الفحم وفحم البترول: أساسيات للمشترين والبائعين

Three different products

Thermal coal specification

• Calorific value: the heat released per kilogram, in kilocalories or megajoules per kilogram. The main price driver.
• Total moisture: water carried by the coal, which adds weight and lowers net heat.
• Ash: the incombustible residue, which reduces heat and creates disposal issues.
• Volatile matter: gases released on heating, which affect ignition and burning.
• Sulphur: causes emissions and corrosion, so limits are tight in many countries.
• Size and grindability: lump size for the burner and the Hardgrove grindability index for pulverised-coal plants.
• Ash fusion temperatures: how the ash behaves at furnace temperatures, which affects slagging.

Understand the basis

Figures can be reported on different bases, and the difference matters. As-received, also called as-delivered, includes the moisture present when sampled. Air-dried removes surface moisture to a standard. Dry basis removes all moisture. Calorific value can be gross, including the heat of water vapour, or net, which subtracts it. Prices often say GAR or NAR, meaning gross or net as received. A quoted figure on one basis cannot be compared with another without conversion.

Coking coal specification

Buyers look at ash, volatile matter, sulphur and phosphorus, but also at how the coal behaves when heated. Coke strength after reaction, often shortened to CSR, shows how strong the resulting coke is. Other tests measure swelling and fluidity as the coal softens. Blending is common, and a buyer selects coals for the blend. Contracts therefore name grades and reference tests rather than a single heat value.

Petcoke specification

Key lines are sulphur, which can be high, calorific value, volatile matter, ash, moisture, grindability and trace metals such as vanadium and nickel. Sulphur matters for environmental limits and for end use, so many importing countries restrict it. Fuel-grade and anode-grade products are different markets with different checks.

Trade terms and shipping

Coal and petcoke ship in bulk on vessels of various sizes. Cargo sizes are large, so quantity tolerance, the laycan and demurrage are central. Contracts commonly use FOB or CFR, with load and discharge rates stated in tons per day. Cargo is weighed by draft survey, sampled automatically or manually, and analysed at an independent laboratory. Self-heating and dust are safety points, and the carrier will ask for the cargo declaration.

Price and quality adjustments

Prices are often tied to published indices for a reference quality, with adjustments for each quality line. A common structure is a base value of calorific content, with a deduction per unit below the base and a rejection limit. The exact method is in the contract, and arithmetic errors in adjustment clauses cause many claims, so write the formula with an example.

Environmental and import rules

Many countries limit sulphur, ash or origin, or restrict imports of certain fuels. Check the importing country's rules and the buyer's permits first. Tonport's commodity pages list coal, coking coal and petcoke with indicative customs codes, and the Energy channel is open for questions.

الأسئلة الشائعة

What does GAR and NAR mean?

Gross as received and net as received are calorific values measured on the coal as it arrives, with the gross figure including the heat of water vapour and the net figure excluding it.

Why is sulphur important?

Burning sulphur produces emissions that many countries limit, and it can corrode equipment. Buyers set a maximum and often penalise above it.

Is petcoke the same as coal?

No. It is a solid residue from oil refining. It has a high carbon content and heat value, but its sulphur and metal content differ from coal.

How is the cargo weight checked?

Usually by a draft survey at loading and sometimes at discharge, performed by an independent surveyor, with the method written into the contract.