EN 15471:2007 – Liquefied petroleum gases – Determination of dissolved residues – High-temperature gravimetric method
1 Scope
This Standard specifies a method, for determining the residual matter in liquefied petroleum gases (LPG),which remains after evaporation at 105 °C. This material represents those products deposited in car LPG vaporizers that are subject to a temperature equal to or greater than the boiling temperature of water. The range of determination extends from 50 mg/kg to 100 mg/kg. Higher concentrations can be determined by adjusting the sample size.
The precision data of the method have been determined from 20 mg/kg to 100 mg/kg, with samples amount from 100 g to 50 g.
This method has been developed as a potential replacement of the commonly used method EN ISO 13757 [1],The advantages of the method are that a small quantity of LPG (100 ml) is required.
NOTE An alternative European Standard, EN 15470 [2], with the same scope, specifies a gas chromatography method with slightly better fidelity.
WARNING — Use of this method involves hazardous materials and operations. It is the responsibility of the user to establish appropriate safety and health precautions. All handling must be performed in a fume hood.
2 Normative reference
The following referenced documents are indispensable for the application of this document. For dated references only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 4257, Liquefied petroleum gases – Method of sampling (ISO 4257:2001)
3 Terms and definitions
For the purposes of this document, the following term and definition applies.
3.1
liquefied petroleum gas (LPG)
petroleum gas that can be stored and/or handled in the liquid phase under moderate conditions of pressure and at ambient temperature, consisting predominantly of propane, butanes, with small proportions of propene,butenes and pentanes/pentenes
4 Principle
A known mass of LPG is sampled and concentrated by evaporation. The concentrate is transferred into a beaker of 100 ml capacity and then evaporated by jet evaporation under controlled conditions of temperature and airflow. The oily residue remaining after this procedure is cooled and weighed.
5 Reagents
5.1 n-heptane, analytical grade.
5.2 2-propanol, technical grade, for the cooling bath.
5.3 Solid carbon dioxide, for the cooling bath.
EN 15471:2007 – Liquefied petroleum gases – Determination of dissolved residues – High-temperature gravimetric method