Guide
Material & Energy Balances
Checking Energy-Balance Units Before Using a Heat-Duty Result
A heat-duty number is only trustworthy if every factor in the energy balance uses compatible units. Check the mass basis of each flow,…
ENGINEERING TOPIC
Material & Energy Balances
Mass and molar flow, mixing, and material and energy balances.
08 RESOURCES
Resources
Guide
Material & Energy Balances
How to Organize Known and Unknown Variables Before Solving a Balance
Organizing knowns and unknowns before solving a balance means defining the system, choosing a basis, listing every known quantity with its units, assigning…
Guide
Material & Energy Balances
A Steady-State Mixing Balance with Two Inlet Streams
At steady state, a mixer that combines two inlet streams obeys two balances: total mass in equals total mass out (P = F1…
Guide
Material & Energy Balances
Choosing a Calculation Basis for a Material Balance
A calculation basis is the reference quantity — an amount of material such as 100 kg, or a time interval such as one…
Guide
Material & Energy Balances
How to Write Assumptions for an Engineering Calculation
Every engineering calculation rests on assumptions. Write each one explicitly and separately, give it a stated basis, quantify it where possible, and record…
Guide
Material & Energy Balances
Mole Fraction vs Mass Fraction: Conversions and Examples
Mole fraction compares a component's share of the molecules in a mixture, while mass fraction compares its share of the mass. Because components…
Guide
Material & Energy Balances
Converting Mass Flow to Molar Flow: Formula and a Worked Example
Divide the mass flow rate by the stream's molecular weight to get the molar flow rate: ṅ = ṁ / M. For example,…
Guide
Material & Energy Balances
Material and Energy Balances: A Worked-Example Guide
Material and energy balances are the conservation-law accounting statements that underpin chemical process design, plant operation, and environmental analysis. This guide defines the…