Report addresses landfill gas pipeline injection issues

The Gas Technology Institute (GTI) has issued a report outlining the process of integrating renewable landfill gas into pipelines.

According to Kristine Wiley, senior scientist in the infrastructure sector of GTI, the purpose of the document is to identify criteria that stakeholders should consider when developing a landfill gas recovery facility for introduction of biomethane into a natural gas pipeline. “The document provides a framework and a structured approach that pipelines, developers and landfill operators can use to begin the critical process of technical collaboration necessary to understand each other’s’ requirements and ultimately, to make each landfill gas development project a success story,” she said.

The report, titled “Guidance Document for the Introduction of Landfill-Derived Renewable Gas into Natural Gas Pipelines,” has been in development since 2007. From 2010 to the end of 2011, GTI obtained 27 samples of renewable gas sourced from participating landfills and found that high-Btu landfill-derived renewable gas may be produced under agreed-upon tolerance specifications needed for use with existing natural gas supplies. The report analyzed the compositional makeup of the biogas, including everything from the relative density and Wobbe number (an indication of the fuel’s interchangeability) to the volatile organic compounds present in the biogas. GTI also included a section in the report providing suggestions for performance testing methods that will allow developers and pipeline operators to find the most efficient options for gas cleanup.

For Dan LeFevers, executive director of GTI’s Washington operations, the engagement between biogas developers and pipeline operations is key in the development of the biogas industry. “Earlier in the biogas market, most of the focus was either on creating electricity or using biogas directly on site for heating and other uses,” he said. But today, biogas is being placed directly into the natural gas pipeline system. Communication between developers and pipeline operations helps the biogas developers understand the quality issues that need to be addressed to inject the biogas, while pipeline operators can benefit by understanding the developer’s typical financing and technology needs, LeFevers said.

The report was funded in part by the U.S. Department of Transportation, the natural gas industry and the Solid Waste Association of North America. According to Wiley, one of the challenges of compiling the data was gaining access to landfills. But her team was able to engage several members, including landfill operators, project developers and gas cleanup companies, to host research sites and allow sample testing.

GTI has also completed a report on dairy farm biogas for use in existing pipelines. To view the report in full, click here.