Processing Biomass Using the Fast Hydropyrolysis Hydrodeoxygenation Method
As we have seen this fast pyrolysis method was developed at Purdue University and is described below.
The feed stock is dried and shredded before being fed into a vertical high pressure and temperature steel reactor. The particular pyrolysis reactor is cylindrical being domed at the top and pointed at the bottom, joined by a parallel section in the centre.
The syngas is injected from the bottom, the biomass also being fed into this area from above, combusting almost immediately to char and gas in temperatures of around 900°F.
The syngas is produced initially by reforming natural gas; until the system is producing its own gas then this is used. As well as containing a high proportion of hydrogen, the syngas also contains CO, CO2, and H2O and is injected to the base of the reactor at around 900F.
The gasses produced by pyrolysis rise up the reactor, exiting at the domed top and feeding into a cyclone. Here the residual char is removed and sent to a combustor from where the heat and steam is directed to the reformer as additional heat input.
Meantime the gasses have passed through a temperature controller to cool them to around 350°C, before being fed through the hydrodeoxygenation (HDO) catalyst treatment section, with sulfate iron oxide being a typical catalyst used to reduce the oxygen content of the gas.
The gas is now split to be fed to the reformer to be reformed to syngas, and piped through a series of condensers which convert the gas to liquid fuel known as H2bioil. This oil is passed through an osmosis membrane, producing a high CO2 content gas for the reformer burners, and the H2bioil is pumped to storage.
So now we have the gas for reforming and the gas to use as fuel in the reforming process.
The reformed gas (Syngas) as previously stated is hydrogen rich containing CO,CO2, and H2O components at a temperature of 900°F.
1. sciencedaily - mobile biomass crops or waste processing proposed.
2. purde - the development of fast-hydropyrolysis-hydrodeoxygenation of biomass.
3. pubsacs - catalysts (feS), oxygen removal from gas streams