[Download] "Biofuels from microalgae: modeling and LCA" by Orlando ~ Book PDF Kindle ePub Free
eBook details
- Title: Biofuels from microalgae: modeling and LCA
- Author : Orlando
- Release Date : January 15, 2020
- Genre: Science & Nature,Books,
- Pages : * pages
- Size : 3236 KB
Description
This book shows studies of biofuels production from microalgae. Literature data related to microalgae culture in open and close systems for hydrogen or oil production allowed identifying two research lines, the first in the mathematical modeling field applied to hydrogen production through biochemical systems, and the second about the economic viability of using close systems (photobioreactors) over open systems, which was carried out through energy life cycle analysis.
This study has two major original contributions. The first one is a metabolic pathway which indicate the mechanism of hydrogen production by microalgae and that was represented by a mathematical model based on power law S systems. The mathematical model correctly predicts start-up and the end timepoints of gas production, as well as the rates of H2 and O2 production. Under normal sulfur-replete conditions the model follows the behavior described in the literature for the response of photosynthetic O2 evolution as a function of irradiance. In nutrient restriction condition (sulfur deprived) the temporal response of O2 and H2 production predicted by the model also reflects literature data. In the validation of the model, it satisfied the calibration requirement, showed O2 production under normal photosynthetic conditions, and showed the switch from O2 to H2 photoproduction without complete shut-off of O2 evolution. Parameter sensitivity analysis of microalgae hydrogen production model indicate the targets for genetic engineering modification regarding the increase of hydrogen production. This analysis point out the over-expression of hydrogenase enzyme, increase in hydrogenase stability, up-regulation of hydrogenase gene transcription, increase in O2 consumption and reduction in electron consumption from starch by fermentation pathway.
The second contribution shows a comparative analysis for two photobioreactors (tubular and flat plate) and one open systems through an energy life cycle approach, indicating the viability of using flat plate photobioreactors for oil production from microalgae biomass. Both systems (flat plate and open pond) showed net energy ratio above the unit (NER>1) and were considered economically feasible for mass cultivation of Nannochloropsis sp. for the purpose of biofuel generation.