Pyrohydrolysis of metal chlorides ... - OLI Software Download...Berthold, OLI (speaker) OLI...
Transcript of Pyrohydrolysis of metal chlorides ... - OLI Software Download...Berthold, OLI (speaker) OLI...
Pyrohydrolysis of Metal
Chlorides Feasibility
StudyOliver Gnotke, Kronos International, Inc. & Jim
Berthold, OLI (speaker)
OLI Simulation Conference October 25, 2016
• Production titanium dioxide creates significant amounts of an aqueous metal chloride solution as a by-product. – Land filling of the solid residue is the normal waste removal process
– pyrohydrolysis is a viable way to convert metal chlorides from TiO2 production into the valuable products hydrochloric acid and metal oxides with iron oxide as main component.
• The metal chloride solutions are complex highly concentrated aqueous solutions of di- and trivalent iron chlorides, other metal chlorides and hydrochloric acid.
• Kronos followed a theoretical approach for a feasibility study to assess the pyrohydrolysis process. – As a first step it was essential to evaluate the applicability of OLI Stream Analyzer for
metal chloride solutions.
– For the simulation of a pyrohydrolysis process especially the prediction of solubility limits of salts and vapor pressures of HCl are important .
– Available literature data was taken for the system FeCl2-HCl-Water and compared with OLI results. The deviation of OLI results and literature data were quite small. This qualified OLI as a valuable tool for the feasibility study.
Abstract
• Pyrohydrolysis: Convert metal chloride solution
into metal oxide and HCl
• Reaction is carried out in fluidized bed or spray
tower at temperature of 600-800°C
• HCl is recovered from gas stream by absorption
columns
Pyrohydrolysis Reaction
4 FeCl2 + 4 H2O + O2 2 Fe2O3 +8 HCl
2 FeCl3 + 3 H2O Fe2O3 +6 HCl
Manufacturing of Titanium Dioxide & potential benefit of
Pyrohydrolysis
Chloride
Process
Rutile
HCl
Leaching
Ilmenite
(High Iron
content)
Neutralisation
& Landfill
Metal
Chloride Pyrohydrolysis
Metal
Chloride Pyrohydrolysis
HCl
Chlorine
TiO2
Metal Oxide
HCl for sale
HCl
Metal chloride solution
Metal chloride solution
PROCESS
Zr, Nb) Steelworks Nickel Production
Metal Separation
Ore Processing Scrap
Pickling Line
Dissolving Station
Extraction Liquid
Extraction Liquid
Dissolving Station
Reactor
Fuel
Air
Cyclone
Venturi
Separator
Absorber Scrubber
Fan
Stack
Off-Gas
Regenerated Acid Treated Oxide Oxide
• Reactor, Cyclone,
Oxide Station
• Preconcentration
• HCl-Absorption
• Gas Cleaning
System
Process Stages:
KRONOS project
• Feasibility Study for Pyrohydrolysis using
OLI
• No pilot unit available
• Economic assessment
• First step: Check OLI Stream Analyzer
results against available literature data
• 0,16 kg/kg HCl und 0,16 kg/kg FeCl2
Vapour Pressure as a function of temperature
0
0,1
0,2
0,3
0,4
0,5
0,6
40 50 60 70 80 90 100
Pre
ssu
re [
ba
r]
Temperature [°C]
Literature
OLI
• Comparison OLI with literature data [Che70 ] @70°C, FeCl2-conc. 0,78
mol/l
• OLI Bubble point calculation, variable pressure
Gas phase composition in the system FeCl2-Water-HCl
0,0001
0,001
0,01
0,1
1
0,00 0,10 0,20 0,30
Mo
l% H
Cl
in g
as p
ha
se
HCl liq. conc. [kg/kg]
Literature OLI
• Comparison OLI with literature data [Che70 ] @70°C, FeCl2-conc.
0,78 mol/l
• Good prediction of azeotrope
System pressure
0
0,05
0,1
0,15
0,2
0,25
0,3
0,35
0,00 0,05 0,10 0,15 0,20 0,25 0,30
To
tal
pre
ssu
re [
ba
r]
HCl-conc. liq.[kg/kg]
Literature
OLI
• HCl concentration in gas phase higher with addition of FeCl2
• Azeotrope shifted by FeCl2 addition
• Solutions with high salt concentrations could deliver over azeotropic hydrochloric acid
(i.e. > 20% HCl)
OLI prediction on influence of FeCl2
1,00E-04
1,00E-03
1,00E-02
1,00E-01
1,00E+00
0 0,1 0,2 0,3
Mo
l% H
Cl
in g
as p
ha
se
HCl liq. conc. [kg/kg]
OLI with FeCl2
OLI without FeCl2
0
0,05
0,1
0,15
0,2
0,25
0,3
0,35
0 0,1 0,2 0,3
Pre
ssu
re [
ba
r]
HCl-conc. liq [kg/kg]
OLI with FeCl2
OLI without FeCl2
FeCl2 /FeCl3 in HCl solubility data from OLI database
0
10
20
30
40
50
60
0 10 20 30 40
wt%
-FeC
l2
wt%-HCl
0C
20C
40C
60C
100C
FeCl2.2H2O
FeCl2.4H2O
FeCl2.6H2O
FeCl2.4H2O
FeCl2.2H2O
0
5
10
15
20
25
30
0 5 10 15 20 25 30m
-FeC
l3
m-HCl
t=25C
FeCl3.6H2O
FeCl3.3.5H2O
FeCl3.2.5H2O
FeCl3.2H2O
FeCl3.HCl
OLI comparison MgCl2 solubility in HCl
0
5
10
15
20
25
30
35
40
0 5 10 15 20 25 30 35 40 45 50
Mg
Cl2
, w
eig
ht
%
HCl, weight %
Magnesium Chloride Solubility in Hydrochloric Acid
-20C
-8C
0C
25C
38C
48C
60C
70C
• Good prediction of OLI both in
– VLE
– Solubility
• Valuable tool for the chloride system
• Next possible step
– Coupling of OLI with ASPEN for full flowsheet
simulation of Pyrohydrolysis
– Aspen needed for high temperature
equipment
Conclusions
• [Che70] Chen, McGuire, Lee: Vapor-Liquid Equilibria of the Hydrochloric Acid-Ferrous
Chloride-Water System. Journal of Chemical and Engineering Data, Vol. 15, No.2, 1970
• [Sch52] Schimmel, F.A.: The Ternary System Ferrous Chloride-Hydrogen Chloride-
Water, Ferric Chloride-Ferrous Chloride-Water, 1952
• Pyrohydrolysis: Fundamentals and Applications for the Ferrous and Non-Ferrous Metallurgy,Dr.
Frank H. Baerhold, Dr. Albert Lebl, Rewas '99: Global Symposium on Recycling, Waste Treatment
and Clean Technology by I. Gaballah (Editor), J. Hager (Editor), R. Solozabal (Editor)
Literature
• Dr.-Ing. Oliver Gnotke, born 1971 in Düsseldorf /Germany is the team leader Chloride Process development for Kronos International, Inc., Leverkusen/Germany a leading producer of titanium dioxide with 6 production locations worldwide. He works for Kronos since 12 years having positions in different technical departments. His main responsibility is the optimization of the production sites with respect to cost, quality and throughput. He has wide experience with CAE tools as for example flowsheet simulation, CFD and thermodynamic properties estimation.
• Prior to his work for Kronos he worked from 1999-2004 as research assistant at the Chair of Energy Technology, University of Darmstadt/Germany. His main research topics were experimental studies and simulation of multiphase flow in chemical and power plants. Graduated 2004 to PhD (Dr.-Ing.).
• He started his studies as Chemical Engineer at the University of Dortmund, Germany. During university studies he made several internships in the chemical industry as Bayer, Henkel, CFPI (France) and Lurgi Engineering where he optimized polymerization reaction using numerical simulations.
Biography