E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Algae Based Technologies"

Quicklinks

A special issue of Energies (ISSN 1996-1073).

Deadline for manuscript submissions: closed (30 September 2014)

Special Issue Editor

Guest Editor
Dr. Paul L. Chen

Center for Biorefining, Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., St. Paul, MN 55108, USA
Website | E-Mail
Phone: 612-625-7721
Interests: pyrolysis; hydrothermal liquefaction; microalgae; food processing

Special Issue Information

Dear Colleagues,

The desire to increase biofuels production renewed the interest in algal biomass. Tremendous efforts were invested in many areas, including strain selection and development, cultivation techniques and facilities, harvest, downstream processing, product development, techno-economic analysis, life cycle analysis, energy policy, etc. In recent years, algae related research has been expanded way beyond biofuels, and is taking new directions. The interest in using algae as a vehicle for production of chemicals, nutraceuticals, medicine, foods, feeds, pigments, etc., and as a means of waste utilization and management, is rapidly growing. This special issue is to solicit high quality and original research contributions and critical reviews on all aspects of algae based technologies.

Dr. Paul L. Chen
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs).


Keywords

  • algae
  • microalgae
  • macroalgae
  • biofuels
  • chemicals
  • nutraceuticals
  • medicine
  • foods
  • feeds
  • pigments
  • waste treatment
  • waste management
  • cultivation
  • harvest
  • downstream processing
  • technoeconomic analysis
  • life cycle analysis

Published Papers (7 papers)

View options order results:
result details:
Displaying articles 1-7
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Fatty Acid Characteristics of Isochrysis galbana Lipids Extracted Using a Microwave-Assisted Method
Energies 2015, 8(2), 1154-1165; doi:10.3390/en8021154
Received: 14 November 2014 / Revised: 24 December 2014 / Accepted: 22 January 2015 / Published: 3 February 2015
PDF Full-text (442 KB) | HTML Full-text | XML Full-text
Abstract
Lipids were extracted from Isochrysis galbana using a microwave-assisted method accompanied by various types of organic solvents. The effects of organic solvent type and microwave input energy on the fatty acid characteristics of the extracted lipids and their biodiesel product were investigated. Variations
[...] Read more.
Lipids were extracted from Isochrysis galbana using a microwave-assisted method accompanied by various types of organic solvents. The effects of organic solvent type and microwave input energy on the fatty acid characteristics of the extracted lipids and their biodiesel product were investigated. Variations in the characteristics of the lipids extracted using a combination of n-hexane and iso-propanol solvents in both emulsion and direct mixtures were also compared. The experimental results showed that greater quantities of Isochrysis galbana lipids, and fatty acid methyl esters transesterified from those lipids, were extracted when using microwave irradiation with an organic solvent mixture of n-hexane and isopropanol in a 2:1 volumetric ratio than when using either n-hexane or isopropanol as the sole solvent. A greater quantity of Isochrysis galbana lipids was extracted when an emulsion of isopropanol solvent evenly dispersed in the continuous phase of n-hexane solvent was used than when a direct mixture of the two solvents was used. In addition, the quantity of lipids extracted from the dried Isochrysis galbana powder with the assistance of microwave irradiation was 9.08 wt% greater than when using traditional Soxhlet extraction without microwave irradiation. Full article
(This article belongs to the Special Issue Algae Based Technologies)
Open AccessArticle Advanced Energy Harvesting from Macroalgae—Innovative Integration of Drying, Gasification and Combined Cycle
Energies 2014, 7(12), 8217-8235; doi:10.3390/en7128217
Received: 2 October 2014 / Revised: 25 November 2014 / Accepted: 2 December 2014 / Published: 10 December 2014
Cited by 7 | PDF Full-text (1010 KB) | HTML Full-text | XML Full-text
Abstract
State-of-the-art integrated macroalgae utilization processes, consisting of drying, gasification, and combined cycle, are proposed and their performance with respect to energy efficiency are evaluated. To achieve high exergy efficiency, the integration is performed through two main principles: exergy recovery and process integration. Initially,
[...] Read more.
State-of-the-art integrated macroalgae utilization processes, consisting of drying, gasification, and combined cycle, are proposed and their performance with respect to energy efficiency are evaluated. To achieve high exergy efficiency, the integration is performed through two main principles: exergy recovery and process integration. Initially, the energy involved in one process is recirculated intensively through exergy elevation and effective heat coupling. Furthermore, the unrecoverable energy from one process will be utilized in the other processes through process integration. As the result, the total exergy destruction from the whole integrated processes can be minimized significantly leading to significant improvement in energy efficiency. The first analysis relates to the performance of integrated drying process, especially the influence of target moisture content to energy consumption. Furthermore, the influences of gasification fluidization velocity to the total generated power and power generation efficiency are also calculated. As the results of study, the proposed integrated-processes proved a very high energy efficiency. A positive energy harvesting with the total power generation efficiency of about 40% could be achieved. Full article
(This article belongs to the Special Issue Algae Based Technologies)
Figures

Open AccessArticle Isolation and Characterization of New Temperature Tolerant Microalgal Strains for Biomass Production
Energies 2014, 7(12), 7847-7856; doi:10.3390/en7127847
Received: 7 August 2014 / Revised: 17 November 2014 / Accepted: 18 November 2014 / Published: 25 November 2014
Cited by 1 | PDF Full-text (843 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Microalgae exhibit great potential for biomass production. Although microalgae display an enormous biodiversity, surprisingly only 15 species are used for large scale production processes worldwide. The implementation of new production strains with good process-oriented properties, especially fast growth rate and heat resistance, could
[...] Read more.
Microalgae exhibit great potential for biomass production. Although microalgae display an enormous biodiversity, surprisingly only 15 species are used for large scale production processes worldwide. The implementation of new production strains with good process-oriented properties, especially fast growth rate and heat resistance, could improve production efficiency and reduce costs. In this study 130 environmental samples collected in Germany, Spain, Italy and Portugal were investigated for fast growing thermotolerant photosynthetic species. Isolates were characterized and identified on a molecular level. In total 21 of the isolated freshwater strains were able to grow at 40 °C. Additionally, 13 of those 21 strains are able to grow at 45 °C. The highest growth rate at room temperature was 1.16 per day (isolate T306A), compared to 0.053 per day at 45 °C (isolate Sp13). In three thermotolerant strains pigment production was induced. Molecular identification by 18S rDNA sequencing revealed that the isolates were all chlorophytes belonging to four different families. Full article
(This article belongs to the Special Issue Algae Based Technologies)
Figures

Open AccessCommunication Optimization of Alkaline Flocculation for Harvesting of Scenedesmus quadricauda #507 and Chaetoceros muelleri #862
Energies 2014, 7(9), 6186-6195; doi:10.3390/en7096186
Received: 11 June 2014 / Revised: 13 August 2014 / Accepted: 17 September 2014 / Published: 24 September 2014
Cited by 3 | PDF Full-text (467 KB) | HTML Full-text | XML Full-text
Abstract
A response surface methodology (RSM) was used to evaluate the effects of pH and microalgal biomass concentration (BC) on alkaline flocculating activity for harvesting one freshwater green algae Scenedesmus quadricauda #507 and one marine diatom Chaetoceros muelleri #862. The pH value and BC
[...] Read more.
A response surface methodology (RSM) was used to evaluate the effects of pH and microalgal biomass concentration (BC) on alkaline flocculating activity for harvesting one freshwater green algae Scenedesmus quadricauda #507 and one marine diatom Chaetoceros muelleri #862. The pH value and BC were in range of 9.0–12.0 and 0.20–2.30 g/L, respectively. Very high regression coefficient between the variables and the response indicates excellent evaluation of experimental data by second-order regressions. Optimum conditions for flocculating activity were estimated as follows: (i) pH 11.6, BC 0.54 g/L for strain #507 and (ii) pH 11.5, BC 0.42 g/L for strain #862. The maximum flocculating activity was around 94.7% and 100%, respectively. Furthermore, the addition of synthetic ocean water (SOW) to the freshwater #507 culture can increase the flocculating activity from 82.13%–88.79% in low algae concentration (0.52 g/L) and 82.92%–95.60% in high concentration (2.66 g/L). Full article
(This article belongs to the Special Issue Algae Based Technologies)
Open AccessArticle Microalgae Harvest through Fungal Pelletization—Co-Culture of Chlorella vulgaris and Aspergillus niger
Energies 2014, 7(7), 4417-4429; doi:10.3390/en7074417
Received: 6 June 2014 / Revised: 3 July 2014 / Accepted: 4 July 2014 / Published: 10 July 2014
Cited by 5 | PDF Full-text (625 KB) | HTML Full-text | XML Full-text
Abstract
Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger) and microalgae (Chlorella vulgaris) to form
[...] Read more.
Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger) and microalgae (Chlorella vulgaris) to form cell pellets was evaluated under different conditions, including organic carbon source (glucose; glycerol; and sodium acetate) concentration; initial concentration of fungal spores and microalgal cells and light. Results showed that 2 g/L of glucose with a 1:300 ratio of fungi to microalgae provided the best culturing conditions for the process to reach >90% of cell harvest efficiency. The results also showed that an organic carbon source was required to sustain the growth of fungi and form the cell pellets. The microalgae/fungi co-cultures at mixotrophic conditions obtained much higher total biomass than pure cultures of each individual strains; indicating the symbiotic relationship between two strains. This can benefit the microbial biofuel production in terms of cell harvest and biomass production. Full article
(This article belongs to the Special Issue Algae Based Technologies)

Review

Jump to: Research

Open AccessReview Macroalgae-Derived Biofuel: A Review of Methods of Energy Extraction from Seaweed Biomass
Energies 2014, 7(11), 7194-7222; doi:10.3390/en7117194
Received: 16 September 2014 / Revised: 24 October 2014 / Accepted: 28 October 2014 / Published: 7 November 2014
Cited by 26 | PDF Full-text (294 KB) | HTML Full-text | XML Full-text
Abstract
The potential of algal biomass as a source of liquid and gaseous biofuels is a highly topical theme, but as yet there is no successful economically viable commercial system producing biofuel. However, the majority of the research has focused on producing fuels from
[...] Read more.
The potential of algal biomass as a source of liquid and gaseous biofuels is a highly topical theme, but as yet there is no successful economically viable commercial system producing biofuel. However, the majority of the research has focused on producing fuels from microalgae rather than from macroalgae. This article briefly reviews the methods by which useful energy may be extracted from macroalgae biomass including: direct combustion, pyrolysis, gasification, trans-esterification to biodiesel, hydrothermal liquefaction, fermentation to bioethanol, fermentation to biobutanol and anaerobic digestion, and explores technical and engineering difficulties that remain to be resolved. Full article
(This article belongs to the Special Issue Algae Based Technologies)
Open AccessReview Effect of Lignocellulose Related Compounds on Microalgae Growth and Product Biosynthesis: A Review
Energies 2014, 7(7), 4446-4481; doi:10.3390/en7074446
Received: 4 May 2014 / Revised: 30 June 2014 / Accepted: 1 July 2014 / Published: 11 July 2014
Cited by 8 | PDF Full-text (936 KB) | HTML Full-text | XML Full-text
Abstract
Microalgae contain valuable compounds that can be harnessed for industrial applications. Lignocellulose biomass is a plant material containing in abundance organic substances such as carbohydrates, phenolics, organic acids and other secondary compounds. As growth of microalgae on organic substances was confirmed during heterotrophic
[...] Read more.
Microalgae contain valuable compounds that can be harnessed for industrial applications. Lignocellulose biomass is a plant material containing in abundance organic substances such as carbohydrates, phenolics, organic acids and other secondary compounds. As growth of microalgae on organic substances was confirmed during heterotrophic and mixotrophic cultivation, lignocellulose derived compounds can become a feedstock to cultivate microalgae and produce target compounds. In this review, different treatment methods to hydrolyse lignocellulose into organic substrates are presented first. Secondly, the effect of lignocellulosic hydrolysates, organic substances typically present in lignocellulosic hydrolysates, as well as minor co-products, on growth and accumulation of target compounds in microalgae cultures is described. Finally, the possibilities of using lignocellulose hydrolysates as a common feedstock for microalgae cultures are evaluated. Full article
(This article belongs to the Special Issue Algae Based Technologies)

Journal Contact

MDPI AG
Energies Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
energies@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Energies
Back to Top