API MPMS 14.5 2009 pdf free download

API MPMS 14.5 2009 pdf free download.Calculation of Gross Heating Value, Relative Density, Compressibility and Theoretical Hydrocarbon Liquid Content for Natural Gas Mixtures for Custody Transfer.
3.2 as-delivered A condition for water vapor entrained in the gas. The term “as-delivered” can reference “saturated gas at flowing conditions” (see 3.13) or “partially saturated gas” (see 3.9). 3.3 base conditions Base conditions are certain pressure and temperature conditions selected for a specific purpose such as defined by state and federal laws and regulations or to meet the needs of contracting parties. Common base pressures in the U.S. include 14.65 psia, 14.73 psia, and 15.025 psia. The base temperature in the U.S. is usually 60 °F. 3.4 Btu The Btu (British thermal unit) is a measurement unit for a quantity of energy transferred as heat. 3.5 compressibility factor The compressibility factor is the ratio of the actual volume of a given mass of gas to its volume calculated from the ideal gas law using given conditions of temperature and pressure. 3.6 dry gas Dry gas contains no water, however, for practical purposes, contracting parties often define “dry” to include small quantities of water. In the U.S., dry gas is typically specified to not exceed 7 lb of water per million standard cubic feet (MMSCF) of gas. 3.7 gross heating value higher heating value HHV The gross heating value, Hv id , is the amount of energy transferred as heat per mole, unit mass or unit volume from the complete, ideal combustion of the gas with oxygen at a base temperature in which all water formed by the reaction condenses to liquid. As explained in Annex A, this is a hypothetical state, but it is acceptable for custody transfer. Reporting the gross heating value on a volumetric rather than a mass or molar basis requires a base pressure along with a base temperature. Spectator water does not contribute to the gross heating value. 3.8 ideal gas An ideal gas is a hypothetical gas which would follow the characteristic equation PV = nRT under all conditions.
3.11 relative density Relative density is the ratio of the mass density of the gas at the measurement temperature and pressure to the mass density of dry air (the assumed composition of air appears in Table A.1) at the same temperature and pressure. In the hypothetical ideal gas state, the relative density becomes the molar mass ratio. 3.12 saturated gas at base conditions Saturated gas at base conditions contains the equilibrium amount of water vapor at base pressure and temperature. In the U.S., the quantity normally is expressed as pounds of water per MMSCF of delivered gas. 3.13 saturated gas at flowing conditions Saturated gas at flowing conditions contains the equilibrium amount of water vapor at flowing pressure and temperature and is normally calculated by means of an algorithm. In the U.S., the quantity normally is expressed as pounds of water per MMSCF of delivered gas. 3.14 spectator water Spectator water is water carried by the gas or air that feeds the combustion reaction. Spectator water does not contribute to the gross heating value. 3.15 theoretical hydrocarbon liquid content The theoretical hydrocarbon liquid content is the amount of liquid theoretically condensable per unit volume of gas at base conditions. In the U.S., the term GPM (gallons of liquid hydrocarbon per thousand cubic feet of gas) is used. 3.16 wet gas Gas that contains water, however, for practical purposes contracting parties often define wet as greater than 7 lb of water per million standard cubic feet of gas, i.e. gas that is either partially or completely water saturated.
7.4 Theoretical Hydrocarbon Liquid Content Plant settlement, accounting and allocation calculations often rely upon the theoretical component liquid volumes for each hydrocarbon component contained in a natural gas stream. These theoretical component volumes result from multiplying the volume of natural gas by the theoretical hydrocarbon liquid content determined from a representative gas sample. In U.S. customary units, liquid volumes are gallons and gas volumes are thousands of cubic feet (MCF) yielding the expression GPM or gallons per thousand cubic feet for this property. The theoretical hydrocarbon liquid content may require adjustment for contractual pressure base conditions (P b ) that are not the same as the standard pressure associated with the physical properties.