Mathematical Tool Based on Breakthrough Curves to Evaluate the Economic Advantages of Chemical Regeneration of Activated Carbon in Power Plants: A Comparative Study

A mathematical tool has been developed to evaluate the economic advantages of in-situ chemical regeneration of fixed-bed industrial adsorbers of granular activated carbon for cooling water treatment systems in Cuban power plants. Two scenarios of activated carbon (AC) management in a power plant were compared by applying the proposed model. The economic profit by implementing the regeneration strategy as a function of the number of regeneration cycles was determined and optimized. Breakthrough curves were obtained to assess the adsorption performance of the AC after progressive saturation–chemical regeneration cycles using synthetic water and hydrochloric acid, respectively. For the first saturation cycle, the breakthrough time was 272 min and after 10 cycles, it was reduced to 58 min, indicating a decrease of the adsorption capacity of 21%. The AC adsorption performance in terms of saturation time as a function of the number of regeneration cycles was considered one of the tool parameters. The proposed tool allows to determine the optimal number of regeneration cycles for a maximum economic profit in the regeneration strategy. It was demonstrated, using the proposed tool, that after an optimum of seven regeneration cycles, the power plant expends only 26% of the total investment. The simplicity of the tool permits a rapid way to find the most profitable number of regeneration cycles by combining economic, technical and adsorption efficiency parameters in one function, thus improving the AC management strategy at an industrial scale with corresponding environmental and economic advantages, including sustainability.

Download Full-text

Adsorption of Synthetic Dye by Betel Nuts Activated Carbon in a Fixed-bed Column, Experiments and Prediction of Breakthrough Curves

Journal of Physics Conference Series ◽

10.1088/1742-6596/1500/1/012051 ◽

2020 ◽

Vol 1500 ◽

pp. 012051

Author(s):

L Cundari ◽

M N Fakhri ◽

M Z Rizki

Keyword(s):

Activated Carbon ◽

Fixed Bed ◽

Breakthrough Curves ◽

Column Experiments ◽

Fixed Bed Column ◽

Synthetic Dye

Download Full-text

Prediction of breakthrough curves for adsorption of lead(II) on activated carbon fibers in a fixed bed

Carbon ◽

10.1016/s0008-6223(99)00206-7 ◽

2000 ◽

Vol 38 (7) ◽

pp. 975-981 ◽

Cited By ~ 34

Author(s):

Guo-hua Xiu ◽

Ping Li

Keyword(s):

Activated Carbon ◽

Carbon Fibers ◽

Fixed Bed ◽

Breakthrough Curves ◽

Activated Carbon Fibers

Download Full-text

Removal of amoxicillin from water by adsorption onto activated carbon in batch process and fixed bed column: Kinetics, isotherms, experimental design and breakthrough curves modelling

Journal of Cleaner Production ◽

10.1016/j.jclepro.2017.05.197 ◽

2017 ◽

Vol 161 ◽

pp. 947-956 ◽

Cited By ~ 74

Author(s):

Marcela Andrea Espina de Franco ◽

Cassandra Bonfante de Carvalho ◽

Mariana Marques Bonetto ◽

Rafael de Pelegrini Soares ◽

Liliana Amaral Féris

Keyword(s):

Activated Carbon ◽

Experimental Design ◽

Fixed Bed ◽

Batch Process ◽

Breakthrough Curves ◽

Fixed Bed Column

Download Full-text

Modelling of NO adsorption in fixed bed on activated carbon

Chemical and Process Engineering ◽

10.2478/v10176-011-0029-z ◽

2011 ◽

Vol 32 (4) ◽

pp. 367-377 ◽

Cited By ~ 2

Author(s):

Lenka Kuboňová ◽

Lucie Obalová ◽

Oldřich Vlach ◽

Ivana Troppová ◽

Jaroslav Kalousek

Keyword(s):

Nitric Oxide ◽

Mass Transfer ◽

Activated Carbon ◽

Fixed Bed ◽

Breakthrough Curves ◽

Force Model ◽

Transfer Coefficients ◽

No Adsorption ◽

Response Curves ◽

Mass Transfer Mechanism

Modelling of NO adsorption in fixed bed on activated carbon Adsorption experiments of nitric oxide in nitrogen carrier gas were held on activated carbon in a fixed bed flow system. Breakthrough curves describing the dependence of exit concentrations of nitric oxide on time were matched with theoretical response curves calculated from the linear driving force model (LDF). The model assumes Langmuir adsorption isotherm for the description of non-linear equilibrium and overall mass transfer coefficient for mass transfer mechanism. Overall mass transfer coefficients were obtained by the method of least squares for fitting numerically modelled breakthrough curves with experimental breakthrough curves. It was found that LDF model fits all the breakthrough curves and it is a useful tool for modelling purposes.

Download Full-text

Comparative Study of CO2 Capture by Adsorption in Sustainable Date Pits-Derived Porous Activated Carbon and Molecular Sieve

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18168497 ◽

2021 ◽

Vol 18 (16) ◽

pp. 8497

Author(s):

Mohd Danish ◽

Vijay Parthasarthy ◽

Mohammed K. Al Mesfer

Keyword(s):

Mass Transfer ◽

Activated Carbon ◽

Molecular Sieve ◽

Fixed Bed ◽

Utilization Factor ◽

Adsorption Performance ◽

Mass Transfer Zone ◽

Date Pits ◽

Porous Activated Carbon ◽

Transfer Zone

The rising CO2 concentration has prompted the quest of innovative tools to reduce its effect on the environment. A comparative adsorption study using sustainable low-cost date pits-derived activated carbon and molecular sieve has been carried out for CO2 separation. The adsorb ents were characterized for surface area and morphological properties. The outcomes of flow rate, temperature and initial adsorbate concentration on adsorption performance were examined. The process effectiveness was investigated by breakthrough time, adsorbate loading, efficiency, utilized bed height, mass transfer zone and utilization factor. The immensely steep adsorption response curves demonstrate acceptable utilization of adsorbent capability under breakthrough condition. The adsorbate loading 73.08 mg/g is achieved with an 0.938 column efficiency for developed porous activated carbon at 298 K. The reduced 1.20 cm length of mass transfer zone with enhanced capacity utilization factor equal 0.97 at 298 K with Cin = 5% signifies better adsorption performance for date pits-derived adsorbent. The findings recommend that produced activated carbon is greatly promising to adsorb CO2 in fixed bed column under continuous mode.

Download Full-text

Treatment of landfill leachate by preozonation and adsorption in activated carbon columns

Water Science & Technology ◽

10.2166/wst.1996.0171 ◽

1996 ◽

Vol 34 (9) ◽

pp. 33-40 ◽

Cited By ~ 10

Author(s):

J. Fettig ◽

H. Stapel ◽

C. Steinert ◽

M. Geiger

Keyword(s):

Activated Carbon ◽

Landfill Leachate ◽

Fixed Bed ◽

Breakthrough Curves ◽

Operating Conditions ◽

Practical Case ◽

Leachate Treatment ◽

Homogeneous Surface ◽

Adsorption Processes ◽

Cost Efficient

Landfill leachate pretreated in an aerobic biological stage was studied with respect to the adsorption behaviour of its organic components with and without preoxidation by different amounts of ozone. Isotherm data evaluated by adsorption analysis showed that the fractions of non-adsorbable and weakly adsorbable species had been increased after preoxidation. As a result, the carbon capacity in a fixed-bed adsorption process was expected to be significantly lower for preoxidized leachate. This conclusion was confirmed by data from column experiments. The breakthrough curves under operating conditions typical for leachate treatment could be predicted quite well by the homogeneous surface diffusion model when no preoxidation was applied. After preozonation about 40% of the remaining organic substances were biodegradable. Data evaluation revealed that biodegradation took place inside the activated carbon beds. Therefore the total removal of ozonated leachate in activated carbon columns will be higher than the removal due to adsorption processes. An economic analysis must show in any practical case whether a combination of preoxidation and adsorption will be more cost-efficient than either of the single processes. The modelling technique applied in this study can be a useful tool for that purpose.

Download Full-text

Removal of Cr(VI) and methyl orange by activated carbon fiber supported nanoscale zero-valent iron in a continuous fixed bed column

Water Science & Technology ◽

10.2166/wst.2020.383 ◽

2020 ◽

Vol 82 (4) ◽

pp. 732-746

Author(s):

Jian Liu ◽

Zhengji Yi ◽

Ziling Ou ◽

Tianhui Yang

Keyword(s):

Activated Carbon ◽

Methyl Orange ◽

Carbon Fiber ◽

Fixed Bed ◽

Oxygen Demand ◽

Breakthrough Curves ◽

Activated Carbon Fiber ◽

Zero Valent Iron ◽

Breakthrough Time ◽

Nanoscale Zero Valent Iron

Abstract The application of activated carbon fiber supported nanoscale zero-valent iron (ACF-nZVI) in the continuous removal of Cr(VI) and methyl orange (MO) from aqueous solution was studied in depth. The breakthrough curves of Cr(VI) in a fixed bed with ACF-nZVI were measured, and compared with those in the fixed bed with ACF. The catalytic wet peroxide oxidation (CWPO) process for MO was also carried out using ACF-nZVI after reacting with Cr(VI) in the same fixed bed. The results showed that the breakthrough time of ACF-nZVI was significantly longer than that of ACF. Higher pH values were unfavorable for the Cr(VI) removal. The breakthrough time increased with decreasing inlet Cr(VI) concentration or increasing bed height. The Yoon–Nelson and bed depth service time (BDST) models were found to show good agreement with the experimental data. The Cr(VI) removal capacity when using ACF-nZVI was two times higher than that when using ACF. Under the optimal empty bed contact time of 1.256 min, the fixed bed displayed high MO conversion (99.2%) and chemical oxygen demand removal ratio (55.7%) with low Fe leaching concentration (<5 mg/L) after continuous running for 240 min. After three cycles, the conversion of MO remained largely unchanged.

Download Full-text