CN104914130A - Small particle coke gasification reactivity determination method and small particle coke gasification reactivity determination apparatus - Google Patents

Abstract

The present invention provides a small particle coke and carbon dioxide gasification reactivity detection apparatus, wherein the data of the coke gasification reaction conversion rate and the gasification reaction rate can be obtained according to the real-timely detected tail gas carbon dioxide concentration. According to the present invention, a reaction gas purification system, a gas flow control device, a particle coke reaction device, an after-reaction gas purification device, an after-reaction gas cooler, a carbon dioxide online detector, and a data acquisition and processing system are sequentially connected to form the apparatus, wherein the particle coke reaction device comprises a heating furnace, a corundum reaction tube with an inner diameter of 18-22 mm and a temperature control thermocouple, the coke sample with a particle size of 3-6 mm is loaded into the reaction tube in the test, and the data acquisition and processing system in the apparatus is used for acquiring and processing the data of the sample temperature and the carbon dioxide concentration during the experiment process, and calculating and real-timely displaying the coke gasification reaction conversion rate and the gasification reaction rate according to four parameters such as (1) the tail gas carbon dioxide concentration, (2) the reaction gas flow, (3) the reaction time and (4) the instrument parameter C measured through the standard sample.

Description

A kind of assay method of granule coke gasification and device

Technical field

The invention belongs to coke chemical technical field, particularly the reactive determination and analysis of blast furnace coke.

Technical background

Coke is the requisite raw material of blast furnace ironmaking, is the origin of heat of blast furnace ironmaking process, reductive agent, stock column skeleton and carburizer.The mating reaction that coke gasification (also claiming thrombolytic agents) and reduction of iron ore react determines the efficiency of blast furnace process.The quantitative concept of coke reactivity is: the sample of unit mass within the unit interval through CO ₂after reaction, the mass loss of carbon.

The test side of coke reactivity is a lot, can be divided into: Powdered coke (usually below tens microns), fine granularity coke (being generally 3 ~ 6mm) and block coke (usual > 19mm) according to sample yardstick.

Because reactor (reaction tube or crucible) needs to match with sample granularity and use amount, the reaction unit of test different scale coke specimen is not general mutually.

The block coke of what the most frequently used at present GB GB/T4000-2008 adopted is 23 ~ 25mm.

GB/T4000-2008 adopts coke and CO ₂the percentage of mass loss before and after reaction as the reactive indices CRI of coke, but can not in reaction process the molten weight losses rate (gasification conversion) of continuous detecting coke and thrombolytic agents speed (gasification reaction speed).And the method needs in 20kg coke, broken, screen, process 200g sample, required sample size is more.Characterize the performance of coke usually through test fine granularity and Powdered coke specimen in laboratory.

GB GB/T220-2001 is applicable to brown coal, bituminous coal, stone coal and coke and CO ₂reactive mensuration.The method sample (800 DEG C, 850 DEG C, 900 DEG C, 950 DEG C, 1000 DEG C, 1050 DEG C, 1100 DEG C) and CO at various temperatures of 3 ~ 6mm ₂generating gasification is reacted, and each thermotonus 2.5min, with the CO of gas after Orsat gas apparatus test reaction ₂concentration, calculates sample carbon dioxide reduction rate at each temperature according to this result.Although the method can detect graininess coke and carbon dioxide carbon dioxide reduction rate at various temperatures, gasification reaction conversion ratio and reaction rate information in coke gasification process can not be obtained continuously

Can the method for the block boudouard reaction weight-loss ratio of continuous detecting and thrombolytic agents speed two kinds: one be had to be hung over by reactor or be sitting on electronic balance, to obtain the weight change information of sample in course of reaction continuously at present.Two is carbon monoxide (or carbon dioxide) concentration adopting the rear gas of gas on-line analyzer continuous detecting reaction, indirectly estimates by this concentration the reaction rate indirectly estimating coke.

Reactor is hung over or is sitting in the method on electronic balance, the granularity of its sample is identical with GB/T4000-2008 with the requirement of weight, be unsuitable for the sample of the little weight of granule, because balance will carry the weight of whole reactor, and have baseline wander phenomenon, be difficult to the measuring accuracy ensureing granule, little gravimetric(al) sample.After current employing gas on-line analyzer continuous detecting reaction, the method for gas can only estimate according to the concentration of carbon monoxide or carbon dioxide the reaction rate indirectly counting coke indirectly, directly accurately can not read to measure the reaction rate of coke and the gasification conversion of coke, and be necessary accurately to gather the gasification conversion of coke and the data of gasification reaction rate in some scientific experiments.

Crucible thermobalance method can the weight change of the Powdered coke of continuous detecting in course of reaction, but thermopair cannot be imbedded sample center by the method, namely cannot the temperature of accurate Control Assay.In addition, be limited to the volume of crucible, the coke granule of a few mm particle size rank cannot be measured.And need to avoid each microstructure in coke to be separated in some researchs, therefore to fine powder be avoided broken as far as possible.

In sum, special a kind of proving installation and the method needing coke gasification conversion ratio and the reaction rate that gasifies in energy continuous detecting fine granularity coke and carbon dioxide reaction process.

Summary of the invention

The object of this invention is to provide a kind of granule coke and the reactive assay method of carbon dioxide gasification and device, this device is converted into the coke gasification conversion ratio and gasification reaction rate data that can read continuously by the tail gas carbon dioxide concentration data that gas on-line analyzer detects by program computation in real time.

The concrete mode that technical solution problem of the present invention is taked is:

The pick-up unit that graininess coke and carbon dioxide gasification react, this device is connected according to this is formed by gas cooler, carbon dioxide on-line detector, data acquisition and processing system after gas cleaning unit, reaction after reacting gas cleaning system, gas flow control device, the burnt reaction unit of grain, reaction; Wherein the burnt reaction unit of grain comprises: heating furnace, internal diameter are corundum reaction tube and the temperature-control heat couple of 18 ~ 22mm, and temperature range is room temperature ~ 1300 DEG C.Temperature-controlling system is connected with temperature-control heat couple, and in experimentation, granularity is that the graininess coke of 3 ~ 6mm is placed in reaction tube, and sample center imbedded by thermopair, in order to the temperature at sample center in Control release process.Gas flow control device to be made up of with mass flowmeter solenoid valve and to be connected with computing machine, can experimentally need, and switches gas and adjusting gas flow by computing machine.Data acquisition and processing system is used for specimen temperature and gas concentration lwevel signal in acquisition and processing experimentation, and according to four parameters: 1. tail gas carbon dioxide concentration, 2. reaction gas flow, 3. reaction time, the instrument parameter C that 4. measured by standard sample, calculates and display coke gasification conversion ratio and gasification reaction rate in real time.

A kind of fine granularity coke and the reactive detection method of carbon dioxide gasification that there is provided are provided, comprise the following steps:

(1) be that the coke specimen of 3 ~ 6mm loads in reaction tube as claimed in claim 1 by 20 ± 0.5g granularity, temperature-control heat couple is embedded in the center of coke specimen;

(2) pass into the nitrogen protection sample that flow is 500mL/min, with the ramp to 1100 DEG C of 10 DEG C/min, after arriving assigned temperature, switch to flow to be 500mL/min carbon dioxide nitrogen;

(3) after passing into carbon dioxide, the dense carbon dioxide degrees of data in the tail gas of collection processes by data acquisition and processing system, in real time display coke gasification conversion ratio and gasification reaction rate.

Data acquisition and processing system calculates according to tail gas carbon dioxide concentration and the principle of display coke gasification conversion ratio and gasification reaction rate is as follows in real time:

Coke specimen at high temperature with carbon dioxide exposure, occur Boudouard reaction (or being called the gasification reaction of coke):

C+CO ₂＝2CO (1)

Because reacting gas only has CO ₂, therefore the gaseous product generated only has CO (ignoring other gases of trace), therefore in tail gas, the concentration of CO is:

α _cO=100-α _cO2, in % (2) formula, α _cOfor the concentration of CO in tail gas, %; α _cO2for CO in the tail gas of detector display ₂concentration, %.

In unit interval, the CO concentration in tail gas can be expressed as:

${\mathrm{\α}}_{\mathrm{CO}}=\frac{V_{\mathrm{CO}}}{V-V_{\mathrm{CO}2}+V_{\mathrm{CO}}}\×100,\%---\left(3\right)$

In formula, V is the CO flowing into reaction tube in the unit time ₂reacting gas volume, L; V _cO2for reacting the CO of consumption in the unit time ₂volume, L; V _cO2for reacting the CO volume of generation in the unit time; L.

Can obtain according to stoichiometric relationship:

V _CO＝2V _CO2(4)

Therefore, can calculate by (2) formula the volume V that unit time generates carbon monoxide _cO.

CO molal quantity according to Clapyron Equation formula can generate in the unit of account time:

$n_{\mathrm{CO}}=\frac{{\mathrm{PV}}_{\mathrm{CO}}}{\mathrm{RT}},\mathrm{mol}---\left(5\right)$

In formula, n _cOfor the unit time generates the molal quantity of carbon monoxide, mol; P is the dividing potential drop of CO in tail gas, Pa; R is ideal gas constant, J/mol K; T is the thermodynamic temperature of tail gas, K.

Because P, T inconvenience is measured, and in course of reaction, P, T of tail gas almost remain unchanged, and C therefore can be set as instrument constant:

$C=\frac{P}{\mathrm{RT}}---\left(6\right)$

C value can according to standard sample reaction before and after mass loss calculate generate CO volume determine.

According to stoichiometric relationship, the Boudouard amount of coke specimen in unit time is:

$m_i=\frac{n_{\mathrm{CO}}}{2}\×12,g---\left(7\right)$

In formula, m _ifor the Boudouard amount of unit time coke specimen, g.

Coke specimen in the molten damage amount of carbon element that certain moment is accumulative is:

$m_t={\mathrm{\Σ}}_0^t{m}_i={\mathrm{\Σ}}_0^t\frac{12\mathrm{CV}}{\mathrm{\α}+2}\×\frac{100-{\mathrm{\α}}_{\mathrm{CO}2}}{100}---\left(8\right)$

In formula, m _tthe molten damage amount of accumulative carbon element for t coke specimen, g.

Through type (8) namely can according to four parameters: 1. tail gas carbon dioxide concentration, 2. reaction gas flow, 3. reaction time, 4. instrument parameter C calculate the carbon element loss amount of coke, can be calculated thrombolytic agents weight-loss ratio and the thrombolytic agents speed of coke by carbon element loss amount further.

Coke specimen at the thrombolytic agents weight-loss ratio in certain moment is:

$R_t=\frac{m_0-m_t}{m_0}\×100=\frac{m_0-{\mathrm{\Σ}}_0^t\frac{12\mathrm{CV}}{\mathrm{\α}+2}\×\frac{100-{\mathrm{\α}}_{\mathrm{CO}2}}{100}}{m_0}\×100,\%---\left(9\right)$

In formula, R _tfor the molten weight losses rate of t coke specimen, %.M ₀for reacting the quality of front coke specimen, g.

The thrombolytic agents speed of coke specimen is:

$v=\frac{{\mathrm{dR}}_t}{\mathrm{dt}},\%/\min ---\left(10\right)$

In formula, v is the thrombolytic agents speed of coke specimen, %/min.

Molten loss rate-the time curve of coke specimen and molten damage rate-time curve can be drawn out according to above calculating.

The test philosophy of instrument constant C is as follows:

Test certain standard sample, certain moment in test process stops heating, carbon dioxide is switched to nitrogen, takes out sample after cooling, and the mass loss rate of test coke specimen, with the R of formula (9) on the value theory of this loss percentage _tunanimously, therefore C is back-calculated to obtain by iterative computation, not C is in the same time got arithmetic average, can obtain instrument constant C.

The beneficial effect that the present invention produces is:

(1) device adopts the reactivity of tail gas on-line analysis test coke specimen, need not use electronic balance.Because balance need carry the weight of whole reactor, and there is baseline wander phenomenon, the sample for granule, little weight is difficult to ensure precision;

(2) after reaction, gas cooler ensure that each sample has close exhaust temperature, the gasification conversion of coke accurately can be derived according to tail gas carbon dioxide concentration, thus directly can obtain the gasification conversion of sample in reaction process and gasification reaction rate data continuously, the reaction rate of coke indirectly need not be estimated according to tail gas concentration;

(3) use 20 ± 0.5g granularity to be the granule coke of 3 ~ 6mm, coordinate internal diameter to be the corundum reaction tube of 18 ~ 22mm, can ensure that reaction gas flow stably flows through sample fixed bed, test reproducible.The method is very applicable when sample size is few.As crucible coking is commonly used in laboratory, economical quick, but gained coke sample amount is less, be not enough to process 200g sample by GB GB/T4000-2008, simultaneously, relative to Powdered coke specimen, it is broken that granularity is that the granule coke of 3 ~ 6mm avoids fine powder, can greatly reduce the separation of each microstructure of coke;

Accompanying drawing explanation

Fig. 1 is apparatus structure schematic diagram of the present invention;

Fig. 2 is the molten weight losses rate-time curve of measurement result of the embodiment of the present invention;

Fig. 3 is the measurement result molten damage rate-time curve of the embodiment of the present invention.

Embodiment

For make object of the present invention and technical scheme distincter, below in conjunction with drawings and Examples, the present invention is described in further detail.

Device is connected according to this is formed by gas cooler, carbon dioxide on-line detector, data acquisition and processing system after gas cleaning unit, reaction after reacting gas cleaning system, gas flow control device, the burnt reaction unit of grain, reaction; Wherein the burnt reaction unit of grain comprises: heating furnace, internal diameter are corundum reaction tube and the temperature-control heat couple of 18 ~ 22mm, and temperature range is room temperature ~ 1300 DEG C.Temperature-controlling system is connected with temperature-control heat couple, and in experimentation, granularity is that the graininess coke of 3 ~ 6mm is placed in reaction tube, and sample center imbedded by thermopair, in order to the temperature at sample center in Control release process.Gas flow control device to be made up of with mass flowmeter solenoid valve and to be connected with computing machine, can experimentally need, and switches gas and adjusting gas flow by computing machine.Data acquisition and processing system is used for specimen temperature and gas concentration lwevel signal in acquisition and processing experimentation, and according to four parameters: 1. tail gas carbon dioxide concentration, 2. reaction gas flow, 3. reaction time, the instrument parameter C that 4. measured by standard sample, calculates and display coke gasification conversion ratio and gasification reaction rate in real time.

The step of the detection of embodiment is as follows:

(1) coke is crushed to 3 ~ 6mm, after dry, rejects the particle of flake and strip;

(2) load in reaction tube as claimed in claim 1 by 20 ± 0.5g coke specimen, temperature-control heat couple is embedded in the center of coke specimen, and full high aluminium ball is filled in the dead zone of sample bottom reaction tube, and the thickness that high aluminium ball is filled on sample top is 20mm;

(3) pass into the nitrogen protection sample that flow is 500mL/min, with the ramp to 1100 DEG C of 10 DEG C/min, arrive and to be switched to by nitrogen after assigned temperature flow to be the carbon dioxide of 500mL/mm;

(4) after passing into carbon dioxide, the dense carbon dioxide degrees of data in the tail gas of collection processes by data acquisition and processing system, in real time display coke gasification conversion ratio and gasification reaction rate;

(5) stop heating after 120min after passing into carbon dioxide, carbon dioxide is switched to nitrogen, take out after sample cooling.

Test 3 kinds of coke, the molten loss rate-time curve obtaining coke specimen is as indicated with 2, and molten damage rate-time curve as shown in Figure 3.The feature of different coke specimen reaction rate change in thrombolytic agents process can be analyzed by molten loss rate-time curve and molten damage rate-time curve.

In order to verify the degree of accuracy of this device, certain moment in process of the test interrupts reaction, namely stops heating, carbon dioxide is switched to nitrogen, weighs, thus obtain the gasification conversion of certain moment sample after sample cooling.Weigh the comparing result of gasification conversion that the gasification conversion that calculates and Tail gas measuring calculate in table 1.

Table 1 is weighed and is calculated the comparing result of the coke specimen gasification conversion calculated with Tail gas measuring

Claims (2)

1. a granule coke and the reactive pick-up unit of carbon dioxide gasification, the tail gas carbon dioxide concentration that gas on-line analyzer can be detected in real time is converted into the data of coke gasification conversion ratio and gasification reaction rate, it is characterized in that: this device is connected according to this is formed by gas cooler, carbon dioxide on-line detector, data acquisition and processing system after gas cleaning unit, reaction after reacting gas cleaning system, gas flow control device, the burnt reaction unit of grain, reaction; The burnt corundum reaction tube that reaction unit comprises heating furnace, internal diameter is 18 ~ 22mm of described grain and temperature-control heat couple; Described gas flow control device to be made up of with mass flowmeter solenoid valve and to be connected with computing machine, switches gas and adjusting gas flow by computing machine; After described reaction, gas cooler is copper snake bend; Described data acquisition and processing system is used for specimen temperature and dense carbon dioxide degrees of data in acquisition and processing experimentation, and according to four parameters: 1. tail gas carbon dioxide concentration, 2. reaction gas flow, 3. reaction time, the instrument parameter C that 4. measured by standard sample calculate and display coke gasification conversion ratio and gasification reaction rate in real time.

2. use a detection method for the fine granularity coke reactivity of pick-up unit described in claim 1, it is characterized in that comprising the following steps:

(1) be that the coke specimen of 3 ~ 6mm loads in reaction tube as claimed in claim 1 by 20 ± 0.5g granularity, temperature-control heat couple is embedded in the center of coke specimen;

(2) pass into the nitrogen protection sample that flow is 500mL/min, with the ramp to 1100 DEG C of 10 DEG C/min, after arriving assigned temperature, switch to flow to be 500mL/min carbon dioxide nitrogen;

(3) after passing into carbon dioxide, the dense carbon dioxide degrees of data in the tail gas of collection processes by data acquisition and processing system, in real time display coke gasification conversion ratio and gasification reaction rate.