Chapter 1B Fundamentals Gas Processing I NGT 140 Chapter 1B Fundamentals “This product was funded by a grant awarded by the U.S. Department of Labor’s Employment and Training Administration. The product was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.” Unless otherwise specified, this work by ShaleNET U.S. is licensed under a Creative Commons Attribution 4.0 International License.

Mixtures of gases – Mole %

Heat Heat = Transfer of energy Three phases of matter (solid, liquid, gas) depend on the amount of heat energy transferred to the substance British Thermal Unit (Btu) 1.0 BTU = amount of heat required to raise 1 lb of WATER by 1 ⁰F [NC – PTP]

Heat Sensible Heat = Heat energy flowing in (out) that causes temperature to rise (fall) NO change of state (phase) occurs Latent Heat = Heat energy that causes a phase transition NO temperature change Latent heat values are usually MUCH larger than sensible heat values [NC – PTP]

Sensible and Latent Heat

Heat Transfer Temperature difference CAUSES heat to transfer (analogous to falling down a hill) Also depends on how much substance you have. e.g. 1 pail of water takes less heat to cause a 1 ⁰F increase than 1 swimming pool of water. Must have temperature difference AND sufficient quantity of cooling fluid [NC – PTP]

Flammability

Combustion Process of burning (oxidizing) Helpful combustion Heaters Boilers Gas turbines and internal combustion engines Understanding combustion helps avoid the harmful effects of unwanted fires Three essential requirements Supply of oxygen Combustible fuel Heat energy (ignition) [NC – PTP]

Combustion control Heaters and boilers – air supply Engines – fuel supply Efficiency Incomplete combustion Dry-gas loss (stack loss) Analysis of off gases (flue gas) to look for products formed by combustion Oxygen content less than 2.5% Increase amount of excess air [NC – PTP]

Combustion control (cont.) Analysis of off gases (flue gas) to look for products formed by combustion Dry gas loss Oxygen content greater than 5% Excessive heat lost to stack Excess fuel consumption for no additional Btu value Reduce excess air supply [NC – PTP]

Combustion control (cont.) Extinguishing Unwanted Fires Cut off fuel supply Cut off supply of oxygen (smother) Cut off supply of heat (cooling) Fuel Properties Flammable range (typically between 1% and 15%) Increasing pressure with normally widen the flammable range Flash point – minimum temperature that produces minimal vapors to “flash” but not burn continuously Fire point – minimum temperature that produces enough vapors to support combustion [NC – PTP]

Applications Light liquids Heavy Liquids Low boiling temperatures High vapor pressures Vaporize easily Heavy Liquids High boiling temperatures Low vapor pressures Do not vaporize easily [NC – PTP]

Volatility Describes the ease with which you can vaporize a fluid Plant operations dictated by relative volatility of the fluids being processed Most processes involve mixtures of fluids composed of individual hydrocarbons Mixture in liquid AND vapor phase Amount present in each dictated by volatility [NC – PTP]

Fluid Mixture Equilibrium Mixture of several fluids has a range of boiling points Initial boiling point = temperature at which the fraction with the lowest boiling temperature boils (vaporizes) Final boiling point = temperature at which the fraction with the highest boiling temperature boils. At any given temperature between these two extremes some of the fluid will be in the vapor phase and some will be in the liquid phase [NC – PTP]

Fluid Mixture Equilibrium Vapor Light Molecules Vaporize Liquid Heavy Molecules Concentrated Heavy Fluid Molecules Light Fluid Molecules

Describing Gas Processes Many pieces of equipment working as a unit. Connection of this equipment normally illustrated with a Process Flow Diagram (PFD) Various symbols are used to describe pieces of equipment. We will use the more common items in this class [NC – PTP]

Simple Separation System Cooling Water Injection Richer Light Component Richer Heavy Component Fire Separation Required!!! Figure 1.11

Simple Separation System Hydrocarbon Separation Required!!!! Steam Heavy Liquid Cooling Water Condenser Condenses vapor Heavy liquid Cools vapor

Cold Hot Figure 1.16