Ethanol: Difference between revisions

From NOWA-CL
Jump to navigation Jump to search
No edit summary
Line 92: Line 92:
| 100
| 100
|}
|}
[[Calcium oxide]] undergoes hydration with the residual water in 95.6% ethanol to form calcium hydroxide, which is not dehydrated under normal distillation conditions; therefore, absolute ethanol will result in the distillation receiver.  Elemental [[calcium]] and  calcium carbide have also been used for this purpose.
The disadvantage to the above approach is that the resultant [[calcium hydroxide]] adsorbs a portion of the ethanol, which is not released under the conditions of normal distillation.
Ethanol canNOT be dried using such agents as calcium chloride and lithium chloride because azeotropic "alcoholates" are formed with these substances.  Ethanol canNOT be dried using such agents as sulfuric acid and phosphorous pentoxide because of their obvious reactivity with ethanol.
The ternary azeotrope of water, ethanol and benzene is a convenient method because the water and benzene are all distilled off by 69 deg C or so, leaving the absolute ethanol to distill off at around 78 deg C.  That's enough of a temperature difference to make this type of fractionation pretty straighforward
==Production==
==Production==
===Extraction===
===Extraction===

Revision as of 15:24, 30 January 2020


Legality: Production of alcohol in the US

In 1978 the US federal government passed laws regarding the home production of undistilled spirits.[1]

27 C.F.R. §25.206 & §24.75

  • Part 25 asserts: With additional limitation set by individual states, it is permissible for an individual to produce up to 100 gallons of beer per year for "home consumption", and this production shall not be subject to tax. A household with two or more adults may produce 200 gallons per year, likewise.
  • Part 24 asserts: With additional limitations set by individual states, it is permissible for an individual to produce up to 100 gallons of wine (including mead, etc) for "home consumption", and this production shall not be subject to tax. A household with two or more adults may produce 200 gallons per year, likewise.

Bottom line: Do not produce this chemical without checking to make sure that you may do so legally.

 
 
Ethanol
aka Alcohol
Chemical formula CH3CH2OH
Index of refraction 1.36 
Molar Mass(g/mol) 46.07 
Density(g/cc) 0.789 
Melting Point(°C) -114 
Boiling Point(°C) 78.3 
Coefficient of Thermal Expansion(×10-6 °C-1) 1120 
Fuel Value(MJ/kg) 26.8 
Solubility in water(g/L) miscible 
Water azeotrope(%w/w) 95.63% 
Water azeotrope bp(°C) 78.2
NFPA 704
NFPA704.png
3
1
0
 

Uses

Primary

Secondary

  • Recreation
  • Pharmacopia: Antiseptic properties
  • Pharmacopia: General Anesthetic

Legality

Distilling potable alcohol may be illegal in your jurisdiction. In some places in the US, it is illegal unless you render it impotable by adding repugnant flavors or poisons such as methanol. It may also be illegal to move the ethanol (even if it is rendered impotable) off your property. Check with local law enforcement before doing anything that might get you in trouble.

Hazards

  • Flammable
  • Toxic in large quantities

Natural Occurrence

  • Ethanol does occur naturally as a biproduct of yeast growth.

Character

% ethanol (v/v) % water (v/v) density (s.g.) bp (°C)
100 0 0.789 78
95.6(az) 4.4 0.798 78.2
90 10 0.810 79
80 20 0.831 82
70 30 0.852 85
60 40 0.873 90
50 50 0.894 92
40 60 0.916 94
30 70 0.937 96
20 80 0.958 98
10 90 0.979 99
0 100 1.0 100
Calcium oxide undergoes hydration with the residual water in 95.6% ethanol to form calcium hydroxide, which is not dehydrated under normal distillation conditions; therefore, absolute ethanol will result in the distillation receiver.  Elemental calcium and  calcium carbide have also been used for this purpose.

The disadvantage to the above approach is that the resultant calcium hydroxide adsorbs a portion of the ethanol, which is not released under the conditions of normal distillation.

Ethanol canNOT be dried using such agents as calcium chloride and lithium chloride because azeotropic "alcoholates" are formed with these substances.  Ethanol canNOT be dried using such agents as sulfuric acid and phosphorous pentoxide because of their obvious reactivity with ethanol.

The ternary azeotrope of water, ethanol and benzene is a convenient method because the water and benzene are all distilled off by 69 deg C or so, leaving the absolute ethanol to distill off at around 78 deg C.  That's enough of a temperature difference to make this type of fractionation pretty straighforward

Production

Extraction

See Fermentation of ethanol

Purification

Distillation

from dilute ethanol

  1. Repeat
    1. Place dilute ethanol in alembic
    2. Place alembic in a double boiler
    3. Heat the boiler such that the water just barely steams
    4. Wait until the solution begins to cross to the receiver
    5. Check again to make sure the boiler is steaming but not boling
    6. Wait until either:
      the solution stops crossing to the receiver
      95% of the solution has been transferred
    7. Your less dilute dilute ethanol is in the receiver.
    8. Re-estimate the percent complete
  2. until either
    the percent complete is between 75% and 99% (R=2)
    the "flare" from tossing a spoonful onto the flame looks "good enough"
    you are tired of doing this

Chemical drying

  1. Get mass of dilute ethanol (M)
  2. Estimate concentration in percent-mass (D)
  3. Calculate mass of calcium oxide required to absorb the water = 3.2 * M * (1-D)
  4. Slowly add the calcium oxide to the ethanol
  5. Mix thoroughly
  6. Filter

Testing

Calculation of percent ethanol
1 - (density of solution)
=========================
0.211
  • Take a spoonful of material and put it on a cool non-flammable surface. Light it with a flame. If it burns away completely, it's nearly 100% ethanol. If it leaves a puddle of water, the amount of water left will give an indication of how much ethanol there is.

See Also

References

  1. "Home Manufacture of Alcoholic Beverages"
    National Conference of State Legislatures
    link last accessed 11 July 2015.