Absorption of CO2 from modified flue gases of power generation Tarahan chemically using NaOH and Na2CO3 and biologically using microalgae

2nd International Conference on Biomass: Toward Sustainable Biomass Utilization for Industrial and Energy Applications

生物科学;工业技术;能源学

Purba, Elida^1 ; Agustina, Dewi^1 ; Pertama, Finka Putri^1 ; Senja, Fita^1

Department of Chemical Engineering, Faculty of Engineering, University of Lampung, Lampung, Indonesia^1

关键词: Biological absorption;    Catalyst concentration;    Chemical absorption;    Gas concentration;    Micro-algae;    Output concentrations;    Palmitic acid methyl esters;    Situ transesterification;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/141/1/012023/pdf
DOI  :  10.1088/1755-1315/141/1/012023

来源: IOP

【 摘 要 】

This research was carried out on the absorption of CO2from the modified flue gases of power generation Tarahan using NaOH (sodium hydroxide) and Na2CO3(sodium carbonate). The operation was conducted in a packed column absorber and then the output gases from the packed column was fed into photo-bioreactor for biological absorption. In the photo-bioreactor, two species of microalgae, N. occulata and T. chuii, were cultivated to both absorb CO2gas and to produce biomass for algal oil. The aims of this research were, first, to determine the effect of absorbent flow rate on the reduction of CO2and on the decrease of output gas temperature, second, to determine the characteristics of methyl ester obtained from biological absorption process. Flow rates of the absorbent were varied as 1, 2, and 3 l/min. The concentrations of NaOH and Na2CO3were 1 M at a constant gas flow rate of 6 l/min. The output concentrations of CO2from the absorber was analyzed using Gas Chromatography 2014-AT SHIMADZU Corp 08128. The results show that both of the absorbents give different trends. From the absorption using NaOH, it can be concluded that the higher the flow rate, the higher the absorption rate obtained. The highest flow rate achieved maximum absorption of 100%. On the other hand, absorption with Na2CO3revealed the opposite trend where the higher the flow rates the lower the absorption rate. The highest absorption using Na2CO3was obtained with the lowest flow rate, 1 l/min, that was 45,5%. As the effect of flow rate on output gas temperature, the temperature decreased with increasing flow rates for both absorbents. The output gas temperature for NaOH and Na2CO3were consecutively 35 °C and 31 °C with inlet gas temperature of 50°C. Absorption of CO2biologically resulted a reduction of CO2up to 60% from the input gas concentration. Algal oil was extracted with mixed hexane and chloroform to obtain algal oil. Extracted oil was transesterified to methyl ester using sodium hydroxide as a catalyst. The results of in-situ transesterification method cannot be identified. Both microalgae achieved maximum yield at 2% catalyst concentration. Nannochloropsis occulata achieved the highest yield of algal oil that is 88.5%. The highest content of methyl ester from Nannochloropsis occulata was undecanoic acid methyl ester by 55.42% and the result from Tetraselmis chuii was palmitic acid methyl ester by 81.58%.