Challenge

The challenge of this project is to provide supplemental soil vapor extraction (SVE) and vapor control to the plants existing vapor recovery system. Additional soil vapor extraction wells were installed on the periphery of the plant due to the expansion of the landfill. The plants SVE blowers are unable to provide sufficient vacuum and the flares lacked the thermal capacity to maintain regulatory compliance. Envent was tasked with designing and implementing a system that could maintain a vacuum of 50 inches of water column on the new SVE header and provide vapor destruction of the extracted Methane gas. SVE and processing of landfill gas has inherent problems; the extracted vapor is entrained with moisture, solids and is highly combustible. An Engineered solution is necessary to separate the moisture and solids while maintaining an inert process stream to allow safe processing.

Solution

Envent Engineered the following system to solve these challenges. The system includes a SVE blower capable of maintaining a vacuum of 60 INWC and a 2500 CFM flow rate. The blower is equipped with a spark resistant housing and fan blade with an explosion proof electrical panel. An EMECS 70 was selected as the vapor destruction unit due to its large thermal capacity of 70 MMBTU/HR, as well as its advanced safety features. The EMECS 70 is a direct fired thermal oxidizer with no addition of dilution air which is well suited for the pressurized and inert process stream coming from the SVE blower. The challenge of moisture and solids entrained in the gas was solved by adding inline liquid knock out pots as well as solid separating filters. An automatic liquid drain system was also installed that allow the liquids to be pumped out of the KO pots and filters without the need to shut down the process system. Envent has operators onsite 24/7, to ensure the equipment is operating at peak performance and to log all compliance data to meet and exceed all regulatory standards.

Benefit

Envent’s solution to this logistical and regulatory challenge provided immense benefit to the landfill by allowing the facility to maintain environmental compliance and continue operating at full capacity. The system enabled the plant to avoid all environmental violations and maintains a safe working environment for its employees and the public.