LPG & NGL Storage Infrastructure

What is Synthetic Natural Gas?

Written by Greg Ezzell | Thu, Nov 19, 2009 @ 10:17 PM

Propane-air, Synthetic Natural Gas, SNG, Propane Blending System, Standby System, Peak Shaving System are all common names in our industry for the application, process or end product that occurs when Liquified Petroleum Gas (LPG or propane) is blended with air.  Let's call it for this article's sake Synthetic Natural Gas (SNG), because that is really what it is by definition.

SNG is a direct replacement for natural gas.  In composition, SNG is a blend of LPG and air.  The ratio of LPG to air will vary depending on the Wobbe Value required to match the energy value of the gas it is replacing.

SNG applications are many, but the main applications in our industry are:

SNG Backup Systems- allow Industrial gas customers to change from "firm" to an "interruptable" natural gas rate structure, providing significant savings.

SNG Peak Shaving Systems of Natural Gas- used by Natural Gas companies and Industrial clients to augment their Natural Gas demand during peak demand periods.

SNG Base-Load Systems- used in areas where Natural Gas is currently unavailable, providing a bridge fuel or a long-term solution for an energy need.

Making SNG.  There are five basic steps for making SNG:

1.  You need two ingredients: LPG (propane) and air.

2.  A pump is needed to pump liquid propane from the storage tank to the vaporizer at an elevated pressure.

3.  At the vaporizer, liquid propane is heated until it becomes vapor.

4. Propane vapor and air are blended at a ratio of approximately 55:45, this mixture is SNG

5.  Lastly the SNG needs to be discharged into the existing natural gas line and into the plant.

These steps are obviously over-simplified.  For more specific information on SNG systems for Standby or Peak Shaving applications, please contact a Propane-air/SNG specialist at TransTech Energy www.transtechenergy.com