ISO 17196 pdf download Dimethyl ether (DME) for fuels — Determination of impurities — Gas chromatographic method
This International Standard specifies a procedure of test for methanol. CO, CO, methvl formate ethymethyl ether, and hydrocarbons up to C4, in DME used as fuel by the gas chromatography method. Thisorocedure is applicable to determine the amount of methanol, CO, CO2, methyl formate, ethyl methylether, and hydrocarbons up to C4, up to the value specified in ISO 16861.
NOTE The precision ofthis method has been studied for alimited set of samples and content levels by aimited number oflabs.lt allows establishment ofa gualitv specification of DME but cannot be consideredas a full precision determination in line with the usual statistical methodology as in ISO 4259.
2 Normative references
The following documents,in whole or in part, are normatively referenced in this document and areindispensable for its application, For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies.ISO 6975, Naturalgas – Extended analysis — Gas-chromatographic methodISO 16861, Petroleum products – Fuels (class F)– Specifications of Dimethylether (DME)ISO 29945, Refrigerated non-petroleum-based liquefied gaseous fuels – Dimethylether (DME)-一- Method ofmanual sampling onshore terminals
3 Terms and definitions
For the purposes of this document, the following terms and definitions given in ISO 6975 and thefollowing apply.
componentsDME, methanol,ethyl methylether, methyl formate, carbon dioxide, carbon monoxide, hydrocarbons upto C4
3.2hydrocarbons (up to C4)components such as ethane (CoH6),ethylene (CH4), propane(C;Hg), propylene(C;H6),i-butane(i-C4H10).n-butane(n-C4H10), i-butene (i-C4Hg), 1-butene (1-C4H8), trans-2-butene (trans-2- C4Hg), cis-2-butenecis-2- C4H8)and 13-butadiene(13-butadiene)
working reference gas mixture
mixtures which are used as working standards for regular calibration of the measuring system
Note 1 to entry: WRM can be prepared by gravimetric method in accordance with ISO 6142 or certified andvalidated by comparison with gas mixtures in accordance with ISO 6143.
The components to be determined in a gaseous sample are separated by gas chromatography andcompared with calibration data obtained under the same set of conditions.
The components are separated using packed or open tubular columns in a gas chromatograph anddetected by TCD or FID or FID with methanizer.
Analysis and analytical requirements5
5.1 Apparatus and materials
5.1.1 Analytical system
The analytical system shall consist of a gas chromatograph and an appropriate data handling systemNOTEExamples of analytical systems and conditions are informatively proposed in this InternationalStandard. See Annex A and Annex B
The gas-chromatographic unit can consist of one or more gas chromatographs capable of isotherma.and/or temperature-programmed operation and equipped with a TCD and an FID and a sample heatedtransfer and introduction system. A methanizer is optional.
The sample is preferably transferred as a gas phase to the injection system through a constant volumesystem according to the annexes.
Ifthe sample is transferred as a gas phase,a specific procedure to allow full vaporization ofliquid sampleis required (see 6.3.1)
A liquid sampling valve can also be used to inject the sample in a liquid phase.
5.1.2 Reference gas mixtures
220.127.116.11 Working reference gas mixture
The concentration ofeach component in the WRM shall be within the tolerances given in Table 1 relativeto the maximum value allowed in the specification in ISO 16861.