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What's New in DWSIM

DWSIM 10 DWSIM 9

1. New Features

1.1 Artificial Intelligence

Date Feature Description
2025-2026 AI-Powered Flowsheet Analysis Automatic AI analysis of the flowsheet, detecting issues and improvement opportunities.
2025-2026 AI Assistant Integrated conversational assistant with support for multiple backends: Ollama (local/offline), LM Studio, llama.cpp, AWS Bedrock, and Google Gemini. Features: flowsheet interaction, report generation, plant data integration, RAG knowledge base, file attachments, chat history, SSL/TLS.
2025-2026 AI-Assisted Convergence Enhancer AI module for solver convergence improvement, featuring a trainable neural network, multiple assistance levels, automatic training data generation, and automatic model retraining.
May/2026 DWSIM MCP Server MCP (Model Context Protocol) server that exposes flowsheets, streams, unit operations, and thermodynamic calculations for integration with external LLM agents. Full documentation with examples.
May/2026 AI Code Assist (Python Vibe Scripting) AI assistance for generating and editing Python code in scripts, with a code diff viewer (FormCodeDiff).
May/2026 AI-Assisted Heat Exchanger Sizing AI-assisted generation of heat exchanger configurations.
Apr/2026 Fluent API Fluent API in Python/VB.NET for programmatic flowsheet automation, with integrated contextual help and a validation test suite.
Apr/2026 LLM Token Usage Statistics Display of token consumption statistics in AI assistant calls.

1.2 Techno-Economic Analysis and Life Cycle Assessment

Date Feature Description
2025-2026 Techno-Economic Analysis (TEA) Complete techno-economic analysis module: equipment cost correlations, automatic capacity parameter extraction, cost indices, vessel sizing, direct and indirect capital cost estimation, operating cost, cash flow (NPV, IRR, payback, ROI), breakeven analysis, sensitivity analysis, Monte Carlo, scenario comparison, Eco-Efficiency Index, CSV export, and programmatic API.
2025-2026 Life Cycle Assessment (LCA) Complete LCA module: 4 phases (scope definition, inventory, impact assessment, interpretation), normalization and weighting, characterization factor database, electricity mix database, AI-assisted analysis.
2025-2026 TEA/LCA Integration Combined techno-economic and environmental analysis module with support for joint optimization and sensitivity analysis.

1.3 New Unit Operations (General)

Date Feature Description
2025-2026 Safety Valve (PSV/Relief Valve) Safety valve with characteristic curves, correction coefficients, orifice area calculation, and detailed specifications.
2025-2026 Fired Heater Process heater model with radiant, shield, and convection sections. Configurations: vertical cylindrical, cabin, and multi-pass. Combustion model, draft model, thermal efficiency, and emissions.
2025-2026 Zeolite Adsorber Zeolite adsorber with isotherm models, working capacity, PSA mode, pressure drop (Ergun equation), adsorption heat estimation, and built-in zeolite presets.
2025-2026 Copper Bed Mercury Adsorber Mercury copper bed adsorber with isotherm models, Wheeler-Jonas breakthrough model, mercury mass balance, pressure drop, and adsorbent presets.
2025-2026 Pipe Network Pipe network simulation (nodes and connections) with pressure drop models, thermal model, and network solver.
2025-2026 Restriction Orifice Restriction orifice with configurable geometry, ISO 5167-2 correlations, discharge coefficient, expansion factor, and iterative solution procedure.
2025-2026 Advanced Heat Exchanger Rigorous shell-and-tube heat exchanger with the Bell-Delaware method, incremental integration (rating mode), two-phase heat transfer correlations, vibration analysis, design/simulation/fouling modes.
2025-2026 Vapor Compression Chiller Vapor compression chiller with thermodynamic model, evaporator and condenser specifications, and equipment sizing.
2025-2026 Air Cooler 2 Second air cooler model using Gnielinski/Petukhov (tube side), Holman (air side), epsilon-NTU method, and evaporation profile.
2025-2026 Falling Film Evaporator Falling film evaporator with stepwise integration, phase separation, and evaporation profile.
2025-2026 Energy Mixer / Energy Splitter / Energy Stream Switch Three new operations for routing energy streams in the flowsheet.
2025-2026 Material Stream Switch Conditional material stream routing with expression-based logic.
2025-2026 Material Stream Mapper Compound mapping between streams with override options.
2025-2026 Thermo Property Editor Thermodynamic property editor for streams to fine-tune calculation results.
Mar/2026 Information Carrier New logical stream type for transporting non-material information between operations.

1.4 New Bioprocess Operations

Date Feature Description
Apr/2026 Biogas Upgrader Biogas purification and upgrading operation.
Apr/2026 Cell Lysis / High-Pressure Homogenizer Cell lysis and high-pressure homogenizer for downstream processing.
Apr/2026 Centrifuge Centrifuge for biomass and liquid separation in bioprocesses.
Apr/2026 Chromatography Purification chromatography with trajectory models and detailed results.
Apr/2026 Crossflow Ultrafiltration / Diafiltration (UF/DF) Crossflow ultrafiltration/diafiltration with trajectory results.
Apr/2026 Crystallizer Crystallizer with yield and kinetics models.
Apr/2026 Biomass Pretreatment Lignocellulosic biomass pretreatment for biorefinery applications.
Apr/2026 Anaerobic Digester (ADM1-Lite) Anaerobic digester with ADM1 (Anaerobic Digestion Model No. 1) implementation, ODE integrator, parameter regression, and 3 pre-configured samples (BSM2 Mesophilic, Swine Manure, Thermophilic 55 C).
May/2026 BioReactor: Batch and Fed-Batch Modes Batch and fed-batch operating mode support in the BioReactor, modeled as cycle-averaged steady state.

1.5 Refining Operations

Date Feature Description
2025-2026 Shared Contaminant Vector Shared contaminant vector across refining operations for consistent tracking along the process train.
2025-2026 PNA-Aware Yield Modulation Yield modulation based on PNA composition (Paraffins-Naphthenes-Aromatics) for refining operations.
Apr/2026 Contaminant Editor for Petroleum Characterization Dedicated panel for contaminant definition in the C7+ and pseudo-component characterization tools.

1.6 New Property Packages

Date Feature Description
2025-2026 Electrolyte NRTL (eNRTL) Electrolyte NRTL package with Pitzer-Debye-Huckel and local NRTL terms, mean ionic activity coefficient.
2025-2026 Extended UNIQUAC Extended UNIQUAC with Debye-Huckel electrostatic term for electrolyte systems.
2025-2026 Sour Water (Edwards Model) Sour water model (H2S, CO2, NH3).
2025-2026 Patel-Teja Patel-Teja cubic equation of state.
2025-2026 Schmidt-Wenzel Schmidt-Wenzel cubic equation of state.
2025-2026 Cubic-Plus-Association (CPA) CPA equation of state with molecular association contribution.
2025-2026 PC-SAFT Perturbed-Chain Statistical Associating Fluid Theory.
2025-2026 SPC-SAFT Simplified PC-SAFT.
2025-2026 SAFT-VR Mie SAFT with Mie potential and residual Helmholtz free energy.
2025-2026 SAFT-VRQ Mie SAFT-VR Mie with quantum correction (for H2, D2, He).
2025-2026 MBWR (Modified Benedict-Webb-Rubin) MBWR19 and MBWR32 equations for pure fluids.
2025-2026 NIST-MEOS NIST Multiparameter Equation of State with high accuracy for selected fluids.
2025-2026 ThermoPack Backend ThermoPack computational backend supporting multiple equations of state.
2025-2026 H2O-HCl (Pitzer) Pitzer model for the H2O-HCl system with crystalline gas hydrate.
Apr/2026 CoolProp Updates Updates and fixes to CoolProp support.

1.7 Corrosion & Scaling Monitor

Date Feature Description
2025-2026 Corrosion & Scaling Monitor Complete new module ionic speciation, corrosion rate models (Waard-Williams CO2, dissolved O2, H2S/SSC), scaling indices, remaining useful life estimation, chemical inhibitor dosing, and incremental analysis in heat exchangers.

1.8 Phase Envelope and Thermodynamics

Date Feature Description
May/2026 Phase Envelope Lookup Table for Streams Generation, storage, and lookup of the phase envelope directly from a material stream, with dedicated editors.
Apr/2026 PhaseQ - Phase Equilibrium Database ThermoML JSON parser (NIST mds2-2422), fluent PhaseEqQuery builder, Herington and Van Ness consistency tests, DOI enrichment via Crossref, and InChIKey search. Integrated into the Data Regression module.
Apr/2026 Local Pure Compound and Equilibrium Database Local database tools for pure compounds and phase equilibria.
Mar/2026 Immiscible Liquids Option Automatic LLE initialization from the list of compounds flagged as immiscible.
Mar/2026 Oslo ODE Solver for PFR Microsoft.Research.Oslo library as an alternative ODE solver for the PFR.
Mar/2026 New CSTR Solver CSTR solution algorithm completely rewritten.

1.9 Extensibility and Automation

Date Feature Description
Apr/2026 Unit Operation Extensions System Framework for loading, saving, and managing UO extensions (FormUnitOperationExtensionManager).
May/2026 Integrated Tutorials Tutorial menu embedded directly in the main interface.
Apr/2026 Markdown Report Viewer New report viewer supporting Markdown format.
Apr/2026 MaterialStream.GetMassEnthalpyAt() New API method to obtain the mass enthalpy of a stream at specific conditions (T, P).
Mar/2026 Flowsheet Metadata Editable metadata fields (author, description, version, keywords) for flowsheets.
Apr/2026 Offline HTML Help Fully offline help documentation bundled in the installation package.
Dec/2025 ZIP Format Support for Flowsheets Flowsheets can be saved and opened in the compressed .zip format.
Dec/2025 Plugin Loading from App Data Folder Plugins and extensions can be installed in the DWSIM application data folder, without requiring access to the installation directory.
Apr/2026 XML API Documentation XML documentation added to public APIs for IntelliSense support.

1.10 Interface and User Experience

Date Feature Description
Mar/2026 Auto-Split Stream on UO Drop Dragging a stream over a unit operation on the canvas automatically splits and reconnects it.
Feb/2026 New Welcome Screen DWSIM startup screen redesigned.
Feb/2026 New Loading Bar Loading progress bar redesigned.
Feb/2026 Stream Property Editing in Side Panel Stream properties are now editable directly in the side panel.
Apr/2026 More Realistic Equipment Icons Canvas icons updated to more realistic visual representations of actual equipment.
Dec/2025 DWSIM Version 10 New splash screen and updated version number.

2. Improvements to Existing Features

Date Feature Description
May/2026 ADM1-Lite: CO2 from Carbon Balance CO2 generation now computed from the carbon balance instead of a fixed 44/16 mass ratio.
May/2026 ADM1-Lite: Biomass Decay Mapping Biomass decay correctly mapped to biomass compound output (inert sludge).
May/2026 Phase Envelope: Convergence Near Critical Point Ziervogel & Poling algorithm implemented for better convergence in the critical region.
May/2026 Phase Envelope: LLE Check Composition check for liquid-liquid equilibrium during phase envelope construction.
May/2026 Phase Envelope: SLE Line on Diagram SLE (solid-liquid equilibrium) curve added to the phase diagram.
Apr/2026 Data Regression: Full Refactor Data regression module refactored with direct integration into the property package editor.
Apr/2026 PFR: Catalyst Particle Sphericity New sphericity parameter for more accurate pressure drop calculation in catalytic beds.
Apr/2026 Heat Exchange in PFR and CSTR Full heat exchange profile support along the PFR and CSTR.
Apr/2026 KDB VLE Database Access Restored KDB (Kyoto Data Bank) VLE equilibrium database access restored.
Mar/2026 Heat Exchanger: Co-Current and MITA Calculation Fixed co-current maximum heat transfer calculation; computed MITA (Minimum Internal Temperature Approach) now available.
Mar/2026 New Nested Loops v2 Algorithms New NL v2 flash implementations with improved performance and stability.
Mar/2026 Column and Flash Algorithm Optimizations Bug fixes and optimizations in the rigorous column, flash, critical point, and phase envelope algorithms.
Mar/2026 Distillation Column Dynamic Initialization Improvements to the column initialization routine in dynamic mode.
Apr/2026 Volumetric Split Specification in Splitter Option to specify the split by volumetric fraction in the stream splitter.
Mar/2026 Sensitivity Analysis: Error Propagation Solver errors during sensitivity analysis are now captured and reported instead of silently ignored.
Jan/2026 Dynamic Mode Clock Synchronization Improved clock synchronization during dynamic simulation.
Apr/2026 Dependency Security Updates Third-party packages updated for security reasons.
Dec/2025 Cross-Platform UI: Additional Buttons and Menu Reordering Additional buttons and menu reordering improvements in the cross-platform UI (Eto.Forms).
Dec/2025 Heat of Combustion Plugin in Cross-Platform UI Heat of combustion plugin now available in the cross-platform UI.
Jan/2026 Heating/Cooling in Separator (Vessel) Support for heat duty directly in the two-phase/three-phase separator operation.
Nov/2025 Vessel Heat Balance + Dynamic Property Editor Full heat balance for vessels; dynamic property editor for operations in dynamic mode.

3. Bug Fixes

Date Issue Description
May/2026 - ADM1-Lite: Reverted biomass decay recycle that was overcounting CH4 production.
May/2026 - ADM1-Lite: Fixed mass balance, HRT/volume consistency, and biomass decay.
May/2026 - ADM1-Lite: Fixed effluent COD conversion (g/L = kg/m3, no extra divide-by-1000).
May/2026 - BioReactor: Fixed 1000x scale error in calculated concentration.
May/2026 - TheoreticalCOD: Fixed formula that was doubling the O2 demand.
May/2026 - BioReactor: Fixed 1000x scale error in biogas flow rate and heat display.
Apr/2026 #990 Spreadsheet: Could not link more than 4 streams simultaneously.
Apr/2026 #1040 Properties: COSTALD liquid density model returning results inconsistent with benchmarks.
Apr/2026 #1041 CSTR: Adiabatic CSTR did not converge for certain reactor volumes.
Apr/2026 #1060 Property Table: Reaction extent not displayed correctly when name contained a colon.
Apr/2026 #1061 Pipe Segment: Thermal profile with overly optimistic (underestimated) heat losses.
Apr/2026 #1063 Pipe Segment: Same as #1061, distinct case.
Apr/2026 #1062 Conversion Reactor: Outlet temperature calculated incorrectly in adiabatic mode.
Apr/2026 - Undo/Redo: Fixed issues with undo/redo functionality.
Apr/2026 #1044 Flash: Second liquid phase absent from the phase equilibrium calculation result.
Apr/2026 - Flash algorithms: General stability fixes.
Mar/2026 #1028 Pipe Segment: Incorrect material mapping in tabulated data (wrong index 5).
Mar/2026 #1023 Interface: Crash when opening the FOSSEE custom model repository in DWSIM 9.0.5.
Mar/2026 #1016 Canvas: Crash when using "Copy flowsheet as image".
Mar/2026 - PFR: Fixed incorrect liters to m3 unit conversion.
Mar/2026 - PFR: Tentative fix for negative molar flows in PFR.
Mar/2026 #1019 PFR: Error in the calculated profile header.
Mar/2026 - NL: Fix in the Nested Loops flash algorithm.
Mar/2026 - HX/Vessel: Several fixes in the heat exchanger and separator vessel.
Feb/2026 - Unit conversion: Fixed kW to Tons of Refrigeration (TR) conversion.
Feb/2026 - UI: Workaround for unwanted sound when pressing Enter in text boxes.
Dec/2025 - Steam Tables: Fixed issue in steam tables (IAPWS-IF97).
Dec/2025 #937 Reactors: Rate-based and advanced kinetics specification with incorrect behavior.
Dec/2025 #968 Pipe Segment: Pressure drop not varying with inner diameter and length.
Changes since v9.0.4:
  • Implemented Unit Operation state restore after error (Beta)
  • Implemented Hydrocarbon solubility in water for Nested Loops Immiscible Flash
  • Fixed an issue with Nested Loops Three-Phase Flash
  • Fixed an issue with Bulk Petroleum Characterization Tool (Classic UI)
  • Fixed an issue with Orifice Plate Unit Operation
  • Fixed issue with Flowsheet Unit Operation
  • Fixed issue #875: Conversion and Concentration Profile Tab missing from Results Section in PFR
  • Fixed issue #801: Buttons in Element Matrix editor is missing
  • Fixed issue #887: Error running a flowsheet block that uses a kinetics reaction script
  • Fixed issue #893: Option to Change Integration Step/ODE Solver Volume Step for PFR in macOS/Windows Cross Platform OS is not available
  • Other minor fixes and UI enhancements
© 2026 Daniel Wagner Oliveira de Medeiros. All Rights Reserved.