I don't mean to rain on your parade but what you are thinking of doing is stupid and foolish.
1. Taking a partner in any business is dumb and reduces the chances for success by a whopping 80% or more.

2. If you partner with someone and set up equipment with them on thier property, they can lock you out any time they get mad at you. You will loose all your investment and there really isnt much you'll be able to do about it.

3. Set up your own biodiesel processor.. start real small, work your way up. Rent a storage unit or something.. You can go ahead and even rent a garage or whatever from someone.. that's ok.. but if you make them a partner, you'll fail.

Just general business advice.