Methanol

From NOWA-CL
Jump to navigation Jump to search
 
Methanol
Chemical formula CH3OH
OTP appearance clear liquid 
Molar Mass(g/mol) 32.04 
Melting Point(°C) -97.6 
Boiling Point(°C) 64.7 
Density(g/cc) 0.7918 
Fuel Value(MJ/kg) 22.7 
Solubility in water(g/L) miscible
NFPA 704
NFPA704.png
3
1
0
 

Methanol, sometimes written MeOH, is a toxic alcohol. Not to be confused with ethanol, which is consumed by humans for recreational purposes.

Uses

Primary

  • Primary feedstock for much organic chemistry
  • Feedstock for formaldehyde
  • Solvent

Secondary

  • Fuel

Natural occurrence

  • Methanol does occur naturally as a secondary metabolite of some monads when they consume pectin, among other things.[1][2]
  • Methanol is also produced by the action of endogenous pectinase and pectinesterase on pectin.

Hazards

  • Ingestion of one mouthful can cause pseudoglaucomatous optic neuropathy (partial or complete blindness) and other neurological problems

Production

Extraction

cf. wood distillation, alkali wood extraction

Biosynthesis

Pectin methyl esterase (PME) from orange (Citrus sinensis L.) fruit peels has a 36-kDa protein with an isoelectric point >9, a pH optimum at 7 and temperature optimum at 50 °C.[3]

Synthesis

from chloromethane

Heat chloromethane and sodium hydroxide, giving methanol

CH3Cl + NaOH
{H2O
heat}
CH3OH + NaCl

from methyl esters

  1. Reflux methyl salicylate or pectin with sodium hydroxide, producing methanol and sodium salicylate or sodium galactate
    NaOH(aq) + C8H8O3
    {
    reflux}
    CH3OH + NaC7H5O3
  2. Distill off Methanol ( water azeotrope 65-95°C )
from producer gas
  • From producer gas[4]
    CO + 2 H2 CH3OHΔH=-21.66
    CO2 + 3 H2 CH3OH + H2OΔH=-11.83
  • High Pressure: 35MPa, 450°C; ZnO.CrO3 catalyst
  • Low pressure: 5-10MPa; 200-280°C; Cu.Zn.Al2O3 (65/25/10) catalyst

Testing

Purification

  • Separation from ethanol
    • Complexes with calcium chloride
      CaCl2•4CH3OH and CaCl2·3 CH3OH at different temperatures.

Storage

Disposal

See Also

References

  1. Siragusa, R J; Cerda, J J; Baig, M M; Burgin, C W; Robbins, F L (1988) "Methanol production from the degradation of pectin by human colonic bacteria".
    The American Journal of Clinical Nutrition 47(5); pp848–851. 
  2. Taher, Edris; Chandran, Kartik (2013) "High-Rate, High-Yield Production of Methanol by Ammonia-Oxidizing Bacteria".; pp3167–3173.
    Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, New York 10027, United States
    DOI:10.1021/es3042912
  3. Tove, M. I. E; ChristensenJohn, E.; NielsenJette, D.; et al (1998) "Pectin methyl esterase from orange fruit: characterization and localization by in-situ hybridization and immunohistochemistry"
    Planta 206(4); pp493–503. 
    link courtesy Springer.
  4. LeBlanc, J.R.; Schneider, Robert III; Strait, Richard B. "Production of Methanol"
    link courtesy M.W. Kellogg Company, Houston, TX.