Reaction path model flush

Flush The flush reaction path model is analogous to the perfectly mixed-flow reactor or the continuously stirred tank reactor in chemical engineering (Figure 2.5). Conceptually, the model tracks the chemical evolution of a solid mass through which fresh, unreacted fluid passes through incrementally. In a flush model, the initial conditions include a set of minerals and a fluid that is at equilibrium with the minerals. At each step of reaction progress, an increment of unreacted fluid is added into the system. An equal amount of water mass and the solutes it contains is displaced out of the system. Environmental applications of the flush model can be found in simulations of sequential batch tests. In the experiments, a volume of rock reacts each time with a packet of fresh, unreacted fluids. Additionally, this type of model can also be used to simulate mineral carbonation experiments. 

It should be noted that the flush model, other reaction path models, such as the fluid-centered reaction path model, and models with the dump option (see Wol-ery, 1992), have become less useful for their originally intended uses in simulating reactive transport. Although the extent of reactions is often monitored by the reaction progress variable (f), no temporal information is included in the model. Additionally,... 

In Chapter 2 we discussed three special configurations for tracing reaction paths the dump, flow-through, and flush models. These models are special cases of mass transfer that can be implemented within the mathematical framework developed in this chapter. 

---