Recovery and Recycle of HCFCs by Activated Carbon Adsorption

1993 ◽  
Vol 36 (2) ◽  
pp. 33-36
Author(s):  
P. Logsdon ◽  
R. Basu
Keyword(s):  
Activated Carbon ◽  
Carbon Tetrachloride ◽  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
Potential Contribution ◽  
Stratospheric Ozone Depletion ◽  
Activated Carbon Adsorption ◽  
Foam Expansion ◽  
Carbon Adsorption ◽  
Methyl Chloroform

Various chemicals, such as chlorofluorocarbons (CFCs) methyl chloroform, carbon tetrachloride, and halons will be phased out globally by 1995 because of their potential contribution to stratospheric ozone depletion. Hydrochloroflurocarbons (HCFCs) are considered as replacements for the CFCs in certain applications (e.g., solvents and foam expansion agents). In a number of applications, CFCs are recovered using adsorption on activated carbon and reused. In this paper, we have described how to use activated carbon to adsorb 1,1-dichloro-1-fluoroethane (HCFC-141b) from an airstream and later recover and recycle using steam desorption. The capacity of commercially available carbons to adsorb HCFC-141b and conditions to be used in the process are described.

scholarly journals Observation-based assessment of stratospheric fractional release, lifetimes, and Ozone Depletion Potentials of ten important source gases

2012 ◽  
Vol 12 (10) ◽  
pp. 28525-28557 ◽  
Author(s):  
J. C. Laube ◽  
A. Keil ◽  
H. Bönisch ◽  
A. Engel ◽  
T. Röckmann ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Ozone Depletion ◽  
Recovery Time ◽  
Stratospheric Ozone ◽  
Air Samples ◽  
Methyl Chloroform ◽  
The World ◽  
Research Aircraft ◽  
Fractional Release ◽  
Hcfc 142B

Abstract. Estimates of the recovery time of stratospheric ozone heavily rely on the exact knowledge of the processes that lead to the decomposition of the relevant halogenated source gases. Crucial parameters in this context are Fractional Release Factors (FRFs) as well as stratospheric lifetimes and Ozone Depletion Potentials (ODPs). We here present data from the analysis of air samples collected between 2009 and 2011 on board research aircraft flying in the mid- and high latitudinal stratosphere and infer the above-mentioned parameters for ten major source gases:CFCl3 (CFC-11), CF2Cl2 (CFC-12), CF2ClCFCl2(CFC-113), CCl4 (carbon tetrachloride),CH3CCl3 (methyl chloroform), CHF2Cl (HCFC-22), CH3CFCl2 (HCFC-141b), CH3CF2Cl (HCFC-142b), CF2ClBr (H-1211), and CF3Br (H-1301). The inferred correlations of their FRFs with mean ages of air reveal less decomposition as compared to previous studies for most compounds. When using the calculated set of FRFs to infer equivalent stratospheric chlorine we find a reduction of more than 20% as compared to the values inferred in the most recent Scientific Assessment of Ozone Depletion by the World Meteorological Organisation (WMO, 2011). We also note that FRFs and their correlations with mean age are not generally time-independent as often assumed. The stratospheric lifetimes were calculated relative to that of CFC-11. Within our uncertainties the inferred ratios between lifetimes agree with those between stratospheric lifetimes from recent WMO reports except for CFC-11, CFC-12 and CH3CCl3. Finally we calculate lower ODPs than WMO for six out of ten compounds with changes most pronounced for the three HCFCs. Collectively these newly calculated values may have important implications for the severity and recovery time of stratospheric ozone loss.

scholarly journals Observation-based assessment of stratospheric fractional release, lifetimes, and ozone depletion potentials of ten important source gases

2013 ◽  
Vol 13 (5) ◽  
pp. 2779-2791 ◽  
Author(s):  
J. C. Laube ◽  
A. Keil ◽  
H. Bönisch ◽  
A. Engel ◽  
T. Röckmann ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Ozone Depletion ◽  
Recovery Time ◽  
Stratospheric Ozone ◽  
Air Samples ◽  
Methyl Chloroform ◽  
The World ◽  
Research Aircraft ◽  
Fractional Release ◽  
Hcfc 142B

Abstract. Estimates of the recovery time of stratospheric ozone heavily rely on the exact knowledge of the processes that lead to the decomposition of the relevant halogenated source gases. Crucial parameters in this context are fractional release factors (FRFs) as well as stratospheric lifetimes and ozone depletion potentials (ODPs). We here present data from the analysis of air samples collected between 2009 and 2011 on board research aircraft flying in the mid- and high-latitude stratosphere and infer the above-mentioned parameters for ten major source gases: CFCl3 (CFC-11), CF2Cl2 (CFC-12), CF2ClCFCl2 (CFC-113), CCl4 (carbon tetrachloride), CH3CCl3 (methyl chloroform), CHF2Cl (HCFC-22), CH3CFCl2 (HCFC-141b), CH3CF2Cl (HCFC-142b), CF2ClBr (H-1211), and CF3Br (H-1301). The inferred correlations of their FRFs with mean ages of air reveal less decomposition as compared to previous studies for most compounds. When using the calculated set of FRFs to infer equivalent stratospheric chlorine, we find a reduction of more than 20% as compared to the values inferred in the most recent Scientific Assessment of Ozone Depletion by the World Meteorological Organisation (WMO, 2011). We also note that FRFs and their correlations with mean age are not generally time-independent as often assumed. The stratospheric lifetimes were calculated relative to that of CFC-11. Within our uncertainties the ratios between stratospheric lifetimes inferred here agree with the values in recent WMO reports except for CFC-11, CFC-12 and CH3CCl3. Finally, we calculate lower ODPs than recommended by WMO for six out of ten compounds, with changes most pronounced for the three HCFCs. Collectively these newly calculated values may have important implications for the severity and recovery time of stratospheric ozone loss.

Treatment of High-Strength, Complex and Toxic Chemical Wastewater: End-of Pipe “Best Available Technology” vs. an In-Plant Control Program

1994 ◽  
Vol 29 (8) ◽  
pp. 221-233
Author(s):  
Shimshon Belkin ◽  
Asher Brenner ◽  
Alon Lebel ◽  
Aharon Abeliovich
Keyword(s):  
Activated Carbon ◽  
Control Program ◽  
High Strength ◽  
Activated Carbon Adsorption ◽  
Acceptable Solution ◽  
Conventional Activated Sludge ◽  
Carbon Adsorption ◽  
Individual Source ◽  
Best Available Technology ◽  
Available Technology

A case study is presented, in which two approaches to the treatment of complex chemical wastewater are experimentally compared: an end-of-pipe “best available technology” option and an in-plant source segregation program. Both options proved to be feasible. Application of the powdered activated carbon treatment (PACT™) process for the combined end-of-pipe stream yielded up to 93% reduction of dissolved organic carbon, with complete toxicity elimination. In order to examine the potential for applying a conventional activated sludge process, a simplified laboratory screening procedure was devised, aimed at establishing baseline data of removability potential, defined either by biodegradation, activated carbon adsorption or volatilization. Using this procedure, the major source of the non-biodegradable fraction in the combined park's wastewater was traced to a single factory, from which twelve individual source streams were screened. The results allowed the division of the tested sources into three groups: degradable, volatile, and problematic. A modified wastewater segregation and treatment program was accordingly proposed, which should allow an efficient and environmentally acceptable solution. This program is presently at its final testing stages, at the conclusion of which a full comparison between the two approaches will be carried out.

The effect of surface metal oxides on activated carbon adsorption of phenolics

1998 ◽  
Vol 32 (6) ◽  
pp. 1841-1851 ◽  
Author(s):  
Lois J. Uranowski ◽  
Charles H. Tessmer ◽  
Radisav D. Vidic
Keyword(s):  
Activated Carbon ◽  
Metal Oxides ◽  
Activated Carbon Adsorption ◽  
Carbon Adsorption ◽  
Surface Metal ◽  
Effect Of Surface

The Study on Formaldehyde Emission of Composite Floor and Activated Carbon Adsorption on Formaldehyde

2011 ◽  
Vol 243-249 ◽  
pp. 4956-4959
Author(s):  
Jian Chao Hao ◽  
Hui Fen Liu ◽  
Dong Ling Wei ◽  
Li Jun Shi ◽  
Jun Li Li ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Kinetic Equation ◽  
Formaldehyde Emission ◽  
Order Kinetic ◽  
Activated Carbon Adsorption ◽  
High Quality ◽  
Carbon Adsorption ◽  
Airtight Chamber ◽  
The Relationship ◽  
Order Kinetic Equation

The relationship between formaldehyde emission and time was researched and a mathematical model was developed which describes the variation of formaldehyde with time in the airtight chamber. It was found that high quality composite floor was in line with 0-order kinetic equation and low quality composite floor was in line with 1-order kinetic equation. Besides, the effect of activated carbon adsorption on formaldehyde was studied and the result showed that activated carbon had poor adsorption on formaldehyde for weak van der waals force.

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