Coal

Coke

Tar

Coal Gas

Synergistic Industries (p.391)

• Coal and coal products were essential for– Fuel for heating and cooking– Fuel for industrial processes (coke for lime,

bricks)– Iron production– Ship building– Steam engine power – Production of textiles, explosives, drugs,

chemicals, glass, ceramics, brewing, etc

Some Products of Coal Distillation (p 389)

• Coke (:charcoal from wood)

• Tar (earlier from wood *) @ 1750

• Pitch (*) same

• Coal gas for lighting and cooking @1800

• Fuel Coal Coke (s) + Tar (viscous liquid) + coal gas (g)

• Other products such as rosin and oils for varnish (p 413, *)

More Products of Coal Distillation

• Cinders or soot for NH4Cl (p 420-21)

– for tinning cast iron, brass and copper– also used by pharmacists– boiling salt – drying malt

• Patents for coal products describe variety (Clow p 396-7 ) and processes

Coal

• Fossil fuel formed millions of years ago by the anaerobic decay of living plants.

• Complex mixture of many compounds.

• The chemical formula of coal has been approximated as C135H96O9NS

• This translates to a material with 85% C (which is the energy producing component)

Coal Formation

• Decaying plants + pressure of rocks varying degrees of removal of impurities, nitrogen, water + Si, Na, Ca, Al, Ni, Cu, Zn, As, Pb, Hg leaving carbon content.

• Some examples of coal– Peat and lignite – high moisture content; like

plant material, soft– Bituminous or soft coal – most abundant– Anthracite – very hard, very high C content

Coal vs Wood

• Recall, IR is associated with the transition from wood and water-based, home-centered, agrarian economy to coal and iron-based, manufacturing -centered, industrial economy.

• Decay products = a mixture of many hydrocarbons (H and C cmps) which have considerable energy stored in the chemical bonds.

Energy Content

• Fuels are rated by energy content; i.e. kJ/g of energy produced.Combustible Material (%C)

kJ/g US source

Wood 10.4.14.1 Various

Peat 13.0 Mississippi

Lignite (71%) 16.2 North Dakota

Subbituminous (77%)

24.0 Washington

Bituminous (80%) 30.7 Maryland

Anthracite (92%)Coke

30.5~30

Pennsylvania

Coke

• Coal + oven temps of 2000 C without oxygen high carbon content coke, with water, coal gas, ammonia, phenol, naphthalene, sulfur and other volatile impurities driven off. (Today, the impurities are collected and processed).

• Used as fuel and reducing material for smelting.

Coal Tar

• Black, viscous liquid that is a by-product of coking (19th c.) and coal gas purification (20th c.) processes.

• Early uses: Essential in shipbuilding as sealant, preservative for ship timber, varnish. Also for roofs and roads.

18th c. Coal Tar Industry

• By variety, methods of production and products, the coal tar industry is sometimes called the precursor to the modern chemical industry and more specifically, the modern petrochemical industry.

Sources of Tar and Pitch

• 1667 – first mention of non-timber sources of tar

• 1700 – Royal Society treatise on using coal and shale as source of tar and pitch

• P 392 on process

• 1719-1779 – Britain offered bounties for timber-based tar from the New World esp for ship building.

British Tar Company

• 1781: patent issued to Earl of Dundonald for the development and production of coal distillation by-products. (Clow p 396)

• Clow p 397-98 describes details of patent

• Clow p 410 lists some of coal-based products.

• Dundonald enjoyed financial success in extracting tar from coal.

British Tar Company (2)

• Although an Earl, he was always on the financial edge, but was curious, educated and ambitious.

• What was his mother’s role in Dundonald’s business development and successes?

• 1782: Dundonald formed the British Tar Company (with 3 other co-investors).

British Tar Company (3)

• Prior to establishing the British Tar Company, Dundonald was in a vulnerable financial situation and not without competitors and men (esp Cuthbert) he owed money.

• In 1785, he emerged victorious with a patent extension until 1806 and a rapidly growing tar and pitch industry across Britain.

British Tar Company (4)

• But this required – Validation of Dundonald’s chemical processes

by Dr. Joseph Black, professor of chemistry at Edinburgh University.

– Validation of Dundonald’s chemical products by related industries.

– Act of Parliament regarding patent.– Dundonald also collaborated with coke

producers to secure coal and coke for stock materials.

British Tar Company (5)

• But by early 1800’s, Dundonald’s fortunes changed. For example, contracts for ship preservatives disappeared as ship building materials improved (e.g. copper sheathing).

British Tar Company (6)

• But the seeds of his success and his failure were deeply rooted in his personal and professional attributes. Discuss.– What were Dundonald’s Achilles’ heels

leading to this downfall?– What other industrial processes did he

pursue?

Tar Tunnel of Coalbrookdale

• A 1000 foot horizontal tunnel leading from the Coalport Canal (then to the River Severn) to the coal deposits of Coalbrookdale.

• It was dug as a shortcut to transportation.• A thick syrup of bitumen (polycyclic

aromatic hydrocarbons) oozing from the tunnel walls and forming pools was discovered in the tunnel 1787.

Tar Tunnel at Coalbrookdale

• Products included waterproofing pitch and caulk, lamp black, rheumatism and scurvy medicine

• Oozing bitumen from the tunnel walls is still observed today.

• http://www.virtual-shropshire.co.uk/vs-gallery2/v/visitor-attractions/tar-tunnel/

Separating the Components of Coal Tar

• Coal tar has numerous organic (C and H based) compounds and some inorganic compounds.

• Fractional distillation is a method of separating them.

• This method depends on the different volatilities or boiling points of each component.

Fractional Distillation

• Apparatus: distillation flask, source of heat, cooling column and collection flask.

• Distillation is basically boiling a liquid at a controlled T and P, and then cooling the “fraction” that boils in order to collect it separately from other compounds in the flask.

Fractional Distillation followed by Purification

• As each fraction comes off, it is collected in separate containers and then furthered purified.

• First, the T is set at the lowest level resulting in the component with the lowest BP boiling off and then collected.

• The T is then raised for the next distillation to capture the second lowest BP component.

http://www.tiscali.co.uk/reference/encyclopaedia/

hutchinson/m0020819.html

Example

• Major products of the petrochemical industry are benzene (+80.1 C = BP), ethylene (-103.7 C) and propylene (-47.6 C).

• Which is a gas at room T?

• Which component distills first?

Coal Gas

• Coal + O2 + steam CO + H2

• Coal CH4

• These and other gases comprise coal gas or syn gas

• For energy production. Products?• Late 18th c., for artificial lighting. Note

Soho House was lit up in 1802 with artificial lighting for celebrate the Peace of Amiens.

Petrochemical Industry

• The petrochemical industry of the 20th century (post World War II) is the modern day coal tar industry.

• Both industries were/are based on the decayed products of living matter that occurred millions of years ago.

• http://www.petrochemistry.net/what-is-petrochemistry.html

Petrochemicals

• These are chemical derived from oil and natural gas. In both cases, chemicals are distilled, separated and purified from the raw material.

• These chemical products – Are used directly– Are used to produce other petrochemicals

Petroleum or oil Products

• Plastic or Petrochemicals

• Asphalt

• Diesel fuels

• Gasoline

• Paraffin

• Tar

• Kerosenes

Three Top Petrochemicals

• Ethylene 110E+6 tons annually

• Propylene 65E+6 tons

• Aromatics (e.g. benzene); PAHs 70E+6 tons

Natural Gas (often found with petroleum)

• Methane; also ethane, butane, propane

• Inorganic gases: N2, H2S, CO2, He

http://en.wikipedia.org/wiki/Image:NatGasProcessing.png

References

• Eubanks, L. P. et. al, Chemistry in Context (5th Edition); McGraw Hill: Boston, 2006.

• http://www.coaleducation.org/lessons/sec/properties/coalderiv/coalder.pdf

• http://en.wikipedia.org/wiki/Image:NatGasProcessing.png

References

• http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0020819.html

• http://www.petrochemistry.net/what-is-petrochemistry.html