Production of Hydrogen as a Potential Source of Renewable Energy from Green Algae - A Review (original) (raw)
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Advances in the biotechnology of hydrogen production with the microalga Chlamydomonas reinhardtii
Critical Reviews in Biotechnology, 2014
Biological hydrogen production is being evaluated for use as a fuel, since it is a promising substitute for carbonaceous fuels owing to its high conversion efficiency and high specific energy content. The basic advantages of biological hydrogen production over other ''green'' energy sources are that it does not compete for agricultural land use, and it does not pollute, as water is the only by-product of the combustion. These characteristics make hydrogen a suitable fuel for the future. Among several biotechnological approaches, photobiological hydrogen production carried out by green microalgae has been intensively investigated in recent years. A select group of photosynthetic organisms has evolved the ability to harness light energy to drive hydrogen gas production from water. Of these, the microalga Chlamydomonas reinhardtii is considered one of the most promising eukaryotic H 2 producers. In this model microorganism, light energy, H 2 O and H 2 are linked by two excellent catalysts, the photosystem 2 (PSII) and the [FeFe]-hydrogenase, in a pathway usually referred to as direct biophotolysis. This review summarizes the main advances made over the past decade as an outcome of the discovery of the sulfur-deprivation process. Both the scientific and technical barriers that need to be overcome before H 2 photoproduction can be scaled up to an industrial level are examined. Actual and theoretical limits of the efficiency of the process are also discussed. Particular emphasis is placed on algal biohydrogen production outdoors, and guidelines for an optimal photobioreactor design are suggested.
Hydrogen Production. Green Algae as a Source of Energy
Plant Physiology, 2001
Hydrogen gas is thought to be the ideal fuel for a world in which air pollution has been alleviated, global warming has been arrested, and the environment has been protected in an economically sustainable manner. Hydrogen and electricity could team to provide attractive options in transportation and power generation. Interconversion between these two forms of energy suggests on-site utilization of hydrogen to generate electricity, with the electrical power grid serving in energy transportation, distribution utilization, and hydrogen regeneration as needed. A challenging problem in establishing H 2 as a source of energy for the future is the renewable and environmentally friendly generation of large quantities of H 2 gas. Thus, processes that are presently conceptual in nature, or at a developmental stage in the laboratory, need to be encouraged, tested for feasibility, and otherwise applied toward commercialization.
Experimental investigation parameters of hydrogen production by algae Chlorella vulgaris
Bio-photolysis to produce the H2 gas carried out using algal strain Chlorella vulagaris. In this study the effect of various parameters affecting on the hydrogen production were investigated to find the optimum conditions that maximize the hydrogen production using standard procedures for experiment design. These parameters include; initial substrate concentration, initial pH and total of nitrogen and phosphate content for the Bold's Basal culture (BBC) media concentration. Glucose as substrate was studied at varied concentrations (5- 40) g/l and the high production of hydrogen was observed at 10 g/l. A set of tests in this study was performed by varying the initial pH from 6.0 ± 0.2 to 9.0 ± 0.2, The most suitable conditions for hydrogen production in a bio-reactor were observed at pH 8.0 ± 0.2. Total of nitrogen and phosphate content for the (BBC) media concentration were increased by mole (10%, 20% and 30%). Results showed that the maximum production of H2 with increasing bot...
Parameters affecting the growth and hydrogen production of the green alga Chlamydomonas reinhardtii
International Journal of Hydrogen Energy, 2011
The unicellular green alga Chlamydomonas reinhardtii has the ability to photosynthetically produce molecular hydrogen under anaerobic conditions. It offers a biological route to renewable, carbon-neutral hydrogen production from sunlight and water. A better understanding of the parameters affecting the algal growth and hydrogen production kinetics is required in order to develop appropriate system parameters and design photobioreactors. It is essential to grow algal biomass efficiently and economically, and to attain high cell densities for effective hydrogen production. The nutrient requirements and process conditions that encourage the growth of dense and healthy algal cultures were explored. Anaerobic conditions were imposed by sulphur deprivation, which requires an exchange of the algal growth medium by centrifugation, dilution or ultra-filtration. A tubular-flow photobioreactor featuring a large surface-to-volume ratio and excellent light penetration through the system was commissioned. It was used to monitor and control the key parameters in the hydrogen production process, including pH, pO 2 , optical density, temperature, agitation and light intensity. Analytical techniques are being developed to characterise the reactor products, including dissolved hydrogen measurement by membrane inlet mass spectrometry. An overall H 2 yield of 3.1±0.3ml/l was measured in the tubular-flow photobioreactor. This information was used to design a novel 1l flat-plate reactor system for further detailed kinetic analysis of the hydrogen production process.
International Journal of Bio-Science and Bio-Technology
Concerns about increasing greenhouse gas emissions are driving many countries to develop renewable energy sources. Enormous efforts are being directed towards the transition from fossil fuels to nonpolluting and renewable energy sources, one of which is bio-hydrogen. This paper explores the use of photosynthetic green microalgae Chlamydomonas reinhardtii immobilized in chitosan and co-cultured with ragi tapai to produce bio-hydrogen in a two-step process. Results show that the immobilization and presence of ragi tapai did not deter the microalgae from production of bio-hydrogen. It in fact enhanced the bio-hydrogen yield by microalgae plus it eases the process of cycling the microalgae cells between growth mode and hydrogen production mode. The maximum amount of bio-hydrogen produced by the microalgae when co-cultured with ragi tapai was 650000 ppm and the best ratio was 1:0.25 (2 g microalgae:0.5 g ragi tapai).
Journal of Biotechnology, 2012
Certain strains of microalgae are long known to produce hydrogen under anaerobic conditions. In Chlamydomonas reinhardtii the oxygen-sensitive hydrogenase enzyme recombines electrons from the chloroplast electron transport chain with protons to form molecular hydrogen directly inside the chloroplast. A sustained hydrogen production can be obtained under low sulfur conditions in C. reinhardtii, reducing the net oxygen evolution by reducing the photosystem II activity and thereby overcoming the inhibition of the hydrogenases. The development of specially adapted hydrogen production strains led to higher yields and optimized biological process preconditions. So far sustainable hydrogen production required a complete exchange of the growth medium to establish sulfur-deprived conditions after biomass growth. In this work we demonstrate the transition from the biomass growth phase to the hydrogen production phase in a single batch culture only by exact dosage of sulfur. This eliminates the elaborate and energy intensive solid-liquid separation step and establishes a process strategy to proceed further versus large scale production. This strategy has been applied to determine light dependent biomass growth and hydrogen production kinetics to assess the potential of H 2 production with C. reinhardtii as a basis for scale up and further process optimization.
Hydrogen Production by Algae Scenedesmus sp. Biomass through Photosynthesis Process
International Journal of Science and Society
The hydrogen production was studied using Scenedesmus sp. by PHM-S media under anaerobic and photosynthesis process. The Investigated of hydrogen gas using by Natural Gas Analyzer (NGA): HP (Hewlett Packard) 6890 with a molecular sieve 5A (CH4, O2. N2, H2) a thermal conductivity detector is used in a mesh-packed column. The results show highest value of hydrogen production in second experiment. It was obtained because the second experiment had longer for incubation time so the photosynthesis process was took longer then algae could produce more hydrogen gas. Interestingly, the hydrogen does not produce within a certain timeframe. We believe that this was related to the reaction enzymatic in algae that was mostly induced by the oxygen, an inhibitor of the hydrogenate enzyme, was reduced during anaerobic adaptation, resulting in an increase in hydrogen production.
Hydrogen Production by Photosynthetic Organisms with Special Reference to Bioreactor Technology
Indo global journal of pharmaceutical sciences, 2015
The review deals with photosynthetic H 2 production by various organisms, paying a special attention to bioreactor technology. It includes a general characterization of the catalyzing enzymes (hydrogenase and nitrogenase), quantum efficiency, the kinetics and mechanism of H 2 photoevolution, the distribution and activity of H 2 photoproducers (bacteria, cyanobacteria & 33 genera of eukaryotic algae) , physiological functions of this process as well as recent development in photobiological hydrogen technology. Hydrogen gas is a potential carrier of energy. For that reason used to bring space shuttles into their orbit .In this case, a fuel cell can generate electricity from hydrogen and oxygen. Its high energy content makes hydrogen gas an interesting energy carrier. An environmental friendly way is to use solar energy. In that particular case, we are talking about photohydrogen. Environmental parameters and physiological factors, which may be of use to optimize algae and cyanobacterial hydrogen generation, are summarizing. These parameters include: light intensity, gas atmosphere (Co 2 , N 2 and O 2), temperature, pH, carbohydrate substrates, metal ions, H 2 uptake systems, age of cyanobacterial culture, cell density, and immobilization of cells. Nitrogenase is a major catalytic enzyme of hydrogen production in cyanobacteria, which can express three distinct nitrogenases: molybdenum nitrogenase, vanadium nitrogenase and iron nitrogenase. Cyanobacterial and algal hydrogenase is an enzyme that catalyzes both hydrogen evolution and hydrogen uptake. Today, several parameters are computer controllable in the photobioreactors. Already the photobioreactor to 20 L and its application for cultivation of various photosynthetic cells, Chlorella, Chlamydomonas, Scenedesmus, Spirulina and Anabaena, scaled up.