Example - 08 AQSol Projects

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Navigation: User Guide ➔ Example Projects ➔ 08 AQSol

AQSol Brine Concentrator

AQSol1.png.

Project Location

..\SysCADXXX\Examples\08 AQSol\AQSolLight\AQSol Brine Concentrator.spf

Features Demonstrated

  1. The use of AQSolModelCfg
  2. The use of AQSolEvaporator

Brief Project Description

  • This aim of this project is to recover water from the brine feed to be used as process water in the plant, the concentrated brine stream is sent off to the solar pond for further evaporation and crystallisation.
  1. Each AQSol project must contain at least one AQSolModelCfg model.
  2. The AQSol Evaporator operates in standalone or Flash Train modes.

Project Configuration

AQSolModelCfg

  1. The AQSol001 dll (AQSol00132.dll) is used by the project.
  2. Salts First algorithm has been selected for species re-building. See Reverse Mapping section for more details.

AQSol Reactor / Flash Tank

  1. The configuration of the AQSol Evaporator is very similar to the normal Evaporator, the main difference is to select the AQSol Chemistry model to be used.

AQSol Fractional Crystallization

AQSol2.png.

Project Location

..\SysCADXXX\Examples\08 AQSol\AQSolLight\AQSol Fractional Crystallization.spf

Features Demonstrated

  1. The use of AQSol Model Configuration
  2. The use of AQSol Reactor
  3. The use of AQSol Flash Tank
  4. The use of AQSol Feeder

Brief Project Description

  1. Each AQSol project must contain at least one AQSol Model Configuration model.
  2. The AQSol Flash Tank operates in standalone or Flash Train modes.

When building a TCE project, one common uncertainty is whether the feed composition is at equilibrium conditions. Here are a few ways to check this:

  1. Add a side calculator (AQSol Side Calc) to evaluate the stream once, then use the results as input into an AQSol Feeder.
  2. Add an AQSol Reactor and set this unit to use FeedT OpMode, with the CalcEnthalpyBal option turned off.
  3. Utilise an AQSol Feeder and input the feed using AQSol speciation. The AQSol Feeder will then reverse map the AQSol species into SysCAD species.

Project Configuration

AQSol Model Configuration

  1. The AQSol001 dll (AQSol00132.dll) is used by the project.
  2. Salts First algorithm has been selected for species re-building. See Reverse Mapping section for more details.

AQSol Feeder and SideCalc

  1. TSC_CHECK_SPECIATION:This unit is configured to evaluate the feed using AQSol speciation at the specified temperature. Since it is not a reactor, the delta heat change is not required, and the CalcEnthalpyBal option is turned off. If the stream composition is far from equilibrium and cannot be solved at the feed temperature, keeping CalcEnthalpyBal off is essential to prevent AQSol from attempting to solve an unsolvable stream.
  2. Salt_Brine_AQSol:The results from the TSC_CHECK_SPECIATION can be used as input in the AQSol Feeder to ensure the feed stream is at equilibrium conditions.

AQSol Reactor

  1. Mixer: This unit operates in enthalpy mode, with the CalcEnthalpyBal option always enabled. This mode calculates the heat for each input stream and the product. Therefore, for each iteration, a tank with two input streams will require at least three AQSol calculations. If the unit needs to iterate for an output temperature, the actual number of calls per iteration could be higher.
  2. NaCl Crystalliser: This unit operates in temperature mode. The CalcEnthalpyBal option can be either on or off. If this option is off, only one AQSol calculation will be performed at the output temperature. If you need to know the delta enthalpy for this unit, turn on the CalcEnthalpyBal option and let AQSol perform calculations for both the feed and the output, allowing the change in energy to be calculated.

Flash Tank

  1. Na2SO4_Crystallizer: The configuration of the AQSol Flash Tank is very similar to the normal FlashTank, the main difference is to select the AQSol Chemistry model to be used. This unit calculates the heat for each input stream and the products. Therefore, for each iteration, a flash tank will require at least three AQSol calculations. If the unit needs to iterate for an output temperature, the actual number of calls per iteration could be higher.

AQSol RO Plant

AQSol RO3.png

Project Location

..\SysCADXXX\Examples\08 AQSol\AQSolLight\AQSol RO Plant.spf

Features Demonstrated

  1. The use of AQSolModelCfg
  2. The use of AQSolReverseOsmosis

Brief Project Description

  1. Each AQSol project must contain at least one AQSolModelCfg model.
  2. This project demonstrates the use of the RO unit for calculating max permeate recovery.
  3. Influence of antiscalant. This is modelled by creating a second AQSol configuration where we allow supersaturation of NaCl and Na2SO4. The concentrate RO skid (RO6) uses this configuration in its calculation of maximum permeate recovery.

Project Configuration

AQSolModelCfg

  1. The AQSol00132 database is used by the RO 01 to 05 units.
  2. A second copy of AQSol00132 database is used by the RO 06 unit to emulate the influence of antiscalant.
    • SatIdx for Na2SO4 and NaCl compounds have been modified in the "AQSolConfig" tab.
  3. Salts First algorithm has been selected for species re-building in both model configuration files. See Reverse Mapping section for more details.

AQSolReverseOsmosis

  1. The configuration of the AQSolReverseOsmosis is similar to the normal Reverse Osmosis (RO) Unit, the main difference are:
    • select the AQSol Chemistry model to be used and
    • model method: MaxYield for maximum permeate recovery.

Simple Reactor Example

AQSolLight SimpleReactorExample.png

Project Location

..\SysCADXXX\Examples\06 AQSol\AQSolLight\SimpleReactor.spf

Features Demonstrated

  1. The use of AQSol Model Configuration
  2. The use of AQSol Reactor
  3. The use of AQSol Feeder
  4. The use of AQSol SideCalc

Brief Project Description

Each AQSol project must contain at least one AQSol Model Configuration model.

When building a TCE project, one common uncertainty is whether the feed composition is at equilibrium conditions. Here are a few ways to check this:

  1. Add a side calculator (AQSol Side Calc) to evaluate the stream once, then use the results as input into an AQSol Feeder.
  2. Add an AQSol Reactor and set this unit to use FeedT OpMode, with the CalcEnthalpyBal option set to OFF.
  3. Utilise an AQSol Feeder and input the feed using AQSol speciation. The AQSol Feeder will then reverse map the AQSol species into SysCAD species.

When using the AQSol reactor model, there are different operating modes you can select. Some modes would require a single AQSol equilibrium calculation while others would require iteration to achieve the results. This example project will show what these different modes are and when they should be selected.

  1. OpMode = FeedT: The equilibrium calculation will be isothermal, with the output temperature equal to the feed temperature.
  2. OpMode = Enthalpy: The equilibrium calculation will be isenthalpic, with the output temperature calculated. Use this mode where species composition changes and the delta energy change is important. For example, use this for all the reaction tanks where heat is released due to acid-base reactions.
  3. OpMode = Temperature: The equilibrium calculation will be isothermal, with the output temperature equal to the temperature setpoint.
  4. OpMode = Species Formation: This is demonstrated using a target calculation to determines the formation of a species.

Project Configuration

AQSol Unit models

  1. TR_001, TF_001
    • The AR_001 unit is set up to evaluate the feed using AQSol speciation at the specified temperature. This is not a real reactor, so the delta heat change is not important, and the CalcEnthalpyBal option is switched off. If the stream composition is far from equilibrium and not solvable at the feed temperature, having CalcEnthalpyBal off is crucial to prevent AQSol from trying to solve an unsolvable stream.
  2. TR_002, TR_011 and TR_12
    • These are all using the enthalpy operation mode. This mode calculates the heat for each input stream, as well as the heat for the product. Therefore, for each iteration, a tank with two input streams will require a minimum of three AQSol calculations. The CalcEnthalpyBal option is always on for this mode.
    • Heat loss has been added to TR_012.
  3. TR_011, TR_011A and TR_011B
    • The primary purpose of this set of reactors is to demonstrate how to configure the system to simulate reagent efficiency. Since some of the reagent may be unreactive, we can account for this by using the WithBypass option (as shown in TR_011A), which excludes the unreactive portion from the solution. When this option is enabled, the input stream used for the TCE calculation is reduced accordingly. The bypassed amount is then added back to the output to form the final discharge stream. TR_011B provides a visual representation of how the WithBypass function operates.
  4. TR_013
    • TR_013 is configured to calculate the temperature needed to produce x moles per hour of Na2SO4*10H2O. This involves an iterative process where the AQSol equilibrium calculation is repeatedly performed until a solution is achieved.

Note: For information on the number of TCE calculations performed per SysCAD iteration, please refer to the Usedby tab in the TMC unit model.

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