JPS5899751A - Measurement of concentration of sulfur in fuel - Google Patents

Abstract

PURPOSE:To measure all ion components in a fuel continuously for an actual time by processing the flow rate of a fuel, the flow rate of a waste gas generated from the combustion thereof and the concentration of sulfur dioxide. CONSTITUTION:A coke gas sampled from a piping system 1 by way of a sampling line 3, a pre-treating device 2<a>, a standard gas feed valve 2<b>, a constant flow valve 2<c> and a gas flowmeter 2<d> and combustion air supplied from an air source by way of a mist separator 2<e>, a constant flow valve 2<f> and an air flowmeter 2<g> are mixed together with a mixer 2<h> and then, sent to a reaction tank 2<k>, where they are burned completely under a platinum catalyst. A waste gas generated by the combustion reaction is fed to an SO2 analyzer 5 via a waste gas flowmeter 4 to measure the concentration of sulfur dioxide. The measurement signals are inputted into an arithmetic unit 6 to compute sulfur components in the fuel.

Description

[Detailed description of the invention] The present invention relates to a method for measuring iota concentration in fuel.

Recently, there has been a need to measure the iodine content in fuel in order to perform combustion control to suppress the total emission of iota dioxide from the perspective of pollution prevention, and it is also necessary to measure the iodine content in fuel gas in order to ensure stable operation of equipment that desulfurizes fuel gas. Therefore, it is necessary to measure the ion content after desulfurization.

Conventionally, various methods have been proposed for measuring the off concentration in fuel. For example, there is a method using a semiconductor sensor to check the electrical conductivity of a semiconductor sensor with excellent selectivity for hydrogen sulfide, and a method using a semiconductor sensor in which a sensitive tape coated with lead acetate is brought into contact with the sample and the reaction of the following formula (1) is carried out. There is a test paper photoelectric photometry method to measure the degree of color development0 □ , (CH3C'OO)2Pb + H2S→2CH3C
OOH + PbS... (1) However, the latter has poor reproducibility and response, and the latter has problems with response, the need to replace the sensitive tape, etc., and both measure only hydrogen sulfide. This is not a method to measure the total ion content.

However, although the iodine content in fuel is mainly hydrogen sulfide, it also contains a considerable amount of other components. For example, the iota concentration in coke gas, as shown in Table 1, contains 250 to 350 ppm of hydrogen sulfide, but also 26 to 42 ppm of other components, so only hydrogen sulfide is measured. In this case, the iota measured value will be lower by 10% or more.

- (blank below) Table 1 Furthermore, the coulometric titration method for measuring the degree of blue color development between an ammonium molybdate solution acidified with hydrochloric acid and hydrogen sulfide using a colorimetric method;
Absorption at specific wavelengths of infrared radiation. There is also an infrared absorption method that utilizes the fact that the degree changes depending on the hydrogen sulfide concentration.
The former has a problem with safety during measurement, and the latter has the disadvantage that the absorption wavelength range of hydrogen sulfide overlaps with the absorption wavelength range of methane, nitrogen dioxide, iota dioxide, etc., and the interference is large.

Furthermore, gas chromatography allows measurement of ions other than hydrogen sulfide, but requires very expensive equipment, and the present invention was developed in view of these circumstances. Another object of the present invention is to provide a method for measuring iota concentration that can continuously measure all iota concentrations in fuel in real time.

The method for measuring the iota concentration in fuel according to the present invention involves determining the iota concentration in the fuel based on the flow rate of the fuel, the flow rate of the waste gas generated by burning the fuel, and the iota dioxide concentration in the waste gas. #f characteristic.

First, regarding gaseous fuel, the present invention will be explained in detail using coke gas as an example. When platinum is used as a catalyst to completely burn coke gas, and the main measurements are the fuel flow rate, light gas flow rate, and iota dioxide concentration in the waste gas, the following equation (2) holds true between the measured values. do. That is, the number of moles M (So,) of iota dioxide in the waste gas generated per hour of coke gas lNd is expressed by the following equation (2).

However, F (Exh, aust): Waste gas flow rate (N-
7 o'clock) C (SO2): Iota dioxide concentration in waste gas (
ppm) F (COG): Coke gas flow rate (Nw 1 hour)
Assuming that all iota of dioxide is generated by one combustion of hydrogen sulfide according to the reaction formula shown in equation (3) below, 91 moles of rice dioxide corresponds to 1 mole of hydrogen sulfide, so all of the iota in coke gas is The value C(H,S) obtained by converting the ion content into hydrogen sulfide is expressed by the following equation (4) from equation (2).

Similar C (H, S): Hydrogen sulfide concentration equivalent value for all ions in coke gas (ppm) Next, in the case of liquid fuel or a mixed fuel of solid fuel and liquid fuel, the fuel is completely combusted; When the fuel flow rate, waste gas flow rate, and iota dioxide concentration in the waste gas are measured, the following equation (5) holds true between the measured values. That is, fuel li
The number of moles M (So2) of iota dioxide in the waste gas generated per f/hour is expressed by the following formula (5).

However, F (L, S): Fuel flow rate (immediate/hour) In this case as well, assuming that all iota dioxide is generated by combustion of hydrogen sulfide according to the reaction formula shown in (3) 2 above, the total ion content in the fuel is The value C(H,S) obtained by converting C(H, S) into hydrogen sulfide is expressed by the following equation (6).

C (H2S) ÷ 34 X 10-”XM (Sow)
...(6) However, C(H,S): Concentration of hydrogen sulfide equivalent to all ions in the fuel (wt%) Concentration of iota dioxide in the waste gas generated by complete combustion of the fuel By measuring 1 degree, the total ion content in the fuel can be determined.

Next, the method of the present invention will be explained based on examples thereof. The drawing is a schematic diagram showing an apparatus used to carry out the method of the present invention, in which a sampling line 3 for sampling coke scum from a coke gas piping system 1 is provided, and the sampling line 3Fi is connected to a combustion device 2. The combustion device 2 includes @processing device 2a, standard gas supply valve 2b,
A constant flow valve 2c and a coke gas flow meter 2d are connected to one of the pipes arranged according to the order of description and a combustion air source (not shown), and a mist separator 2C1 and a constant flow valve 2f are connected to each other.
and the other pipe in which the air flow meters 2g are arranged according to the order listed are both connected to the mixer 2h, and after the sampled coke gas and combustion air are mixed, the reaction tank containing the platinum catalyst is connected. 2, where it is completely combusted under a platinum catalyst. The pretreatment device 2
A consists of a pump that sucks coke gas from the coke gas piping system 1 and supplies it to the reaction tank 2, and coolers and filters provided before and after the pump for dehumidification and dust removal.

Further, the standard gas supply valve 2b switches the line leading to the mixer 2h from the line leading to the pretreatment device 2a to the line leading to the standard gas cylinder via the constant flow valve 2c and the coke gas flow meter 2d, thereby controlling the entire system. can be calibrated using standard gas. Further, the coke gas flow meter 2d detects the coke gas flow adjusted to a constant flow rate by the constant flow valve 2c.
The flowmeter 2dK is used to measure F(COG).
The signal related to the measured value F (COG) is sent to the arithmetic unit 6.
It is now transmitted to. Note that if a constant flow rate is sufficiently ensured by the constant flow rate valve 2C, a signal related to the constant flow rate may be transmitted to the calculation device 6 instead of the measured value F (COG ) by the coke gas flowmeter 2d. Then, the waste gas generated by the combustion reaction in reaction m2k is sent to the S, O, and analyzer 5 via the waste gas flow meter 4, and the waste gas flow rate and the sulfur dioxide concentration in the waste gas are measured, respectively. The measured values F (Exhaust) and C (SO
F) Signals related to K are input together to the arithmetic unit 6)
-! Based on the input signal, the arithmetic unit 6 performs the arithmetic operation according to equation (4).

Considering the accuracy when using the apparatus configured as described above, it is assumed that the iodine content in the fuel is completely combusted in the reaction tank 2, and that the density of coke gas does not change. Measurement accuracy of coke gas flow meter 2d is ±1%,
Measurement accuracy of waste gas flow meter 4 is ±1%, SO, analyzer 5
Measurement accuracy of ±2%, calculation accuracy of calculation unit [6] ±0.5
%, the measurement accuracy of the total energy content in the fuel is ±2.
It will be 5%.

In Kio's example, the case of determining the sulfur concentration in gaseous fuel was explained, but when determining the sulfur concentration in liquid fuel or a mixed fuel of solid fuel and liquid fuel, the above equation (5) can be used. Of course, if the calculation is performed by , then the total eocs can be calculated with high precision.

In addition, in this example, the fuel was sampled in order to achieve complete combustion, but in an actual line controlled for complete combustion, the fuel is combusted in the actual line, and the fuel flow rate and combustion waste are measured. The sulfur concentration may be determined based on the gas flow rate and the sulfur dioxide concentration in the combustion waste gas.

As detailed above, in order to measure the sulfur concentration in the fuel, the sampled fuel is completely combusted, or the fuel is combusted in an actual line that is controlled to achieve complete combustion, and the fuel flow rate and Since the sulfur concentration in the fuel of the actual line is determined based on the combustion waste gas flow rate and the sulfur dioxide concentration in the combustion waste gas, the method using a semiconductor sensor,
Unlike methods such as test strip photoelectric photometry, the total amount of rice in the fuel can be determined with high precision, and the cost of the equipment required for this is lower than methods such as gas chromatography, and it is also safe at a certain time. Unlike the amperometric titration method, there are no problems with this method. ``Therefore, wood-fired EJA will provide a very effective means to take measures against pollution from fuel combustion waste gas.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing the apparatus used to carry out the method of the invention. 1..." Coke gas piping system 2... Combustion device 2d
...Coke gas flow meter 2h...Mixer 2k.
... Reaction tank 4 ... Waste gas flowmeter 5 ... SO7 analyzer Patent applicant: Sumitomo Metal Industries Co., Ltd. Agent (patent attorney) Noboru Kono

Claims (1)

[Claims] L. A method for measuring iota concentration in fuel, which comprises determining the concentration of iota dioxide in the fuel based on the flow rate of the fuel, the flow rate of tiger gas produced by burning the fuel, and the iota dioxide concentration in the waste gas.