# PCI calorific fuel gas and PCS

## domestic fuels and calorific values: PCI and PCS (Fuels: thermal power). Source of these figures varied: internet document engineering course ...

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gross calorific value: PCS

Definition: the constant volume calorific value of a fuel is the amount of heat generated by the combustion of unit mass of fuel:
- In oxygen saturated water vapor,
- Product and reacting the products formed being at the same temperature,
- In the same enclosure,
- The water formed being liquid.

This trial is the subject of NF-M 07 030, and uses a container called bomb calorimeter.

The definition of calorific value at constant volume does not correspond to industrial combustion taking place at constant pressure, in an open forum, but in fact the difference is small and generally neglected.

The PCS is "useful" when water condenses combustion (eg condensing boiler).

lower heating value: PCI

Most of the time the fumes out of the exchange surfaces to a temperature above the dew point. The water is emitted as steam.

PCI is calculated by deducting by convention, the PCS, the heat of condensation (2511 kJ / kg) of the water formed during the combustion and optionally water in the fuel.

If the fuel does not produce water, while PCS = ICH.

calorific mixtures

The precise analysis of a gas or a liquid is used to calculate the calorific value from the calorific value of its constituents with the aid of the relation:

PCm = sum (xi * PCi)

with:
- PCm: calorific value of the mixture
- PCi: calorific constituents
- Xi: mass fraction of each component

units

The calorific value is expressed as:

- Kcal / kg
- KJ / kg
- KWh / kg (= 861 kcal / kg)
- PET / tonne (= 10000 therms / tonne) (TOE: Tonne of Oil Equivalent)

The other units are the following:

- Milithermie / kg (= kcal / kg) (désué)
- Therm / tonne (= kcal / kg) (désué)
- BTU / pound (= 0,5554 kcal / kg) (Anglo-Saxon)

For gas: not expressed per kg but Nm3.

calorific gas

PCI / PCS kcal / Nm3

Hydrogen: 2570 / 3050
Carbon monoxide: 3025 / 3025 (PCI = PCS as there is no water training)
hydrogen sulfide: 5760 / 6200
Methane: 8575 / 9535
Ethane: 15400 / 16865
Propane: 22380 / 24360
Butane: 29585 / 32075
Ethylene: 14210 / 15155
Propylene: 20960 / 22400
Acetylene: 13505 / 13975

calorific value of liquid fuels. PCI / PCS in kcal / kg

Hexane 10780 / 11630
Octane: 10705 / 11535
Benzene: 9700 / 10105
Styrene: 9780 / 10190
Heavy oil: 9550
Heating oil: 10030 (= 11.7 kWh / kg or 9.9 kWh / L density 0.85)

calorific value of commercial fuels

Gas:

poor natural gas: 9.2 kWh / Nm3
rich natural gas: 10.1 kWh / Nm3
Butane: 12.7 kWh / kg or kWh 30.5 / 3 Nm7.4 or kWh / L (liquid) to 15 ° C
Propane: 12.8 kWh / kg or kWh 23.7 / 3 Nm6.6 or kWh / L (liquid) to 15 ° C

(Boiling point: 0 ° C butane, propane -42 ° C)

Liquid:

heating oil: 9.9 kWh / L
Light Oil: 10.1 kWh / L
10.5 average fuel kWh / L
Heavy oil: 10.6 kWh / L
Oil extra heavy: 10.7 kWh / L

Solid:
Coal: 8.1 kWh / kg
Coke: 7.9 kWh / kg
Anthracite 10 / 20: 8.7 kWh / kg

calorific various in kCal / kg

Wood (30% moisture): 2800
Dry wood: 4350 or 5 kWh / kg (2 kg of dry wood thus produce about the equivalent of 1 L of oil)

Emission CO2

The problem posed by the emission of greenhouse gases by industry requires considering the fuel in terms of issuing CO2 generated by their use.

The table below reports the emission of CO2 different fuels with calorific unit.

Unit: Tons CO2 PET on the PCI

Hydrogen: 0
Natural gas: 2,37
GPL: 2,67
Heavy oil: 3,24
Heating oil: 3,12
Dry wood: 3,78

Conversion factors in PET

Conversion factors in TOE (Tonne of Oil Equivalent) of various energy sources:

Coal-Briquettes: 1T = 0,619 toe
Lignite coal poor: 1T = 0,405 toe
Coke: 1T = 0,667
Petroleum coke: 1T = 0,762 toe
Butane Propane: 1T = 1,095
Heavy fuel oil (FOL): 1T = 0,952
heating oil (FOD): 1T 1200L = = 1 toe
Electricity: 1000kwh = 0,222
Species: 1T 1320L = = 1 toe
Super Fuel: 1T 1275L = = 1 toe
Diesel: 1T 1200L = = 1 toe

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