Review
Agronomy
Wasif Farooq
Summary: Commercial-scale production of microalgae biomass for biofuel and biochemicals requires a substantial amount of water and nutrients, but the presence of toxic organic compounds in post-harvest water limits its recyclability. Research is focused on finding effective methods for nutrient recovery to facilitate sustainable microalgae cultivation.
GLOBAL CHANGE BIOLOGY BIOENERGY
(2021)
Review
Green & Sustainable Science & Technology
Alejandro Ayala-Cortes, Pedro Arcelus-Arrillaga, Marcos Millan, Camilo A. Arancibia-Bulnes, Patricio J. Valades-Pelayo, Heidi Isabel Villafan-Vidales
Summary: Hydrothermal processes are attractive for transforming biomass mixtures with high water content, utilizing water's properties as a reaction medium. However, the main challenge lies in the high energy requirement for heating reactants, prompting the integration of renewable energy sources to reduce consumption.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Green & Sustainable Science & Technology
Radhakrishnan Yedhu Krishnan, Sivasubramanian Manikandan, Ramasamy Subbaiya, Woong Kim, Natchimuthu Karmegam, Muthusamy Govarthanan
Summary: Algal biomass is a promising feedstock for biofuel production. Thermochemical conversion processes, such as hydrothermal liquefaction, pyrolysis, and gasification, have been evaluated for their effectiveness in converting microalgae into bio-oil and syngas. Hydrothermal liquefaction produces bio-oil with superior fuel properties and storage stability, while pyrolysis achieves higher yield. Gasification is an energy-saving approach for microalgae conversion. Supercritical water gasification might be a good option for producing high-heating-value gas from microalgae without the need for drying. The prospects and challenges of converting microalgal biomass to biofuels were also discussed.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Engineering, Environmental
Eunjin Jwa, Oh Soo Na, Yoon-Cheul Jeung, Namjo Jeong, Joo-Youn Nam, Sekyung Lee
Summary: The membrane filtration-electrolysis-ultraviolet hybrid water treatment method improves biomass productivity and enables nutrient medium disinfection and recycling, reducing water consumption and nutrient costs.
Article
Energy & Fuels
Sarah Regina Vargas, Marcelo Zaiat, Maria do Carmo Calijuri
Summary: The research investigated the influence of sulfur concentration and light intensity on hydrogen and ethanol production by Chlamydomonas reinhardtii. The best hydrogen production occurred without sulfur addition and under higher light intensity, while ethanol production was higher under higher light intensity with the presence of sulfur. Additionally, nutrient removal was increased under conditions with the presence of sulfur.
BIOENERGY RESEARCH
(2022)
Article
Agricultural Engineering
Bo Zhang, Zhixia He, Zhixiang Xu
Summary: This study investigated the interactions between liquefaction temperature and residence time of the model compound, C-PC, and optimized the operation parameters based on the experimental design. It also found that recycling the aqueous phase (AP) significantly increased the bio-oil yield and led to the transformation of organic acids from the AP to the oil phase. The proposed reaction pathway provides insights into the liquefaction process of C-PC with AP recycling.
BIOMASS & BIOENERGY
(2022)
Article
Agricultural Engineering
N. Hasport, D. Krahe, C. M. Kuchendorf, S. Beier, U. Theilen
Summary: Integration of a photobioreactor for wastewater treatment by microalgae is considered as a cost-efficient and environmentally-friendly alternative for nutrient removal in municipal WWTPs. The high growth rates and biogas yields of algal biomass can greatly improve the WWTP energy balances. This study focuses on temperate climate zones, analyzes the energy potential of microalgae-enhanced wastewater treatment in an existing WWTP in Central Germany, and calculates the shift in the energy balance.
BIORESOURCE TECHNOLOGY
(2022)
Article
Agricultural Engineering
Ruoyu Chu, Dan Hu, Liandong Zhu, Shuangxi Li, Zhihong Yin, Yunjiang Yu
Summary: The study found that using harvested water with specific nitrogen-to-phosphorus ratios can significantly affect the growth and lipid synthesis of microalgae, thus affecting the efficiency of biodiesel production.
BIORESOURCE TECHNOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Sherif Ishola Mustapha, Usman Aliyu Mohammed, Faizal Bux, Yusuf Makarfi Isa
Summary: This study investigates the hydrothermal gasification of Scenedesmus obliquus microalgae and their derivatives, revealing that temperature, biomass concentration, and feedstock composition significantly impact the composition of gaseous products. Low temperature and high biomass concentration are favorable for methane-rich gas production, while high temperature and low biomass concentration favor hydrogen-rich gas production.
BIOFUELS BIOPRODUCTS & BIOREFINING-BIOFPR
(2021)
Article
Green & Sustainable Science & Technology
Bhasha Sharma, Yagyadatta Goswami, Shreya Sharma, Shashank Shekhar
Summary: The conversion of plastic waste into energy is an innovative strategy to address plastic pollution issues, with significant commercial and environmental value. However, this transformation may face obstacles such as operational costs, fund investments, and legal barriers.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Agricultural Engineering
Adriana Ramirez-Romero, Marion Martin, Alana Boyer, Romain Bolzoni, Lucie Matricon, Jean-Francois Sassi, Jean-Philippe Steyer, Florian Delrue
Summary: Hydrothermal liquefaction (HTL) can produce bio-crude oil from wet algae, along with an aqueous phase (AP) containing minerals. However, the presence of inhibitors limits the utility of minerals in AP. Adaptive laboratory evolution can counterbalance AP toxicity and restore the fitness of microalgae.
BIORESOURCE TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Claudia Patricia Perez-Rodriguez, Luis Alberto Rios, Carmen Sofia Duarte Gonzalez, Andres Montana, Catalina Garcia-Marroquin
Summary: Currently, governments from around the world are compromising to develop new or more efficient ways of producing bioenergy. This study quantifies and characterizes the energy potential of residual biomass produced in agricultural, agro-industrial, and forestry processes in Colombia using gasification as the selected transformation technology. The research estimates the technical biomass-energy potential of the country and proposes a gasification plant to process all biomasses.
Article
Thermodynamics
Jiandong Jia, Hongwei Chen, Ruikun Wang, Hantao Liu, Zhenghui Zhao, Haoyang Lei, Qingzhuang Jin
Summary: The study proposed a co-hydrothermal carbonization (co-HTC) method for converting sewage sludge and corn stalk into solid fuel, focusing on the mass and energy equilibrium characteristics. The energy efficiency was improved by coupling a flash-organic Rankine Cycle (FSPG-ORC) system to recover the waste heat. The HTC-FSPG-ORC coupled process showed a good application prospect by converting organic wastes into lignite-like solid fuel in a low-energy manner.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Engineering, Environmental
Uttam K. Roy, Tanja Radu, Jonathan Wagner
Summary: This study explores the potential of using hydrothermal carbonisation (HTC) to fractionate anaerobic digestate of sewage sludge into hydrochar and aqueous phase (AP), which is then used to cultivate alkali halophilic microalgae. The results show that the AP obtained from HTC can serve as a suitable growth medium substitute, promoting microalgae growth and increasing biomass yield.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
E. Agathokleous, J. Guo, J. Penuelas
Summary: The target of achieving carbon neutrality by governments worldwide have given negative emission technologies a crucial role. Algae-based renewable bio-energy is expected to play a larger role in meeting this target. Recent evidence has shown that low doses of toxicants stimulate algae growth, contradicting the belief that toxicants only suppress algae at high doses. Low-dose stress can enhance photosynthesis, growth, biomass, and biochemical quality of algae, suggesting their potential as feedstock for carbon-neutral fuel production. Further scientific developments are needed to improve algae's performance, reduce cultivation costs, and enhance their resilience to toxicant-containing wastewater.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)