Caffeine extraction from green coffee with supercritical CO2

I finally succeeded in extracting caffeine from green coffee beans by using supercritical CO2. I built a high pressure chamber from 2" steel pipe fittings, and poured in 200mL of water. There is an aluminum screen above the water line, which held 0.75 lbs of moisturized green coffee beans in the upper part of the chamber. I added liquid CO2 to the chamber, then closed all valves and raised the temperature, making the CO2 pass into the supercritical phase. I left the system overnight at about 60*C, 3000 psi, then drained the water. It was very black due to impurities and some bean burning that occurred where my electric strip heater caused localized overheated zones in the chamber. The water was highly caffeinated, and tasted somewhat like coffee. I used a typical hydrocarbon extraction process to isolate the caffeine from the water (will show this in a later video).

Category:

Science & Technology

Tags:

• caffeine
• caffeine extraction
• supercritical co2
• co2
• supercritical
• decaffeination
• Carbon Dioxide

[uddagiri]

hey ur simply amzaing !!!

im kinda new to Chemicals and stuff

im just wondering can you extract Caffeine form regular Cool Drinks like COKE n PEPSI

they contain Caffeine im wondering how much percent they contain every time i drink them

and if you can extract Caffeine from them wat would be the procedure.....

it would be good to c some video about it from you!!!!

[bkraz333]

@uddagiri A Coke has about 35mg of caffeine per serving. You can extract it simply by mixing the soda with methylene chloride as I demonstrated in my other video. A youtube user called hkparker also shows caffeine extraction from an energy drink.

[mJusticz]

What camera do you use to record these? The quality is fantastic! Great project.

[bkraz333]

@mJusticz Thanks! My camera is a Lumix GH1. I set the shutter to 1/30 at f/4.0 for indoor work, then adjust the ISO to get a good exposure (usually ISO 400). If there is too much light, I'll stop down as far as f/8. I have full spectrum fluorescent lights in my shop, and I've manually adjusted the camera white balance to match the lights. I almost always use manual focus in my videos since each shot is pretty well controlled and done on a tripod.

[xRaw381]

@bkraz333 i dont mean to sound rude, but where do you get the money for all this? and where do you find the time? do you have a job?

[bkraz333]

@xRaw381 Fair questions. I am unmarried and don't have kids. I don't own a TV. I don't play or follow sports, and I only occasionally travel for leisure. So, finding time to work on my projects isn't too difficult. However, I recently started working for Valve Software, which means I will probably have less time to tinker. Previously, I ran my own business, so I could set my own hours. I am also working on some writing projects that will keep me busy for a little while.

[bkraz333]

@eggroll9000 It's not a bad idea at all. The taste was different from coffee or espresso, but really pretty good in its own way.

[19Maxx68]

Appreciate your efforts to upload your experiments. Great stuff!

[jerec576]

@jerec576 I think Ethyl Alcohol would be an appropriate co-solvent for the coffee beans. I think it also becomes supercritical at relative levels to CO2

[rvasquez6089]

i love you bro, i want a shop like you when i get older

[jerec576]

Could you explain the design mentioned at 4:40-5:00? I thought the entire tube was 1 sealed chamber with a piece of aluminum for a physical separation, but the video shows as though you have some piece leading to another chamber? I'm very much interested in replicating this design but with a slight difference with water and beans.

[xRaw381]

@bkraz333 oh right thanks for telling me that man, atleast you respond to your viewers, which cant be easy when you have 35k views :)

[MightBiteYa]

You're a mad scientist, sir, and I salute you.

[joemplascencia]

FYI robusta coffee beans contain more caffeine than arabica beans.

Btw you're set up is awesome. I've tried the crystallized caffeine, it has a rather nasty taste.

[GNBrews]

Safety glasses.... :)