Reduction of energy demand by use of air sparging during ultrafiltration of alkali-extracted wheat bran hemicelluloses

• The flux during membrane filtration can be enhanced by the use of a two-phase gas–liquid flow. This has been shown to be an energy-efficient alternative to increasing the cross-flow velocity. In this work, air sparging was used to increase the flux during ultrafiltration of alkali-extracted wheat bran hemicelluloses. Batch filtration was performed in a pilot unit with a ceramic ultrafiltration membrane with a nominal cut-off of 10 kDa. Parametric studies with and without air sparging were performed at temperatures of 30 °C, 50 °C and 80 °C and cross-flow velocities of 1, 3, 5 and 7 m/s. The limiting flux was not affected by air sparging at 30 °C, while a slight increase was observed at 50 °C and a considerable increase was obtained at 80 °C. Air sparging reduced the energy demand per m3 permeate produced during dead-end batch ultrafiltration at 80 °C and 1 m/s from 0.96 kWh/m3 to 0.51 kWh/m3.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Annan kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Other Chemical Engineering (hsv//eng)

Keyword

Two-phase gas–liquid flow

Ultrafiltration

Hemicelluloses

Wheat bran

Flux enhancement

Publication and Content Type

art (subject category)

ref (subject category)