CWS produced from coal of different types has different characteristics: ash, calorific value, viscosity, ignition temperature. Also depending on coal types different size of coal particles is required.

CWS characteristics from different coals are provided in Table 1. Depending on the source of coal (from mine to mine) these characteristics are changing.

Table 1. CWS characteristics.

Coal type Initial Coal CWS
Wrt ,% Аd,% Qri,MJ/kg Wrt ,% Аd,% Qri,MJ/kg
Flame Coal 11 12 24,0 35 12 16,9
Gas Flame Coal 8 16 25,3 33 16 17,8
Fat Coal 6 15 27,4 30 15 19,8
Forge Coal 8 17 26,0 35 17 17,6
Non baking Coal 7 20 25,1 30 20 18,3
Anthracite 10 13 26,0 35 13 18,1

Table 2. CWS characteristics, CWS from brown coal

Coal type Initial Coal CWS
Wrt ,% Аd,% Qri,MJ/kg Wrt ,% Аd,% Qri,MJ/kg
Б3 25 18 16,9 48 19 11,0
Б2 33 7,0 16 50 7,0 11,3
Б1 53 17 8,56 60 17 6,9

 

Results given in Tables 1&2 are based on series of experiments which were conducted during the realization of Belovo-Novosibirsk pipeline project in 1989-1993 and confirmed later during further researches, including results obtained by Amalthea in Murmanskaya region.

Reactions on the surface of coal particles together with activation by water steam (produced after water evaporation) enforcing intensification of combustion and reduce ignition temperature of CWS comparing to initial coal.

For anthracites igniton temperature reduced from 1000°C to 500°C, for flame ignition temperature reduced from 600°C to 400°C (see Figure below).

Dependence of ignition temperature (°C) from % of volatiles in initial coal (γ,%).

Dependence of ignition temperature (°C) from % of volatiles in initial coal (γ,%).