Basic principles
When the sample is introduced into the high temperature pyrolysis furnace, the sulfur in the sample is quantitatively converted to sulfur dioxide (SO2) and the nitrogen compound is quantitatively converted to nitric oxide (NO) through oxidation pyrolysis. The reaction process is shown in Formula (1). The reaction gas is carried by the carrier gas through the membrane drying and dehydration before entering the reaction chamber.
（1）R－S＋R－N＋O２ SO２＋NO＋ SO3+CO２＋H２O +MOX （1）R－S＋R－N＋O２ SO２＋NO＋ SO3+CO２＋H２O +MOX
Nitric oxide (NO) reacts with ozone (O₃) from an ozone generator within the reaction chamber. During this process, some NO is converted into excited-state nitrogen dioxide (NO2*). When NO2* transitions from its excited state to the ground state, it emits photons. These photon signals are captured and amplified by a photomultiplier tube, then processed through amplifiers and computer systems to generate electrical signals proportional to the luminescence intensity. Under specific conditions, the chemiluminescence intensity produced during the reaction correlates directly with NO formation levels, which in turn are proportional to the total nitrogen content in the sample. Therefore, measuring chemiluminescence intensity enables accurate determination of total nitrogen content. The complete reaction process is illustrated in Equation (2):
（2）NO + O3 ————> NO2* + O2————> NO2+hγ
In the reaction chamber, some SO₂ is converted into excited-state sulfur dioxide (SO₂⁺) when exposed to ultraviolet light. When SO₂⁺ transitions back to its ground state, it emits photons. These photoelectron signals are captured by a photomultiplier tube, amplified through an amplifier, and processed by a computer to generate electrical signals proportional to the light intensity. The fluorescence intensity generated during the reaction directly correlates with the amount of sulfur dioxide produced, which in turn corresponds to the total sulfur content in the sample. Therefore, total sulfur content can be determined by measuring the fluorescence intensity. The entire reaction process is illustrated in Equation (3):
（3）SO2 + hγ，————> SO2*————> SO2 + hγ
Before analyzing the sample, a standard sample similar to the sample is used to make a standard calibration curve. Then the sample is analyzed under the same conditions, and the sulfur and nitrogen content of the sample is calculated automatically according to the standard calibration curve.
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Technical parameters
|
order number |
project |
Instrument technical indicators |
|
1 |
Applicable methods |
SH T 0689, ASTM D545, ASTM D4239, etc |
|
2 |
analytic sample |
Used to determine the total sulfur content of crude oil, distillate oil, petroleum gas, coal, plastic, naphtha raw materials and pre-hydrogenation raw materials and other petrochemical products |
|
3 |
Measurable sample status |
Solid, liquid, gas |
|
4 |
sample size |
Solid: 5mg (weigh according to the size of the sample) Liquid: 5-50ul Gas: 5ml (The sample should be able to be completely burned) |
|
5 |
measuring range |
Light oil: 0.2mg/L~10000mg/L~ percentage content Heavy oil: 1~5000ppm (if greater than 5000ppm, the sample should be diluted) Gas: 1 mg/m³~5000 mg/m³ |
|
6 |
Lower detection concentrations |
0.1mg/L |
|
7 |
Control range and precision: |
0℃～1150℃，±2℃ |
|
8 |
repeatability error |
0.1 mg/L ≤ the concentration of the sample (or standard sample) is less than 1.0mg/L, and ± 0.1mg/L When the concentration of 1.0mg/L ≤ sample (or standard sample) is less than or equal to 10mg/L, it is less than or equal to 10% When the concentration of sample (or standard sample) is>10mg/L, it is less than or equal to 5% When the concentration of sample (or standard sample) is>10mg/L, it is less than or equal to 5%
|
|
9 |
Negative pressure |
DC400V~1200V can be set according to the high and low concentration of measurement |
|
10 |
baseline drift |
Not more than 5mv/min |
|
11 |
Air source requirements |
Oxygen purity 99.999%, output pressure ≤0.2MPa Argon purity 99.999%, output pressure ≤0.2MPa |
|
12 |
parsing time |
2min-3min |
|
13 |
Data communication interface |
RS232 |
|
14 |
weight ，kg |
60 |
|
15 |
size ，mm |
Temperature control of fluorescence sulfur analyzer: 520 × 490 × 460 |
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Performance Features
|
order number |
project |
Instrument performance characteristics |
|
1 |
A quartz pyrolysis tube |
Sulfurized quartz pyrolysis tube; Sulfen chloromethane blind sleeve quartz pyrolysis tube to improve the detection accuracy of the instrument. |
|
2 |
Gas pressure stabilization system |
The gas circuit is equipped with a voltage stabilizing system to avoid the interference of gas pressure fluctuation |
|
3 |
temperature-control system |
The automatic control device of the cracking furnace fan and the automatic switch of the cooling fan do not require personnel to wait for the shutdown |
|
4 |
Testing room |
The sulfur reaction chamber device, filter, photomultiplier tube and ultraviolet lamp are used to improve the stability and detection accuracy of the instrument. The total sulfur content was determined by ultraviolet fluorescence method to improve the ability of anti-impurity interference and avoid the complicated operation of electrolytic method on the titration pool and the resulting unstable factors. |
|
5 |
analytic system |
High sensitivity, fast analysis speed, wide linear range and good repeatability |
|
6 |
drying system |
The original American film dryer is used instead of the traditional magnesium perchlorate dehydration, which does not need to be replaced frequently and has stable performance |
|
7 |
Key components |
Using original components, the performance is stable and reliable, and the detection accuracy is high |
|
sampling system |
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|
1 |
Injection system of the injector |
The injection speed is constant and can be adjusted according to the sample |
|
software system |
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|
1 |
data handling |
The combination of single point correction and multi-point correction automatically generates the correction curve. High pressure can be adjusted arbitrarily, and standard sample correction can be carried out by single point correction, which is convenient, fast and accurate. It has the function of automatic calculation of concentration and content, screen display of parameters, measurement peak shape and measurement results, and can be stored or printed |
|
2 |
data display |
Parameter setting, calibration and sample detection are carried out on the same interface |
|
3 |
service platform |
The Windows operating platform has the function of man-machine dialogue, and the analysis process and data processing process are controlled by the computer, so the operation is convenient. The computer displays parameters, analysis curves and analysis data. |
|
4 |
Results printed |
Print test data and analysis reports |
