Steady-State and Dynamic Desorption of Organic Vapor From Activated Carbon With Electrothermal Swing Adsorption

摘要

A new method to achieve steady-state and dynamic tracking desorption of organic compounds from activated carbon was developed and tested with a bench-scale system. Activated carbon fiber cloth (ACFC) was used to adsorb methyl ethyl ketone (MEK) from air streams. Direct electrothermal heating was then used to desorb the vapor to generate select vapor concentrations at 500 ppmv and 5000 ppmv in air. Dynamic-tracking desorption was also achieved with carefully controlled yet variable vapor concentrations between 250 ppmv and 5000 ppmv, while also allowing the flow rate of the carrier gas to change by 100%. These results were also compared to conditions when recovering MEK as a liquid, and using microwaves as the source of energy to regenerate the adsorbent to provide MEK as a vapor or a liquid. There are numerous industrial processes (e.g., coating operations) that generate organic vapors with a wide range of highly variable concentrations (e.g., paint spray booths). Many of these gas streams need to be treated by devices such as biofilters or oxidizers before the gas streams are emitted to the atmosphere. Such variable vapor concentrations make it challenging to effectively remove the vapors from the gas streams without over-sizing the biofilter or oxidizer to achieve a specified removal efficiency of the vapor, or to produce more than necessary CO2 emissions from burning excessive amounts of auxiliary fuel with a thermal oxidizer (1-6). Combining adsorption with concentration controlled.