Mass in minus mass out plus generation equals accumulation.
For any system: input + generation = output + consumption + accumulation. Steady state sets accumulation to zero. Procedures: draw a flowsheet, choose basis, write balances per component, solve. Recycle, purge and bypass streams complicate the calculation.
A distillation column balance finds product flows from feed composition.
A material balance accounts for every mass flow in a process, so it reveals losses, recycle flows and the true size of equipment.
Mass in minus mass out plus generation equals accumulation.
A material balance accounts for every mass flow in a process, so it reveals losses, recycle flows and the true size of equipment.
Mass in minus mass out plus generation equals accumulation, which applies to each component and to total mass.
When flows and accumulation are constant with time, so the accumulation term is zero and the balance is simpler.
Typical applications include checking the mass of solvent lost in a distillation column, sizing a recycle stream in an ammonia plant and confirming the yield of a reactor from measured inlet and outlet flows.
Study "Stoichiometry" first (topic 64 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
Degrees of freedom analysis. Tie components. Atomic balances.
A distillation column balance finds product flows from feed composition.
The next topic is "Energy balances in processes", which builds directly on this one.
It is classed as Intermediate in Materials & Chemical (topic 65 of 100). It is an intermediate topic. Work through the beginner topics in Materials & Chemical first.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.