BioH2 Production Using Microalgae: Highlights on Recent Advancements from a Bibliometric Analysis

Abstract

Demand for clean energy has increased due to the proliferation of climate change impact from excessive emission of greenhouse gases (GHG) from the combustion of fossil fuels. H2 is a clean energy source since water vapor is the only byproduct after its combustion. Growing microalgae offers a promising low-energy and low-cost approach for bioH2 production. In this study, a bibliometric analysis was performed for the production of H2 using microalgae to evaluate the conceptual, intellectual, and social structure of the dataset. In addition, a scoping review of articles was conducted to highlight recent advancements and identify future research recommendations. A total of 184 relevant publications over 23 years (2000–2022) were retrieved from the Scopus database for analysis. The results demonstrated an exponential increase in citations from 283 to 996 in the last decade, indicating the interest in bioH2 production from microalgae. Results also revealed that the International Journal of Hydrogen Energy accounted for more than 25% of the published articles, of which China contributed almost 28%. Oxygen sensitivity of the H2ase enzyme and sulfur deprivation were highlighted as the main limiting factors of bioH2 production using microalgae. It was also evident that the most widely studied microalgae species were green algae, especially Chlamydomonas and Chlorella. Effective process modifications, particularly hybridizing microalgae with bacteria consortium and implementing oxygen regulating strategies, were shown to give up to a 10-fold increase in H2 yield. This study also discusses recent developments in technologies, strategies, microalgal species, and optimizing controlling factors affecting bioH2 production.

Dark Fermentative Production of Biohydrogen from Organic Biomass: A Bibliometric Analysis

“…Importantly, the total number of publication indicates the Other institutions domiciled in Taiwan and Vietnam reported low collaboration among co-authorships in the field of dark fermentation. [19] noted the same trend of low international collaboration in studies related to biohydrogen production. The low collaboration could be attributed to difficulties in connecting potential collaborators in different countries, acquiring funding for the projects, and evaluating and sustaining the projects between collaborating international institutions are some of the barriers impeding successful international collaborations.…”

“…The VOSviewer (version 1.6.19.0) and Microsoft Excel (version 2302) software were used in data visualization and qualitative analysis, respectively. VOSviewer is good at the graphical presentation of bibliometric maps in a manner that is easy to interpret [19]. The data were imported into the VOSviewer software, and bibliometric analysis was performed.…”

From Microalgae to Bioenergy: Recent Advances in Biochemical Conversion Processes

“…PNS bacteria use a nitrogenase enzyme for simultaneous biohydrogen production and nitrogen fixation, making nitrogen-limited conditions a requirement for the evolution of biohydrogen. During this process, organic acids are first degraded using light energy to generate electrons and adenosine triphosphate (ATP) that drive nitrogenase to evolve biohydrogen and fix molecular nitrogen into ammonium ions [170]. Examples of the commonly used purple non-sulfur bacteria species for biohydrogen production are Rhodopseudomonas palustris, Rhodobacter capsulats, Rhodobacter sphaeroides, Rhodospirillum rubrum, and Rubrivivax gelatinosus [169].…”