Package: chemicals
ContentsKey Features & CapabilitiesInstallationDocumentationGetting StartedRoadmapLatest source codeBug reportsLicense informationCitationKey Features & CapabilitiesThe chemicals library features an extensive compilation of pure component
chemical data that can serve engineers, scientists, technicians, and anyone
working with chemicals. The chemicals library facilitates the retrieval and
calculation of:Chemical constants including formula, molecular weight, normal boiling and
melting points, triple point, heat of formation, absolute entropy of
formation, heat of fusion, similarity variable, dipole moment, acentric
factor, etc.Assorted information of safety and toxicity of chemicals.Methods (and their respective coefficients) for the calculation of temperature
and pressure dependent chemical properties including vapor pressure,
heat capacity, molar volume, thermal conductivity, surface tension, dynamic
viscosity, heat of vaporization, relative permittivity, etc.Methods to solve thermodynamic phase equilibrium, including flash routines,
vapor-liquid equilibrium constant correlations, and both numerical and
analytical solutions for the Rachford Rice and Li-Johns-Ahmadi equations.
Rashford Rice solutions for systems of 3 or more phases are also available.Data for over 20,000 chemicals are made available as local databanks in this
library. All databanks are loaded on-demand, saving loading time and RAM. For
example, if only data on the normal boiling point is required, the chemicals
library will only load normal boiling point datasets. This on-demand loading
feature makes the chemicals library an attractive dependence for software
modeling chemical processes. In fact,The Biorefinery Simulation and Techno-Economic
Analysis Modules (BioSTEAM)is reliant on the chemicals library for the simulation of unit operations.The chemicals library also supports integration withNumba, a powerful accelerator that works
well with NumPy;PintQuantity
objects to keep track of units of measure; and
NumPyvectorizedfunctions.If you need to know something about a chemical, give chemicals a try.InstallationGet the latest version of chemicals fromhttps://pypi.python.org/pypi/chemicals/If you have an installation of Python with pip, simple install it with:$ pip install chemicalsIf you are usingconda, you can install
chemicals from conda-forge channel:$ conda install -c conda-forge chemicalsTo get the git version, run:$ git clone git://github.com/CalebBell/chemicals.gitDocumentationchemicals’s documentation is available on the web:http://chemicals.readthedocs.io/Getting StartedThe library is designed around SI units. The retrieval of constant
chemical properties is done by CASRN:>>>fromchemicalsimportCAS_from_any,MW,Tb,Tm,Tc,Pc,Vc,Hfus,Hfs,Hfl,Hfg,S0s,S0l,S0g>>># Search for CASRN by a common name or a unique identifier such as the IchI key>>>CAS_water=CAS_from_any('Water')>>>MW(CAS_water)# Molecular weight [g/mol]18.01528>>>Tb(CAS_water)# Normal boiling point [K]373.124>>>Tm(CAS_water)# Melting point [K]273.15>>>Tc(CAS_water)# Critical temperature [K]647.096>>>Pc(CAS_water)# Critical pressure [Pa]22064000.0>>>Vc(CAS_water)# Critical volume [m^3/mol]5.59480372671e-05>>>Hfus(CAS_water)# Heat of fusion [J/mol]6010.0>>>Hfs('101-81-5')# Solid heat of formation of Diphenylmethane, [J/mol]71500.0>>>Hfl(CAS_water)# Liquid heat of formation [J/mol]-285825.0>>>Hfg(CAS_water)# Gas heat of formation [J/mol]-241822.0>>>S0s('101-81-5')# Absolute solid enthalpy of formation of Diphenylmethane [J/mol/K]239.3>>>S0l(CAS_water)# Absolute liquid enthalpy of formation [J/mol/K]70.0>>>S0g(CAS_water)# Absolute gas enthalpy of formation [J/mol/K]188.8Such “lookup functions” search through many databanks until the value for the
given CASRN is found. When no value is available, None is returned. Note that chemicals
is not a project to exhaustively obtain recommended property values for all properties
and chemicals; it is a collection of cited and openly published data and equations.You can optionally pass a “method” to select  which from databank to retrieve data:>>>Tb(CAS_water,method='YAWS')373.15To view all available methods for a given chemical, just use the functions with
“_methods” tagged at the end of the name:>>>fromchemicalsimportTb_methods>>>Tb_methods(CAS_water)['HEOS','CRC_INORG','COMMON_CHEMISTRY','WEBBOOK','YAWS','WIKIDATA']The databanks can also be accessed through their respective module:>>> from chemicals.critical import critical_data_Yaws
>>> critical_data_Yaws # doctest: +SKIP
                               Chemical       Tc         Pc        Vc  omega        Zc
CASRN
100-00-5           p-chloronitrobenzene   751.00  3980000.0  0.000432  0.491  0.275355
100-01-6                 p-nitroaniline   851.00  4420000.0  0.000406  0.782  0.253621
100-10-7    p-dimethylaminobenzaldehyde   832.00  3070000.0  0.000471  0.527  0.209027
100-18-5           p-diisopropylbenzene   689.00  2450000.0  0.000598  0.390  0.255749
100-21-0              terephthalic acid  1113.00  3950000.0  0.000424  1.059  0.180981
...                                 ...      ...        ...       ...    ...       ...
99814-65-0            1-pentadeceN-3-ol   713.00  1500000.0  0.000850    NaN  0.215149
999-21-3                diallyl maleate   693.00  2330000.0  0.000606  0.789  0.245054
999-52-0                3-chloroheptane   621.08  2693000.0  0.000476  0.418  0.248495
999-78-0         4,4-dimethyl-2-pentyne   552.81  3416000.0  0.000378  0.191  0.281303
999-97-3           hexamethyldisilazane   544.00  1920000.0  0.000613  0.510  0.260213[7549 rows x 6 columns]An extensive set of functions for calculating all sorts of chemical properties
are available along with their respective coefficients for a wide range of chemicals:>>> from chemicals import Antoine
>>> from chemicals.vapor_pressure import Psat_data_AntoinePoling
>>> antoine_coefficients = Psat_data_AntoinePoling.loc[CAS_water] # For calculating saturated vapor pressure
>>> antoine_coefficients  # doctest: +SKIP
Chemical     water
A              10.1
B          1.69e+03
C               -43
Tmin            273
Tmax            473
Name: 7732-18-5, dtype: object
>>> A, B, C = antoine_coefficients['A'], antoine_coefficients['B'], antoine_coefficients['C']
>>> T = 373.15 # Temperature [K]
>>> Antoine(T, A, B, C) # Vapor pressure [Pa]
101047.2535To use JIT compiled functions, import thenumbamodule:>>> from chemicals import numba  # doctest: +SKIP
>>> numba.Antoine(T, A, B, C)  # doctest: +SKIP
101047.2535To use Quantity objects, import theunitsmodule:>>> from chemicals import units
>>> from chemicals.units import u
>>> units.Antoine(T * u.K, A, B * u.K, C * u.K)
<Quantity(101047.254, 'pascal')>To use vectorized functions, import thevectorizedmodule:>>> from chemicals import vectorized
>>> vectorized.Antoine([300, 350], A, B, C)
array([ 3546.98, 41603.98 ])RoadmapThe authors’ main development item is to provide the latest methods
for the calculation of chemical properties (both thermodynamic and transport)
and extending the local databank.Latest source codeThe latest development version of chemicals’s sources can be obtained athttps://github.com/CalebBell/chemicalsBug reportsTo report bugs, please use the chemicals’s Bug Tracker at:https://github.com/CalebBell/chemicals/issuesLicense informationSeeLICENSE.txtfor information on the terms & conditions for usage
of this software, and a DISCLAIMER OF ALL WARRANTIES.Although not required by the chemicals license, if it is convenient for you,
please cite chemicals if used in your work. Please also consider contributing
any changes you make back, and benefit the community.CitationTo cite chemicals in publications use:Caleb Bell, Yoel Rene Cortes-Pena, and Contributors (2016-2023). Chemicals: Chemical properties component of Chemical Engineering Design Library (ChEDL)https://github.com/CalebBell/chemicals.