Effect of embedded activated carbon nanoparticles on the performance of polydimethylsiloxane (PDMS) membrane for pervaporation separation of butanol

Abstract

BACKGROUND: The pervaporation separation method is considered to be a promising technique for biobutanol recovery from fermentation broths. In this work, activated carbon nanoparticles were embedded in polydimethylsiloxane (PDMS) membranes to improve the pervaporation performance. RESULTS: Adding 6 wt% nano-additives in PDMS membranes increased the flux and separation factor by 42.6% and 51.9%, respectively, compared with neat membranes at 37 ∘ C. Enhanced performance is due to: 1 the presence of additional sorption sites within the membrane with a high affinity for butanol; and 2 the porous structure of the nanofillers generate new pathways for facilitated mass transport through the membrane. The effect of the operating temperature and particle concentration on membrane performance was investigated. Membrane performance improved with an increase in the operating temperature. Higher temperature resulted in increased free volume in the PDMS chains leading to higher diffusion of butanol. Mechanical tensile tests showed that nanocomposite membranes have better mechanical stability in comparison with neat PDMS membranes with the best performance observed at 6 wt% of the nano-additives. CONCLUSION:The presence of activated carbon nanoparticles in the matrix of PDMS membranes leading to higher flux and separation factor can be beneficial for pervaporation separation of butanol from fermentation broths.

Activated Carbon-Loaded Polydimethylsiloxane Membranes for the Pervaporation of 1-Butanol from Aqueous Solutions

“…PDMS membrane showed a high separation factor, 154, which is one magnitude higher than similar works in the literature, varying from 9-40 4,19,22,23 . Probably this high selectivity is regarded to the use of a commercial glue instead of the usual PDMS kit.…”

“…They concluded that the addition of activated carbon caused a decrease in 50% on the energetic barrier for the alcohol transport. On the other hand, Azimi and coworkers 19 found activation energy of 66.4 and 43.9 kJ/ mol for butanol and water, respectively, in the permeation of binary solutions to activated carbon-loaded PDMS, leading to the conclusion that butanol permeation is more susceptible to temperature changes. However, although water has the highest apparent activation energy in this work and the lower affinity to PDMS, it showed the highest flux since it is the smaller specie and its concentration in feed is the highest one (higher driven force for transport) 22,23 .…”

“…Azimi and coworkers 19 investigated the use of activated carbon-loaded PDMS membranes for the separation of model binary solution of butanol in water (5 g/L). The results showed that the addition of activated carbon content from 2 to 8 wt% caused an increase in membrane selectivity, while the flux showed a maximum value at 6 wt% of the filler.…”

The impact of pH on VLE, pervaporation, and adsorption of butyric acid in dilute solutions

“…The flux is the permeate flow per unit membrane surface area and per unit time, which is normally determined for each species from the individual permeation flow rates. [26][27][28]…”

Modelling of Mixed Matrix Membranes Using a Resistance Based Model

“…The validation of the extended RB model was performed using experimental data obtained in our laboratory for the pervaporation separation of butanol from aqueous binary solutions using a PDMS/Super Activated Carbon Powder membrane [10]. Fig.…”