[Gasification] Engine knock

[Harmon Seaver]

    What about just methane (or rather biogas) in a diesel? There seems
to be a lot of talk in the trucking industry lately about running on
compressed biomethane, and I know some people use propane injection in
their diesels for extra power. Any idea what the compression limits
would be there?
   Maybe it would be better to run a digester for the genset and reserve
the woodchips and gasifier for direct heat of a boiler. Or steam, I
suppose.


doug.williams wrote:
> 
> Hi Fredrik, and Colleagues,
> 
> You are correct.
> 
>> A compression ratio of 1:25 sounds very high. Can someone come up with
>> more
>> information about this?
> 
> Duel fuel diesels will only work reliably with compression ratios of
> 16:1, as the spontaneous ignition temperature of producer gas is about
> the same as for diesel. You cannot control the engine over this ratio,
> as spontaneous ignition takes over. Engines with higher ratios, have a
> separate pre-combustion chamber, and these are well proven to be
> unsuitable for producer gas.
> 
> If you are setting up a spark ignition engine, the compression ratio has
> little merit over 12.5:1 as the increase in frictional forces consume
> any extra power that a high ratio might provide. this has been well
> researched and proven, my papers go back to before WW2.
> Hope this clarifies the issue of compression ratios.
> Regards,
> Doug Williams.
> Fluidyne Gasification.
> 
> 


-- 
Harmon Seaver