Methane and C1 Chemicals

• Chemicals are divided into organic and inorganic categories.
• Organic compounds contain carbon and have covalent bonds.
• Inorganic compounds usually lack carbon and have ionic or hydrogen bonds.
• Organic compounds with one carbon atom are basic chemicals, abundant as C-1 feedstock.
• Fossil fuels like petroleum and coal are sources of these basic chemicals.
• C1 series chemicals have few functional groups and are more stable than C2-C4 organics.
• Their manufacturing involves liquid or vapor phase reactors.
• They are used as domestic fuels and in the production of motor solvents, C2-C5 compounds, polymers, pharmaceuticals, petroleum, and in agriculture.

Methane

• Methane is a simple hydrocarbon with one carbon and four hydrogen atoms.
• Methane has a greenhouse gas potential 27.9 times higher than carbon dioxide.

Methane properties

• IUPAC name: Methane
• Other names: Methyl hydride, Marsh gas, Biogas, Carbane, Tetrahydrocarbon
• Formula: CH₄
• Molecular weight: 16.04 g/mol.
• It is a colorless, odorless gas.
• Solubility: Insoluble in water, slightly soluble in acetone; soluble in ethanol, ethyl ether, benzene, toluene, methanol
• Melting point: -182°C
• Boiling point: -161°C
• Flash Point: -188°C
• Density: 0.554

Manufacturing Process

• Methane is produced via the Sabatier reaction, reacting hydrogen and carbon dioxide at high temperatures using a nickel or ruthenium on alumina catalyst.
• Bugante et al. prepared methane from a gas mixture of carbon monoxide and carbon dioxide in 1989.
• Methane can also be produced from the degradation of septic systems, natural materials, sewers, landfills, and marshes.
• Raw materials: Carbon dioxide, hydrogen, and a catalyst are needed for the production of methane.
• Chemical reaction: CO₂ + 4H₂ → CH₄ + 2H₂O (ΔH = -165.0 kJ/mole)
• Carbon monoxide is a byproduct and can be reacted with water vapor to produce carbon dioxide and hydrogen (reverse water-gas shift reaction).
• To produce 1000 kg of methane, 3000 kg of carbon dioxide, 750 kg of hydrogen, and 500 kg of catalyst are needed

Process description

• Air is separated into hydrogen and carbon dioxide.
• Carbon dioxide is compressed.
• Recycled hydrogen gas is mixed with carbon dioxide and heated to 400°C.
• The mixture is sent to a tubular Sabatier reactor with a catalyst at 400-420°C, maintained by hot oil.
• Vapors of water and methane are condensed, water is separated, and methane is purified and stored.
• Water undergoes electrolysis to produce hydrogen (recycled) and oxygen.
• Carbon monoxide from the separator and Sabatier reactor is processed in a reverse water gas shift reactor with added water.

Engineering problems

• The reaction is endothermic and needs large energy input from nuclear reactors or solar arrays.

Uses

• Methane is utilized as fuel in gas turbines or steam generators.
• Methane is used to manufacture chemicals like methanol, hydrochloric acid, chloroform, ammonia, and carbon black.
• Methane is transferred as refrigerated liquid (LNG).
• Methane is utilized as a rocket fuel.

Methanol

• Methanol is naturally produced by anaerobic metabolism in bacteria being present in vapor form in small amounts in the environment.
• It oxidizes in sunlight into carbon dioxide and water.
• Overconsumption of methanol leads to accidental, suicidal, and epidemic poisoning.
• Dehydrogenase (ADH) and aldehyde dehydrogenase is prepared by the metabolization of methanol.

Methanol Properties

• IUPAC name: Methanol
• Other names: Methyl alcohol, Carbinol, Wood alcohol, Methylol, Wood spirit, Colonial spirit _ Molecular formula: CH4O
• Molecular weight: 32.04 g/mol
• Physical description: Colorless liquid with a characteristic pungent odor
• Solubility: Miscible with water, ethanol, ether, benzene, most organic solvents and ketones
• Melting point: -98°C
• Boiling point: 65°C
• Flash point: 9°C
• Density: 0.792 g/cm³ at 20°C

Manufacturing process

• Synthesis gas (CO + H₂O) reacts at high temperature and pressure, converts into methanol, and is purified through columns.
• Raw Material: Synthesis gas (mixture of hydrogen and carbon dioxide with a 2:25 molar ratio) is used.
• Chemical Reaction: CO + 2H₂ → CH3OH
• Quantitative requirement: 900 kg of carbon monoxide and 150 kg of hydrogen gas are needed to produce 1000 kg of methanol.

Process description

• Synthesis gas (2:25 hydrogen to carbon monoxide ratio) is compressed to 200–350 atm.
• The compressed feed goes into a high-pressure jacketed converter (reactor) with copper containing zinc, chromium, manganese, or aluminum oxides as a catalyst.
• Steam passes through the jacket to maintain 300–375°C.
• The exothermic reaction volume decreases and pressure increases, favoring faster reactions.
• The vapor mass is cooled in a heat exchanger and undergoes phase separation; liquid containing methanol and vapor containing high molecular weight components is separated.
• Vapor is recycled, and potassium permanganate enters the reactor to purify the methanol and is collected from the bottom and enters the ether column.
• A distillation column separates water and heavy alcohols from the methanol, yielding 98-99% methanol.

Engineering problems

• Temperature and pressure: An exothermic reaction occurs and a 50% conversion at optimum conditions needs 240 atm and 300°C.
• Reactor design: A thick-walled pressure vessel with copper lining is selected, preventing poisonous iron carbonyl formation and corrosion.
• Heat exchanger: The heat exchanger controls the temperature of the reaction mixture to preheat the compressed gas and cool the heat-treated steel pressure shell.
• Catalyst fouling: Catalyst fouling can be avoided by maintaining a proper carbon monoxide to hydrogen gas ratio of 2:25.
• Inert gas accumulation: Inert gas accumulation avoided with a side-stream purge on the recycle gas.

Uses

• Methanol is utilized as an industrial solvent for inks, resins, adhesives, and dyes.
• Methanol is utilized to manufacture compounds like methyl tertiary butyl ether (MTBE), formaldehyde, acetic acid, and dimethyl ether (DME).
• It is used in the preparation of cholesterol, streptomycin, vitamins, hormones, and other pharmaceuticals.
• It is a component of renewable fuel (biodiesel) and is an antifreeze agent and petrol ingredient.

Formaldehyde

• Formaldehyde is the simplest aldehyde (R-CHO).

Properties

• IUPAC name: Formaldehyde
• Other names: Formalin, Formol, Methanal, Oxomethane, Methylene oxide, Formic aldehyde, Paraform.
• Molecular formula: CH₂O
• Molecular Weight: 30.02 g/mol.
• It is a white solid with a light pungent odor.
• Solubility: soluble in water, ethanol, and chloroform.
• Melting Point: -92°C
• Boiling Point: -20°C
• Flash Point: 83°C
• Density: 0.815 g/cm³ at -20°C

Manufacturing process

• Formaldehyde is industrially produced by catalytic oxidation of methanol, using silver metal or a mixture of iron, molybdenum, or vanadium oxides as the catalyst (Formox process).
• Raw materials: React methanol and oxygen.
• Chemical reaction: Methanol and oxygen react at 250–400°C with an iron oxide catalyst to produce formaldehyde.

Chemical Reactions

• Reaction of methanol and oxygen: 2CH3OH + O2 → 2CH2O + 2H2O
• Side Reaction: Complete combustion of methanol: CH3OH + 3/2O2 → 2H₂O + 2CO2
• Quantitative requirement: 1100 kg of methanol, 550 kg of air (oxygen), and 750 kg of catalyst are needed to produce 1000 kg of formaldehyde

Process description

• Preheated compressed air (oxygen) and methanol (30–50% ratio at 55°C) enter the catalytic vapor phase reactor.
• The feed ratio for CH₂OH: O₂ is about 30-50%.
• The reaction is exothermic and produces a vapor mixture at 450–900°C.
• Cool the gaseous product, and feed the reaction into the absorption tower, where the water has formaldehyde and its recycled.
• Another formaldehyde and methanol rich water stream is feed Alcohol Stripper and un-reacted methanol is collected from the top.
• Purified un-reacted methanol is collected from the top; and the collected un-reacted methanol is purified and recycled and a 37% formaldehyde is collected from the bottom of the stripper.

Engineering problems

• Pyrolysis of methanol: Methanol is pyrolyzed at high temperatures in the presence of Mo, V, and Fe for a 90-95% yield of formaldehyde.
• Choice of Space Velocity: High CO combustion occurs at low velocity and the moderate space velocity is maintained.

Uses

• Formaldehyde is mainly used to manufacture phenol-formaldehyde resin and melamine.
• It is used in building materials, fiber board, cigarette smoke, fuel burning appliances, preservatives, sterilizers and keratin products.

Chloromethanes

• Chloromethanes have four types: Methyl chloride (monochloromethane), Dichloromethane (methylene chloride), Trichloromethane (chloroform), and Tetrachloromethane.
• Chlorine atoms increase in the methane molecule, increasing electron-withdrawing capacity, electrophilicity, and toxicity of the carbon atom.

Properties

• IUPAC name: Chloromethane
• Other names: Methyl chloride, Monochloromethane, Artic, Clorometano
• Molecular Formula: CH3Cl
• Molecular Weight: 50.48 g/mol
• Physical description: Colorless gas with a faint sweet odor
• Solubility: Soluble in water, ethanol, ethyl ether, acetone, benzene, and chloroform
• Melting Point: -98°C
• Boiling Point: -24°C
• Flash Point: -45°C
• Density: 0.911 g/cm³ at 20°C

Manufacturing process

• Chloromethane was first prepared by J. Dumas and E. Peligot, and later by C. Groves.
• Industrial vapor phase chlorination of methane was conducted by Hoechst in 1923 and Chloromethanes are prepared by two routes; thermal chlorination and catalytic oxychlorination of methane.
• Raw Material: Methane, Chlorine gas and Sodium hydroxide are used.
• Chemical reaction: Chloromethanes are prepared using the chlorination of methane in the presence of sunlight at 380–390°C and all hydrogen atoms are replaced by chlorine atoms gradually.

Chemical Reactions

• CH₄ + Cl₂ → CH3Cl + HCl (ΔH = 103.5 kJ/mole)
• CH3Cl + Cl₂→ CH2Cl2 + HCl (ΔH = 102.5 kJ/mole)
• CH2Cl2 + Cl₂ → CHCl + HCl (ΔH = 99.2 kJ/mole)
• CHCl + Cl₂→ CCl + HCl (ΔH = 94.8 kJ/mole)

Quantity requirement

• High methanol/chlorine ratios (1.8/1) favor monochloromethane production; limited methanol favors tetrachloromethane and trichloromethane; the feed ratio matters

Manufacturing process

• Mix pure dry methane and chlorine gas , pre-heat the gas and transferred to the hot oil reactor.
• The reaction mixture is heated at a temperature of 380–390°C with stirring; Chloromethanes are collected from the top of the reactor and quenched in the heat exchanger.
• The cooled gaseous mass is passed through the absorber with water sprayed from the absorber top to removed the HCl and is neutralized using NaOH for further Carbon Dioxide removal.

Uses

• Chloromethanes are utilized as intermediates in various industrial segments such as pharmaceuticals, agrochemicals, automobiles, and electronics.
• Methyl chloride is employed in surfactants, pharmaceuticals and dyes.
• Dichloromethane acts as a solvent in metal degreasing, polycarbonates, and triacetates.
• Chloroform is employed for the assembly of HCFC 22 (R 22), which is utilized as a refrigerant and pioneer for fluoropolymers.
• Tetrachloromethane is used as preparation in pharmaceutical, polymer, agro-based chemical and refrigerant manufacture and as a solvent in specialty chemical industries.

Methylamines

• Methylamines have four types: monomethylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA).
• Initially methylamine was prepared by Charles Wurtz in 1849 via methyl isocyanate hydrolysis and the properties of monomethylamine are as follows:
• IUPAC Name: Methanamine
• Chemical and other names: Aminomethane, Monomethylamine, methylamine hydride
• Molecular Formula: CH5N
• Molecular Weight: 31.06 g/mol
• Physical description: Yellow to colorless gas or a liquid with pungent fishy odor
• Solubility: Soluble in water, ethanol, benzene, and acetone; miscible with ether
• Melting point: -93.6°C
• Boiling point: -6.3°C
• Flash point: -10.0°C
• Density: 0.693 g/cm³ at 20°C

Properties

• Raw Material: Raw Meterials include Ammonia, Methanol and Catalyst

Reactions

• CH3OH + NH3 → CH3NH2 + H2O

• CH3NH2 + CH3OH → (CH3)2NH + H₂O

• (CH3)2NH + CH3OH → (CH3)3N + H₂O

• The raw materials depends on methanolamine and its required on a quantitative measure.

• Reactors are already impregnated with amorphous aluminosilicate catalyst.

• The reaction mixture is heated upto 400–420°C with stirring and high pressures (> 20 atmospheres).

• Methylamines and the un-reacted mass are transferred to the ammoniation column. Un-reacted ammonia is separated out; and the Methylammonium mass is transferred to MMA column to separate the monomethylamine (MMA).

Uses

• Methylamines are used in interim products in explosives, electronics, and catalysts.
• Monomethylamine is used to make herbicides, pesticides, Tovex, and soil disinfectants.
• Dimethylamine is used in the production of solvents, water-treating agents, and rubber-processing compounds.
• Trimethylamine is used in the manufacture of sweeteners, choline salts, and disinfectants.

Formic Acid

• Formic acid (methanioc acid) is the simplest carboxylic acid.
• The properties of Formic acid are as follows:
• IUPAC Name: Formic acid
• Chemical and other names: Methanoic acid, Formylic acid, Aminic acid, Bilorin, Formisoton.
• Molecular formula: CH₂O₂
• Molecular weight: 46.02 g/mol
• Physical Description: Colorless liquid with a pungent, penetrating odor.
• Solubility: Miscible with water, ether, acetone, ethyl acetate, methanol, ethanol; partially soluble in benzene, toluene, xylenes
• Melting Point: 8.3°C
• Boiling Point: 101°C
• Flash Point: -69.2°C
• Density: 1.22 g/cm³ at 20°C

Manufacturing process

• Raw Meterials include Methanol, Air (Oxygen) and Catalyst
• Chemical Reactions: It is prepared by several routes, which are mentioned below.

Chemical Reactions

• A two step vapor phase oxidation reactions of methanol are performed to give formic Acid

• CH3OH + ½O2 → CH₂O

• CH₂O + ½O2 → HCOOH

• Both reactions are exothermic.

• 700 kgs of methanol, 1300 kgs of air (oxygen) and 750 kgs of catalyst are required on a quantity measure to produce 1000 kgs of formic acid

Process description

• Methanol and air (oxygen) are compressed individually and pre-heated in a heat exchanger to convert the vapor form.
• The compressed reaction is done in Tubular Reactor and is cooling water circulates to maintain temp between 300-400 °C.
• 2nd reaction is a catalyst which is already impregnated with vanadium-titanium oxide catalyst; this reaction is also exothermic.
• 3rd stage is a glycol solution.

Uses

• Most of the formic acid produced is used as a preservative and antibacterial agent in livestock feed.
• Formic acid is used as a modern fuel source in proton exchange, leather, textile, and its uses an ingredient that is corrosion inhibitor.

Nitromethane

• Nitromethane is the simplest organic nitro compound.
• Mixing Tank Methane, Heat exchanger, and extraction.

Properties

• IUPAC Name: Nitromethane
• Chemical and other names: Nitrocarbol
• Molecular formula: CH3NO2
• Molecular weight: 61.04 grams/mol
• Physical description: Colorless, oily, liquid with a disagreeable odor
• Solubility: Soluble in water, ethanol, ethyl ether, acetone, carbon tetrachloride, and alkali
• Melting point: −28.7°C
• Boiling point: 101°C
• Flash Point: 36°C
• Density: 1.1371 grams/cm³ at 20°C

Manufacturing process

• Pre heated and mixed the Nitric Acid/Methane gas to be ready for Vapor Conversion reaction and maintaining a temperature of 400°C-600°C.
• Chemical Reactions: It is prepared by the nitration of methane with trace amounts of Formaldehyde byproducts and using Raw Meterials.
• • Methane with Nitric Acid

Chemical Reactions

• Pre heated and mixed the Nitric Acid/Methane gas to be ready for Vapor Conversion reaction and maintaining a temperature of 400°C-600°C.
• For the production of 1000 kgs Nitromethane it requires 300 kgs of Methane and and 1100 Kgs of Methane.

Process description

• Is similar to mixing first the Nitric acid and Methane in the tank with pre-heater and passed to tubular reactor where the temp is between 400°C and 600 °C via hot oil and the mixture is at Vapour phase to a stripping column.
• The manufacturing is a recycling and closed loop system extracting the Nitromethane.

Uses

• Is a Additive for fuel and some plastics and acrylics.

This lesson explores C1 chemicals, focusing on methane. It details the properties, sources, and applications of these basic organic compounds. It also highlights methane's environmental impact as a potent greenhouse gas and common names.