Diethyl ether can actually be a rather complicated synthesis certainly not safe on the small scale. You want rather large reactors to do this due to the large headspace as pressure builds up easily when adjusting ethanol flow to heated sulfuric acid producing ethene gas. The extra headspace also leads to a purer starting product to purify much less water and ethanol carried over. Generally speaking if you are not used to running at least a 22 L reactor or larger on the daily basis you probably dont want to try this synthesis unless you like ruined chem equipment and sulfuric acid/ ethanol/ ether mix all over your work space.
Crushed silica is a far greater boiling surface for the reaction. i believe it is do to the large size of the chips vs sand as sand will form a black gum like coating over its top while the silica chips have lots of large gaps for the goo to deposit through before it has a smooth serface which ether cannot boil from. basically more serface area on the large scale also on the microscopic scale to.
A large unpacked column (4 ft or more) is helpful along with the increased headspace... The ethanol returns to the reactor for rereaction and the water only makes it over as the azeotrope. Also this is safer more room for gases when pressure builds up and also if the reaction gets to vigorous sulfuric acid **** wont taint the product.
Nothing will do except a large alhin condensor, I really mean this. 3 ft minimum. If you try this with a straight condensor you wont condense all your ether and you may leave your lab looking like nagasaki.
Parts of this reaction are extremely exothermic while others are endothermic. It all really depends on the water and ethanol concentration in your reactor. if there is less than a certain ammount of ethanol you will increase your heat substantially by addition and of course ounce you cross over this certain ammount your reactor will cool by addition.
As for using denatured ethanol as far as I know most companies use a mixture of about 30-60 % methanol this would not do as dimethyl ether and diethyl ether will probably mix together and form a lower boiling azeotrope not condensable as I know dimethyl ether is no where even close to a liquid at roomtemp.
At the end of the process you are left with a rather blackened sulfuric acid/ethanol/water/ether mix. This is not good for much in the lab and certainly no good for the environment so do a favor for everyone on the planet and nutralize your waste. A small investment in a 5 dollar bag of hydrated lime (55 pounds) from your local home improvement store can do many gallons of sulfuric acid. Watch out this is extremely exothermic and can be dangerous but better than dumping that stuff down the drain.
There really is so much to the safe and ethical synthesis of ether that I simply cannot explain it all in a forum it deserves an article of its own(I am sure many exist) as there are so many factors to it. This is an incredibly dangerous, nasty synth and I highly recomend against it for anything but someone who has more than a few years of experience dealing with the glassware.
Forgive my choice to not use spell correct on this post as I am a chemist
not an english teacher