Influence of Carbon Dioxide Concentration on Microalgal Growth in a Bubble Column Photobioreactor

2012 ◽  
Vol 599 ◽  
pp. 137-140 ◽  
Author(s):  
Shu Wen Li ◽  
Sheng Jun Luo ◽  
Rong Bo Guo

The CO2 sequestration by microalgae is thought to be one of the most sustainable strategies to relieve global warming. To produce 1 ton of microalgal dry biomass, 2 ton of CO2 is required. However, insufficient supply of CO2 will limit microalgal growth, and excessive CO2 both means wasting and inhibits microalgal growth. In the present study, the dissolved CO2 concentration in culture limiting and inhibiting microalgal growth (Chlorella vulgaris) in a bubble column photobioreactor was studied. The experimental results showed that the dissolved CO2 concentration ranging from 107μmol/L to 1500 μmol/L could meet microalgal growth’s need, which provides the guidance for microalgal CO2 biofixation with high efficiency.

2008 ◽  
Vol 39 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Reza Ranjbar ◽  
Ryota Inoue ◽  
Hironori Shiraishi ◽  
Tomohisa Katsuda ◽  
Shigeo Katoh

2018 ◽  
Vol 42 ◽  
pp. 01004
Author(s):  
Andang W. Harto ◽  
Mella Soelanda

The rising of atmospheric CO2 concentration is the major source to global warming system. Many methods have been proposed to mitigate global warming, such as carbon penalty, carbon trading, CO2 sequestration, etc. However these proposed methods are usually uneconomical, i.e., these methods do not produce economic valuable substances. This paper will propose a method to absorb atmospheric CO2 to produce economic valuable substances such as methanol, dimethyl ether, ethylene, several hydrocarbon substances and derivatives and several graphite substances. This paper is focused on methanol production using atmospheric CO2 capture. The overall process is endothermic. Thus a sufficient energy source is needed. To avoid more CO2 emission, the energy source must not use conventional fuels. To assure the continuity of energy deliberation, nuclear energy will be used as the energy source of the process. In this paper, the Passive Compact Molten Salt Reactor (PCMSR) will be used as the energy source. The 460 MWth PCMSR is coupled with atmospheric CO2 capture, desalination, hydrogen production and methanol production facilities. The capturing CO2 capacity is 7.2 ton/h of atmospheric CO2. The valuable outputs of this system are 3.34 ton/h of H2, 34.56 ton/h of O2, 5.24 ton/h of methanol and 86.74 MWe of excess electricity.


2000 ◽  
Vol 18 (No. 3) ◽  
pp. 110-114
Author(s):  
J. Čermák ◽  
M. Rychtera ◽  
P. Nechvíle ◽  
J. Náhlík ◽  
K. Melzoch ◽  
...  

Ergosterol is a major sterol in yeast cells. Intermediates of ergosterol biosynthesis or products of ergosterol biotransformation occur in cells too. Sterols mainly form components of cell membranes. Fluidity of membranes is affected by sterols. The amount of sterols in cells can be influenced above all by cultivation conditions and by the yeast genotype. Specific growth rate is an important factor which affects the amount of sterols present in yeast cells. We carried out a series of 24-hour cultivations to find out the impact of specific growth rate on sterol biosynthesis. Inflow of synthetic medium to the bioreactor was controlled by means of a profile of carbon dioxide concentration in the outlet gases. This profile was acquired by simulation according to a mathematical model of cultivation. Profile of carbon dioxide concentration corresponded to a precalculated profile of specific growth rate. Cultivation was divided into two phases with different growth rate values. A constant value of the specific growth rate was maintained in the 1st phase. The specific growth rate value decreased by controlling the inflow in the 2nd phase (beginning at 12th hour of cultivation). Other cultivations were carried out using so-called physiological control which consisted in determining the immediate physiological state (e.g., RQ) and the choice of control strategy according to the metabolic state. Selected control strategy ensures an immediate action (inflow of the medium). If the specific growth rate decreased in the 1st phase, the amount of total sterols in yeast dry biomass increased (to 2.7% in yeast dry biomass). But the purity of ergosterol decreased (amount of sterol contaminants increased up to 23.3% in the sterol fraction). If a constant value of respiratory quotient was maintained (at about 1.1), the amount of total sterols in yeast dry biomass and the purity of ergosterol were constant. If the value of respiratory quotient was changed in the growth and final phase of cultivation, the amount of total sterols in yeast dry biomass increased (to 2.83% in yeast dry biomass). However, the purity of ergosterol decreased (amount of sterol contaminants increased up to 21.2% in sterol fraction).


2020 ◽  
Vol 44 (27) ◽  
pp. 11824-11828 ◽  
Author(s):  
Tingting Zhao ◽  
Yu Tian ◽  
Likai Yan ◽  
Zhongmin Su

Converting CO2 into useful fuels and chemicals offers a promising strategy for mitigating the issues of energy crisis and global warming.


2018 ◽  
Vol 219 ◽  
pp. 1-8 ◽  
Author(s):  
Hoang-Nhat-Phong Vo ◽  
Xuan-Thanh Bui ◽  
Thanh-Tin Nguyen ◽  
Dinh Duc Nguyen ◽  
Thanh-Son Dao ◽  
...  

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1309 ◽  
Author(s):  
Antonio Rodero ◽  
Dorota Anna Krawczyk

Carbon dioxide concentration is an important parameter to know Indoor Air Quality of a building. One of the most important sources of CO2 in poor ventilated building is human activity. This work presents a method for experimental determination of human CO2 generation rate based on measuring of time evolution of indoor CO2 concentration. The method is applied to 5 rooms of an educational building from Bialystok (Poland). Similar carbon dioxide gains were obtained in all rooms, around 0.0046 L/s, which correspond to theoretical CO2 generation rates of a sedentary activity for persons, males and females, between 21–30 years old, characteristics of occupants of analyzed rooms.


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