scholarly journals Sustainable Production of Monoraphidium Microalgae Biomass as a Source of Bioenergy

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5975
Author(s):  
Małgorzata Hawrot-Paw ◽  
Adam Koniuszy ◽  
Małgorzata Gałczyńska

Microalgae are a renewable source of unconventional biomass with potential application in the production of various biofuels. The production of carbon-neutral fuels is necessary for protecting the environment. This work determined the possibility of producing biomass of microalgae belonging to Monoraphidium genus using saline wastewater resulting from proecological salmon farming in the recirculating aquaculture system. The tests were carried out in tubular photobioreactors using LED light. As a part of the analyses, the growth and productivity of microalgal biomass, cell density in culture, and lipid concentration and ash content in biomass were determined. In addition, the concentration of selected phosphorus and nitrogen forms present in wastewater corresponding to the degree of their use by microalgae as a nutrient substrate was determined. The biomass concentration estimated in the tests was 3.79 g·L−1, while the maximum biomass productivity was 0.46 g·L−1·d−1. The cells’ optical density in culture measured at 680 nm was 0.648. The lipid content in biomass was 18.53% (dry basis), and the ash content was 32.34%. It was found that microalgae of the genus Monoraphidium effectively used the nitrogen as well as phosphorus forms present in the wastewater for their growth. The total nitrogen content in the sewage decreased by 82.62%, and total phosphorus content by over 99%. The analysis of the individual forms of nitrogen showed that N-NO3 was reduced by 85.37% and N-NO2 by 78.43%, while orthophosphate (V) dissolved in water was reduced by 99%. However, the content of N-NH4 in wastewater from the beginning till the end of the experiment remained <0.05 mg·L−1.

Author(s):  
Marta Kisielewska ◽  
Marcin Dębowski ◽  
Marcin Zieliński ◽  
Joanna Kazimierowicz ◽  
Piera Quattrocelli ◽  
...  

AbstractThe aim of the study was to investigate the potential of microalgal cultivation on anaerobic liquid digestate as a growth medium. The two methods of liquid digestate treatment including centrifugation and distillation and the two algal strains (Chlorella vulgaris and Arthrospira platensis) were compared. Additionally, the volume of the liquid digestate used to prepare the culture medium constituted from 10 to 50% of the medium volume. The study demonstrated that the highest C. vulgaris and A. platensis biomass productions of 2490 mg TS/L and 2990 mg/L, respectively, were obtained by adding 50% of distilled digestate to a growth medium. Regarding centrifuged liquid digestate, only 10% dilution was required to obtain the maximum final biomass concentration. A. platensis removed 81.1% and 66.4% of the total nitrogen from medium prepared on distilled and centrifuged digestate, respectively, while C. vulgaris ensured 64.1% and 47.1% of removal, respectively. The phosphorus removal from both culture media was higher than 94.2% with A. platensis, while it was 70.4% from distilled and 87.4% from centrifuged media with C. vulgaris. The study confirmed a great potential of microalgal biomass production on anaerobic liquid digestate with a high treatment efficiency of digestate.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ângelo Paggi Matos ◽  
Regina Coeli de Oliveira Torres ◽  
Luiz Rodrigo Ito Morioka ◽  
Elisa Helena Siegel Moecke ◽  
Kepler Borges França ◽  
...  

Desalination wastewater, which contains large amount of salt waste, might lead to severely environmental pollution. This study evaluated the effect of dilution rate (0.1≤D≤0.3day−1) on microalgal biomass productivity, lipid content, and fatty acid profile under steady-state condition ofChlorella vulgarissupplemented with concentrated desalination. Continuous culture was conducted for 55 days. Results show that the biomass productivity (Px) varied from 57 to 126 mg L−1 d−1(dry mass) when the dilution rate ranged from 0.1 to 0.3 day−1. At lowest dilution rate (D=0.1day−1), the continuous culture regime ensured the highest values of maximum biomass concentration (Xm=570±20 mL−1) and protein content (52%). Biomass lipid content was an increasing function ofD. The most abundant fatty acids were the palmitic (25.3±0.6%) atD=0.1day−1and the gamma-linolenic acid (23.5±0.1%) atD=0.3day−1ones. These fatty acids present 14 to 18 carbons in the carbon chain, being mainly saturated and polyunsaturated, respectively. Overall, the results show that continuous culture is a powerful tool to investigate the cell growth kinetics and physiological behaviors of the algae growing on desalination wastewater.


Author(s):  
Antonio Zuorro ◽  
Janet B. García-Martínez ◽  
Andrés F. Barajas-Solano

Over the last decades, microalgal biomass has gained a significant role in the development of different high-end (nutraceuticals, colorants, food supplements, and pharmaceuticals) and low-end products (biodiesel, bioethanol, and biogas) due to rapid growth and high carbon fixing efficiency. Therefore, microalgae are considered a useful and sustainable resource to attain energy security while reducing our current reliance on fossil fuels. From the technologies available for obtaining biofuels using microalgae biomass, thermochemical processes (pyrolysis, HTL, gasification) have proven to be processed with higher viability, because they use all biomass. However, the biocrudes obtained from direct thermochemical conversion have substantial quantities of heteroatoms (oxygen, nitrogen, and sulfur) due to the complexity of the biomass's content of chemical components (lipids, carbohydrates, and proteins). As a solution, catalyst-based processes have emerged as a sustainable solution for the increase in biocrude production. This paper's objective is to present a comprehensive review of recent developments on catalyst mediated conversion of algal biomass. Special attention will be given to operating conditions, strains evaluated, and challenges for the optimal yield of algal-based biofuels through pyrolysis and HTL.


2020 ◽  
Author(s):  
Lucielen Oliveira Santos ◽  
Pedro Garcia Pereira Silva ◽  
Sharlene Silva Costa ◽  
Taiele Blumberg Machado

Use of fuels from non-renewable sources has currently been considered unsustainable due to the exhaustion of supplies and environmental impacts caused by them. Climate change has concerned and triggered environmental policies that favor research on clean and renewable energy sources. Thus, production of third generation biofuels is a promising path in the biofuel industry. To yield this type of biofuels, microalgae should be highlighted because this raw material contains important biomolecules, such as carbohydrates and lipids. Technological approaches have been developed to improve microalgal cultivation under ecological conditions, such as light intensity, temperature, pH and concentrations of micro and macronutrients. Thus, magnetic field application to microalgal cultivation has become a viable alternative to obtain high yields of biomass concentration and accumulation of carbohydrates and lipids.


2015 ◽  
Vol 52 (2) ◽  
pp. 59-70 ◽  
Author(s):  
J. Vanags ◽  
L. Kunga ◽  
K. Dubencovs ◽  
V. Galvanauskas ◽  
O. Grīgs

Abstract Optimization of the microalgae cultivation process and of the bioprocess in general traditionally starts with cultivation experiments in flasks. Then the scale-up follows, when the process from flasks is transferred into a laboratory-scale bioreactor, in which further experiments are performed before developing the process in a pilot-scale reactor. This research was done in order to scale-up the process from a 0.4 1 shake flask to a 4.0 1 laboratory-scale stirred-tank photobioreactor for the cultivation of Desmodesmus (D.) communis microalgae. First, the effect of variation in temperature (21-29 ºC) and in light intensity (200-600 μmol m-2s-1) was studied in the shake-flask experiments. It was shown that the best results (the maximum biomass concentration of 2.72 g 1-1 with a specific growth rate of 0.65 g g-1d-1) can be achieved at the cultivation temperature and light intensity being 25 °C and 300 μmol m2s-1, respectively. At the same time, D. communis cultivation under the same conditions in stirred-tank photobioreactor resulted in average volumetric productivities of biomass due to the light limitation even when the light intensity was increased during the experiment (the maximum biomass productivity 0.25 g 1-1d-1; the maximum biomass concentration 1.78 g 1-1).


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hee Su Kim ◽  
Won-Kun Park ◽  
Bongsoo Lee ◽  
Gyeongho Seon ◽  
William I. Suh ◽  
...  

AbstractThe heterotrophic cultivation of microalgae has a number of notable advantages, which include allowing high culture density levels as well as enabling the production of biomass in consistent and predictable quantities. In this study, the full potential of Chlorella sp. HS2 is explored through optimization of the parameters for its heterotrophic cultivation. First, carbon and nitrogen sources were screened in PhotobioBox. Initial screening using the Plackett-Burman design (PBD) was then adopted and the concentrations of the major nutrients (glucose, sodium nitrate, and dipotassium phosphate) were optimized via response surface methodology (RSM) with a central composite design (CCD). Upon validation of the model via flask-scale cultivation, the optimized BG11 medium was found to result in a three-fold improvement in biomass amounts, from 5.85 to 18.13 g/L, in comparison to a non-optimized BG11 medium containing 72 g/L glucose. Scaling up the cultivation to a 5-L fermenter resulted in a greatly improved biomass concentration of 35.3 g/L owing to more efficient oxygenation of the culture. In addition, phosphorus feeding fermentation was employed in an effort to address early depletion of phosphate, and a maximum biomass concentration of 42.95 g/L was achieved, with biomass productivity of 5.37 g/L/D.


2021 ◽  
pp. 267-286
Author(s):  
Manoj Kumar Enamala ◽  
A. Sai Kumar ◽  
P. Divya Sruthi ◽  
Murthy Chavali ◽  
Meenakshi Singh ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 413 ◽  
Author(s):  
Esveidi Montserrat Valdovinos-García ◽  
Juan Barajas-Fernández ◽  
María de los Ángeles Olán-Acosta ◽  
Moisés Abraham Petriz-Prieto ◽  
Adriana Guzmán-López ◽  
...  

A current concern is the increase in greenhouse gas emissions, mainly CO2, with anthropogenic sources being the main contributors. Microalgae have greater capacity than terrestrial plants to capture CO2, with this being an attraction for using them as capture systems. This study aims at the techno-economic evaluation of microalgae biomass production, while only considering technologies with industrial scaling potential. Energy consumption and operating costs are considered as parameters for the evaluation. In addition, the capture of CO2 from a thermoelectric plant is analyzed, as a carbon source for the cultivation of microalgae. 24 scenarios were evaluated while using process simulation tools (SuperPro Designer), being generated by the combination of cultivations in raceway pond, primary harvest with three types of flocculants, secondary harvest with centrifugation and three filtering technologies, and finally the drying evaluated with Spray and Drum Dryer. Low biomass productivity, 12.7 g/m2/day, was considered, achieving a capture of 102.13 tons of CO2/year in 1 ha for the cultivation area. The scenarios that included centrifugation and vacuum filtration are the ones with the highest energy consumption. The operating costs range from US $ 4.75–6.55/kg of dry biomass. The choice of the best scenario depends on the final use of biomass.


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