2 replies to this topic

[daraj]

Hi,

 

I am looking at an application where natural gas (devoid of co2) is used as a reactant and needs to be preheated before sending into the reactor. Lets say reactor temperature is 790-840C

 

I want to know if this temperature can be achieved by preheating in a natural gas fired heater/furnace or is there any temperature limitation? is methane prone to coking  beyond a certain temperature?

if so, what is the max. temperature to which it can be heated in a fired heater and how can its temperature be raised to target temperature?

[Bobby Strain]

Natural gas contains heavier components that will crack to produce olefins, which will further react, eventually forming coke. So, you are out of luck using this approach. You might get some suggestions if you provide some information about the process. This appears to be an academic exercise.

 

Bobby

[daraj]

Hi Bobby, thanks. the feed that I want to pre-heat before sending it to a reactor(where it may be converted to olefins/aromatics) is

basically pipeline natural gas from which CO2 has been removed(as well as sulfur compounds). So lets say it is predominantly methane with <5-7 mol% of ethane and propane and some inerts. The reactor temperature can be between 790-840C and is an adiabatic reactor.

Inlet feed temperature needed will be more than 820C. How do you pre-heat this feed and what is the limitation of using a fired heater/furnace? If the natural gas is compressed to say 3 or 5 bar will that minimize coking in furnace?