کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1742095 1521826 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Aeration energy requirements for lipid production by Scenedesmus sp. in airlift bioreactors
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی انرژی های تجدید پذیر، توسعه پایدار و محیط زیست
پیش نمایش صفحه اول مقاله
Aeration energy requirements for lipid production by Scenedesmus sp. in airlift bioreactors
چکیده انگلیسی


• CO2 availability is dependent on power input for aeration and CO2 content of gas.
• Critical minimum CO2 supply and transfer rates exist for algal growth.
• Above the critical values, aeration energy is expended with no increased production.
• By considering these critical values, improved net energy ratios (NER) were obtained.
• The positive NERs in the airlift reactor facilitate algal bioenergy production.

Microalgae have potential to yield various bioenergy products, including algal biodiesel. For algal energy production, the process energy input must be substantially lower than the product energy. Airlift photobioreactors provide controlled environments with good mixing and mass transfer; however, previous work reports a net energy ratio (NER; energy produced divided by energy consumed) less than 1. Here, the energy consumption in these reactors was improved by combined optimisation of superficial gas velocity and its CO2 concentration. Increasing CO2 concentration resulted in increased tolerance to lower superficial gas velocities, down to a critical minimum value. A 75% reduction in aeration power input was obtained by reducing superficial gas velocity from 0.0210 to 0.0052 m s− 1 at 5 400 ppm CO2, without substantial reduction in biomass concentration (2.27 to 1.93 g L− 1, respectively) or productivity (0.189 to 0.173 g L− 1 d− 1, respectively). The NER under these conditions was 5.47 for biomass plus lipid and 1.01 for lipid only. The CO2 supply rate, product of superficial gas velocity and CO2 concentration, correlated with the CO2 transfer rate which influenced algal productivity. The range of NERs measured across the superficial gas velocities studied indicates the ability to optimise algal cultivation in photobioreactors for the improved feasibility of algal bioenergy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Algal Research - Volume 5, July 2014, Pages 249–257
نویسندگان
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