Diary of a Mad Scientist

I tried to take some photos of the Methoxide Mixer From Hell but they didn’t look very impressive and it still looks like a pile of steel parts.

However, I’ve also been working on another project the past few months- Hot Mama. Hot Mama is a big 350-gallon heavy steel IBC tank, which I’ve been doing oil dewatering experiments with- it’s got a lot of horizontal surface area and it’s weldable. Most of the weldable free tanks I come across are vertical cylinders without a lot of surface area available, which you need for evaporation or boiling. this weekend me and Jeff ran a batch of particularly disgusting grease through the Hot Mama boiler to test out various nozzles:

This photo is a 40 psi spray through one of the nozzles we’re trying out- turned out to be a flat 180 degree despite the nozzle’s claims of 60 degree cone spray:

I’m in a position to buy yellow grease at an attractively cheap price for the Machine Shop setup, but it’s got major hurdles to overcome- one of them being water. The price is low enough that if I can figure out how to use the nasty stuff, it might really make the cost of running the Machine Shop generator system a lot easier on the “labor costs” (collections is a big issue when you use 300 gallons a month for just one user, not counting anyone else’s vehicles). Our generator had a disasterous experience with some bad homebrew bought from my friend jess last winter, so I’m kind of concerned about quality control a bit more than usual.

Yellow Grease is rendering industry terminology for recycled fats that are of a certain percentage free fatty acids. Many people in homebrewing assume that yellow grease is the stuff you get from the local restaurant fryers. The industry reality is quite a bit nastier than just what’s in the barrels- either it rots on the way in or they mix in some trap grease type stuff. In either case it’s been found by many peopel to be a LOT nastier than the nastiest stuff you may find, for example the nastiness that’s in back of McDonald’s on San Pablo and 63rd in Berkeley. You can’t just go buy some yellow grease ad expect to throw the journeytoforever biodiesel webpage at it, and actually get biodiesel.

The big challenge with the stuff I’m playing with is water. I use KOH as a catalyst so I can handle solid fats and high FFA at once without getting ‘glop’ like you’d see with NaOH. But it’s also got a fair amount of water in it. I can ‘heat to 140F and let settle’ after filtering the nastiness but the bottom third gets all the water.

That’s where Hot Mama comes in. her current incarnation is as a boiler tank for the vacuum-assist flash evaporator system I"m going to build someday. In the meantime I’ve boiled oil dry in Hot Mama, and boy is it disgusting.

high-FFA grease STINKS something fierce. I actually gave up on dewatering at all when I was first making biodiesel , because the smell of heated oil is just foul and carries far and away to the nearest yuppie neighbor’s nosehairs- if I were neighbors with a rendering plant I"d be upset. So I haven’t been able to experiment with the bad grease that the urban Machine Shop coop needs- lord knows the neighbors are the last thing we need to antagonize. here in the foothills I can go to a metal shop in the middle of no where and make bad odors with yellow grease to my heart’s content, the odor control for the city version will come later.

There IS somethign nastier than yellow grease- brown grease. That’s a category of ‘product’ from a rendering plant which contains trap grease, fats from dead rotten animals, and other free fatty acids (with a bit of triglycerides thrown in). One of the participants of the Infopop biodiesel forum, the Diff, earns my great and undying respect for being able to apply homebrew technology and some of the ISU processes to making successful biodiesel out of brown grease. He described it as ‘it looks like crap and it smells like feces’. That pretty much describes the yellow grease I’m working with- looks like some sort of diarrhea. ANd I"m boiling this goo and spraying it through the air to try and separate the water content out.

Hot Mama has a heating element in the tank and a pair of them inline in the pipe, and a spray nozzle from McMaster-Carr at the end. It’s also got a Harbor Freight Pump circulating the oil through these features. This weekend Jeff re-plumbed the piping circuit to add a pressure gauge and a place for a future pressure switch and a pressure bypass around the pump so we could spray the grease that looks like crap and smells like feces through a sprayer nozzle and see if any (water) vapor comes off of it. BLORT is right.

Well, it works OK- but man what a nasty odor. We turned on the tank and ran away for the evening (and burned out the in-tank heating element which I havne’t seen happen before, might have something to do with really wet grease and steam pockets, somehow?????). You really had to pretty much turn it on and run. The point was to be able to see the spray pattern and that took some serious nausea-supression:

me trying to not run away from the nauseating stench:

Jeff did in fact run away and still looked like he was about to heave:

it’s a really good thing that you cant’ transmit odors via computer yet. I am getting these horrible odor flashbacks just looking at the photos!

Mark