Not to be argumentative, but that's not entirely true. Many restaurants own their grease reservoirs and contract to have them emptied. And they can have whoever they want take it out. Now certainly, if they contracted with a grease company, and that company is leaving the barrels out or owns the reservoir, then yes, the grease belongs to the collecting company. Just ask the restaurant.

As far as how much WVO you'll need to get, it really depends upon the reaction process. I've seen some get only 85-90% yield, but a good processor can get close to 1 to 1. You're pulling glycerin out, but you're also adding methane in.

TX