JPH03115856A - Analyzing method for naphtha composition by gas chromatography - Google Patents

Abstract

PURPOSE:To accurately analyze a naphtha composition by dividing data into a plurality of blocks and comparing key peaks at every blocks to correct the holding times of the peaks. CONSTITUTION:Detected data and base data 3 are compared on the basis of the signal from a detector by a data processor 2 and, according to pattern confirmation, it is judged which of the base data 3 is near to the detected data and the kind of oil is judged from the corresponding base data 3. Thereafter, the corresponding reference data and the detected data are respectively divided into a plurality of blocks and correction is performed with respect to respective peaks on the basis of the holding times of the key peaks corresponding to the respective blocks and the same correction is performed with respect to the respective blocks. By performing correction at every blocks as mentioned above, correction accuracy can be markedly enhanced and the holding times are accurately determined to make it possible to determine a composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for analyzing the composition of naphthas using gas chromatography.

[Conventional technology]

Generally, there are more than 10 types of naphthas that can be used as a base material for low-boiling gasoline. These naphthas are produced as crude naphtha as a semi-finished product by cracking feedstock oil in a catalytic cracker, and then high-octane gasoline is produced in a reformer such as a Barhomer hydroformer. When producing crude naphtha from feedstock oil, what process does decomposition proceed, how can efficient fractional taq be achieved, or what kind of reforming is necessary to improve the octane number? When considering the above, it is extremely important to analyze the composition of naphtha, which contains 150 to 350 types of compounds.

Conventionally, FrA, a type of liquid chromatography, has been used to analyze the composition of naphtha.
Separation into saturated aliphatic substances, etc. is being carried out. Furthermore, capillary gas chromatography is also used as a method for effectively separating the composition of naphtha into single compounds.

In the composition analysis method using capillary gas chromatography, as shown in FIG.
It is supplied to a capillary-shaped column 15 placed in a constant temperature bath 14 (in the case of a temperature rising type instead of a constant temperature type, a temperature rising oven) together with a sample introduced from the gas sample inlet 18 or the liquid sample inlet 19 through the do. The column 15 is made of a stainless steel or glass tube with an inner diameter of 0°2 and whose inner surface is coated with silicone oil or the like.

In such a configuration, when a sample is introduced into the column 15 together with a carrier gas, the sample is discharged from the other end of the column at a retention time specific to each component contained in the sample, which is detected by the detector 16 and recorded by the recorder 20. to be recorded. in this case,
Since the retention time for each component is known in advance, recorder 2
The content of each component can be determined by determining the area of the zero peak waveform.

That is, as shown in FIG. 6, the retention time specific to each component is 1. The peak value is recorded at
At this time, each component has a retention time of 1. Since this is known, it is possible to determine what type of component and how much is included from the peak position and the area of the peak waveform. Note that the spatially corrected holding time t8' in the figure is a time obtained by correcting the detection delay time due to the column volume.

[Problem to be solved by the invention]

By the way, when determining components from data obtained by gas chromatography, compare the standard gas chromatography data with the detected data, and if there is a peak in the detected data that corresponds to the peak position of the standard data, the predetermined In this way, the contained components are determined by comparing the reference data and the detected data over the entire range, and the content of each component is determined by determining the area of each peak waveform. There is. However, since the retention time varies depending on temperature, pressure, etc., the peaks of the reference data and the peaks of the detected data do not necessarily match, and as a result, it takes a very long time to compare the entire range with the reference data, and it is possible to make mistakes. There is also the possibility of further identification.

The present invention is intended to solve the above problems, and automatically:
Another object of the present invention is to provide a method that can accurately analyze the composition of naphtha using gas chromatography.

[Means to solve the problem]

To this end, the naphtha composition analysis method using gas chromatography of the present invention includes a step in which oil type is determined by comparing gas chromatography standard data obtained in advance for each type of naphtha with gas chromatography detection data for the naphtha to be measured; Divide the reference data and detection data corresponding to the measured naphtha into multiple blocks, associate two specific peaks of the reference data and detection data for each block, and calculate any peak that appears between the two peaks. The retention time of the detection data is corrected based on a ratio of the two peak time intervals of the reference data to the two peak time intervals of the detected data.

[Effect]

The present invention compares the gas chromatography composition analysis standard data obtained in advance for each naphtha with the detected gas chromatography data to determine the oil type, and when the corresponding standard data is specified, the standard data and detection Divide the data into multiple blocks, and within each block M4
The key peak retention time of the eruption data is determined by selecting two specific peak values corresponding to the one data and the detected data as key peaks, and for each block, the ratio of the key peak time interval of the reference data to the key peak time interval of the detected data is determined. Accordingly, the retention time of an arbitrary peak between key peaks can be corrected, and the retention time can be accurately determined.

〔Example〕

Examples will be described below with reference to the drawings.

Figure 1 is a diagram showing the overall configuration of a vessel for carrying out the composition analysis method of the present invention, Figure 2 is a diagram showing base data for each oil type, and Figures 3 and 4 explain the composition analysis method. This is a useless diagram. In the figure, ■ is a detector, 2 is a data processing device, 2a is an oil type determination processing section, 2b is a retention time identification processing section, and 3 is base data.

A signal detected by a detector 1 provided at the end of a gas chromatography column (not shown) is input to a data processing device 2 consisting of a calculator such as a personal computer. As shown in FIGS. 2(A), (B), and (C), the data processing device 2 has standard composition analysis data for all naphthas as base data 3, and the read detection data and Compare with base data 3, perform pattern DI to determine which of the base data the data obtained from the sample is close to,
Determine the corresponding base data and determine the naphtha oil type. After determining the oil type, the corresponding standard data and detected data are compared.

Figure 3(a) is the data detected from the sample,
FIG. 3(b) shows the corresponding reference data. Select a specific peak in the detected data as a key peak, e.g. Q+
, Q2 , Qs , Q4 , Qs, Q6, and the key peaks of the corresponding reference data are P, , P by matching.
,,P,,P,,P.

, P6. By the way, the peak positions of key beaks Q, , Q2...Q6 are originally Pl, P
, . . . should match P6, but in reality, the holding time varies due to temperature changes, pressure changes, etc. Therefore, by making the detection data and reference data correspond to each other, for example, block 1
~ Divide into 5. For example, focusing on block 3, key beaks Q 3 and Q 4 are respectively key beaks P,
If it corresponds to P, then the retention time [Q of peak q appearing between peak Q and 01 is corrected by However, t3, t is the key beak P3, P
4, the retention times, h', t,' are the key beak Q 3
, Q-. Based on the retention time determined in this way, the peak q is P! It can be determined that this corresponds to the peak p appearing between and P.

The above correction is performed for each peak, and the same correction is also performed for each block. Since the correction is performed for each block in this way, the correction accuracy can be significantly improved compared to the case where the entire range is corrected at once, and the composition can be determined by accurately determining the retention time.

〔Effect of the invention〕

As described above, according to the present invention, gas chromatography standard data for each naphtha can be maintained, oil type can be automatically determined by comparison with gas chromatography detection data, and multiple data can be stored. Since the key peaks are compared for each block and the retention time of any peak within them is corrected, the accuracy of correction is significantly improved compared to when the entire range is corrected at once. This makes it possible to perform accurate compositional analysis.

[Brief explanation of drawings]

Figure 1 shows the overall configuration for carrying out the composition analysis method of the present invention, Figure 2 shows the base data for each oil type, and Figures 3 and 4 explain the composition analysis method. No picture,
FIG. 5 is a diagram showing the configuration of the gas chromatography analysis apparatus, and FIG. 6 is a diagram for explaining the gas chromatography analysis method. ■...Detector, 2...Data processing device, 2a...
Oil type determination processing section, 2b... Retention time identification processing section, 3.
...Base data. Applicant: Tonen Corporation

Claims (1)

[Claims] (1) Step of comparing gas chromatography standard data obtained in advance for various naphthas with gas chromatography detection data of the naphtha to be measured to determine the oil type; detection with standard data corresponding to the naphtha to be measured determined by the oil type determination; Divide the data into multiple blocks, associate two specific peaks of the reference data and the detected data in each block, and calculate the retention time of any peak that appears between the two peaks from the two specified peaks of the detected data. A naphtha composition analysis method using gas chromatography, characterized in that correction is performed based on a ratio of the two peak time intervals of the reference data to the peak time interval.