I just got to the same step. I have a barrel full of Bio Chaff (lol yes that's 64 stacks of it, a lot of AFK'ing while compressing/macerating my wheat) and I just made my first bit of Bio Gas.
I stopped, only because I'm not sure if I can just pump the Bio Gas into a Basic Gas Turbine using my Fluid Conduits right from the Distillery, or if I have to put it into Empty Cells and use those in the Basic Gas Turbine.
NEI shows the Gas Turbine recipe as the Bio Gas being inside an Empty Cell, but that might just be how NEI shows it. If I recall (this is my second play-thru but I never used Gas last time), you can pump the Bio Gas directly into the Basic Gas Turbine just like you can pump steam fluid directly into the Basic Steam Turbine. You might be restricted to just the top and bottom of the Turbine for fluid access, I'm wondering if perhaps you tried to put the Bio Gas in thru the side of the Turbine?
But since I wasn't sure, and since I was due for a break, I shut my game down once I reached this point. Glad you asked the question, hopefully when somebody gives the right answer, I'll fire the game back up and get to it.
The one thing I noticed during testing of my Bio Gas processing setup is... holy cow is that Distillery SLOW. Geez. There's a bunch of posts a few pages back which talks about having "30 Distilleries running" and now I can understand why... ouch. Is this all really worth the time and effort spent on it? I sure hope Bio Gas is a step up from Steam, but so far it seems like a lot of work and trouble, for an unknown benefit.