Investigations on through recirculation drying of dead pupae for recovery of pupae oil: An ideal source for biodiesel activities

Abstract

A ‘through type recirculation dryer’ has been designed, developed and used for drying of pupae waste which is attractive and economical. Dried product obtained is employed for biodiesel activities. Drying of pupae is studied with hot air blown through the pupae bed at 110<span style="font-family:Symbol; mso-ascii-font-family:" times="" new="" roman";mso-hansi-font-family:"times="" roman";="" letter-spacing:-.1pt;mso-char-type:symbol;mso-symbol-font-family:symbol"="" lang="EN-GB">°C. Pupae loading and moisture contents of pupae influence drying times and rates of drying. Drying rates increases from a low value of 3 kg/hr.m²to 13 kg/hr.m²when pupae loading is increasedfrom 1 kg per tray to 2 kg per tray.Drying rates (N)reduces from 13kg/hr.m²to 1kg/hr.m²when moisture contentsare reduced from 100 to 5%. Moisture contents are readily reduced lower than permissible limits (≤ 10%) within 2 hour of drying. Dried pupae remain stable even after 4 months of storage in polythene bags. High quality nutritious pupae meal is obtained as byproduct during extraction of pupae oil. Biodiesel produced from pupae oil meets the ASTM specifications.

</span>