Gas composition and calorific value analysis of producer gas from gasifiers 

All articles for this topic or copying prohibited uploaded to other sites

Keywords: furnace, heating, gas composition, coal gas, coal gasifier, coal gasification, coal gas producer

The gas component is based on the chemical analysis or analysis of the results obtained by chromatographic, the combustible gas component based on the percent volume of combustible components and the heat value of a single, gas heat value is calculated. Producer gas composition analysis and calculation of calorific value gasifier runs on furnace conditions of judgment plays an important role.
General business, usually uses the Austrian gas analyzer for furnace gas composition analysis. This gas analyzer, the measured value is more accurate, to meet the requirements of industrial production and control, simple structure, easy to operate. The measurement principle is: the use of gas in the absorption characteristics of different chemical components, in turn corresponding to the liquid chemicals in the different absorption bottle repeatedly contacts to achieve the allowable error of the chemical equilibrium, and for the content of each component calculation.
1, the configuration of absorbent
All absorbent medicines, be sure to use the term, otherwise it will affect the detection accuracy.
(1) CO2 absorbent KOH:
Absorption of 33% KOH solution bottle weight percentage, be sure to put the bottle in the absorption liquid paraffin to prevent absorption of atmospheric CO2 and water vapor dissolved and thinning.
(2) CmHn absorbent silver nickel salt solution is acidic:
Silver sulphate and concentrated sulfuric acid solution of nickel sulfate, wherein the weight percent of each component is:
Ag2SO4-0.65% NiSO4-0.065% H2SO4-99.285%
(3) oxygen absorber is focus of gallic acid solution:
Pyrogallic sub-pH solution concentration of each component: Focus of gallic acid 10%, KOH 24%, the rest is water; absorption solution bottle sealing surface liquid paraffin mask, to prevent their oxidation failure.
(4) CO absorber is a copper ammonia complex solution:
Hydrochloric acid was added at a 1:1 cuprous chloride to saturation, and allowed to stand 24 hours; Ø
Alkaline copper chloride solution, the weight percentage of the components: 12% cuprous chloride, ammonium chloride, -10%, -36% concentrated aqueous ammonia, 42% of water, stirring until completely dissolved and cuprous chloride was blue color transparent. After adding absorption bottle with liquid paraffin isolated from the air. Ø
(5) sulfuric acid solution (10%) of preparation: 10% sulfuric acid was added 2-3 drops of methyl red solution instructions.
2, the absorption
Gas samples taken at the sampling bottle 100ml, one by one in order absorb CO2, CmHn, O2, CO, then explode with determination of oxygen content of H2 and CH4.
(1) CO2 absorption
100ml gas sample volume was reduced after absorption into the V1. Reaction is:
CO2 +2 KOH = K2CO3 + H2O
CO2 + KOH = KHCO3
(2) the absorption of unsaturated hydrocarbons CmHn
Absorbed by the sample gas volume V1 reduced to V2, absorption reaction:
C2H4 + H2S2O7 = C2H5S2O7 • H (vinyl sulfonate)
C2H2 + H2SO4 = C2H4SO4 (vinyl sulfate)
(3) the absorption of oxygen
Oxygen absorption reaction is as follows, after absorption gas sample volume reduced to V3:
C6H3 (OH) 3 +3 KOH = C6H3 (OK) 3 +3 H2O
2 C6H3 (OK) 3 +1 / 2O2 = 2 C6H2 (OK) 3 + H2O
(4) CO absorption complexation
Complexation of CO absorption feature, remaining after the reaction gas samples under V4:
2CO + Cu2Cl2 = Cu2Cl2 • 2CO
Cu-COONH4
Cu2Cl2 • 2CO +4 NH3 +2 H2O = 2NH4Cl + Cu-COONH4
(5) CH4 and H2 determination
Albright instrument, CH4 and H2 featureless absorbers, so the use of explosive combustion method to make it into CO2 and water, otherwise condensation and absorption, they calculate the amount. Method of operation is to take V5 volume of air in the combustion explosion explosive bottle, after first taking into account the volume of condensate V6, liquid fall into water in order to calculate the concentration of H2, and then calculate the CH4 content:
CH4 +2 O2 = CO2 +2 H2O
2H2 + O2 = 2H2O (condensed water)
Then by KOH absorption volume reduced to V7:
KOH + CO2 = KCO3 + H2O
KOH + CO2 = KHCO3
3, gas composition and calorific value calculation results
According successive amount of volume, were calculated according to the following methods in the gas volume percentage of the components. Remember that the initial volume of gas samples V of 100ml.
(1) CO2 = (v-v1) / v * 100%
(2) CmHn = (v1-v2) / v * 100%
(3) O2 = (v2-v3) / v * 100%
(4) CO = (v3-v4) / v * 100%
(5) CH4 = (v6-v7) / v * 100%
(6) H2 = 2/3 [v4 + v5-v6-(v6-v7)] / v * 100%
(7) Nitrogen is an inert gas absorption reaction did not participate, the method to reduce the differential count.
N2 = 100% - (CO2% + CmHn% + O2% + CO2% + CH4% + H2%)
(8) Gas calorific Qnet, v is calculated as the algebraic and values that identify each pure component low calorific value, multiplied by the volume percentage of the additive. High calorific value calculation method of the same, only substituting the corresponding calorific value of each component parameters only:
Qnet, v = CmHn% × 59.846 + H2% × 10.797 + CH4% × 35.832 + CO% × 12.697 (MJ/Nm3