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I found a great link. 3 videos 1st one should be just what you are looking for. Hope it helps, I will build the double lever soon.
Grass and leaves can be pressed with a simple lever and plunger setup with a pipe or bucket to form.They will need to dry after pressed because some moisture is needed to make the briquettes stay together.Used cooking oil makes a good binder but with enough heat [generated by pressure] the plant material releases a natural binder. These materials produce more ash than hardwood but the ash is potash and can be added to compost pile for fertilizer.
I am building a wood gasifier now to produce electricity for house and greenhouse and will use the heat bi-product to heat greenhouse and home. The 'smoke' generated by burning the biomass in low oxygen is mainly h and co which is used as fuel for the generator engine, the exhaust from the engine being mainly co2 can be fed into greenhouse or back into pyrolysis zone where it is stripped of one o molecule and turned into co, then fed back into gas stream to run engine. It is all really much easier than it sounds.
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