do i need yeast and sugar for fermentation grass for ethanol?

Answer 1

If you're using sugar, don't waste your time with grass. By itself, the grass contributes nothing to the fermentation. If you're converting the grass to fuel ethanol, you first need to break the cellulose down into starches with acid...then convert the starches to fermentable sugars with enzymes, THEN you can ferment it with grass.
If you ferment grass and sugar, you just get grassy beer...then what's the point of the grass?

Answer 2

John what are you doing with the alcohol? Drinking? As a fuel?

The only grasses that I know that has enough sugar to ferment are the ones we use as food. Barley, wheat, rice, rye, also some vegetables such as corn, sorghum, tapioca

The most commonly used grass for fermentation purposes is barley. It is malted (germination) which develops enzymatic activity within the barleycorn-seed. This enzymatic activity in turn in used to convert the starch in the grain to sugars.

Then the sugars are fermented by yeast. Thus producing ethanol (alcohol) and carbonic acid (CO2).

Any further question? Shoot me an email.