Identification and Development of an Analyzer for Siloxane Measurement

Fig. 1: Repeating structural units for Linear (Left) and Cyclic (Right) Siloxanes

Fig. 2: Sample Portable Siloxane Analyzer

Description: State of the art assessment for identification of a portable siloxane analyzer technology that meets NYSEARCH sponsor(s) specification.

Status: Five analyzers identified that are being evaluated in North America.


The benefit of this study is to leverage expertise of gas research centers of excellence in Europe by conducting an expansive search for a siloxane measurement tool. The approach will allow us to understand the technical requirements and solutions that are necessary to quantify the presence of siloxanes in Renewable Natural Gas (RNG).

The program could result in a future solution necessary to qualify a biogas clean-up facility as acceptable and to bring data to the discussion about reasonable limits/ methods for addressing trace levels of siloxanes in specific RNG applications.


NYSEARCH has been discussing several needs related to de-carbonization and potential challenges to implementation of Renewal Natural Gas (RNG) using our members existing LDC infrastructure. Gas quality questions arise regarding trace constituents from various sources of RNG.

In recent years, scientific groups such as the California Council on Science and Technology have done literature search and other work to understand what levels and measurement thresholds should exist for different constituents in processed biogas. In the case of biogas that is produced from wastewater and landfills, where household agents come into play, siloxanes [family of man-made compounds consisting of silicon and oxygen (See Figure 1)] have been found that may carry forward minute quantities to processed biomethane after processing. Siloxanes are used in anti-foaming agents, fire retardants and consumer products such as deodorants and shampoos].

GRT Gaz/RICE and others in Europe have also studied the impacts of trace constituents and now refer to a standard in Europe known as EN-16723-1 that has adopted a maximum value for siloxanes. Research organizations, including NYSEARCH, have attempted to develop a sensor that can measure siloxanes at very minute (ppb) concentrations. An unsuccessful attempt to measure siloxanes was made as part of an advanced chemical sensor project at NYSEARCH. With that technology, we used nano-sensor technology that worked for an array of chemicals but not siloxanes. Reports by GRT Gaz and others indicate that there still is an open need for a reliable tool for siloxane measurement. Thus, it was proposed to work within the European scientific community and use the resources that GRT Gaz/RICE have to find a tool that would meet LDC’s specifications for siloxane measurement.

Technical Approach

The objectives of the project are to identify a suitable technology, technology provider and workplan to develop a siloxane tool, preferably portable, that can measure concentrations of siloxanes at regulated threshold levels (as low as 0.1 mg Si/m3). A subsequent program objective is to work collaboratively with other gas company users and developers who are implementing RNG plants to use the developed tool to inform our-selves and others about the presence of siloxanes in equipment that use RNG and to ultimately use that information to develop a practical standard for acceptable levels of siloxanes.

GRT Gaz, who is the main Transmission System Operator (TSO) in France with over 20,000 miles of transmission main, is counting on its Innovation Department, RICE, to address the same needs that our members, who are active or interested in getting active in implementation of RNG have expressed. RICE also works with other European research agencies such as GERG, DNV and others. RICE and its partners in France have spent considerable time in the RNG arena to understand State-of-the-Art technologies because of the growing use of RNG in France with (49) RNG sites in service on the distribution network, (4) in the transmission network and (30) more expected by the end of 2018.

In this first effort, we worked with NYSEARCH funding members in a stepwise process to set technical specifications. RICE then researched what is available in state-of-the-art technology and how that applied to NYSEARCH specifications. In the final step, an assessment (with the involvement of our funders) was performed of the various analyzers identified and the most promising technologies selected for a siloxane tool. Data was collected to justify the ‘Technology Readiness Level (TRL)’ and the pros and cons of the differ-ent solutions.

Program Status

The State-of-art (SOA) assessment has been completed and the shortlisted analyzers have been presented to the project sponsor(s) for their review. A next phase has been launched to evaluate these analyzers further through laboratory and field testing. The final goal is to help reduce the list of suitable technologies for siloxane measurement and to define the anticipated work and time necessary to fully apply/develop the tool.

For more information Contact NYSEARCH.


For over thirty years, NYSEARCH has worked as a consortium of natural gas Local Distribution Companies (LDCs) who have a common interest and need for research and technology development and demonstration. Today, as part of the Northeast Gas Association (NGA), NYSEARCH manages over (30) projects in various stages of development for LDCs, transmission companies, federal agencies and their manufacturing and commercial partners. NYSEARCH is located in Parsippany, NJ and NGA is headquartered in Needham, Massachusetts.