r john

Michael Galloway wrote:R John, ok that's cool. I wonder what the land area to power a charcoal slurry diesel would be including the resources to power the fuel processing. The simplicity of chop up the wood and put it in the firebox appeals greatly to me. You could use a small steam generator to run an electric chain saw for that too.

You have to think of the whole process and that it all can be renewable. Harvest of biomass electric chainsaw and wood chipper. Drying of woodchip Thermal oil plate dryer turns woodchip into torrefied wood with biogas as by-product which can be used in diesel generator converted to gas. Thermal oil heated by solar and exhaust heat from gas fired diesel generator. Torrefied wood milled down to 20 micron in ball mill using electric. Rape seed oil cold pressed using electric then correct quantities of charcoal dust, water and rape seed oil emulsified in similar method to making peanut butter using electric to produce your diesel substitute. Given how efficient diesel is compared to steam probably 10% of the land area that steam requires and thats only due to the large area required to grow rape for the yield produced.

Douglas Alpenstock wrote:

r john wrote:If you want to get into steam safely then forget about water boilers and use thermal oil and thermal oil steam evaporators. The technology is out there off the shelf and is used in the commercial bakery industry.

Very interesting! And it makes sense, from a large scale point of view.

Any thoughts on how you would build a backyard system that mirrors this technology? That would be seriously cool!

The reason I suggested the bakery systems is because it is small scale, Think of France and a bakery on every street corner. The biomass boiler heats thermal oil instead of water. This hot oil is then used to heat the bread oven at the right temperature. Obviously this is a very dry heat unlike gas so the hot oil is also used to generate steam using a thermal oil steam evaporator so that steam can be injected into the dry oven to produce the perfect cakes and pastries.

I would not suggest building your own backyard system as hot thermal oil is normally around 230C and can cause serious damage to humans. Just think of working with a hot chip pan full of oil. Please leave it to the professionals

Michael Galloway wrote:R John: I'm not familiar with running a diesel engine on charcoal slurry so I can't compare them in detail but I suspect there would be issues affecting the important seals in the cylinder. What I can say is that the steam engine was widespread enough for it's issues and weakness to be known, so we know where we're starting and where we're going.

David: old steamengines were normally 3 or 4% efficient at converting the energy in wood to useful crankshaft work, we're expecting to be over 10% based on what was achieved at the end of the steam age but not widely applied.
For some harder numbers how does 2.48 kg of wood per kWh or 9.9L of wood chip per kWh (250kg/m^3) and 5.8L of water per kWh (assuming no condensing which would add complication) sound?

Douglas: I totally agree with you on the dangers of high pressure steam technology. The boss is certified to issue steam certificates for heritage style steam locomotives and I'm a mechanical engineer with healthy fear of death from steam explosion.
Recently I got to operate the prototype boiler that we've used to prove the key differences with our technology; when I was operating it I commented that I felt much safer operating it than I would have an old style boiler. I could describe it as the pressurised tubes being contained in a mobile bunker, the outer shell is only containing exhaust gasses. I've also done the calculations proving that the worst case scenario of stuff blowing up (which it's designed not to do!) will only result in a lot of steam blowing out the funnel. We're not amateur's playing around, we're young professionals changing the world! (cynicism hasn't set in yet!).

Thanks all

There are no outstanding issues the charcoal slurry is a direct substitute for diesel and is a blended fuel using torrefied wood,rape seed oil and water. Used in an efficient diesel generator will produce approx 45% electrical efficiency. Compare that to my Bellis and Morcom steam engines at 15% electrical efficiency and there really is no comparison.

If you want to get into steam safely then forget about water boilers and use thermal oil and thermal oil steam evaporators. The technology is out there off the shelf and is used in the commercial bakery industry.

But why would you want to do this. If you want to use biomass then just use charcoal slurry in a diesel engine.

Brian Shaw wrote:This is four months since this topic was up and i'm wondering if it went anywhere...

This is definitely a case that I personally would want to get some diesel military generator and use that to run the equipment.  I wouldn't even try to run it off solar.

I can get the idea of wanting to use electric equipment - our reasons might not be the same, but i'm aware some used 400-480v 3 phase stuff thats more powerful can go for cheaper than 240volt stuff because the latter is more used in home garages and the 400-stuff almost never so there's less buyers.  I'd hoped/wanted to buy up a bunch of 4xx volt machine tools and such for a large workshop in the future when I found good deals...  but I expect to be deeply rural and off grid/unfeasible to run a big powerline i'd think without $$$.  So my plan was to just use a big diesel generator and run the tools off that instead - I wouldn't be using the equipment so much that a few gallons diesel would bother me...  I want tools for capability not nonstop industrial machining, so the intermittent power of a genset would work fine.  (or so I think)

You dont sound as if you have had much experience of  large 3 phase motors. The problem with large 3 phase motors is the initial start up current required to get the motor going. Dont whatever you do buy a 15kw generator to run a 15kw motor as you will be disappointed. If your clever you can work out the maths or let the generator supplier know what the maximum size motor is that you want to run and they will spec the generator. Simple rule I was told was to size generator 3 times larger than largest motor so 15kw motor would require 45kw generator.  Dont have this problem with solar and batteries as the batteries can handle the temporary surge so long as the battery bank and controls a strong enough for the job.

You will find it hard to get "free" woodchip in the UK when it can be sold in bulk to the biomass generating plants. If the woodchip is produced to a G30 or G50 spec than it can be sold at a premium price in excess of 100 pounds a tonne.

In UK I had the same problem to power a briquette press but just installed a hybrid inverter to obtain the 3 phase. Would mean a rewire of your existing solar but is neat solution if you have sufficient solar panels to run it.