[Gasification] Difference between biomass and coal gasification

[Arnt Karlsen]

On Mon, 25 May 2015 11:34:08 +0530, Saiteja wrote in message 
<CAH6fn7A8LGFaTVeYZQjBjcJKctX6jRsPA8=vUg5wNGEnytBjqA at mail.gmail.com>:

> Hi all,
> 
> Thanks for the response, but I am once again stating my question with
> some specifications.
> 
> I am interested in coal gasification where coal used is with high ash
> content and less reactive.
> 
> Capacity of gasifier is around 30 Tons of coal per day and technology
> is updraft fixed bed.

..can this be modified to fit e.g. a 1 - 2 meter tall "battery 
of Imberts" inside your current reactor vessel?  I haven't made
up my mind on the ideal sizes for my gasifier and I have a few 
ideas I'd like to try out.  

..regardless of sizes,  the hot section of my gasifier is going 
to be about 1 to 2 meters tall, and I'd like to consentrate on 
that rather on the other junk I need to test my ideas.

> If the reactor is operated at high temperature to crack any tar, ash
> would come out in molten form (Not desired) as conditions will cross
> ash melting point.

..in my gasifier (75kWe-300kWth "V-hearth Imbert" with tar vapor 
flare on top of the combustion zone "lens") I simply draw my tar 
vapors off my fuel hopper that sits on top of my combustion zone 
"lens", pipe it and some air straight down into my flare and use
the combustion zone "lens" to ignite and burn my tar vapors, this
also agitates and stabilizes the Imbert combustion zone "lens."

..for updraft, this becomes a little harder, as you have tar vapors 
"all over" your gas, and not just in your fuel hopper.

> So in this sense, tar generated after gas cooling be recycled into
> gasifier?

..your tar vapors generated in your gasifier and then 
condensed into tar droplets when you cool your gas.

..with your upstream gasifier, you have to clean your 
entire product gas stream, how much does that cost?

..with my setup, I keep my tar vapors away from my product gas,
instead I use them to heat, agitate and stabilize my "Imbert" 
combustion zone, and then to fuel it, around 2/3 to 4/5 of it.  


> Regards,
> 
> Saiteja


-- 
..med vennlig hilsen = with Kind Regards from Arnt Karlsen
...with a number of polar bear hunters in his ancestry...
  Scenarios always come in sets of three: 
  best case, worst case, and just in case.