Reducing agitation energy-consumption by improving rheological properties of corn stover substrate in anaerobic digestion

• Improving rheological properties was tried to reduce agitation energy-consumption.
• Size-reduction & temperature-increase reduced shear stress by 10.4% & 11.7%.
• 9.2% PTS-reduction was achieved by size-reduction from 20 to 80-mesh at 35 °C.
• 10.3%/10 °C PTS-reduction was achieved at 20-mesh compared with 9.0%/10 °C at 80-mesh.

Rheological properties of corn stover substrate were investigated to explore agitation energy reduction potential for different total solid (TS) in anaerobic digestion. The effects of particle size and temperature on rheological properties and corresponding energy reduction were studied. The results indicated that corn stover slurry exhibited pseudo-plastic flow behavior at TS of 4.23–7.32%, and was well described by Power-law model. At TS of 4.23%, rheological properties were not obviously affected by particle size and temperature. However, when TS was increased to 7.32%, there was 10.37% shear stress reduction by size-reduction from 20 to 80-mesh, and 11.73% shear stress reduction by temperature-increase from 25 to 55 °C. PTS was advanced as variations of power consumption by TS-increase from 4.23% to 7.32%. There was 9.2% PTS-reduction by size-reduction from 20 to 80-mesh at 35 °C. Moreover, PTS-reduction of 10.3%/10 °C was achieved at 20-mesh compared with 9.0%/10 °C at 80-mesh.