May 12, 2020 | AD & Biogas, Food Waste

Depackaging And Digestion Demo In California

A multiyear food waste-to-energy demonstration project in Goleta, California has been evaluating a source separated organics (SSO) food waste depackaging system followed by anaerobic digestion (AD) of the slurried organics.

Lystek International Ltd, the Goleta Sanitary District (GSD), University of California-Santa Barbara (UCSB), and the California Energy Commission (CEC) are involved in the project. Lystek received partial funding for the demonstration project from the CEC (about $1.5 million) in 2017 under the CEC’s Electric Program Investment Charge (EPIC) program.

Food waste from UCSB is preprocessed using the Smicon depackaging technology and codigested in two 8 m³ mobile skid-mounted anaerobic digesters. The slurried organic material is pumped to the digester feed tank, and slowly fed to the anaerobic digesters. A primary goal of the project is to validate that SSO can be decontaminated to an acceptable level (typically less than 1%) for efficient AD. The digesters are being fed at variable rates to document the level of biogas generation from food waste. As part of the CEC grant, the project aims to verify the amount of biogas and the energy conversion potential of SSO processed material.

Lystek will complete the first phase of the project over the next few months and submit results to the CEC for future publication. As a continuation of the overall project objectives, Lystek and GSD will investigate use of Lystek’s patented low-temperature thermal hydrolysis and refeed processes for AD optimization. The technologies are designed for post-digestion processing of biosolids and recirculation of the processed material to improve biogas yield and increase energy generation. The system utilizes a combination of heat, alkali, and high shear mixing to achieve effective lysis (breakdown) of the biological material in the processed organics.

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