In the production process of coke, semi-coke, shale oil, calcium carbide and ferroalloy refining enteprises, a large number of low-calorific value industrial exhaust will be produced. Most of them are dry distillation gas. The components of these combustible gases are mainly hydrogen and carbon monoxide, featured by complicated components, contain impurities, unstable components, large toxicity, inflammable and explosive, and most of the exhaust are burned and discharged except for a few for refinery's own use.
Our genset can adapt to a variety fuel of high, medium and low calorific value. Industrial tail gas that can be used for power generation includes coke oven gas, semi-coke gas, converter gas, blast furnace gas, oil shale tail gas, calcium carbide tail gas, ferroalloy tail gas, and the likes of these.
1. Coke Oven Gas (COG) refers to a kind of combustible that is associated with coke and tar when several kinds of bituminous mixture of coking coal, was carbonized in high temperature in the Coke oven, is a by-product of coking industry. Due to much combustible ingredient, it belong to high heat value gas. Its calorific value is 17-19 MJ/Nm³ or 4,063-4,541 kcal/Nm³, and its low calorific value is 18,250 kJ/Nm³.
Coke Oven Gas is Mixture, its yield and composition is different according to the quality of coking coal and coking process condition, generally a ton of dry coal can produce 300 ~ 350 Nm³ of coke oven (standard). The main ingredient include hydrogen (55% ~ 60%) and methane (23% ~ 27%), and also a small amount of carbon monoxide (5% ~ 8%), above C2 unsaturated hydrocarbon (2% ~ 4%), carbon dioxide (1.5% ~ 3%), Oxygen (0.3% ~ 0.8%), nitrogen (3% ~ 7%), and the hydrogen, methane, carbon monoxide, above C2 unsaturated hydrocarbon are combustible components, carbon dioxide, nitrogen, and oxygen belong to non-flammable components.
2. Semi Coke Gas refers to the combustible tail gas associated with the semi-coke produced by dry distillation of coal at 600 ℃ in a coke oven, and secondary combustion and drying of recycled gas. Six to seven hundred Nm³ semi coke gas per ton of semi coke around is produced in a dry distillation kiln. The calorific value of semi coke gas is 6,732-8,439 kJ/Nm³ or 1,609-2,017 kcal/Nm³, which is low calorific value gas. It can be used as fuel for power generation.
The main components of semi coke gas are CH4 (8.8% - 17.6%), H2 (12% - 28%), CO (6% - 22%), unsaturated hydrocarbons (0.8% - 1.2%), N2 (44% - 52%), O2 (0.2% - 5%), CO2 (2% - 12%) and H2S (0.4% - 0.8%).
3. Converter gas refers to the combustible gas produced by the action of carbon and oxygen in molten iron during the oxygen-blown converter steelmaking process. The content of carbon monoxide is high, with a volume of 60% to 80%, and its low calorific value is about 6,200 kJ/Nm³ under standard conditions. Converter gas is a very ideal fuel and chemical raw material because it contains little hydrogen and no sulfur. Converter gas of about 60 m³ can be recovered from 1t steel to be used in HRSG. The steam generated can basically meet the heat consumption of oxygen required for 1t steel smelting and the energy required for converter auxiliary equipment.
Gas requirement of Industrial Tail Gas：● Gas temperature ≤ 40℃, ● Gas pressure 2.5～10 kPa, ● Pressure change rate ≤ 1 kPa/min, ● Gas calorific value ≥ 4.0 MJ/Nm³, ● Moisture content ≤ 40 g/Nm³，no free water ● Impurity size ≤ 5 μm, ● Impurity content ≤ 30 mg/Nm³, ● Tar content ≤ 50 mg/Nm³, ● H2S ≤ 50 mg/Nm³, ● Total sulfur content ≤ 100 mg/Nm³, ● NH3 ≤20 mg/Nm³, ● C6H6 ≤ 50 mg/Nm³, ● C10H8 ≤ 50 mg/Nm³, ● H2 ≤ 60%, ● O2 ≤ 1%.