Background technology
Facing the day by day exhausted epoch of the energy, biogas, can be in commercial production and people's life as the reproducible biomass energy of one.Due to the raw material difference of fermentation generation biogas, the each component content of biogas is also different, and in biogas, main composition is methane, account for 50%~70%, all the other are carbon dioxide, nitrogen, hydrogen, oxygen, sulfuretted hydrogen etc., and its characteristic is similar to rock gas, after purifying, can directly use as combustion gas.No matter biogas is for burning or marsh gas power generation, all must carry out to biogas the processing such as necessary desulfurization, decarburization, dehydration, dedusting.In country and industry, sulfuretted hydrogen also having been done to concrete standard in the concentration of different occasions carries out, because sulfuretted hydrogen is a kind of harmful corrosive gas of severe toxicity, pipeline, burner and instrument and meter etc. are had to strong corrosive attack, after burning, produce sulphuric dioxide, contaminated environment also affects the healthy of people.Based on this reason, removing of sulfuretted hydrogen becomes a requisite link in methane purification process.
Sulfur method is mainly divided into dry desulfurization, wet desulphurization, bioanalysis desulfurization etc. at present.Wet desulphurization is conventionally applicable to process the biogas large-minded, sulfur content is high and carries out thick desulfurization, and its shortcoming is that purification precision is not high, does not generally remove the organic sulfur in biogas; And dry desulfurization is relatively simple to operate, equipment investment is less, and its maximum feature is to belong to smart desulfurization, can reach well national purification standard, and the dry desulfurization having can remove multiple organic sulfur.The wherein iron oxide process in dry desulfurization, has been relatively traditional and ancient method, because it is with respect to the desulfurizing agent such as activated charcoal, molecular sieve low price, and aboundresources, and can repeatedly regenerate, thereby be widely applied industrial.Iron oxide desulfurization regeneration method is simple to operate, is placed on shady and cool ventilation place and can realizes good regeneration.
The speed of desulphurization reaction speed has determined the input cycle of raw material, the output output of product and the size of retort, directly affect the cost of the disposable investment of enterprise and operation maintenance, efficiently reaction rate for reducing energy consumption, raise the efficiency and increase profit and have great importance, so measuring chemical reaction rate and obtaining its corresponding rate equation is the important measures that address the above problem.
Summary of the invention
The object of the invention is to utilization capacity method and measure the proving installation of ferric oxide desulfurizer and stink damp reaction rate, hold transformation mode by grade and guaranteeing can to carry out real time dynamic measurement to gas pressure intensity by high-precision pressure sensor under the condition that gas volume is constant, avoid traditional equal-pressure method measurement volumes cannot realize the drawback of robotization, reduce labour cost, improve efficiency, there is real-time and reliability.
Utilize volumetric method to measure the proving installation of gas solid chemical reaction speed, that the mode that the appearance methods such as utilization adopt buffer container step measurement air inlet or step measurement to give vent to anger is controlled turnover to reactant or product, calculate the output speed of wear rate or the product of reactant by the pressure change of gas in monitoring chemical reaction in good time, and then calculate rate constant and the reaction rate equation of chemical reaction process.This proving installation is made up of gas system to be measured, vacuum system, gas measurement system, gas-solid reaction system, heating system and data acquisition system (DAS) six parts altogether.
Wherein proving installation gas system to be measured is made up of gas bottle to be measured, gas pressure reducer, pneumoelectric magnet valve to be measured and gas joint flange to be measured.Gas bottle to be measured, for holding the gas of participating in chemical reaction, because storage pressure is higher, need to reduce to chemical reaction by pressure through gas pressure reducer and operate required pressure, and gas pressure reducer is connected with gas bottle to be measured by high pressure sealing screw thread.Pneumoelectric magnet valve to be measured is opened or closed by programmed control, enter middle gas-holder for controlling through the gas to be measured of decompression, pneumoelectric magnet valve to be measured is connected with gas joint flange to be measured with gas pressure reducer by pipeline, and gas joint flange to be measured is used for connecting gas system to be measured and middle gas-holder.
Proving installation vacuum system is made up of vacuum joint flange, vacuum solenoid and vacuum pump.Vacuum system is joined by vacuum joint flange and middle gas-holder, for middle gas-holder is vacuumized, gets rid of the impact of residual gas.Vacuum pump, vacuum solenoid and vacuum joint flange are connected by pipeline, and vacuum solenoid is controlled and opened or closed by program.
Proving installation gas measurement system is by middle gas-holder, middle gas-holder thermocouple sheath, middle gas-holder thermopair, all press joint flange, middle gas-holder pressure measurement joint flange and middle gas-holder pressure transducer to form.Middle gas-holder thermopair is placed in middle gas-holder thermocouple sheath, middle gas-holder thermocouple sheath stretches in middle gas-holder, link together by welding technology and middle gas-holder, middle gas-holder thermopair is for the temperature of gas in gas-holder in the middle of measuring.Middle gas-holder pressure transducer is connected with middle gas-holder by middle gas-holder pressure measurement joint flange, for the pressure of gas in gas-holder in the middle of measuring.Middle gas-holder is by all pressing joint flange to be connected with equal pressure electromagnetic valve.
Proving installation gas-solid reaction system is made up of equal pressure electromagnetic valve, retort pressure transducer, gas-solid reaction tank, gas thermometric galvanic couple sleeve pipe, gas temperature thermocouple; Gas temperature thermocouple is placed in gas thermometric galvanic couple sleeve pipe, gas thermometric galvanic couple sleeve pipe is put into gas-solid reaction tank top, link together by welding technology and gas-solid reaction tank, gas temperature thermocouple is for measuring the temperature of gas-solid reaction tank upper space gas; Retort pressure transducer is arranged on wireway top, for measuring the pressure of gas in gas-solid reaction tank.
The gas heating system of proving installation is made up of temperature-control heat couple, heater wire, heater strip, soaking metal and temperature control instrument.Heater strip, is connected with temperature control instrument by heater wire in soaking metal inside by insulating material uniform winding, and temperature-control heat couple is placed on the inside of soaking metal, with gas-solid reaction tank close contact, to reach the effect of quick temperature measurement and temperature control.Soaking metal is looped around gas-solid reaction tank periphery, and the heat that soaking metal produces heater strip is evenly distributed on gas-solid reaction tank wall, the reactant of gas-solid reaction tank inside is heated by heat conducting mode.
The data acquisition system (DAS) of proving installation is made up of data acquisition and controlling circuit board and main control computer.The voltage that data acquisition and controlling circuit board imports middle gas-holder thermopair, gas temperature thermocouple, solid temperature thermocouple, middle gas-holder pressure transducer and retort pressure transducer into or current analog signal import main control computer into as computational data after being converted into digital signal.In the time that the satisfied setting of pressure condition requires, main control computer sends digital switch instruction to data acquisition and controlling circuit board, digital signal is converted into voltage signal by data acquisition and controlling circuit board, drive pneumoelectric magnet valve to be measured, vacuum solenoid or equal pressure electromagnetic valve to open or closure, realize the automatic control of program.
In the middle of proving installation, the gentle body examination temperature of gas-holder thermocouple sheath galvanic couple sleeve pipe front end, through attenuate processing processing, strengthens heat conducting performance, thus the sensitivity of the gentle body temperature thermocouple of gas-holder thermopair in the middle of its raising.
The gas-solid reaction rate test process of the device that utilizes volumetric method measurement gas solid chemical reaction speed of proving installation is as follows: first, desulfurizing agent is put into gas-solid reaction tank, with the upper and lower two parts of flange sealed reaction tank, open temperature control instrument, set the temperature of heating, gas-solid reaction tank is carried out to the control of temperature, open main control computer and data acquisition and controlling circuit board.Then, open vacuum pump, open vacuum solenoid, all pressure electromagnetic valve and pneumoelectric magnet valves to be measured, gas circuit and tank body are vacuumized, remove foreign gas, in the time that pressure reaches the value of appointment, close vacuum solenoid, pneumoelectric magnet valve to be measured and all pressure electromagnetic valve, open gas bottle to be measured, in the time that gas pressure reducer pressure is adjusted to specified pressure value, open pneumoelectric magnet valve to be measured, when after the temperature stabilization that force value that middle gas-holder pressure transducer is surveyed and middle gas-holder thermopair are surveyed, force value and the temperature value of the interior gas of gas-holder in the middle of record, because middle gas-holder volume can measure, calculate the molal quantity that enters middle gas-holder gas according to the equation of gas state.Then, when the difference of the numerical value of the temperature thermocouple in gas-solid reaction tank and temperature control instrument setting value is constant, record the temperature value of the gentle body temperature thermocouple of force value of retort pressure transducer, according to gas-solid reaction tank volume and the institute's solid volume that fill calculating gas-solid reaction tank upper space gas volume, then according to the molal quantity of equation of gas state calculating solid steam.Now, open equal pressure electromagnetic valve, because gaseous tension in middle gas-holder is higher than gas-solid reaction tank internal pressure, gas in middle gas-holder enters gas-solid reaction tank through equal pressure electromagnetic valve, with solid generation chemical reaction, when force value difference that the pressure value of surveying when middle gas-holder pressure transducer and retort pressure transducer are surveyed is constant, close equal pressure electromagnetic valve, recording gas-solid reaction tank internal pressure by data acquisition and controlling circuit board is worth over time, can calculate according to the daltonian law of partial pressure molal quantity that in gas-solid reaction tank, gas reduces, thereby calculate the speed of gas-solid reaction.
The temperature-control heat couple of proving installation can adopt and meet the thermometric such as thermal resistance, the thermistor components and parts that temperature-controlled precision requires.
The soaking metal of proving installation adopts the materials such as the stainless steel that heat conductivility is good.
The middle gas-holder thermopair of proving installation, the gentle body temperature thermocouple of solid temperature thermocouple can adopt respectively other thermometric components and parts that meet on-the-spot accuracy requirement.
The appearance pressure measurement such as the middle gas-holder that the present invention proposes, gas solid separation thermometric, endless metal homogeneous heating, external heated for controlling temperature, divided dose are thrown in the modes of operation such as reaction gas and have been guaranteed the reliable and stable of this contrive equipment test performance, simple and convenient, it is the effective test unit of research gas-solid reaction speed, be applicable to reacting of various gas and solid under different temperatures, different pressures, can also measure as required reaction rate and the gas at rest uptake of gas-solid reaction in the time of mobile equilibrium of solid desorption gas inverse process.
Embodiment
The chemical reaction rate of examples measure ferric oxide desulfurizer and hydrogen sulfide gas, select 20g ferric oxide desulfurizer, in the middle of calculating by volumetric method meter, gas-holder (5) volume is 21.3377mL, gas-solid reaction tank (21) volume is 111.6664mL, middle gas-holder thermopair (7) gentle body temperature thermocouples (24) all adopt the T-shaped thermopair of one-level, and its precision is ± 0.5 ℃.It is 0~1MPa that middle gas-holder pressure transducer (10) adopts pressure limit, precision is ± 0.06% piezoelectric transducer, it is 0~0.2MPa that retort pressure transducer (15) adopts working pressure range, and maximum is born pressure 1MPa, the piezoresistive transducer that precision is ± 0.06%.Vacuum pump (13) speed of exhaust is 0.5L/s, the sulfuretted hydrogen gas cylinder that gas bottle to be measured (1) is 8L, and top pressure is 9MPa, gas pressure reducer (2) maximum range is 1.4MPa.
Referring to Fig. 1, open temperature control instrument (18), the temperature of setting heating is 25 ℃, open main control computer (16) and data acquisition and controlling circuit board (17), open vacuum pump (13), open vacuum solenoid (12) and equal pressure electromagnetic valve (14), gas circuit and tank body are vacuumized, when pressure instantaneous value is during lower than 1Pa, close equal pressure electromagnetic valve 14 and vacuum solenoid 12, open gas bottle 1 to be measured, open gas pressure reducer (2), be adjusted to 0.22MPa.Open pneumoelectric magnet valve to be measured (3), be filled with the carbon dioxide of 0.22MPa to middle gas-holder (5), after middle gas-holder pressure transducer (10) pressure vary stable, close pneumoelectric magnet valve to be measured (3), in the middle of calculating according to the equation of gas state, in gas-holder (5), be filled with the molal quantity of hydrogen sulfide gas.Open equal pressure electromagnetic valve (14), when the difference of the force value of surveying when middle gas-holder pressure transducer (10) force value and retort pressure transducer (15) meets program setting and requires, close equal pressure electromagnetic valve (14).Now, the changing value of monitoring retort pressure transducer (15) pressure, makes curve to the time, until its force value rate of change is while being less than 120Pa/s, reaction finishes.Calculate according to the equation of gas state and the daltonian law of partial pressure hydrogen sulfide gas molar weight that enters gas-solid reaction tank (21).By reaction pressure curve calculation hydrogen sulfide gas dividing potential drop rate over time, then calculate chemical reaction rate by the volume of gas-solid reaction tank (21), thereby provide the rate equation that sulfuretted hydrogen reacts with ferric oxide desulfurizer.