1. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) Safe operation of Natural Gas Appliances Fueled with Hydrogen/Natural Gas Mixtures (Progress Obtained in the Naturalhy-Project) Dr. H. de Vries, Ir. O. Florisson and Ir. G.C. Tiekstra N.V. Nederlandse Gasunie 2nd ICHS, San Sebastian, 13-09-2007

2. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD)  Preparing for the Hydrogen Economy by using the existing natural gas system as a catalyst Socio-economic and LCA aspects Safety Durability of pipeline material Integrity of pipeline system End-use and separation Naturalhy project  Physical and Chemical properties of Hydrogen differ from Natural Gas, with impact on:

3. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) Preliminary Conclusion * = Based upon current testresults, more tests are planned First indications: Max allowable Hydrogen for End-use might be the most limiting Integrity & Durability* Safety & Risk* End-use 0100

4. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) Thank you for your attention Gjalt Tiekstra Coordinator Naturalhy project www.naturalhy.net

5. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 5 Safe operation: NG appliances: NG/H 2  Focus on domestic appliances  [H 2 ] max limit by Wobbe index conditions in NG distribution  [H 2 ] max limit by combustion safety aspects (light back) Gasunie, 2nd ICHS 13-09-’07

6. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 6 Common safety practice in NG appl n  Gas Appliances Directive (GAD): Council Directive 29-06- 1990  About 70 harmonised standards on appliances and fittings  EN437: Test gases – Test pressures – Appliance categories:  Gas classification: Wobbe index: W = H s /, (T 1,T 2 ) (MJ/m 3 )  Type testing: short term tests of new appliances Gasunie, 2nd ICHS 13-09-’07

7. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 7 Distributed gases and Test gases Gasunie, 2nd ICHS 13-09-’07 (overheating limit gas) reference gas light back limit gas flame lift limit gas W EN 437 group test range distribution range: “normal use” incompl. combustion / sooting limit gas

8. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 8 [H 2 ] max limit by distribution condition Gasunie, 2nd ICHS 13-09-’07 W W max EN437 group W max distr W min EN437 group W min distr W NG W NG/H2 [H 2 ] max Distribution condition: W NG/H2 ≥ W min distr > W min EN437 group

9. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 9 Premixed appliance operation Gasunie, 2nd ICHS 13-09-’07 FUEL GAS C x H y,N 2,H 2, …AIRN 2,O 2, … flow rate F flow rate A constant flow rate F + A Burner in appliance vuvu cold mixture:  prim : fuel-rich or fuel-lean primary flame front SLSL

10. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 10 Premixed appliance operation (2)   prim = (F/A) / (F/A) stoich  Behaviour upon changing fuel gas composition  Constant fuel gas pressure, constant air flow rate  Stable flame front: appliance safety (S L = v u ) FA Gasunie, 2nd ICHS 13-09-’07

11. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 11 Risk of light back with H 2  Light back: when everywhere in the flame front S L > v u holds, the flame will propagate upstream into the burner  Well-known: S L (H 2 ) > S L (hydrocarbons)  CH 4 /H 2 mixtures are sufficiently representative for NG/H 2 mixtures for the present purposes Gasunie, 2nd ICHS 13-09-’07

12. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 12 S L,  and H 2 admixture Gasunie, 2nd ICHS 13-09-’07 CH4 CH4/H2 = 70/30 CH4/H2 = 20/80 H2 fuel-leanfuel-rich  -shift:  ( NG/H2 ) <  ( NG )

13. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 13  S L for appliances (fuel-lean/fuel-rich) Gasunie, 2nd ICHS 13-09-’07 CH4 CH4/H2 = 90/10 CH4/H2 = 70/30

14. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 14 [H 2 ] max limit by light back (fuel-rich)  Practically useful [H 2 ] max values needed: experimentally comparing the light back behaviour of NG/H2 mixtures with that of a light back reference gas  “incipient light back” experiments on simple Bunsen tubes for most critical situations:  prim ~ 1.2 – 1.3  Gasunie (Prof. Dr. H.B. Levinsky et al) ; EET Program of the Dutch Ministry of Economic Affairs Gasunie, 2nd ICHS 13-09-’07

15. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 15 Bunsen tube experiments Gasunie, 2nd ICHS 13-09-’07

16. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 16 [H 2 ] max from incipient light back expts.  These Bunsen tube experiments set – for the first time – light back limited [H 2 ] max values for appliances that are light back critical upon H 2 addition (cooking burners) in general, as acceptable from common safety practice  At the same time, one should realize that existing NG appliances were not designed for long-term use with H 2 containing mixtures (corrosion, leakage)  large amount of testing effort needed Gasunie, 2nd ICHS 13-09-’07 * * *

17. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 17 Viewpoint: W-band  EN437 testgas Wobbe bands and Wobbe distribution bands apply on a national or regional scale  The appliances of different type all are connected to one and the same national or regional NG distribution grid  It is practical to consider detailed results from the viewpoint of a W-band  Safety aspect limited [H 2 ] max per appliance type  W NG/H2 = W min distr. determined [H 2 ] max limit  The lowest [H 2 ] max value counts Gasunie, 2nd ICHS 13-09-’07

18. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 18 H-band situation Gasunie, 2nd ICHS 13-09-’07 W max H W min H [H 2 ] max

19. Preparing for the Hydrogen Economy by Using the Existing Natural Gas System as a Catalyst // Project Contract No.: SES6/CT/2004/502661 NATURALHY is an Integrated Project funded by the European Commission’s Sixth Framework Programme (2002-2006) for research, technological development and demonstration (RTD) 19 NG/H 2 : where are we now ?  It is not yet justified to present statements on what level of hydrogen concentration could be safely allowed in which specific natural gas distribution region  More clarity obtained on some essential H 2 admixing issues:  Combustion safety aspects of existing domestic appliances  The connection with the Wobbe distribution condition  More work needed on domestic appliances:  Fundamental calculations (straightforward)  Carefully designed experiments (straightforward)  Long-term corrosion tests Gasunie, 2nd ICHS 13-09-’07