Effect of ultrasonic pretreatment on pyrolysis of microalgae

Abstract

Pyrolysis has been considered a method for recovering the power from combined micro alga bio mass here, next executing heat probe of or involving sound waves with a frequency above the upper limit of human hearing as a pretreatment to increase the bio-crude yield. Pyrolysis of mixed-microalgae was carried out in a batch reactor made up of steel at a temperature range 350-600 C°, nitrogen gas was used as sweep gas for maintaining oxygen free atmosphere in the pyrolysis. The results show that the using ultrasonic probe for both frequency 60 &90 KHz increase the bio-crude yield from 50.72 to 44.13 and 44.83 % respectively at 550C°. The thermal degradation temperature of microalgae are studied using TGA. Also the results show that the ash content after applying ultrasonic sound as a pretreatment for both frequency 60 &90 KHz were reduced from 7.21 to 4.83 and 4.21 % respectively. The aim of the work was to study the effect of using ultrasound for different frequency on algae pyrolysis as a pretreatment steps.