Electric Valves for Steam Engine
Two things that I see on the very near horizon put steam back on top, both efficiency- and cost-wise in bio fuels.
First is catalized refractory. For years, I have been getting a wonderful catalytic reaction using 'cera-blanket' as a liner in my wood burning fireboxes. Now, by layering a layer of perforated firebrick, behind that a layer of cerablanket, behind that thin steel plate that is perforated and an airgap behind that with casing on the other side. This allows air to be pumped from the casing thru the blanket and then thru the perf brick. We are talking small amounts here of air, but enough to ignite and glow. It is similar to indoor propane heaters used today(ventless).
With such a reaction between the esters and carbon monoxide burning in such a way as to really put out the i.r. rays, The firebox is improved in many ways. Including smaller amount of headroom from fuel pile to cieling. This allows fuel pile to be surrounded by the high radiation/refraction refractory. In doing so, the fuel pile distills quite easily, and requires far less incoming air thru the grate which is a big source of nox. The gasses driven off the fuel pile can now be reignited in a controlled situation and where most beneficial.
Of even bigger benefit, is this kind of firebox can utilize wood 3' or even longer. This signifigantly reduces material handling energy and cost (hogging). It also makes hand firing feasable. That means a lot in third world countries.
The biggest news for steam is electric valves. Finally, they are commercially available. Volvo will put them out in a year. Valve timing on a piston type steam engine is everything. Without getting too fancy already, I manufacture engines that eat far less steam than a turbine up to about 500hp. The cost is less than half also.
If I can operate the valve via electric sylinoid instead of mechanical, I have infinite adjustment on cutoff and expansion which allows for perfect governing and a consumption rate of 10-15lbs per hp, vs 50-70 on a turbine. Again, this is in the up to 500hp bracket, but in the real world, biomass falls into this catagory. Only the big lumbermills do it larger and they are not everywhere. And....they are more user friendly and cheaper.
I am making the statement now that the catalytic refractories and the electric valving will become the foundation for new technologies in the combustion of bio fuels. If you do the math, you will see that the fuel rates come close to diesel engines, but without all the hassles. Boilers are more versatile as diesel engines are limited to mainly motive powers and electricity is the main one. While a boiler can give you the means of production and manufacturing. This means a genuine return on investment. ...it could be that the grant process will become history. :)
Skip Goebel - Sensible Steam International