60 megawatts of energy produced from landfill gas

HMI, SCADA, controllers from GE Fanuc Intelligent Platforms used to recover methane gas and convert it to electricity.

07/01/2009


GE Fanuc Intelligent Platforms’ customer Innovative Energy Systems (IES) has developed a clean energy solution that recovers methane gas from landfills and converts it into electricity as an alternative energy source. The solution uses GE Fanuc Intelligent Platforms’ controllers, HMI/SCADA software and operator interface equipment to facilitate the processing of the gas and keep the system running efficiently and effectively, providing IES with a sustainable and competitive advantage.
IES, headquartered in New York state, has nine power plants in New York and Vermont, producing more than 60 megawatts of capacity with more than 25 additional megawatts coming online over the next two years. In addition to its own facilities, the company also designs and constructs plants using this innovative system for other companies.
IES uses GE Fanuc controllers on its proprietary gas collection and scrubber unit and other equipment used to collect and process the gas. GE Fanuc’s QuickPanel View and Proficy HMI/SCADA– Cimplicity monitor kilowatt-hours produced, display engine diagnostics, fuel flow and quality. This solution also provides an overview of the gas scrubbing system operation. IES plant managers use the system on a daily basis to monitor the engines and gas scrubbing system. This information allows the plant managers to complete preventative maintenance, limiting downtime on the engines. Information provided by the system includes: generator loading and unloading, alarm history, engine diagnostics including engine hours, oil temp and pressure, jacket water temp and pressure, fuel flow and quality, and exhaust port temperatures.
Beyond providing energy from landfill gas, IES is also using the waste heat generated from jacket water and engine exhaust to heat a 12-acre greenhouse facility that produces vine-ripened, hydroponic tomatoes. The heat generated is transferred in continuous loop from heat exchangers at the company’s power plants to the heat exchangers at the greenhouse. Because of the unique way in which the plants are grown, they have a growth season which lasts approximately eight to nine months, allowing the greenhouse to produce more than 6 million pounds of tomatoes annually.
How IES converts methane into electricity
Landfill gases are colorless vapors produced at solid waste landfills where trash and garbage are buried in the ground and covered with dirt. Over time, bacteria in the soils will break down organic wastes in the landfill. The by-product of these bacteria breaking down the garbage will produce gases. The amount and type of landfill gas depends on a number of factors such as the amount of garbage buried, the age of the landfill, the depth of the landfill, and the chemical environment inside the landfill.
Landfill gas consists of methane, carbon dioxide, and hydrogen sulfide. Methane is a very potent greenhouse gas that is a key contributor to global climate change, over 21 times more potent than carbon dioxide. Methane also has a short, 10-year, atmospheric life. Because methane is both potent and short-lived, reducing methane emissions from municipal solid waste landfills, the second largest source of methane in the United States, is one of the best ways to achieve a near-term beneficial impact in mitigating global climate change.
It is estimated that landfill gas to energy projects will capture roughly 60 to 90% of the methane emitted from the landfill, depending on system design and effectiveness. The gas is collected and conveyed using a system of vertical and horizontal wells and a positive displacement blower to the landfill gas to energy facility. Prior to the landfill gas going to the internal combustion engines it is processed through IES’ proprietary gas scrubbing system, which has been designed and developed to provide low maintenance, extended life to the internal combustion engines. The scrubbing system cools the gas and uses dehydration process, which removes particulates and water that otherwise, would have harmed the engines. After the landfill gas is processed through the scrubbing system is it delivered to the internal combustion engines where the captured methane is destroyed, converted to water and a much less potent carbon dioxide, when the gas is burned to produce electricity.
Read other Control Engineering articles on using landfill gas for energy:

– Edited by David Greenfield , editorial director

Control Engineering Sustainable Engineering News Desk

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