Natural Gas Midstream
Methane Mitigation Thermoelectric Generator (MMTEG) Last Reviewed December 2017

DE-FE0029060

Goal
The project goal is to develop Natural Gas (NG) leak mitigation technologies that will enable companies to effectively mitigate leaks from midstream equipment and/or facilities (including pneumatic valves, controllers, and field gathering lines) and capture additional natural gas while removing their individual contribution to overall methane emissions. The project will develop and test an integrated thermo-electric generator (TEG)/burner system as well as complete the design for a field pilot for oil and gas field operations. Targeted objectives for this project include:

  1. Design a prototype 12 We MMTEG with >7% efficient low NOx field system
  2. Fabricate an integrated TEG/burner per the 12 We MMTEG design
  3. Demonstrate the integrated TEG/burner in component testing
  4. Field system cost target of $1500 for 6 We system
  5. Equivalent greenhouse gas (GHG) reduction of >1000:1 (assuming long term factor)
  6. Target reliability of >99.99% for the TEG subsystem
  7. TEG module efficiency > 9% peak (600ᵒC basis)

Performer
Gas Technology Institute, Des Plaines, IL 60018

Background
This project will use demonstrated advanced thermoelectrics to provide significantly higher system efficiency over commercially available TEG materials, coupled with an integrated burner-heat exchanger to achieve a low-cost system. The integration will utilize experience gained from another DOE program which developed a 1kW-class TEG for high-grade waste heat from automotive exhaust. The automotive TEG program is being completed by the Jet Propulsion Laboratory (JPL), who are the TEG developers for this program. This integration includes hot-side and cold-side heat exchangers, electrical circuitry and control electronics.

Impact
The project provides a near-term energy opportunity to recover between 1-2 million metric tons of methane emitted by intermittent pneumatic controllers annually in the U.S., and potentially 6-12 million metric tons per year globally. This is a significant portion of greenhouse gas emissions. The proposed system offers a low-cost, direct retrofit solution that will provide a short payback to increase implementation of the system.

Accomplishments (most recent listed first)
The Program Kickoff Meeting was held October 25, 2016, the Program Management Plan was updated, and the Space Act Agreement with NASA/Jet Propulsion Laboratory (JPL) was finalized and signed. The following technical items have been completed to date:

  • The Systems Requirement Review was completed with GTI and JPL
  • JPL suggested employing a derivative of a previously developed TEG for this application
    • Analysis of the derivative TEG showed it will meet or exceed the MMTEG program requirements, so the derivative TEG was selected
    • Adopting this previously developed TEG as a starting point reduces development, cost, and schedule risk for this program
  • Continued MMTEG system design efforts, including sizing the combustor/heat exchanger/hot shoe/TEG/cold shoe/heat rejection to meet program requirements using the derivative TEG
  • Continued Risk Mitigation efforts to verify analytically defined heat transfer coefficient for the combustor/heat exchanger/hot shoe
    • Updated heat exchangers to complete testing
    • Assembled the test article. Test setup has been completed. The test article instrumentation and insulation is in work
  • System balance has been updated for the overall system performance/requirements.
  • Heat exchanger and “hot shoe” designs have been updated and are being iterated with JPL.
  • Cold shoe/heat rejection designs have been updated and are being iterated with JPL.

Current Status (December 2017)
Near term tasks include iteration of combustor/heat exchanger/hot shoe/TEG/cold shoe/heat rejection configuration to meet efficiency requirements. In addition, the model will be used to determine operating loads and acceptability of the design. Compliant designs for the system will be evaluated with JPL. In addition, the heat transfer risk mitigation test will be completed to verify heat transfer coefficients.

Subsequent tasks include an Integrated TEG/Burner Design and review followed by assembly and test of the test article. Trade studies will be completed as part of the System Engineering task to define the overall system and its cost and optimize recoverable revenue by evaluating the following variables: TEG configuration, Burner configuration and geometry, compressor reliability, controls minimization, safety, and burner pressure drop.

Project Start: October 1, 2016
Project End: September 30, 2018

DOE Contribution: $1,212,969
Performer Contribution: $349,138

Contact Information
NETL – Gary Covatch (gary.covatch@netl.doe.gov or 304-285-4589)
Gas Technology Institute – Jeff Mays (jeff.mays@gastechnology.org or 818-405-9549)