The first internal combustion engines were fueled by town-gas. Which can be made from coal, wood (chips, or small cubes), or even waste. Not even complex to make!
Keywords:
- producer gas
- syngas
- woodgas
- holzver-gasser
- downdraft gasifier
Overview
V3 and round firmware was modified to control mixture via PWM-solenoid (there is also a manual valve so the PWM-valve need not be too big even for bigger engines) to reach lambda-target
- under testing; expected release late 2010-03. In v3 the PID-boost can be configured for lambda-target instead of MAP-target
- in the unlikely case that boostcontrol is also needed, alternate boost is still available for boostcontrol
Other (simple) features like "time-relay" for the ash-removal screw or shaker (often windscreen-wiper motor) could be useful.
We built severak FEMA-type downdraft gasifiers and collected experience.
In short, the zones in the FEMA-tarmaker wander up and down, cooling the oxydation zone and creating a HUGE amount of tar (which is somewhat like mineral oil: good in some places, but not good when sticking the intake valve to its seat).
The best gasifier design for 2-200 kWe lets air in tangentially, swirling in a toroid at a certain location, keeping temperature up and tar-forming down:
Why ?
For farmers, to use the sunflower seed (in oil form) as heat-engine fuel (for tractors, water-pumping, grinding, heat-pump, generate electricity or other shaft-power) is suboptimal. They have the stalk, straw and weed. The intelligent and environment-friendly choice is to use these growing (CO2 neutral) fuel instead of depending on fossile.
A 100 kW genset generates appr. 400 EUR / day electricity PLUS 400 EUR / day heat (partially warm water, partially exhaust that can be used for absorption heat pump also: for even higher heating value). Appr fuel cost is 200 EUR / day when purchased (only appr 130 EUR for many farmers that have the straw anyway, just need to feed it to the gasifier). ROI (return of investment) could be ~ 1 year or lower.
Combined cycle - brainstorming
There are several choices.
- gasification + spark ignition 4-stroke engine
- very cheap engines. New, or in junkyards. Also cost-efficient to maintain
- gasification + Ericsson cycle (regenerated or recuperated) gas turbine or piston engine probably the BEST cycle!
- unfortunately the hot piston is expensive (the turbine even more expensive). But gasification + spark ignition 4-stroke engine + (Ericsson OR beta-Stirling) can be a relatively cost-efficient IGCC (integrated gasification combined cycle)
- direct burning + rankine cycle: steam engine or steam turbine or ORC (organic ranking cycle)
- a combination of the above.
Links, videos
More links and images [here] (Hungarian. We will continue in English here)
Other trivial improvements and dropped plans
- obvious improvement (in any gasifier): better heat-exchange between the incoming air and the wood-gas output, like gekgasifier.com
- or a simple but efficient long (6m or longer) tube-in-tube counterflow heat exchanger
- temporarily dropped: one that is a big hole underground (covered) with pipes for primary and secondary air-in, gas-out, steam in. A big, corrosion resistant heat-exchanger (condensating for Nx10kW) cools output gas (warming the house at the same time)
- the target is to try the multiphase technology that was used for blue water-gas production (gas rich in Hydrogen, multiple times the heating value of continuous wood-gas). This might be an exteremely cheap and efficient way to reclaim heat with a "rotating" regenerator, otherwise wasted from Otto engines or gas turbines (or other powerplants with high waste-heat temperature, not steam-Rankine cycle of course!), making fuel consumption better
temporarily dropped: using the wood-gas in radial-compressor gas turbines and MembersPage/MarcellGal/DetonationCycleGasTurbine (way too loud)
Use the VEMS Round to control the clean air feed "throttle" of a gasifier in order to improve the output
- vacuum accumulator
- PWM valve
- the VW 2 pin valve with 7.8 Ohm resistance seems to "prell" (using 18-21 Hz, but other freq also when it moves at all).
- pneumatic solenoid valve
- vacuum actuator
- Marcell found several in the junkyard. eg BMW had near the manifold in several 6 cyl engines around 1990.
- most cars have flaps in the cabin-heating / air conditioning system actuated by vacuum valves
- audi (and other VW consortium) vehicles have pneumatic door-lock. These do not seem good, because designed for on/off operation
Stepper would be nice. Unfortunately round does not have enough outputs to control 4 wire stepper.
We have a v3 with blue LCD inside - mounted on a standalone 1.6L 4 cyl engine. The LCD equipped genboard v3 looks very cool TODO: photo, video