## Fhf dhd bhb whw qrqc

X KjiXji — 1 " 0 The enthalpy terms, H and h, are per mole of mixture.

Note that the enthalpies of the top and side products

For a simple column (single feed, no side products), are written so that a vapour or liquid enthalpy can be the overall component balance equation is: substituted, depending on the phase of the product.

The energy balance for the simple stage, j, of Figure 2

The component balance for the simple stage (no feed vj + 1Hj + 1 # Lj-1hj-1 VjHj Ljhj — 0

The enthalpies (energy per mole) for each phase 1 # /ji1 — v — /ji = 0 are functions of temperature, pressure and com position:

The component balance for feed stage, f, of Figure 2

will add the liquid portion of the feed, lFi, while the Hj = Hj(Tj, Pj, yji)

vapour portion, vFi, is added to the component balance for stage f — 1. For the product stage, p, the hj = hj(Tj, Pj, j

For feed stages, side product stages, and stages with inter-condensers or inter-reboilers, additional terms are included in the energy balance equations. The energy balance for the reboiler is:

and for a partial condenser with both vapour and liquid products:

Subcooling is accounted for in h0 (the enthalpy of the reflux, L0, and the liquid distillate, d).

Most computer simulations work with ideal stages but to characterize a stage for the deviation from ideality or equilibrium, stage efficiencies are often used in some software. Commonly, a Murphree vapour efficiency is used for each component, given as:

## Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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