Results from my eugenol extraction experiment:
Instead of steam distillation (I don't have the equipment), I decided to extract the eugenol from cloves by soaking it in 95% EtOH. I put around 25 g of powdered clove into a flask-shaped beaker, and added c. 70 g of 95% EtOH, and let this digest for a couple of weeks with occasional swirling. (I was not in any hurry.) I filtered this off, and added a similar amount of fresh solvent, let it digest again, then filtered, and combined the two filtrates which were green liquids. I evaporated c. 2/3 of the solvent, and then pretended like this was what I got from steam distillation.
My extraction procedure plan, based on the stuff from James Gore as well as some other sources I could find was:
Extract from the initial stuff, with 25,20,20 mL dichloromethane (DCM). Combine these extracts, then wash the DCM with 25,25 mL water. Extract from the DCM with 30,25,25 mL of 5% NaOH. Wash the NaOH with 15 mL DCM.
Next, acidify the NaOH (with 5% HCl) to pH 1. This step was a little different in the various procedures I read. James' proc said to acidify to pH 9, others said pH 1, I aimed for 1. The mixture turns cloudy as it becomes acidic.
Extract the acidified aq solution with 20,25 mL DCM. Wash this DCM with 15 mL H2O, then 15 mL of half-saturated NaCl solution. Take the DCM, add anh MgSO4 to dry, filter, and evaporate the solvent, yielding eugenol.
When I started to actually do this, the first part had a complication. I added the DCM to my EtOH extract, but I did not get two layers. So, I added c. 20 g of H2O to force separation to occur. After that, it mostly proceeded as planned. I need to improve my drying technique, my final DCM solution wasn't in fact dry from the amount of MgSO4 I used. Anyways, I did end up with a small amount (c. 0.25 g) of a yellow-brown oil which I assume is eugenol.
I'm not sure what yield I should expect, but I think my results (c. 1 % yield) are very low. I think the reason is that the initial EtOH extraction didn't take up most of the eugenol. I don't think I lost that much in the processing. (After evaporating the waste DCM portions, there did seem to be some eugenol in there, along with a bunch of other goopy junk, but not enough to explain the low yield.)
So, I think I really did want to use steam distillation, after all.
In any case, I did get some eugenol, so I am happy.