5 replies to this topic

[prabha]

Hi everybody
any refinery is using two extreme fueld that is natural gas and or hydrogen rich gas from reformer as fuel to heaters. If so, what is their experience of heater performance when fuel is changed from natural gas to hydrogen rich gas and vice versa. regards

[Zauberberg]

That is the story about heating value (HHV). The more Hydrogen you have in the fuel gas, less is the weight (and higher the volume!) of the gas you have to burn for the same heat input requirements - as opposed to hydrocarbon-rich fuel gas. Wobbe Index (WI) has been widely used in fired heater control scheme to manage deviations of heat input due to changing composition of fuel gas.

Read more at:

http://www.engineeri...ases-d_823.html
http://www.engineeri...ndex-d_421.html
http://www.documenta...ation Solutions
http://www.dcgpartne...Wobbe_Index.pdf

[iyer]

Hi everybody
any refinery is using two extreme fueld that is natural gas and or hydrogen rich gas from reformer as fuel to heaters. If so, what is their experience of heater performance when fuel is changed from natural gas to hydrogen rich gas and vice versa. regards

Well as expected
1. The calorific value or the HHV changes, this changes the requirement needs for providing fuel for the same quantity heat.
2. High hydrogen content in the fuel gas results in greater velocities through the burner tips and hence erosion of these tips. This ultimately results in a bad flame profile due to damaged tips. Better check the burner data sheets.
3. The continuous change calls for a lot of adjustment in operations, hence a bit of a difficulty in heater optimization.

Zauberbergs doucments on Wobbe index are worth a read.

[S.AHMAD]

Hi everybody
any refinery is using two extreme fueld that is natural gas and or hydrogen rich gas from reformer as fuel to heaters. If so, what is their experience of heater performance when fuel is changed from natural gas to hydrogen rich gas and vice versa. regards

Hi prabha

More volumetric flow will be required for firing hydrogen rich gas and thus will limit the heat duty. In the refinrery I worked with (couple of years ago) we change the burner so as to have the right firing capacity. Perhaps you may consult burner vendor for a dual type of firing. Normally we have dual firing for oil and gas, in your case may be dual firing between heavy and light gases.

Edited by S.AHMAD, 05 January 2010 - 02:34 AM.

[Root]

Hi everybody
any refinery is using two extreme fueld that is natural gas and or hydrogen rich gas from reformer as fuel to heaters. If so, what is their experience of heater performance when fuel is changed from natural gas to hydrogen rich gas and vice versa. regards

Hi prabha

More volumetric flow will be required for firing hydrogen rich gas and thus will limit the heat duty. In the refinrery I worked with (couple of years ago) we change the burner so as to have the right firing capacity. Perhaps you may consult burner vendor for a dual type of firing. Normally we have dual firing for oil and gas, in your case may be dual firing between heavy and light gases.

S. Ahmad,

If flame length is hi due to more rich H2 fuel gas then what startegy we can adopt to correct heat duty problem and reduce convection zone tempearture.
awaiting for your reply.
Thanks
Toor