Glossary of PSA Plants,PSA Plants Terms,PSA Plants Glossary

Glossary of PSA Plants

A	B	C	D	E	F	G	H	I	K
L	M	N	O	P	R	S	T	V	Z

Ambient environment: The undisturbed condition (temperature and humidity), that surrounds the material in question.

Activated Alumina: Kind of an adsorption type Dessicant.

Adsorbent Filter: A filter medium that is specified to hold both soluble and insoluble contaminants on its surface by molecular adhesion.

Atmospheric Dew point: It is the temperature at which the water vapour starts to condense at atmospheric pressure. It is the same as Dew point, but related only to atmospheric air.

Absorb: It refers to the process when a molecule from the fluid state (gas or liquid) dissolves in a solid. Please note Absorb is different from adsorb.

Adsorb: The process when a molecule from a fluid state (gas or liquid) hits the surface of a solid and stays there albeit for a short while.

Adiabatic Compression: A type of compression where no heat is transfered to/from the gas during the compression process.

Atmospheric pressure: This is the weight of the earth's atmosphere over an unit area of earth's surface. It gets measured with mercury barometer at sea level. This refers to the pressure required to lift the column of mercury 760 mm.

Aftercooler: An equipment that cools a gas after it has been compressed.

Anhydrous: Refers to the things that does not contain water of hydration. It is totally devoid of any water.

Blow down: The difference in pressure between opening pressure and reclose pressure of a valve. May be expressed in psig.

Blanketing: The method of creating an inert atmosphere to block unwarranted reactions from taking place.

Bulk modulus: This term is used to denote measure of resistance offered to compressibility for a fluid. Bulk modulus is the reciprocal of compressibility.

Butane(C₄H₁₀): Any of the two saturated hydrocarbons or alkanes with chemical formula. In these compounds an open chain joins the carbon atoms.

Bar: One bar equals 100 kPa

Cracking: A term that covers any reaction from a variety of reactions and processes which is able to convert high boiling fractions to more precious lower boiling fractions.

Cryogenic: Applies to the field of low temperatures, usually -195 ^oC or below.

Catalytic steam cracking: A process that is used for the production of hydrogen. Methane is mixed with steam by applying a nickel catalyst at a temperature of approximately 1,200 degrees Celsius. In addition to hydrogen, carbon monoxide(CO) is also produced. The resulting gas mixture is called as synthesis gas.

Condensation: This term is used to denote the process of change from a gas to the liquid or solid state.

Compressor: A device that is used to convert mechanical force and motion into pneumatic fluid power.

Celsius: A form of temperature scale standard that has been set up so that the temperature at which ice melts is 0° and water starts boiling at 100°C.

Constant air volume systems: Refers to air handling system that is able to give a continuous air flow while changing the temperature to meet heating and cooling requirements.

Dew point: The temperature in which vapors in a gas tend to condense. For practical use, it must be contextualised to a stated pressure.

Dissolved water: Water that is dispersed at a molecular level in hydraulic fluid for the formation of a single phase.

Dry gas: The volume of gas that remains after all water and natural gas liquids have been removed.

Entrained air: It is a mechanical mixture of air bubbles. It displays a tendency to get separated from the liquid phase.

Ethanol: From the family of Hydrocarbons, a colorless liquid that when burnt produces water and carbon dioxide. Used as a fuel in internal combustion engines as the vapor can form an explosive mixture with air.

Fuel cell: Energy converter for reversing the electrolysis process. Typically in a fuel cell, a reaction takes place between hydrogen and oxygen under controlled conditions ("cold" combustion).

Flaring and venting: Flaring is the process of burning of hydrocarbon gases for purely commercial proposition. Venting is the process of releasing gases to the atmosphere.

Fahrenheit: The temperature scale that has been set up as a standard. Here, ice melts at 32°and water starts boiling at 212°.

Gas Detector: An instrument that is able to detect presence of gases.

Generator: An effective device that is able to convert mechanical energy into electrical energy. The mechanical energy required is provided by the engine or turbine.

Greenhouse Gases: A very important term these days. It is referred to those gases that can trap the heat of the sun in the Earth's atmosphere. Thus producing the greenhouse effect. The two important greenhouse gases are water vapour and carbon dioxide. Other greenhouse gases can include chlorofluorocarbons(cfcs), methane, ozone, and nitrogen oxides.

Gas sorption: Devices that are applied for reducing levels of airborne gaseous compounds. This is done by passing the air through materials that has the capacity to extract the gases. The performance of solid sorbents generally depends on the concentration of the pollutants, airflow rate, presence of other gases or vapors, and a host of other factors.

Hydrocarbon: Can be defined as molecules containing only hydrogen and carbon. The term is often used broadly to include molecules in petroleum. These can also contain molecules with S, N, O, and various other organically bounded metals.

HTS (High Temperature Shift): One of the steps in hydrogen manufacture that involves the water-gas shift reaction.

Hose: A flexible conductor or line whose nominal size is denoted by the diameter of its interior.

Heat of adsorption: Heat of Adsorption refers to the total heat involved in the adsorption process beginning from zero adsorbate loading to the final adsorbate loading. The temperature remains constant in the process.

Inert Gas: Gases that shows stability and extremely low reaction rates under normal temperature and pressure conditions. The noble gases (He, Ar, Kr, Xe), in which no reaction takes place under NPT, are referred to as inert gases.

Isotherm: It is the process occurring at a constant temperature. To compress the gas from one state to the other heat must be removed so that the temperature remains in a constant state. The pressure change is reciprocal to the change in volume.

Kinetics: It is the study of the rates of chemical reactions.

Kilocalorie (kcal): 1000 calories is 1 Kilocalorie.

Linde process: The Cooling of gas (e.g. air) under high pressures using counter flow along with subsequent throttling. This causes formation of liquid.

Molecular Sieves: A variety of high surface area solids that has pores approximately the size of individual molecules. Thus enabling them to adsorb smaller molecules while excluding bigger ones.

Mole: The amount of a substance that contains the same number of atoms as 12 grams of pure carbon (C₁₂). A gram-mole (grammolecule) has 6.0225 x 1023 molecules of that particular substance.

Normal Temperature and Pressure: Acts as an reference base for the gas industry of the things at 70°F temperature and a pressure of 14.696 psia.

Ozone: Ozone is an Allotropic form of oxygen. It has three atoms in each molecule denoted by the formula O3. Ozone is formed in the atmosphere from organic gases and nitrogen oxides that are emitted by vehicles and industrial sources.

Outlet Pressure: The term refers to the fluid pressure from the discharge connection of a control device.

Oxidizer: A chemical reagent that causes oxidation of other substances and is thus reduced in the process.

PPM (Parts Per Million): An easy way of expressing very low concentrations of a substance in a mixture, or a low level contaminant in a product that is pure.

PPB: Parts per Billion

PSIG (Pounds per Square Inch Gauge): Gauge pressure ignores the first atmosphere absolute (14.696 psia).

Purging: Process of eliminating unwanted gases or liquids from a system by introducing a different gas or liquid until the last traces of unwanted gas or liquid have been removed.

Purifier: A device to purify a gaseous product stream from impurity.

Permeability: The rate at which a gas or liquid under pressure gets passed through a solid material by the process of diffusion and solution.

Pressure Drop: It is the resistance to flow. Defined as the difference in pressure up stream and down stream.

Regeneration: A general term that is applied to any process or step that treats used catalyst for starting fresh activity.

Regenerative dryer: The ability of the dryer to separate moisture that can be restored without changing the drying compound.

Synthesis Gas: Typically a mixture of hydrogen and carbon monoxide. It is useful as a feed for making ammonia, hydrogen, methanol, and various other hydrocarbons, depending on the catalyst.

Steam Reforming: A catalytic process that is used for converting a mixture of hydrocarbon and steam to synthesis gas, a mixture of carbon monoxide and hydrogen.

SCFM (Standard Cubic Feet per Minute): Flow of air measured at some reference point and converted to a standard set of reference conditions.

Saturation: This occurs when the vapour at dew point or saturation temperature corresponding to its partial pressure. A gas is never saturated with vapour. The space occupied jointly by the vapour and gas gets saturated.

Throughput: The volume of natural gas that is delivered to end users.

Turbulence: Flow that is caused by super imposition of irregular currents on a flow that is uniform.

Vacuum pump: An equipment that uses mechanical force and motion to evacuate gas from a connected chamber for creating a subatmospheric pressure.

Valve: A device that is used to control fluid flow direction, pressure or flow rate.

Vapor Pressure: This term is used to denote the pressure that is exerted by the vapor above a liquid as the two phases are in the state of equilibrium.

Volatile organic compounds (VOCs): Refers to the compounds that has the tendency to vaporize (become a gas) at normal room temperature. It has the potential to be a health hazard.

Zeolite: Any of the big family of crystalline metal oxide materials that are characterized by the presence of extensive regular interconnected pore systems. Mostly they are based on mixtures of aluminum and silicon oxides, others may have phosphorous and other elements as well. See Molecular Sieve also.

Zero Gas: Calibration gas that is used for setting the minimum reference point on the scale of an analyzer.