology, 2020Co-Authors: Dillirani Nagarajan, Jo Shu Chang, Duujong LeeAbstract:Abstract Biohydrogen is a plausible alternative fuel solution for the contemporary issues regarding global warming and the steadily increasing greenhouse gas emissions, because of its high energy content and carbon-free combustion properties. Hydrogen does not exist in its natural state and the current hydrogen production technologies (steam methane reforming, water splitting) are energy-intensive, accompanied by a huge carbon footprint. Dark fermentative hydrogen production by anaerobic hydrogen-producing bacteria is a green, sustainable and emission-free pathway for hydrogen production. Microalgal Biomass is considered as the third generation biofuel feedstock and is receiving academic and industrial research attention for its carbon sequestration abilities. This review discusses in detail about the pretreatment methods that could be adapted for Microalgal Biomass for effective biohydrogen production. Microalgal cell wall structure and the associated polymeric carbohydrates that offer certain recalcitrance are critically analyzed and future research perspectives are presented.
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A review of thermochemical conversion of Microalgal Biomass for biofuels: chemistry and processes
Green Chem., 2017Co-Authors: Gopalakrishnan Kumar, Sang-hyoun Kim, Quang-vu Bach, Sutha Shobana, A E Atabani, Wei Hsin Chen, Jo Shu ChangAbstract:g Renewable Biomass sources are organic materials, in which solar energy is stored in bio-chemical bonds, and which commonly contain carbon, hydrogen, oxygen, and nitrogen constituents, along with traces of sulfur. Renewable Biomass is now considered as a crucial energy resource, which is able to meet a range of energy requirements, including generating electricity and fueling vehicles. Among all the renewable energy sources, Microalgal Biomass is unique, since it profitably stores solar energy. It is one of the renewable sources of carbon that can be effectively converted into expedient solid, liquid, and gaseous biofuels through different conversion techniques. In this review, thermochemical conversion technologies involving Microalgal Biomass are highlighted, with emphasis on the background chemistry and chemical processes. Thermochemical conversion of Microalgal Biomass via pyrolysis, hydrothermal liquefaction, gasification, torrefaction, and direct combustion for bioenergy production from Microalgal species is dis-cussed, though there are limited literature sources available on these technologies. The unique features of hydrothermal gasification and supercritical gasification technologies are described, with the chemical reactions involved in these processes. The decomposition pathways of the main chemical components present in the Microalgal Biomass, such as carbohydrates and proteins, are well elucidated with the chemical pathways. The pros and cons of direct combustion are also spotlighted.
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simultaneous Microalgal Biomass production and co2 fixation by cultivating chlorella sp gd with aquaculture wastewater and boiler flue gas
Bioresource Technology, 2016Co-Authors: Chiu Mei Kuo, Jo Shu Chang, Jhong Fu Jian, Tsung Hsien Lin, Yu Bin Chang, Xin Hua Wan, Jinn Tsyy Lai, Chihsheng LinAbstract:A Microalgal strain, Chlorella sp. GD, cultivated in aquaculture wastewater (AW) aerated with boiler flue gas, was investigated. When AW from a grouper fish farm was supplemented with additional nutrients, the Microalgal Biomass productivity after 7days of culture was 0.794gL-1d-1. CO2 fixation efficiencies of the Microalgal strains aerated with 0.05, 0.1, 0.2, and 0.3vvm of boiler flue gas (containing approximately 8% CO2) were 53, 51, 38, and 30%, respectively. When the Microalgal strain was cultured with boiler flue gas in nutrient-added AW, Biomass productivity increased to 0.892gL-1d-1. In semi-continuous cultures, average Biomass productivities of the Microalgal strain in 2-day, 3-day, and 4-day replacement cultures were 1.296, 0.985, and 0.944gL-1d-1, respectively. These results demonstrate the potential of using Chlorella sp. GD cultivations in AW aerated with boiler flue gas for reusing water resources, reducing CO2 emission, and producing Microalgal Biomass.
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supercritical fluid extraction of valuable compounds from Microalgal Biomass
Bioresource Technology, 2015Co-Authors: Hongwei Yen, Sheng Chung Yang, Chi Hui Chen, Jo Shu ChangAbstract:Many studies have demonstrated that the global demand for renewable biofuels, natural food pigments, and antioxidants has made microalgae a more attractive alternative resource. The application of supercritical fluid extraction (SFE) on the valuable compounds recovery from Microalgal Biomass has several advantages as compared to the conventional organic solvent extraction methods, especially for environmental considerations. This review presents comprehensive information on the current state of using SFE to recover valuable components from Microalgal Biomass, such as total lipids, long chain fatty acid and pigments, as well as the utilization and characteristics of the SFE technology. In addition, key factors and challenges that should be addressed during the application of SFE technology are also discussed. This report provides a useful guide that can aid in the future development of more efficient microalgae-based biorefinery process.
Razif Harun - One of the best experts on this subject based on the ideXlab platform.
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Potential Applications of Nanotechnology in Thermochemical Conversion of Microalgal Biomass
Nanotechnology for Bioenergy and Biofuel Production, 2017Co-Authors: Abdul Raheem, Liaquat Ali Memon, Yun Hin Taufiq-yap, Michael Kobina Danquah, S A Abbasi, Razif HarunAbstract:The rapid decrease in fossil reserves has significantly increased the demand of renewable and sustainable energy fuel resources. Fluctuating fuel prices and significant greenhouse gas (GHG) emission levels have been key impediments associated with the production and utilization of nonrenewable fossil fuels. This has resulted in escalating interests to develop new and improve inexpensive carbon neutral energy technologies to meet future demands. Various process options to produce a variety of biofuels including biodiesel, bioethanol, biohydrogen, bio-oil, and biogas have been explored as an alternative to fossil fuels. The renewable, biodegradable, and nontoxic nature of biofuels make them appealing as alternative fuels. Biofuels can be produced from various renewable resources. Among these renewable resources, algae appear to be promising in delivering sustainable energy options.Algae have a high carbon dioxide (CO2) capturing efficiency, rapid growth rate, high Biomass productivity, and the ability to grow in non-potable water. For algal Biomass, the two main conversion pathways used to produce biofuel include biochemical and thermochemical conversions. Algal biofuel production is, however, challenged with process scalability for high conversion rates and high energy demands for Biomass harvesting. This affects the viable achievement of industrial-scale bioprocess conversion under optimum economy. Although algal biofuels have the potential to provide a sustainable fuel for future, active research aimed at improving upstream and downstream technologies is critical. New technologies and improved systems focused on photobioreactor design, cultivation optimization, culture dewatering, and biofuel production are required to minimize the drawbacks associated with existing methods.Nanotechnology has the potential to address some of the upstream and downstream challenges associated with the development of algal biofuels. It can be applied to improve system design, cultivation, dewatering, Biomass characterization, and biofuel conversion. This chapter discusses thermochemical conversion of Microalgal Biomass with recent advances in the application of nanotechnology to enhance the development of biofuels from algae. Nanotechnology has proven to improve the performance of existing technologies used in thermochemical treatment and conversion of Biomass. The different bioprocess aspects, such as reactor design and operation, analytical techniques, and experimental validation of kinetic studies, to provide insights into the application of nanotechnology for enhanced algal biofuel production are addressed.
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Thermochemical conversion of Microalgal Biomass for biofuel production
Renewable and Sustainable Energy Reviews, 2015Co-Authors: Abdul Raheem, W. A.k.g. Wan Azlina, Yun Hin Taufiq-yap, Michael Kobina Danquah, Razif HarunAbstract:Abstract Reliable and sustainable energy supply is critical to effective natural resource management, and it encompasses functioning efficiency of energy resources as well as socio-economic and environmental impact considerations. The complete reliance on fossil fuels is recognized as unsustainable throughout the world, and this is due to, amongst others, the rapid declining of fossil fuel reserves and the emission of significant quantities of greenhouse gases associated with their production and combustion. This has resulted in escalating interest in research activities aiming to develop alternative and somewhat carbon neutral energy sources. Algal biofuels, so called third generation biofuels, appear to be promising in delivering sustainable and complementary energy platforms essential to formulate a major component of the renewable and sustainable energy mix for the future. Algal Biomass can be converted into various portfolios of biofuel products, such as bio-hydrogen, biodiesel, bioethanol and biogas, via two different pathways: biochemical and thermochemical pathways. Thermochemical conversion is considered as a viable method to overcome the existing problems related with biochemical conversion such as lengthy reaction time, low conversion efficiency by microbes and enzymes, and high production costs. This paper discusses process technologies for microalgae-to-biofuel production systems, focusing on thermochemical conversion technologies such as gasification, pyrolysis, and liquefaction. The benefits of exploiting upstream Microalgal Biomass development for bioremediation such as carbon dioxide mitigation and wastewater treatment are also discussed.
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exploring alkaline pre treatment of Microalgal Biomass for bioethanol production
Applied Energy, 2011Co-Authors: Razif Harun, W S Y Jason, Tamara Cherrington, Michael K DanquahAbstract:We have investigated, for the first time, the alkaline pre-treatment of Microalgal Biomass, from the species Chlorococcum infusionum, using NaOH for bioethanol production. This pre-treatment step aims to release and breakdown entrapped polysaccharides in the microalgae cell walls into fermentable subunits. Three parameters were examined here; the concentration of NaOH, temperature and the pre-treatment time. The bioethanol concentration, glucose concentration and the cell size were studied in order to determine the effectiveness of the pre-treatment process. Microscopic analysis was performed to confirm cell rupturing, the highest glucose yield was determined to be 350mg/g, and the maximum bioethanol yield obtained was 0.26g ethanol/g algae using 0.75% (w/v) of NaOH and 120°C for 30min. Overall, the alkaline pre-treatment method proved to be promising option to pre-treat Microalgal Biomass for bioethanol production.
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enzymatic hydrolysis of Microalgal Biomass for bioethanol production
Chemical Engineering Journal, 2011Co-Authors: Razif Harun, Michael K DanquahAbstract:Abstract Increasing global energy demands and the potential for significant climate change have led to burgeoning interest in alternative fuels which are sustainable, environmentally friendly and cost efficient. One of the key options is to produce bioethanol from renewable Biomass. Due to its numerous advantages, including fast growth rate, non-edibility, and the ability to accumulate substantial amounts of carbohydrates, microalgae, a second generation cellular Biomass, have the potential to be used as a fermentation feedstock for bioethanol production. The present study examines the enzymatic hydrolysis of Chloroccum sp. by using cellulase obtained from Trichoderma reesei, ATCC 26921. The hydrolysis was conducted under varying conditions of temperature, pH and substrate concentration, with constant enzyme dosage. The kinetics of hydrolysis was fitted with Michaelis–Menten's model of rapid equilibrium. The highest glucose yield of 64.2% (w/w) was obtained at a temperature of 40 °C, pH 4.8, and a substrate concentration of 10 g/L of Microalgal Biomass. Comparative kinetic studies on glucose and cellobiose formation showed twice as fast glucose production than cellulobiose. The value of Km,app was higher for the hydrolysis of cellobiose (Km,app = 15.18 g/L) compared to that of the substrate (Km,app = 1.48 g/L), thus displaying a competitive type of inhibition. The results were in keeping with the obtained reaction velocities. Overall, the enzymatic hydrolysis process proved to be an effective mechanism to enhance the saccharification process of Microalgal Biomass.
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influence of acid pre treatment on Microalgal Biomass for bioethanol production
Process Biochemistry, 2011Co-Authors: Razif Harun, Michael K DanquahAbstract:Abstract The utilisation of Microalgal Biomass as feedstock for bioethanol production has been very promising owing to the large amounts of carbohydrates embedded in the physiology of the Microalgal cell. This is coupled with the potential of microalgae to achieve targets required for high growth rate bioethanol production, climate change mitigation and economic growth. The high content of complex carbohydrates entrapped in the cell wall of the microalgae makes it essential to incorporate a pre-treatment stage to release and convert these complex carbohydrates into simple sugars prior to the fermentation process. Hence, this study explores the influence of acid exposure as a Microalgal pre-treatment strategy for bioethanol production. Different parameters were investigated: acid concentration, temperature, microalgae loading and pre-treatment time. A central composite design technique was employed to optimize the acid pre-treatment conditions. Results showed that the highest bioethanol concentration obtained was 7.20 g/L and this was achieved when the pre-treatment step was performed with 15 g/L of microalgae at 140 °C using 1% (v/v) of sulphuric acid for 30 min. In terms of ethanol yield, ∼52 wt% (g ethanol/g microalgae) maximum was obtained using 10 g/L of microalgae and 3% (v/v) of sulphuric acid under 160 °C for 15 min. The statistical analysis revealed amongst the parameters investigated that temperature is the most critical factor during acid pre-treatment of microalgae for bioethanol production.
Ivet Ferrer - One of the best experts on this subject based on the ideXlab platform.
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Anaerobic co-digestion of Microalgal Biomass and wheat straw with and without thermo-alkaline pretreatment
Bioresource Technology, 2017Co-Authors: Maria Sole Bundo, Cigdem Eskicioglu, Marianna Garfí, Hélène Carrère, Ivet FerrerAbstract:This study aimed at analyzing the anaerobic co-digestion of Microalgal Biomass grown in wastewater and wheat straw. To this end, Biochemical Methane Potential (BMP) tests were carried out testing different substrate proportions (20-80, 50-50 and 80-20%, on a volatile solid basis). In order to improve their biodegradability, the co-digestion of both substrates was also evaluated after applying a thermo-alkaline pretreatment (10% CaO at 75°C for 24h). The highest synergies in degradation rates were observed by adding at least 50% of wheat straw. Therefore, the co-digestion of 50% microalgae - 50% wheat straw was investigated in mesophilic lab-scale reactors. The results showed that the methane yield was increased by 77% with the co-digestion as compared to microalgae mono-digestion, while the pretreatment only increased the methane yield by 15% compared to the untreated mixture. Thus, the anaerobic co-digestion of microalgae and wheat straw was successful even without applying a thermo-alkaline pretreatment.
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settling velocity distribution of Microalgal Biomass from urban wastewater treatment high rate algal ponds
Algal Research-Biomass Biofuels and Bioproducts, 2016Co-Authors: Raquel Gutierrez, Enrica Uggetti, Ivet Ferrer, Carme Arnabat, Humbert Salvado, Joan GarciaAbstract:The aim of this study was to evaluate the settling velocity distribution of Microalgal Biomass with and without flocculant (Tanfloc SG). Microalgal Biomass was obtained from two experimental wastewater treatment high rate algal ponds (HRAPs) operated with 4 and 8 days of hydraulic retention time. Two sets of dynamic sedimentation tests were carried out using a water elutriation apparatus. In the first set, most of the Biomass of the 8 days-HRAP (63%) had settling velocities between 16.5 and 4 m/h, while most of the Biomass of the 4 days-HRAP (65%) had settling velocities between 16.5 and 1 m/h. In the second set, most of the Biomass from both HRAPs (60% from the 8 days-HRAP and 80% from the 4 days-HRAP) had settling velocities between 6.5 and 0.4 m/h. In this second set, settling velocities of 6.5 m/h, compared to 10% and 14% of Microalgal Biomass without flocculant for the 8 days-and 4 days-HRAPs, respectively. With flocculant, a very small amount of Biomass (3% for the 4 days-HRAP and 8% for the 8 days-HRAP) had settling velocities of 10(5) microalgae individuals/mL). According to our results, a settler designed with a critical settling velocity of 1m/h would reach Biomass recoveries as high as 90-94% with flocculant compared to 77-88% without flocculant.
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influence of hydrothermal pretreatment on Microalgal Biomass anaerobic digestion and bioenergy production
Water Research, 2015Co-Authors: Fabiana Passos, Ivet FerrerAbstract:Microalgal Biomass grown in wastewater treatment raceway ponds may be valorised producing bioenergy through anaerobic digestion. However, pretreatment techniques seem to be necessary for enhancing microalgae methane yield. In this study, hydrothermal pretreatment was studied prior to batch and continuous reactors. The pretreatment increased organic matter solubilisation (8-13%), anaerobic digestion rate (30-90%) and final methane yield (17-39%) in batch tests. The highest increase was attained with the pretreatment at 130 degrees C for 15 min, which was attested in a laboratory-scale continuous reactor operated at a hydraulic retention time of 20 days with an average organic loading rate of 0.7 g VS/L center dot day. The methane yield increased from 0.12 to 0.17 L CH4/g VS (41%) in the pretreated digester as compared to the control. Microscopic images of Microalgal Biomass showed that pretreated cells had unstructured organelles and disrupted cell wall external layer, which may enhance the hydrolysis. Indeed, images of the pretreated reactor digestate showed how cells were more degraded than in the control reactor. (C) 2014 Elsevier Ltd. All rights reserved.
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anaerobic digestion of Microalgal Biomass after ultrasound pretreatment
Waste Management, 2014Co-Authors: Fabiana Passos, Sergi Astals, Ivet FerrerAbstract:High rate algal ponds are an economic and sustainable alternative for wastewater treatment, where microalgae and bacteria grow in symbiosis removing organic matter and nutrients. Microalgal Biomass produced in these systems can be valorised through anaerobic digestion. However, microalgae anaerobic biodegradability is limited by the complex cell wall structure and therefore a pretreatment step may be required to improve the methane yield. In this study, ultrasound pretreatment at a range of applied specific energy (16-67. MJ/kg. TS) was investigated prior to microalgae anaerobic digestion. Experiments showed how organic matter solubilisation (16-100%), hydrolysis rate (25-56%) and methane yield (6-33%) were improved as the pretreatment intensity increased. Mathematical modelling revealed that ultrasonication had a higher effect on the methane yield than on the hydrolysis rate. A preliminary energy assessment indicated that the methane yield increase was not high enough as to compensate the electricity requirement of ultrasonication without Biomass dewatering (8% VS).
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impact of low temperature pretreatment on the anaerobic digestion of Microalgal Biomass
Bioresource Technology, 2013Co-Authors: Fabiana Passos, Joan Garcia, Ivet FerrerAbstract:Abstract The aim of this study was to investigate the effect of low temperature pretreatment on the anaerobic digestion of Microalgal Biomass grown in wastewater. To this end, microalgae were pretreated at low temperatures (55, 75 and 95 °C) for 5, 10 and 15 h. Biomass solubilisation was enhanced with the pretreatment temperature and exposure time up to 10 h. The methane yield was improved by 14%, 53% and 62% at 55, 75 and 95 °C, respectively; and was correlated with the solubilisation increase. The pretreatment at 95 °C for 10 h increased VS solubilisation by 1188%, the initial methane production rate by 90% and final methane yield by 60% compared to untreated microalgae. With diluted Biomass (∼1% VS) positive energy balance was not likely to be attained. However, with concentrated Biomass (>2% VS) energy requirements may be covered and even surplus energy generated.
Michael K Danquah - One of the best experts on this subject based on the ideXlab platform.
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exploring alkaline pre treatment of Microalgal Biomass for bioethanol production
Applied Energy, 2011Co-Authors: Razif Harun, W S Y Jason, Tamara Cherrington, Michael K DanquahAbstract:We have investigated, for the first time, the alkaline pre-treatment of Microalgal Biomass, from the species Chlorococcum infusionum, using NaOH for bioethanol production. This pre-treatment step aims to release and breakdown entrapped polysaccharides in the microalgae cell walls into fermentable subunits. Three parameters were examined here; the concentration of NaOH, temperature and the pre-treatment time. The bioethanol concentration, glucose concentration and the cell size were studied in order to determine the effectiveness of the pre-treatment process. Microscopic analysis was performed to confirm cell rupturing, the highest glucose yield was determined to be 350mg/g, and the maximum bioethanol yield obtained was 0.26g ethanol/g algae using 0.75% (w/v) of NaOH and 120°C for 30min. Overall, the alkaline pre-treatment method proved to be promising option to pre-treat Microalgal Biomass for bioethanol production.
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enzymatic hydrolysis of Microalgal Biomass for bioethanol production
Chemical Engineering Journal, 2011Co-Authors: Razif Harun, Michael K DanquahAbstract:Abstract Increasing global energy demands and the potential for significant climate change have led to burgeoning interest in alternative fuels which are sustainable, environmentally friendly and cost efficient. One of the key options is to produce bioethanol from renewable Biomass. Due to its numerous advantages, including fast growth rate, non-edibility, and the ability to accumulate substantial amounts of carbohydrates, microalgae, a second generation cellular Biomass, have the potential to be used as a fermentation feedstock for bioethanol production. The present study examines the enzymatic hydrolysis of Chloroccum sp. by using cellulase obtained from Trichoderma reesei, ATCC 26921. The hydrolysis was conducted under varying conditions of temperature, pH and substrate concentration, with constant enzyme dosage. The kinetics of hydrolysis was fitted with Michaelis–Menten's model of rapid equilibrium. The highest glucose yield of 64.2% (w/w) was obtained at a temperature of 40 °C, pH 4.8, and a substrate concentration of 10 g/L of Microalgal Biomass. Comparative kinetic studies on glucose and cellobiose formation showed twice as fast glucose production than cellulobiose. The value of Km,app was higher for the hydrolysis of cellobiose (Km,app = 15.18 g/L) compared to that of the substrate (Km,app = 1.48 g/L), thus displaying a competitive type of inhibition. The results were in keeping with the obtained reaction velocities. Overall, the enzymatic hydrolysis process proved to be an effective mechanism to enhance the saccharification process of Microalgal Biomass.
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influence of acid pre treatment on Microalgal Biomass for bioethanol production
Process Biochemistry, 2011Co-Authors: Razif Harun, Michael K DanquahAbstract:Abstract The utilisation of Microalgal Biomass as feedstock for bioethanol production has been very promising owing to the large amounts of carbohydrates embedded in the physiology of the Microalgal cell. This is coupled with the potential of microalgae to achieve targets required for high growth rate bioethanol production, climate change mitigation and economic growth. The high content of complex carbohydrates entrapped in the cell wall of the microalgae makes it essential to incorporate a pre-treatment stage to release and convert these complex carbohydrates into simple sugars prior to the fermentation process. Hence, this study explores the influence of acid exposure as a Microalgal pre-treatment strategy for bioethanol production. Different parameters were investigated: acid concentration, temperature, microalgae loading and pre-treatment time. A central composite design technique was employed to optimize the acid pre-treatment conditions. Results showed that the highest bioethanol concentration obtained was 7.20 g/L and this was achieved when the pre-treatment step was performed with 15 g/L of microalgae at 140 °C using 1% (v/v) of sulphuric acid for 30 min. In terms of ethanol yield, ∼52 wt% (g ethanol/g microalgae) maximum was obtained using 10 g/L of microalgae and 3% (v/v) of sulphuric acid under 160 °C for 15 min. The statistical analysis revealed amongst the parameters investigated that temperature is the most critical factor during acid pre-treatment of microalgae for bioethanol production.
He Huang - One of the best experts on this subject based on the ideXlab platform.
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lipid production of heterotrophic chlorella sp from hydrolysate mixtures of lipid extracted Microalgal Biomass residues and molasses
Applied Biochemistry and Biotechnology, 2015Co-Authors: Hongli Zheng, Zhen Gao, He Huang, Yiqin Wan, Min Min, Wenguang Zhou, Yuhuan Liu, Paul Chen, Roger RuanAbstract:This study investigated the feasibility of lipid production of Chlorella sp. from waste materials. Lipid-extracted Microalgal Biomass residues (LMBRs) and molasses were hydrolyzed, and their hydrolysates were analyzed. Five different hydrolysate mixture ratios (w/w) of LMBRs/molasses (1/0, 1/1, 1/4, 1/9, and 0/1) were used to cultivate Chlorella sp. The results showed that carbohydrate and protein were the two main compounds in the LMBRs, and carbohydrate was the main compound in the molasses. The highest Biomass concentration of 5.58 g/L, Y Biomass/sugars of 0.59 g/g, lipid productivity of 335 mg/L/day, and Y lipids/sugars of 0.25 g/g were obtained at the hydrolysate mixture ratio of LMBRs/molasses of 1/4. High C/N ratio promoted the conversion of sugars into lipids. The lipids extracted from Chlorella sp. shared similar lipid profile of soybean oil and is therefore a potential viable biodiesel feedstock. These results showed that Chlorella sp. can utilize mixed sugars and amino acids from LMBRs and molasses to accumulate lipids efficiently, thus reducing the cost of Microalgal biodiesel production and improving its economic viability.
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effect of co2 supply conditions on lipid production of chlorella vulgaris from enzymatic hydrolysates of lipid extracted Microalgal Biomass residues
Bioresource Technology, 2012Co-Authors: Hongli Zheng, Zhen Gao, Fengwei Yin, He HuangAbstract:The hydrolysates from lipid-extracted Microalgal Biomass residues (LMBRs) were used as a source of nutrients for the cultivation of Chlorella vulgaris for lipid production under various CO(2) supply conditions, including different CO(2) concentrations and aeration rates. Both parameters had a significant effect on lipid production. A CO(2) concentration of 5% was found to be most suitable for Microalgal growth. Microalga grew best at a CO(2) aeration rate of 0.5 vvm. At this rate, Biomass concentration and lipid productivity were at a maximum of 3.83 g L(-1) and 157 mg L(-1)d(-1), respectively, but decreased at lower or higher aeration rates. The present results showed that LMBRs utilization was effective in Microalgal lipid production under suitable CO(2) supply conditions.
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lipid production of chlorella vulgaris from lipid extracted Microalgal Biomass residues through two step enzymatic hydrolysis
Bioresource Technology, 2012Co-Authors: Hongli Zheng, Zhen Gao, Fengwei Yin, He HuangAbstract:Abstract Lipid-extracted Microalgal Biomass residues (LMBRs) were treated using cellulase, neutrase and alcalase in a two-step process and the resulting hydrolysates were used as a source of nutrients for the cultivation of Chlorella vulgaris under non-aerated and aerated conditions for lipid production. Aeration was favorable for cell growth and lipid accumulation and a Biomass of approximately 3.28 g L −1 , lipid content of 35% and lipid productivity of 116 mg L −1 d −1 were obtained. Thus, the tested mode of LMBRs utilization was effective for nutrient recycling in Microalgal biodiesel production.