Hydrogen (H<sub>2</sub>) production from experiments with Spirulina maxima 2342 is reported in this work. The performance of this photosynthetic microorganism for producing H<sub>2</sub> was ev...Hydrogen (H<sub>2</sub>) production from experiments with Spirulina maxima 2342 is reported in this work. The performance of this photosynthetic microorganism for producing H<sub>2</sub> was evaluated for the first time under specific experimental conditions (e.g., a biomass concentration of 0.34 ± 0.02 g, a light intensity of 150 μE.s<sup>-1</sup>.m<sup>-2</sup> and reaction times of 19.3 ± 1.2 h). The performance of this photosynthetic microorganism for producing hydrogen was successfully improved by the addition of sodium dithionite (a reducing agent) as an innovative method for increasing the gas production, and as a main contribution of this work. Quantitative gas chromatography (GC) analyses of H<sub>2</sub> to verify the production performance were successfully carried out at low concentration levels. GC analyses were performed by means of a conventional thermal conductivity detector coupled to a separation system of a Molecular Sieve column 500 mm × 3175 mm (L × ID). Low detection limits were consistently obtained with the GC system used. The separation of H<sub>2</sub> in culture samples was efficiently achieved in average retention times of 1.47 min. The H<sub>2</sub> produced in this process was subsequently used for power generation using a Proton Exchange Membrane Fuel Cell (PEMFC).展开更多
Catalysts play a significant role in transesterification of vegetable oils.Currently,chemical and biological catalysts are being investigated,and both have their inherent merits and demerits.In large-scale application...Catalysts play a significant role in transesterification of vegetable oils.Currently,chemical and biological catalysts are being investigated,and both have their inherent merits and demerits.In large-scale applications,these catalysts are expected to be cost effective and environmentally friendly.If the catalyst is homogeneous in its physical form it is more effective than is the heterogeneous catalyst,but its separation from the mixture is a major issue.Some of the heterogeneous catalysts suffer leaching in harsh reaction conditions.Of late,nanocatalysts that demonstrate high efficiency are being studed.Nanoparticles are used in biological catalysts as solid carriers for lipase immobilization.Lipase immobilized on magnetic nanoparticles has proved to be a versatile biocatalyst for biodiesel production.This article reviews the role of various catalytic systems commonly used in the transesterification reaction of oils in biodiesel generation.展开更多
文摘Hydrogen (H<sub>2</sub>) production from experiments with Spirulina maxima 2342 is reported in this work. The performance of this photosynthetic microorganism for producing H<sub>2</sub> was evaluated for the first time under specific experimental conditions (e.g., a biomass concentration of 0.34 ± 0.02 g, a light intensity of 150 μE.s<sup>-1</sup>.m<sup>-2</sup> and reaction times of 19.3 ± 1.2 h). The performance of this photosynthetic microorganism for producing hydrogen was successfully improved by the addition of sodium dithionite (a reducing agent) as an innovative method for increasing the gas production, and as a main contribution of this work. Quantitative gas chromatography (GC) analyses of H<sub>2</sub> to verify the production performance were successfully carried out at low concentration levels. GC analyses were performed by means of a conventional thermal conductivity detector coupled to a separation system of a Molecular Sieve column 500 mm × 3175 mm (L × ID). Low detection limits were consistently obtained with the GC system used. The separation of H<sub>2</sub> in culture samples was efficiently achieved in average retention times of 1.47 min. The H<sub>2</sub> produced in this process was subsequently used for power generation using a Proton Exchange Membrane Fuel Cell (PEMFC).
文摘Catalysts play a significant role in transesterification of vegetable oils.Currently,chemical and biological catalysts are being investigated,and both have their inherent merits and demerits.In large-scale applications,these catalysts are expected to be cost effective and environmentally friendly.If the catalyst is homogeneous in its physical form it is more effective than is the heterogeneous catalyst,but its separation from the mixture is a major issue.Some of the heterogeneous catalysts suffer leaching in harsh reaction conditions.Of late,nanocatalysts that demonstrate high efficiency are being studed.Nanoparticles are used in biological catalysts as solid carriers for lipase immobilization.Lipase immobilized on magnetic nanoparticles has proved to be a versatile biocatalyst for biodiesel production.This article reviews the role of various catalytic systems commonly used in the transesterification reaction of oils in biodiesel generation.
