CCIA – Cogeneration for On-Site Evaporation of Landfill Leachate RO Concentrate

Challenges

The CCIA Solid Waste Complex, like all landfills, generates landfill leachate. A treatment facility utilizing a combination of ultra-filtration and reverse osmosis (RO) system removes contaminates and generates clean water. The contaminates, however, are separated into a smaller waste stream, called RO Concentrate, which is generally 3 to 4 times the strength of raw leachate, and which requires further treatment for disposal.

Changes in regulation and a requirement to have multiple disposal options forced the Authority to haul significant amounts of the concentrated liquid over 40 miles to the Delaware County Regional Water Quality Authority (DELCORA) in Chester PA. With 25 truck trips per week, transport and disposal costs rose to over $1M per year. 

Solution

In early 2018, Energy Power Partners (EPP) saw an opportunity to help the Authority address its leachate disposal challenges and increase the overall efficiency of the landfill gas-to-energy plant at the same time by beneficially using engine waste heat to evaporate concentrated leachate using the CoVAP™ configuration of Heartland’s LM-HT Concentrator®.

CoVAP™ Configuration

The Authority’s CoVAP configuration utilizes, ~900°F engine exhaust from three Caterpillar 3520 engines. The exhaust is ducted together and transferred to the Heartland Concentrator™ which evaporates the concentrated leachate. The concentrator operates under slight negative pressure and pulls the heat across wastewater using a direct contact approach. Additionally, heat from jacket loss is reused to pre-heat feed water and increase the efficiency of the process. B.y beneficially reusing the exhaust and jacket water, thermal energy costs, which is often the most significant cost associated with evaporation, was removed.