December 2020 – Biogas Case Study
Location: Medora, Indiana
Customer: Archaea Energy
Industry: Renewable Energy
Project Type: Biogas
Equipment Type: Blower and Flare Skid Package
Executive Summary: Gulf Coast Environmental Systems was tasked with finding a solution that would assist with VOC abatement and biogas processing at a landfill in Medora, Indiana.
Customer Summary: This customer, Archaea Energy, is a long-standing partner to GCES, purchasing multiple solutions to support their landfill applications which processes the landfill biogas into clean Renewable Natural Gas (RNG). Founded by landfill owners and technology developers in the energy sector, they partner with other landfills to harness the power of their biogas. They source, build, and manage projects through the entire lifecycle of the project. GCES has been supporting Archaea in this goal since 2018 with several sites already operational and many more in development across the US. Archaea chose GCES to assist in the creation of these landfill gas to energy plants because of our extensive background in waste to energy projects with nearly 500 units currently in operation.
Project Summary: Potentially dangerous gases like methane (CH4), carbon dioxide (CO2), sulfides, and ammonia are created by the decomposition and evaporation of organic compounds as well as chemical reactions between waste components. These gases and other hydrocarbons are often considered greenhouse gases and play a huge role in global warming. According to the EPA, in the United States landfills are the third most prevalent source of methane and other greenhouse gases. When condensed into a small space, methane is considered an explosive gas and should be handled with extreme caution. While a minimal amount of oxygen is present in this particular stream of waste gas which eliminates risk of the process concentration becoming combustible, it is important to note that the methane is still highly flammable. However, poorly designed or maintained landfills run the risk of higher levels of oxygen entrainment leading to elevated danger and uncontrolled greenhouse gas emissions.
The goal of this project was to provide environmental benefits by meeting or exceeding regulatory pollution control requirements while taking advantage of previously untapped revenue opportunities through RNG.
“Landfills are long-term energy resources that require the right partner to harvest. We are very excited to add an additional plant to our portfolio and assist the Medora community with maximizing the value of its landfill.”
– Nick Stork, CEO Archaea Energy
Solution: For this specific application, GCES proposed the use of a 3,000 SCFM Blower / 81.9 MMBTUH Flare Skid Packaged System designed to treat the Volatile Organic Compound (VOC) and Hazardous Air Pollutant (HAP) emissions from the landfill reject gas.
The method of reduction of Volatile Organic Compounds (VOCs) in a Flare revolves around thermal destruction. The chemical process of thermal destruction is quite simple; the exhaust stream temperature is raised to a point that the chemical bonds that hold the molecules together are broken. The VOCs in the process exhaust stream are converted to various combinations of carbon dioxide (CO2), water (H2O), and thermal energy by the high temperature of the Flare’s flame. As process gas is used to fuel the main flame, a natural draft is created in the burner tip that draws in the required air for combustion.
The packaged skid consisted of a process stream safety feed train, serving as the point of connection of the landfill gas stream to the system package inlet. The safety feed train included all of the piping (stainless steel) for safely routing the gas from the edge of the skid, through the suction scrubber, through the process blower, and to the flare stack.
The system was equipped with an automatic control system with a touchscreen operated, and fully automated, sequence of operation. Hardware and software was integrated to allow for remote monitoring and troubleshooting as part of GCES’ GulfStar program.
The Value in Abating Landfill Biogas Streams:
Renewable natural gas (RNG), also known biomethane, is biogas that has been cleaned to a purity level where it is fungible with standard natural gas and can be readily distributed via existing pipeline. RNG also qualifies as an advanced biofuel under the Renewable Fuel Standard (D3 RINS).
The end result of RNG development takes otherwise unused or underutilized gases and turns them into valuable sources of energy while aiding in the prevention of global warming.
With this technology and application, auxiliary fuel use for maintaining heat in the unit is minimal at a wide range of operating parameters, and a destruction removal efficiency of up to 98% of the VOCs was achieved.