Methanol Production
Chemical Structure of Methanol
Toxicity of Methanol
Methanol is very toxic to humans if ingested and it is also absorbed transdermally(percutaneous absorbtion by the skin) or inhalation as a vapour as it is very volatile. A symptom-free period of 10-48 hours is followed by effects such as nausea, blurred vision,headches, vomiting and abdominal pain, mainly caused by the hyperacidity of blood as a result of formic acid production in the bloodstream.
Ullmann’s Encyclopedia of Industrial Chemistry identifies the Threshold limit value - Time weighted average (TLV-TWA) of exposure to be 200ppm(skin) and lethal dosage for oral ingestion to be between 30-100 ml .Also recommended is protective clothing and air supply via respirators for exposure to methanol for a long period of time when aerial concentration exceeds 0.5 vol%.
Lethal effects include irreversible blindness, coma and death.
Most Important Industrial Usage
The most important industrial usage of methanol is in the chemical syntheses of secondary derivatives such as formaldehyde( as a solvent in paints and varnishes), acetic acid,MTBE(used as an octane enhancer in automotive fuels), methyl methacrylate and other chemicals.Approximately 70% of total methanol production is used to manufacture such industrial chemicals which have applications in chemical products and pharmaceutical industries.
Other minor uses of methanol include uses in refrigerant systems,as an absorption agent in gas scrubbers to remove carbon dioxide and as a fuel source for Otto Engines as fuel additives.
Steam Reforming Process
Methanol is made from synthesis gas. Synthesis gas is produced by the catalytic cracking of natural gas in the absence of oxygen, with the addition of water in the form of steam to produce Carbon Monoxide (CO) and Hydrogen gas (H2). Synthesis gas is then used to produce methanol. The mechanism to produce syngas is as follows:
CH4 + H2O → CO + 3 H2
CO + H2O → CO2 + H2
Catalyst: Ni or Pt Catalyst Temperature used is around 850 Pressure used is approximately 3MPa
Synthesis gas is then converted to methanol in the mechanism (low-pressure synthesis) given by the equations: CO+2H2→ CH3OH CO2+3H2→ CH3OH+H2O
Catalyst: Cu-ZnO-Al2O3 Catalyst Temperature used is around 220 -230 Pressure used is approximately 5MPa
Partial OxidationPartial Oxidation involves the catalytic cracking of methane in the absence of a catalyst to produce synthesis gas which consists of CO and H2 gases which are then reacted to form methanol with a catalyst. The reaction is exothermic, and energy consumption is lower than in the endothermic reaction of steam reforming.The mechanism for partial oxidation is given by the following equations:
CH4 + 0.5O2 → CO+2H2 (Production of Syngas)Temperature used is around 750 -1500 Pressure used is approximately 0.1-9MPa
CO + 2H2 → CH3OH (Syngas conversion to Methanol)
Net Balanced Equation for Steam Reforming:
To produce syngas: CH4+2H2O →CO2+4H2
To produce methanol: CO+CO2+5H2 →2CH3OH+H2O
Overall: CH4 + H2O+ CO+H2 →2CH3OH
Net Balanced Equation for Partial Oxidation:
Overall: CH4 + 0.5 O2 → CO + 2 H2 → CH3OH
Task 4)
Fractional Atom Utilisation=
Steam Reforming:
2 CH4 + 3 H2O -> CO + CO2 + 7 H2
CO + CO2 + 7 H2 -> 2 CH3OH + 2 H2 + H2O
2 CH4 3 H2O CO CO2 7H2 2 CH3OHmol 2 3 1 1 7 2
kg/mol 16.04 18.02 28.07 44.07 2.016 32.05kg 32.08 54.06 28.07 44.07 14.11 64.10
Table 1: Weight calculation for steam reforming
Partial Oxidation:
CH4 + ½ O2 -> CO + 2 H2 -> CH3OH
CH4 ½ O2 CO 2 H2 CH3OHmol 1 ½ 1 2 1
kg/mol 16.04 31.998 28.07 2.016 32.05kg 16.04 15.999 28.07 4.032 32.05
Table 2: Weight calculation for partial oxidation
Price, Profit or Loss
Steam Reformation
2 CH4 + 3 H2O -> 2 CH3OH + 2 H2 + H2O
Hydrogen: $1.62/kg x1000kg/tonne = $1620/tonne
Prices TonneCH4 USD 90.18H2O USD 1.046
CH3OH USD 440H2 USD 1620
Table 3: Price of materials per tonne
2 CH4 3 H2O 2 CH3OH 2H2 H2Omol 2 3 2 2 1
kg/mol 16.04 18.02 32.05 2.016 18.02kg 32.08 54.06 64.10 4.032 18.02
ratio 0.5004 0.843 1 0.0629 0.281Cost(USD$
)90.18 1.046 440 1620 1.046
Production Price
45.13 0.882 440 101.90 0.294
Table 4: Production price for products and reactants
Gross Profit = (Total Production) – (Total Reactant) = $542.194 - $46.012 = $496.18/tonne
Partial Oxidation
CH4 + ½ O2 -> CH3OH
If Air is made up of 79% Nitrogen gas, and 21% oxygen gas by estimation, Oxygen Gas should be free.
Prices TonneCH4 USD 90.18H2O USD 1.046
CH3OH USD 440Table 5: Price of materials per tonne
CH4 ½ O2 CH3OHmol 1 0.5 1
kg/mol 16.04 31.998 32.05kg 16.04 15.999 32.05
ratio 0.5004 0.4992 1
Cost(USD$) 90.18 0 440Production Price 45.13 0 440
Table 6: Production price for products and reactants
Gross Profit = (Total Production) – (Total Reactant) = $440 - $45.13 = $394.87/tonne
Safety of handling methanol
Both production uses methane to produce the final product which is methanol. As above
explained the toxicity, methanol is a highly toxic substance if not handled with extreme care.
Methanol can be absorbed by 3 ways, by exposing skin, by inhaling or by swallowing. As for workers
who are working on site in production of methanol, if methanol is inhaled continuously, the person
will experience dizziness, weakened body, migraine, nauseating, vomiting, blurred vision, or may
cause permanent blindness, or death. Thus warning and hazard signs must be posted and to be
informed to workers to prevent the consequences. (methanol.org, 2011)
Environmental Consequences
Methanol doesn’t affect the environment much, because, methanol is soluble in water and
biodegradable, and in addition, it is naturally formed. Methanol as such, are used in the industry
such as wastewater management, as methanol not only cleans up water, but also de-nitrify the
waste water.
Furthermore, as fuel production is starting to decline, methanol in the other hand, is a
cleaner yet, an alternative source of fuel for transportation. It doesn’t affect environment much
because methanol burns much cleaner than gasoline or other available fuel sources.
Greenhouse gasses are the main issue that has been rising for the past decade. Hence, from
the introduction of methanol production, green house gasses has been significantly reduced by 40%.
If methanol were to be spilt to waters or rivers, it will biodegrade quickly, thus not affecting both the
people and the environment. (methanol.org, 2011)
Summary
Factors Steam Reformation Partial Oxidation
Profit $496.18/tonne $394.87/tonne
Safety
Both having same product which is: methanol
Causes:
Dizziness
weakened body
migraine
nauseating
vomiting
blurred vision
permanent blindness
death
Flamable
Prevent consequences by putting up warning and hazard signs to
inform workers.
Environment
Both routes produces methanol
Biodegradable
Cleaner fuel
Reduces greenhouse gasses from production
Table 7: Summary of gross profit, safety and environment consequences of both route
From an overall review and analysis of the methanol production from both steam
reformation and partial oxidation, we can conclude that steam reformation will be chosen, as steam
reformation has the highest gross profit from production, as it is generally environmental friendly
yet giving a good use to the world.
Reference
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http://www.methanol.org/Methanol-Basics/Methanol-Applications.aspx(Accessed 15th March 2012)
methanol.org, July 2011, Methanol facts, Methanol Health Effects
http://www.methanol.org/Health-And-Safety/Safety-Resources/Health---Safety/Methanol-Health-Effects.aspx(Accessed 15th March 2012)
methanol.org, 2011, Methanol Institute, Environment
http://www.methanol.org/Environment.aspx(Accessed 22nd March 2012)
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http://www.methanol.org/Environment/Environmental-Impact.aspx(Accessed 22nd March 2012)
Bullis. K, August 2009, technological review, Energy, Better Gas-to-Methanol Catalyst, An improved
catalyst could reduce the cost of making methanol from methane
http://www.technologyreview.com/energy/23313/(Accessed 16th March 2012)
Periana. R, 2010, Research Focus, Design and Study of Coordination Catalysts for Small Molecule Conversion
http://www.scripps.edu/research/faculty/periana(Accessed 16th March 2012)
N.A, 2001, PolymerProcessing.com, Polymer, POM
http://www.polymerprocessing.com/polymers/POM.html(Accessed 16th March 2012)
Quanli. Z, Xutao. Z, Youquan. Deng, November 2004, Journal of Natural Gas Chemistry, Advances in the Partial Oxidation of Methane to Synthesis Gas, Brief thermodynamic analysis of methane partial oxidation, pg. 192
http://www.bjb.dicp.ac.cn/jngc/2004/2004-04-191.pdf(Accessed 16th March 2012)
N.A. 2011, Material Safety Data Sheet, Hazards Identification, Ingestion
http://www.midi-inc.com/pdf/MSDS_Methanol.pdf(Accessed 22nd March 2012)
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http://www.coogeeenergy.com.au/images/methanol/processdiag.jpg(Accessed 22nd March 2012)
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Steam Reforming
Steam Reforming is where methane or natural gas is used to react with steam, to convert into synthesis gas which consists of CO, CO2, and H2.
2 CH4 + 3 H2O -> CO + CO2 + 7 H2
Then the synthesis gas is then converted to methanol by using a catalyst. The catalyst used is made with carbon, nitrogen and platinum, developed by Roy Periana, directly converts the methane to methanol at low temperatures. Furthermore, the conversion produces less carbon dioxide gas or by-products. In addition, less energy is used to convert methane to methanol by using the catalyst.
CO + CO2 + 7 H2 -> 2 CH3OH + 2 H2 + H2O
Partial Oxidation
Partial oxidation is the chemical process where methane undergoes oxidation to produce carbon monoxide and hydrogen gas, which then the carbon monoxide and hydrogen gas is converted to methanol. A catalyst POM (polyoxymethylene) is used to speeden up the chemical reaction of methane and oxygen.
CH4 + ½ O2 -> CO + 2 H2 -> CH3OH
Balanced Equation for both processes.
Steam Reforming:
2 CH4 + 3 H2O -> CO + CO2 + 7 H2
CO + CO2 + 7 H2 -> 2 CH3OH + 2 H2 + H2O
Partial Oxidation:
CH4 + ½ O2 -> CO + 2 H2 -> CH3OH
Atom Economy Yield
Steam Reforming:
2 CH4 + 3 H2O -> CO + CO2 + 7 H2
CO + CO2 + 7 H2 -> 2 CH3OH + 2 H2 + H2O
2 CH4 3 H2O CO CO2 7H2 2 CH3OHmol 2 3 1 1 7 2
kg/mol 16.04 18.02 28.07 44.07 2.016 32.05kg 32.08 54.06 28.07 44.07 14.11 64.10
Partial Oxidation:
CH4 + ½ O2 -> CO + 2 H2 -> CH3OH
CH4 ½ O2 CO 2 H2 CH3OHmol 1 ½ 1 2 1
kg/mol 16.04 31.998 28.07 2.016 32.05kg 16.04 15.999 28.07 4.032 32.05
Price, Profit or Loss
2 CH4 + 3 H2O -> 2 CH3OH + 2 H2 + H2O
2 CH4 3 H2O 2 CH3OH 2H2 H2Omol 2 3 2 2 1
kg/mol 16.04 18.02 32.05 2.016 18.02kg 32.08 54.06 64.10 4.032 18.02
ratio 0.5004 0.843 1 0.0629 0.281cost
Will find out the cost tomorrow. But you can find how to solve this question in our 1st lecture given by faye (solution “example” in blackboard)
http://www.world-wire.com/news/0708080001.html
brunei-methanol.com/products.htm www.ucc.ie/academic/chem/dolchem/html/comp/methanol.html
www.ics.trieste.it/media/139813/df6496.pdf
http://academic.scranton.edu/faculty/cannm1/organicmodule.html