Abstract:
The present disclosure may include a method for preparing gas mixtures of use in testing catalysts, where the method may include using separate banks of mass flow controllers for mixing the gas composition to the desired composition and for controlling the flow of the gas composition through the heater. A separate bank may be used for controlling any suitable mix of reducing agents while another separate bank may be used for controlling any suitable mix of oxidizing gases.

Description:
BACKGROUND 
       [0001]    1. Field of the Disclosure 
         [0002]    The present disclosure relates to laboratory test device and, more particularly, to a method for controlling test gas temperatures in a test bench. 
         [0003]    2. Background Information 
         [0004]    Catalysts may need to be tested to evaluate their performance and their response to parameter changes. Devices of use in testing catalysts may include one or more combustion engines; however, the use of these engines may be expensive, require higher maintenance than desired, and be more time consuming. Additionally, the use of these engines may not allow individual parameter variations or calibrations of use when testing catalysts. Other test devices suitable for testing catalysts may include Laboratory Scale Reactors, commonly referred to as Test Benches, and may allow a greater control over the testing conditions of the catalyst. 
         [0005]    However, preparing a suitable variety of test gases in Laboratory-scale reactors suitable for testing a variety of samples may remain a challenge, including preparations where oxidizing and reducing materials may be mixed. 
         [0006]    As such, there is a continuing need for improvements in test devices so as to allow a greater range of testing conditions. 
       SUMMARY 
       [0007]    The present disclosure may include a method for preparing gas mixtures of use in testing catalysts. 
         [0008]    The method may include using separate banks of mass flow controllers for mixing the gas composition to the desired composition and for controlling the flow of the gas composition through the heater. A separate bank may be used for controlling any suitable mix of reducing agents, nitric oxide, and diluent gas; while another separate bank may be used for controlling any suitable mix of oxidizing gases, carbon dioxide, and diluent gas. The flow of gas through each bank may be controlled so as to result in any suitable gas composition, including embodiments where the amount of gas flowing through each bank may be controlled to be about half of the flow, where the amount of gas flowing through each bank may be regulated by regulating the amount of diluent gas flowing through each bank. 
         [0009]    Embodiments where each of the banks may contribute about half of the flow may allow the events that may be generated in each of the banks to reach the catalyst sample at about the same time. In embodiments where the length of paths from the banks may differ, the ratio of the total flows for each bank may adjusted in any suitable way so as the events generated may reach the sample at about the same time. Suitable adjustments may take into account the volume of gas flowing through each branch. 
         [0010]    Numerous other aspects, features and advantages of the present disclosure may be made apparent from the following detailed description, taken together with the drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    These and further features, aspects and advantages of the embodiments of the present disclosure will be apparent with regard to the following description, appended claims and accompanying drawings where: 
           [0012]      FIG. 1  is a flow chart for testing a sample in a laboratory scale reactor. 
           [0013]      FIG. 2  shows a diagram for a gas feed system. 
           [0014]      FIG. 3  shows test gas generator. 
       
    
    
       [0015]    It should be understood that these drawings are not necessarily to scale and they can illustrate a simplified representation of the features of the embodiments of the present disclosure. 
       DETAILED DESCRIPTION 
     Definitions 
       [0016]    As used here, the following terms have the following definitions: 
         [0017]    Mass flow controller (MFC) refers to any computer controlled analog or digital device of use in controlling the flow rate of fluids and/or gases. 
         [0018]    Temperature controller refers to any device of use in controlling temperature in a process. 
         [0019]    Laboratory Scale Reactor/Test Bench refers to any apparatus suitable for testing a material with a test gas. 
         [0020]    Oxidizing agent refers to any substance that may take electrons from another substance in a redox chemical reaction. 
         [0021]    Reducing agents refers to any substance that may give electrons to another substance in a redox chemical reaction. 
         [0022]    Gas mixture refers to the mixture obtained from combining oxidizing agents, reducing agents, inert gases, or any other suitable gases. 
         [0023]    Water-gas mixture refers to the mixture obtained from combining water vapor with a gas mixture. 
         [0024]    Test Gas refers to any gas mixture of use in chemically testing an interaction between it and one or more materials. 
         [0025]    Catalyst refers to one or more materials that may be of use in the conversion of one or more other materials. 
       Description 
       [0026]    The description of the drawings, as follows, illustrates the general principles of the present disclosure with reference to various alternatives and embodiments. The present disclosure may, however, be embodied in different forms and should not be limited to the embodiments here referred. Suitable embodiments for other applications will be apparent to those skilled in the art. 
         [0027]      FIG. 1  is a flowchart of a method for testing a catalyst sample. Test Method  100  includes Oxidizing Component Mixture  102 , Reducing Component Mixture  104 , Full Component Mixture  106 , Water Vapor Addition  108 , Heating  110 , Sample Interaction with Test Gas  112 , and Analysis  114 . 
         [0028]    Test Method  100  may include mixing any number of suitable Oxidizing Components in Oxidizing Component Mixture  102 . Test Method  100  may also include mixing any number of suitable reducing components in Reducing Component Mixture  104 . The gas mix from Oxidizing Component Mixture  102  and the gas mix from Reducing Component Mixture  104  may then be mixed in Full Component Mixture  106 , where the mixture may then undergo any suitable Water Vapor Addition  108 . Test gas exiting Water Vapor Addition  108  may then undergo any suitable Heating  110 , and any suitable portion of test gas having undergone Heating  110  may then undergo any suitable Sample Interaction with Test Gas  112 . Any portion of test gas having undergone Sample Interaction with Test Gas  112  may then undergo any suitable Analysis  114 . 
         [0029]      FIG. 2  shows Gas Feed System  200 . Gas Feed System  200  may include Gas Source  202 , Control Valve  204 , Pressure Regulator  206 , one or more Mass Flow Controllers  208 , and one or more Output Lines  210 . 
         [0030]    Gas Source  202  may be any source suitable for delivering any suitable gas to the system, including any tank or line able to provide N2, C3H6, C3H8, H2, CO, NO, NO2, CO2, SO2 or any suitable combination thereof at any suitable concentration. 
         [0031]    Control Valve  204  may be any valve suitable for restricting or allowing flow from Gas Source  202 , including solenoid valves, hydraulic valves, pneumatic valves, or any suitable combination. 
         [0032]    Pressure Regulator  206  may be any device suitable for regulating the pressure of gas in Gas Feed System  200 , including devices including any suitable pressure gauge or pressure transducer as well as any suitable valve, including solenoid valves, hydraulic valves, pneumatic valves, or any suitable combination. 
         [0033]    Mass Flow Controllers  208  may be any mass controller or series of mass controllers suitable for controlling the flow of gas from Gas Source  202  to one or more Output Lines  210  at a suitable frequency. Suitable Mass Flow Controllers  208  may include mass flow controllers able to provide any suitable flow rate. 
         [0034]      FIG. 3  shows Test Gas Generator  300 , having Oxidizing Components Branch  302 , Reducing Components Branch  304 , Heavy Hydrocarbon Addition  306 , Evaporation Block  308 , Pump  310 , Water Reservoir  312 , 
         [0035]    Oxidizing Components Branch  302  may include any number of suitable Gas Feed Systems  200 , where the included Gas Feed Systems  200  may provide any number of oxidizing gases, dilutants, and combinations thereof, including N2, NO2, O2, and CO2. 
         [0036]    Reducing Components Branch  304  may include any number of suitable Gas Feed Systems  200 , where the included Gas Feed Systems  200  may provide any number of reducing gases, dilutants, and combinations thereof, including N2, H2, CO, NO, and any suitable hydrocarbons. Suitable Hydrocarbons may include C3H8. Suitable heavy hydrocarbons may also be added using any suitable method in Heavy Hydrocarbon Addition  306 , including liquid injection and evaporation. Suitable heavy hydrocarbons may include decane, tolune, and dodecane. 
         [0037]    The flow of the mixture of gases generated by Oxidizing Components Branch  302  and Reducing Components Branch  304  may then be preheated by any suitable means, including heated lines, where the heated lines may be heated using heat jackets. Suitable temperatures may include temperatures in the range of 130° C. to 180° C., including 150° C. The flow paths from Oxidizing Components Branch  302  and Reducing Components Branch  304  may be of any suitable length, where the flow of gas from Oxidizing Components Branch  302  and Reducing Components Branch  304  may be adjusted to be suitable so as to create the required events in Sample Interaction with Test Gas  112 . 
         [0038]    Evaporation Block  308  may be any device suitable for evaporating water and adding it to the flow of gas generated by the combination of gas flows from Oxidizing Components Branch  302  and Reducing Components Branch  304  in Test Gas Generator  300 . Evaporation Block  308  may evaporate water which may be provided by one or more suitable Pumps  310 , where Pump  310  may be any pump suitable for pumping water from Water Reservoir  312  to Evaporation Block  308 . Suitable temperatures in Evaporation Block  308  may include temperatures in the range of 110° C. to 150° C., including 130° C. 
         [0039]    The resulting test gas exits Test Gas Generator  300  through Output  314 , where it may undergo any suitable Heating  110  before undergoing any suitable Sample Interaction with Test Gas  112  and any suitable Analysis  114 .