Separation and Mixing Processes in Petroleum Refining

       Flow splitting and flow mixing are fundamental operations in petroleum refining simulation and refinery process modeling. Refinery simulation models continuously distribute, combine, and route material streams between process units, storage facilities, pipelines, blending systems, and other operations. Flow splitting distributes one incoming stream among multiple downstream streams (1 → N), while flow mixing combines multiple incoming streams into a single output (N → 1). Both operations can use predefined flow ratios or operate without fixed ratios, depending on the modeling requirements. These operations can be represented by standalone components or embedded within more complex refinery components. By combining splitting and mixing operations, a refinery simulation model can represent complex refinery flow networks and routing configurations. As a result, flow splitting and mixing are basic building blocks of refinery process simulation, essential for representing material flow throughout a refinery.

       In a refinery simulation model, flow splitting distributes a single material stream between multiple downstream paths, while flow mixing combines multiple streams into one output.The required flow distribution can be controlled by predefined ratios or determined automatically when no ratios are specified, depending on the refinery flow model. For a flow splitter, the specified ratios define how the incoming flow is distributed between the available outlets. For a flow mixer, they define the required proportions of the incoming streams. If one input stream has a limited flow rate, the flow rates of the other streams are reduced to maintain the specified mixing ratio. When no ratios are specified, the flow is distributed automatically by the underlying AnyLogic flow system. Regardless of how the streams are distributed or combined, mass conservation and material balance must be maintained. During splitting, the incoming mass flow is distributed among the outlets, while during mixing, the incoming mass flows are combined into a single output flow. Splitting and mixing can also be combined to create more complex refinery flow networks. A stream can be split into several paths and selected streams can then be mixed again, allowing refinery models to represent a wide range of routing and processing configurations.

       Flow splitting and mixing occur throughout a refinery simulation model because material streams are continuously routed, combined, and redistributed between different refinery operations.
       They can be used to:
        - distribute a material stream between different refinery process units or operating lines;
        - route material to different tank farms and storage facilities;
        - combine intermediate streams before further processing;
        - connect pipelines and transfer systems;
        - direct products to different loading racks or destinations;
        - combine components for refinery product blending.
       These operations can appear as standalone flow-routing elements or be embedded in larger refinery components, including process units, tank farms, loading racks, and other flow-processing systems. This makes flow splitting and mixing an essential part of refinery model topology and material flow modeling. By combining these operations, a simulation can represent complex material-flow networks without requiring every routing configuration to be modeled as a separate specialized process.

       The AnyLogic Fluid Library provides basic components for splitting and combining fluid streams in simulation models. Fluid Split divides one incoming stream into two outputs, while Fluid Merge combines two incoming streams into one output. These binary components provide the basic flow-routing functionality needed in many fluid simulation models. Refinery models can also require more flexible configurations, such as distributing one stream among several destinations or combining multiple streams into a single product flow. The Petroleum Refining Library extends this basic functionality with components designed for petroleum refining simulation models. Its flow-splitting and mixing components support multiple input and output streams and provide additional control over material flow routing in refinery models. Petroleum Refining Library components are built on the underlying flow mechanisms of the AnyLogic Fluid Library, while adding functionality required for more complex refinery flow networks.

       The Petroleum Refining Library provides four components for flow splitting and mixing in refinery simulation: Separator, Separator Lite, Mixer, and Mixer Lite. The Separator distributes one incoming material stream among multiple outputs, supporting a 1 → N flow configuration. Separator Lite provides a 1 → 2 configuration with the ability to reliably direct the flow to a selected outlet. The Mixer combines multiple incoming material streams into a single output, supporting an N → 1 flow configuration. Mixer Lite provides a simpler 2 → 1 configuration.These components can be used as standalone elements or as building blocks within more complex Petroleum Refining Library components. Their combination allows refinery models to represent a wide range of material-flow and routing configurations. Detailed properties, parameters, methods, and operating behavior of each component are covered in dedicated articles and tutorials in the Petroleum Refining Library documentation.

       Flow splitting and mixing are fundamental building blocks of petroleum refining simulation and refinery process modeling. They allow material streams to be distributed between multiple destinations, combined into common flows, and connected into complex refinery flow networks. These operations can be used independently or combined to represent the topology of process units, tank farms, pipelines, blending systems, and other refinery operations. The Petroleum Refining Library extends the basic flow capabilities of the AnyLogic Fluid Library with components for multi-stream splitting and mixing, providing additional flexibility for refinery flow modeling and digital twin development.

1. What is flow splitting in petroleum refining simulation?
Flow splitting is the distribution of one incoming material stream among multiple downstream streams. It is typically represented as a 1 → N flow configuration.

2. What is flow mixing in petroleum refining simulation?
Flow mixing is the combination of multiple incoming material streams into a single output stream in petroleum refining simulation, typically represented as an N → 1 configuration.

3. Why are flow splitting and mixing important in refinery simulation?
They are fundamental operations for routing and combining material streams between refinery process units, tank farms, pipelines, blending systems, and other refinery operations.

4. What is the difference between a Separator and a Mixer in Petroleum Refining Library?
A Separator distributes one incoming stream among multiple outputs, while a Mixer combines multiple incoming streams into one output.

5. What is the difference between Separator and Separator Lite?
Separator supports multiple output streams, while Separator Lite provides a simpler two-output configuration with additional flow-routing control.

6. What is the difference between Mixer and Mixer Lite?
Mixer supports multiple input streams, while Mixer Lite provides a simpler two-input configuration.

7. How does flow splitting work when split ratios are specified?
The specified ratios define the required proportions between the output streams.

8. How does flow mixing work when mixing ratios are specified?
The specified ratios define the required proportions of the incoming streams. The mixer maintains these proportions when combining the streams.

9. What happens when no flow ratios are specified?
The flow is distributed automatically by the underlying AnyLogic flow system.

10. Does flow splitting and mixing preserve mass balance?
Yes. Mass conservation is maintained: the incoming mass is distributed between outlets during splitting and combined into the output during mixing.

11. Can splitting and mixing be combined in one refinery model?
Yes. Separators and mixers can be connected in different sequences to create complex flow-routing configurations, including multiple splitting and mixing stages.

12. How does Petroleum Refining Library extend the AnyLogic Fluid Library?
AnyLogic provides basic binary Fluid Split and Fluid Merge components. Petroleum Refining Library builds on this functionality with components that support multi-stream flow splitting and mixing and additional refinery flow-routing capabilities.