I really like #7, but the center droplet is too orange. Consider the color palette used by entry #9. Additionally, I would like to see more details in the leaf on the left. Finally, I don't mind the word "BIOFUELS" being small, but it needs to still be readable from far away, so a bit bigger would be good.
Entry #2 is pretty blocky, but if you can make it less angular (and thereby a little less aggressive), it could be interesting.
Thanks for making the changes with #11, but aside from the color/font size thing, we agreed that we like the simplicity of #7 more.
I got an idea while looking at #10: if both "leaves" were green, and the full droplet were centered above them, it could be reminiscent of a flower. I dunno: might look weird, but might work. I'd be okay with losing the blue in that situation.
Also, I still want to see "BIOFUELS" just a little bit bigger. Thanks.
Also, #16 is the most elegant design we've received. I like the color play a lot. Unfortunately, it doesn't speak enough to what we are or what we do.
#17 is very nice. You got the size of "BIOFUELS" perfect this time. I'd like to see it with a full droplet though, like the one in #7. I'm not sure how it will look, but it could be interesting.
#18 is very pleasant. I'm not sure how I think about it yet as a logo for us, but I didn't want to throw it into the not interested pile.