The FACT  FTPulp Pulp and paper Database 

The FACT FTpulp Database has been developed for thermodynamic and phase equilibrium calculations involving molten and solid alkali salts related to the combustion of black liquor in the recovery boiler of pulp and paper mills. It is also related to combustion and corrosion-related processes in biomass combustion

The FTpulp Database is a self-contained database for the Na-K-S-C-O-Cl-H system.  No additional phases from other databases are needed for calculations in this 7-component system.

The Gibbs energy parameters of the FTpulp Database have been obtained by critical analysis and optimization of all available thermodynamic and phase equilibrium data of the Na-K-S-C-O-Cl-H system.  These include electromotive force data (emf), calorimetric data (mixing enthalpies, dissolution enthalpies, heating curves, etc…), liquid-gas equilibria data (vapor pressures), and phase diagram data (liquidus, solubilities, eutectic temperatures, etc…).

List of optimized systems

1. Na-K-S system taking into account alkali polysulfide species Na₂Sn, K₂S_n (n=1-8) in the liquid phase and dissolution of alkali metal. Optimized taking into account solid-liquid-gas equilibria.

Reference:

Thermodynamic evaluation and optimization of the (Na + K + S) system. Daniel Lindberg, Rainer Backman, Mikko Hupa, Patrice Chartrand. The Journal of Chemical Thermodynamics, Volume 38, Issue 7, July 2006, Pages 900-915

2. Na⁺,K⁺//SO₄^2-,S₂O₇^2- system. Optimized taking into account solid-liquid-gas equilibria

Reference:

Thermodynamic evaluation and optimization of the (Na2SO4 + K2SO4 + Na2S2O7 + K2S2O7) system. Daniel Lindberg, Rainer Backman, Patrice Chartrand.

The Journal of Chemical Thermodynamics, Volume 38, Issue 12, December 2006, Pages 1568-1583

3. Na⁺,K⁺//CO₃^2-, SO₄^2-,S^2- system.

Reference:

Thermodynamic evaluation and optimization of the (Na2CO3 + Na2SO4 + Na2S + K2CO3 + K2SO4 + K2S) system. Daniel Lindberg, Rainer Backman, Patrice Chartrand. The Journal of Chemical Thermodynamics, Volume 39, Issue 6, June 2007, Pages 942-960

4. Na⁺,K⁺//CO₃^2-, SO₄^2-,Cl^- system. Thermodynamic data are identical to FTSalt database

Reference:

Thermodynamic evaluation and optimization of the (NaCl + Na2SO4 + Na2CO3 + KCl + K2SO4 + K2CO3) system. Daniel Lindberg, Rainer Backman, Patrice Chartrand.

The Journal of Chemical Thermodynamics, Volume 39, Issue 7, July 2007, Pages 1001-1021

PHASES

The following SOLUTIONS are found in the FTPulp solution database:

Salt-liquid                                                                                   FTPulp - Melt

High-temperature (Na,K)₂(CO₃,SO₄) solid solution                   FTpulp - Hexa

partially dissolving (Na,K)₂S

Low-temperature (Na,K)₂(CO₃,SO₄) solid solution                   FTpulp - OrtA        

            rich in Na₂SO₄

Low-temperature (Na,K)₂(CO₃,SO₄) solid solution                   FTpulp - OrtB        

            rich in K₂SO₄

Low-temperature (Na,K)₂(CO₃,SO₄) solid solution                   FTpulp - KCO        

            rich in K₂CO₃

Low-temperature (Na,K)₂(CO₃,SO₄) solid solution                   FTpulp - NKCB     

            rich in Na₂CO₃

Very-low-temperature (Na,K)₂(CO₃,SO₄) solid solution            FTpulp - NKCA     

            rich in Na₂CO₃

Glaserite, non-stoichiometric K₃Na(SO₄)₂                                              FTpulp - Gsrt

Alkali pyrosulfate (Na,K)₂S₂O₇ solid solution                            FTpulp - NPYR     

            rich in Na₂S₂O₇

Alkali pyrosulfate (Na,K)₂S₂O₇ solid solution                            FTpulp - KPYR     

            rich in K₂S₂O₇

Na-K BCC solid solution                                                           FT-Pulp - ALKA   

Alkali sulfide (Na,K)₂S solid solution                                        FTpulp - NAKS     

Alkali disulfide (Na,K)₂S₂ solid solution                                    FTpulp – KNS2     

Alkali chloride (Na,K)Cl solid solution                                      FTpulp - ACl          

            partially dissolving (Na,K)OH

Alkali chloride (Na,K)OH solid solution                                    FTpulp - AOH       

Note:  The FTPulp database is compatible with the FACT53 (FS53) Compound Database except for pure sulfur and solid sodium and potassium sulfides and polysulfides: Na₂S, Na₂S₂, Na₂S₄, Na₂S₅, K₂S, K₂S₂, K₂S₃, K₂S₄, K₂S₅, K₂S₆.  In general, the simultaneous use of data for Na₂S, K₂S, Na₂S_n, K₂S_n (n>1) from FTPulp and the Fact53 database may give rise to problems of compatibility.

 For calculations, data for the gas phase can be taken from the FACT53 database, except for pure sulfur species (S, S₂, S₃, ….)

The following compounds in FTPulp are either not in the FACT53 (FS53) database or are not compatible with it:

Na2K(s)                           S 

Na2S2O7                             S    L   

K2S2O7                            S1   S2    L   

KNaS2O7                             S    L   

KNaS                       S

Na2S                       S

Na2S2                      S

Na2S4                      S

Na2S5                      S

K2S                        S

K2S2                       S

K2S3                       S

K2S4                       S

K2S5                       S

K2S6                       S

S                          S1   S2     L     G

S2                         G

S3                         G

S4                         G

S5                         G

S6                         G

S7                         G

S8                         G

Note: The liquid and solid solutions in the NaCl-Na₂CO₃-Na₂SO₄-KCl-K₂CO₃-K₂SO₄ subsystem are identical to those in the FTSalt database.