Enhanced productivity of lipid extraction by urea stress conditions on marine microalgae Coelastrum sp. for improved biodiesel production

2021 ◽  
pp. 100696
Author(s):  
Prakash Bhuyar ◽  
Sathyavathi Sundararaju ◽  
Mohd Hasbi Ab. Rahim ◽  
Gaanty Pragas Maniam ◽  
Natanamurugaraj Govindan
2020 ◽  
Vol 18 (1) ◽  
pp. 874-881
Author(s):  
Laras Prasakti ◽  
Sangga Hadi Pratama ◽  
Ardian Fauzi ◽  
Yano Surya Pradana ◽  
Arief Budiman ◽  
...  

AbstractAs fossil fuels were depleting at an alarming rate, the development of renewable energy has become necessary. One of the promising renewable energy to be used is biodiesel. The interest in using third-generation feedstock, which is microalgae, is rapidly growing. The use of third-generation biodiesel feedstock will be more beneficial as it does not compete with food crop use and land utilization. The advantageous characteristic which sets microalgae apart from other biomass sources is that microalgae have high biomass yield. Conventionally, microalgae biodiesel is produced by lipid extraction followed by transesterification. In this study, combination process between hydrothermal liquefaction (HTL) and esterification is explored. The HTL process is one of the biomass thermochemical conversion methods to produce liquid fuel. In this study, the HTL process will be coupled with esterification, which takes fatty acid from HTL as raw material for producing biodiesel. Both the processes will be studied by simulating with Aspen Plus and thermodynamic analysis in terms of energy and exergy. Based on the simulation process, it was reported that both processes demand similar energy consumption. However, exergy analysis shows that total exergy loss of conventional exergy loss is greater than the HTL-esterification process.


2014 ◽  
Vol 28 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Agata Piasecka ◽  
Izabela Krzemińska ◽  
Jerzy Tys

Abstract The prospect of depletion of natural energy resources on the Earth forces researchers to seek and explore new and alternative energy sources. Biomass is a composite resource that can be used in many ways leading to diversity of products. Therefore, microalgal biomass offers great potential. The main aim of this study is to find the best physical method of microalgal biomass pretreatment that guarantees efficient lipid extraction. These studies identifies biochemical composition of microalgal biomass as source for biodisel production. The influence of drying at different temperatures and lyophilization was investigated. In addition, wet and untreated biomass was examined. Cell disruption (sonication and microwave) techniques were used to improve lipid extraction from wet biomass. Additionally, two different extraction methods were carried out to select the best method of crude oil extraction. The results of this study show that wet biomass after sonication is the most suitable for extraction. The fatty acid composition of microalgal biomass includes linoleic acid (C18:2), palmitic acid (C16:0), oleic acid (C18:1), linolenic acid (C18:3), and stearic acid (C18:0), which play a key role in biodiesel production.


2020 ◽  
pp. 152-158
Author(s):  
Gour Gopal Satpati ◽  
Ruma Pal

The increase of total lipid and fatty acids production was studied under different nutrient stress conditions using the macroalga, Chaetomorpha aerea. The effects of nitrogen, phosphorus, ethylene diamine tetra-acetate and sodium chloride on the growth and lipid accumulation were systematically investigated in laboratory conditions. The biomass was harvested at different stages of cultivation and assessed. The maximum changes of growth and lipid accumulation were observed in the exponential phase at different cultural conditions. The two-fold increase of total lipid was found in the order of 28.27±0.04 % (at 0.1 g/L nitrogen) > 27.30±0.37 % (at 0.5 g/L of phosphorus) > 25.86±0.77 % (at 0.05 g/L of EDTA)> 24.37±0.04 % (at 0.05 g/L NaCl) on 8th day of cultivation. The fatty acids were identified and quantified by gas chromatography mass spectrometry (GC-MS). The alga produces significantly high amount of monounsaturated fatty acid (MUFA) and saturated fatty acids (SFA) than the polyunsaturated fatty acids (PUFA) in different cultural conditions. The elevated levels of C16:1, C18:1 and C20:1 was identified under nitrate, phosphate and salt stress conditions, which are more suitable for biodiesel production.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Shihong Liu ◽  
Husam A. Abu Hajar ◽  
Guy Riefler ◽  
Ben J. Stuart

Microalgae are one of the most promising feedstocks for biodiesel production due to their high lipid content and easy farming. However, the extraction of lipids from microalgae is energy intensive and costly and involves the use of toxic organic solvents. Compared with organic solvent extraction, supercritical CO2(SCCO2) has demonstrated advantages through lower toxicity and no solvent-liquid separation. Due to the nonpolar nature of SCCO2, polar organic solvents such as methanol may need to be added as a modifier in order to increase the extraction ability of SCCO2. In this paper, pilot scale lipid extraction using SCCO2was studied on two microalgae species:Spirulinasp. andSchizochytriumsp. For each species, SCCO2extraction was conducted on 200 g of biomass for 6 h. Methanol was added as a cosolvent in the extraction process based on a volume ratio of 4%. The results showed that adding methanol in SCCO2increased the lipid extraction yield significantly for both species. Under an operating pressure of 4000 psi, the lipid extraction yields forSpirulinasp. andSchizochytriumsp. were increased by 80% and 72%, respectively. It was also found that a stepwise addition of methanol was more effective than a one-time addition. In comparison with Soxhlet extraction using methylene chloride/methanol (2:1, v/v), the methanol-SCCO2extraction demonstrated its high effectiveness for lipid extraction. In addition, the methanol-SCCO2system showed a high lipid extraction yield after increasing biomass loading fivefold, indicating good potential for scaling up this method. Finally, a kinetic study of the SCCO2extraction process was conducted, and the results showed that methanol concentration in SCCO2has the strongest influence on the lipid extraction yield.


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