With the free time from the bank holiday, not wanting to spend the whole weekend inside I decide to devote sometime to my BioGas project. Having considered the last run a success, apart from producing a lot of smoke the gas produced did eventually light, leading me to believe that the reactor was working and just needed to continue to warm up to operating temperature.
I loaded the base full of charcol and get started again. Within minutes the base was hot and I loaded the chamber with wood pellets – sealing the top.
After 5 minutes the colour and quantity of the smoke changed and I used my blow torch to ignite the smoke. Instantly I was presented with a hot yellow flame, while the flame was not able to maintain itself I believe this is due to the water content and lack of mixed air – a problem soon to be fixed.
Below is a ‘basic’ drawing of the setup
I have installed flare stacks at all the post-process points so that I can check the output of the gas – The last thing I want to do is do all this work and end up with something that doesnt ignite!
So project one complete, I can successfully make flamable gas from waste wood! Next step – Clean, Condense and find a use for the wood gas.
*UPDATE 14th October 2012*
Having now purchased my own air compressor (yay!) I was able to fire up the reactor again and do an extended test. Below is a snippit of video I was able to record:
Project 2: Cleaning & Condensing
Fresh from the reactor the gas is still very hot and contains dissolved in the smoke a number of unhelpful substances – water being the biggest. In its highly energised state the gas moclules lack density and compressing them would be very difficult.
From my research I have found several methods of cooling hot gas (the top 2 being):
- Heat Exchanger / Radiator
- Water bubble tank
To keep things simple I opted to use a sealed water bubble tank. This is where the end of the outlet from the reactor is fed under water and the gasses are bubbled up through the water, both cooling the gas and seperating the water / water soluable substances at the same time. Keeping the water as cold as possible will hopfully force more of the waste componensts to seperate from the flamable gas cloud.
If needed a further process using hay as a filter medium can be slotted into place to absorb waste if needed – however I do not think this well be required if the ice water filter goes to plan.