pycatalicism 0.1

Program controls catalytic activity of materials measurement equipment as well calculations

pycatalicism

Program controls catalytic activity of materials measurement equipment (to be developed...) as well as calculates main parameters relevant for catalyst functional properties characterization (conversion, activity, selectivity, stability, activation energy).

Contents

1. Installation
2. Calculation of catalyst functional properties
3. Furnace control
4. Chromatograph control
5. Mass flow controllers

Installation

Arch Linux

Install python:

pacman -S python

Install python libraries:

pacman -S python-matplotlib python-numpy python-pyserial

pip install pymodbus bronkhorst-propar

Install git:

pacman -S git

Clone repository (this will create pycatalicism directory inside your current directory):

git clone https://github.com/leybodv/pycatalicism.git

Create alias in your .bashrc file:

pycat='PYTHONPATH="/path/to/pycatalicism-parent-directory" /path/to/pycat.py'

Windows

Install python from python.org

Install python libraries (better to start cmd as administrator):

pip install matplotlib numpy pyserial pymodbus bronkhorst-propar

Install git for windows from gitforwindows.org

Clone repository in git bash:

cd path/to/repository-storage-dir

git clone https://github.com/leybodv/pycatalicism.git

Add PYHTONPATH system variable with path/to/repository-storage-dir value

Download and install driver for usb -> com from silabs.com

Calculation of catalyst functional properties

NB: on Windows pycat must be replaced with python path/to/pycat.py

pycat calc --conversion|--selectivity [--output-data OUTPUT_DATA] [--show-plot] [--output-plot OUPUT_PLOT] [--products-basis] [--sample-name SAMPLE_NAME] input-data-path initial-data-path {co-oxidation|co2-hydrogenation}

positional arguments:

input-data-path	path to directory with files from concentration measurement device
initial-data-path	path to file with data of initial composition of gas
{co-oxidation|co2-hydrogenation}	reaction for which to calculate data

parameters:

--conversion|--selectivity	whether to calculate conversion or selectivity for the specified reaction (at least one must be specified, can be specified both of them)
--ouput-data OUPUT_DATA	path to directory to save calculated data
--show-plot	whether to show data plot or not
--ouput-plot OUTPUT_PLOT	path to directory to save plot
--products-basis	calculate conversion based on products concentrations instead of reactants
--sample-name	sample name will be added to results data files and as a title to the resulting plots

To calculate conversion and selectivity for the reaction of interest program needs to know initial parameters, i.e. the ones before catalytic reaction started, and results of measurement at different temperatures of catalytic reaction. Minimal parameters are reaction participants concentrations in mol.% and temperatures of catalytic reaction. Parameters are provided as files with strictly defined format:

    Температура<tab>temperature
    <br>
    Название<tab>Время, мин<tab>Детектор<tab>Концентрация<tab>Ед, измерения<tab>Площадь<tab>Высота
    compound-name<tab>retention-time<tab>detector-name<tab>compound-concentration<tab>concentration-units<tab>peak-area<tab>peak-height
    [<br>
    Темп. (газовые часы)<tab>flow-temperature
    Давление (газовые часы)<tab>flow-pressure
    Поток<tab>flow-rate]
    

If program encounters file with wrong format, the file is ignored and corresponding warning is logged to console.

temperature	temperature of catalytic reaction which will be used as X coordinate	units does not matter, but expected to be the same for one series of experiment
compound-name	chemical formula of compound	table with these parametes is simply copy-pasted from chromatec analytics software
compound-concentraion	concentration of compound in mol.%
flow-temperature	temperature at the point of gas total flow rate measurement in °C	These parameters are optional and should be measured by means of gas clocks. If they are absent, program still will be able to calculate results, however, there will be error due to the change in reaction volume.
flow-pressure	pressure at the point of gas total flow rate measurement in Pa
flow-rate	gas total flow rate

Calculations are made using following equations:

CO oxidation

where
- CO conversion
, - concentrations of CO before and after catalytic reactor, respectively, in mol.%
, - total gas flow rates before and after catalytic reactor, respectively, in m³/s
, - pressure of gas at point of total gas flow rate measurement before and after catalytic reactor, respectively, in Pa
, - temperature of gas at point of total gas flow rate measurement before and after catalytic reactor, respectively, in K

CO₂ hydrogenation

where
- CO₂ conversion
, - concentrations of CO₂ before and after catalytic reactor, respectively, in mol.%
, - total gas flow rates before and after catalytic reactor, respectively, in m³/s
, - pressure of gas at point of total gas flow rate measurement before and after catalytic reactor, respectively, in Pa
, - temperature of gas at point of total gas flow rate measurement before and after catalytic reactor, respectively, in K

where
S - selectivity towards i^th component
- concentration of i^th component among CO, CH₄, C₂H₆, C₃H₈, i-C₄H₁₀, n-C₄H₁₀, i-C₅H₁₂, n-C₅H₁₂, in mol.%
n - stoichiometry coefficient in CO₂ hydrogenation reaction (number of C atoms in product molecule)

CO₂ hydrogenation, products basis

Sometimes the results obtained with above equation give erroneous results with large negative conversions. It is useful to calculate CO₂ conversion based on products. However, this method is prone to error due to the assumption, that only certain products are formed.

where
- concentration of CO₂ before catalytic reactor, respectively, in mol.%
- concentrations of p^th component among CO, CH₄, C₂H₆, C₃H₈, i-C₄H₁₀, n-C₄H₁₀, i-C₅H₁₂, n-C₅H₁₂, in mol.%
n - stoichiometry coefficient in CO₂ hydrogenation reaction (number of C atoms in product molecule)
, - total gas flow rates before and after catalytic reactor, respectively, in m³/s
, - pressure of gas at point of total gas flow rate measurement before and after catalytic reactor, respectively, in Pa
, - temperature of gas at point of total gas flow rate measurement before and after catalytic reactor, respectively, in K

If flow rate measurement data is not provided, conversion is calculated based solely on concentrations and warning is logged to console in this case.

Furnace control

Furnace control is performed with Owen TPM101 controller. Communication is over serial port. All configuration values must be in a config.py file and must match controller's settings.

pycat furnace set-temperature temperature

Set setpoint value of furnace controller to specified value.

positional arguments:

temperature

temperature in °C

pycat furnace print-temperature

Print current furnace temperature.

Chromatograph control

Chromatec Crystal 5000 chromatograph can be controled via modbus protocol. The protocol requires modbus server to be run. Chromatec Control Panel and Chromatec Analytic with special module from chromatec installation media surve as modbus server (see chromatec documentation for details). Before using this python program, modbus server must be configured at Control Panel and Analytic software and relevant holding and input registers must be added. For the list of required registers see config.py file at the root of pycatalycism package.

Commands:

pycat chromatograph set-method method

Sets instrumental method to the specified one and starts preparation to analysis step. The list of methods must be in a config.py file. If chromatec Control Panel or Analytic are not ON, starts these programs and connects to chromatograph. In this case, program waits for successful connection establishment, so, if chromatograph is not on, program will be hang forever.

positional arguments:

method

instrumental method

pycat chromatograph start-analysis

Starts measurement.

pycat chromatograph set-passport --name NAME [--volume VOL] [--dilution DIL] [--purpose {analysis|graduation}] --operator OP --column COL [--lab-name LN]

Set parameters to a passport of chromatogram. This method should be run only after the analysis step is over and before next analysis is started.

required parameters:

--name NAME	name of chromatogram
--operator OP	name of operator
--column COL	name of column

optional parameters:

--volume VOL	sample's volume, 0.5 by default
--dilution DIL	sample's dilution, 1 by default
--purpose {analysis|graduation}	purpose of chromatogram, analysis by default
--lab-name LN	name of lab, Inorganic Nanomaterials by default

Mass flow controllers

Program controls Bronkhorst F201CV mass flow controllers to control flow rates of He, CO2, O2, H2, CO or CH4 gases. Parameters of corresponding mass flow controllers must be added to config.py file.

pycat mfc set-flow-rate --gas {He|CO2|O2|H2|CO|CH4} --flow-rate FR

Set gas flow rate to specified value in nml/min

--gas {He|CO2|O2|H2|CO|CH4}	gas to set flow rate for. Program chooses mass flow controller based on this value
--flow-rate FR	Flow rate in nml/min

pycat mfc set-calibration --gas {He|CO2|O2|H2|CO|CH4} --calibration-number CN

Set calibration of specified mass flow controller to the calibration number CN

--gas {He|CO2|O2|H2|CO|CH4}	Gas to set calibration for. Program chooses mass flow controller based on this value.
--calibration-number CN	Calibration number which can be found in the documentaion supplied with mass flow controller

pycat mfc print-flow-rate --gas {He|CO2|O2|H2|CO|CH4}

Print current flow rate in nml/min for specified gas.

--gas {He|CO2|O2|H2|CO|CH4}

Gas to print current flow rate for. Program chooses mass flow controller based on this value.

ToDo

• write co_oxidation.py script
• rewrite calc module. Selectivity should be calculated automatically if applicable. There should be two separate commands to calculate activity and conversion
• add furnace read temperature interface
• convert p, T, f data from gas clock to SI units before usage