A two-stage fixed bed for rice husk tar secondary thermal cracking was designed.

Tar yield is 11.7 mg/Nm³ at 1200 °C, and no tar is collected above 1300 °C.

Naphthalene in the tar reaches the maximum at 800 °C.

With temperature rise, tar converts from PAHs to non-condensable gas and char.

Tar is cracked completely at high temperature with short residence time.