Removal of CO2 from flue gases coupled to the photosynthetic generation of organic matter by cyanobacteria

Removal of CO2 from flue gases coupled to the photosynthetic generation of organic matter by cyanobacteria

New Biotechnology · Volume 25S · September 2009 This technique is based on precision measurements of parameters of high frequency acoustical waves, p...

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New Biotechnology · Volume 25S · September 2009

This technique is based on precision measurements of parameters of high frequency acoustical waves, propagating through the analyzed sample (reaction container). HR-US allows continuous analysis of opaque, heterogeneous or viscous media in a wide range of temperatures and pressures. It does not require sample preparation, or optical activity and can be used in opaque samples. The presented data include enzymatic hydrolysis of microcrystalline cellulose (50 mM acetate buffer solution, pH 5.0) by commercial cellulase (Celluclast 1.5 L) at 50◦ C. Ultrasonic velocity and attenuation in cellulose suspensions have been measured in the frequency range from 2 to 20 MHz as a function of reaction time using a HRUS 102 ultrasonic spectrometer. Ultrasonic reaction profiles were used to analyze the reaction progress curves. Reaction rates have been compared with the measurements of concentrations of reducing sugars during the reaction using a discontinuous colorimetric assay (DNS method). Moreover, kinetic parameters and changes in particle size have been evaluated from the analysis of the ultrasonic data. Overall, these results show the high potential of HR-US for direct real time monitoring of kinetics of cellulose hydrolysis in complex systems.

ing the contaminants was depurated in flat-panel photobioreactors with Anabaena attaining CO2 fixation rates 15—90 g m−2 d−1 (year average). Finally, the biomass was recovered by centrifugation, filtration and sedimentation. The results show that the settling velocity of Anabaena is sufficient for 90% recovery by sedimentation. Dry biomass analysis showed a high content in proteins and carbohydrates, with 20 kJ g−1 combustion heat. Although photosynthetic microorganisms were proposed to remove CO2 half a century ago, a working process has not been established yet. The process proposed here optimizes the key steps for a feasible CO2 abatement using microalgae, setting new landmarks in the removal of contaminant gases and biomass generation. The economic viability of the integrated process depends on the final use of the generated organic matter.

doi:10.1016/j.nbt.2009.06.591

Z.N. Alekseeva ∗ , A.D. Rosental, A.H. Enikeev, V.A. Galinkin, A.V. Garabadgiu

3.1.47 Removal of CO2 from flue gases coupled to the photosynthetic generation of organic matter by cyanobacteria C.V. González López 1,∗ , F.G. Acien Fernández 1 , J.M. Fernández Sevilla 1 , M.D.C. Cerón García 1 , B. Llamas Moya 2 , E. Molina Grima 1 1

2

Universidad de Almería, Almería, Spain Endesa Generación, Almeria, Spain

Rising greenhouse gas emissions are contributing to global warming. Fossil fuel burning, the main anthropogenic source of CO2 , is not likely to cease in the near future and will have to be mitigated to limit the climatic change. This huge task cannot be tackled with the use of a single technology. All available options should be used jointly and new alternatives will have to be developed. An option is the use of photosynthetic microorganisms to convert CO2 into organic matter to be afterwards transformed into valuable products as bioethanol, biofuel, amino acids, etc. Microalgae and cyanobacteria are the most productive biotransformers of CO2 and the aim of this work is to use them to develop a bioprocess to remove CO2 from flue gases. Flue gases from a diesel boiler were absorbed at laboratory scale using a packed or a bubbled column. NO, NO2 , SO2 were added to simulate more aggressive conditions. Then, a biological treatment of the absorbed gasses was done outdoors in vertical flat-panel photobioreactors and open raceways with Anabaena sp. ATCC 33047. Culture medium was water with commercial grade fertilizers. Downstream experiments were performed with the harvest. Biochemical composition and combustion heat of the dry biomass were determined. The proposed process consists of three steps. First, the cleanup of flue gases in bubble column using carbonated water (patented process) was the optimal option reaching 70% CO2 , 80% NOx and 99% SO2 recoveries. Second, the aqueous solution contain-

doi:10.1016/j.nbt.2009.06.592

3.1.48 The fermentations hydrolyze of alga polysaccharides

ZAO “Rosbio”, 192019, St. Petersburg, Melnisnaya, 12a, Russian Federation

The harvested biomass alga is fermenting of complex ferment — cellulase, gemicellulase and pectinase. The cellular structure of the biomass begins to decay (e.g. cell wall rupture) and release the carbohydrate contained therein. This decay can occur without mechanical assistance or with mechanical assistance. The decay cells occur with selected pH and temperature (40—50—60). The decay of biomass is used by a bioreactor. A bioreactor includes any device or system that supports a biologically active environment. Inciting decay of the biomass is treated in such a way that the cellular structure of the biomass begins to decay and release the carbohydrates contained therein called alga carbohydrates that can be cultured as a source carbohydrate after decayed ferment — cellulase, pectinase, gemicellulase. doi:10.1016/j.nbt.2009.06.593

3.1.49 Optimization of biogas yield from anaerobic digestion of silages and industrial wastes A. Kacprzak ∗ , L. Krzystek, S. Ledakowicz Technical University of Lodz, Lodz, Poland

The biggest energy potential of biomass lies in agricultural sector. Directives of the European Union put stress on the increase of renewable energy consumption and reduction of uncontrolled methane emissions. Biogas production from agricultural biomass is of growing importance as it offers considerable environmental benefits. Because of increased European biodiesel production, glycerol (by-product) is beginning to flood the market, and urgently needs new uses. Researchers are examining its use as a cattle and poultry www.elsevier.com/locate/nbt S265