echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Chemicals Industry > Chemical Technology > Determination of trace water in ethylene and propylene for industrial use (1)

    Determination of trace water in ethylene and propylene for industrial use (1)

    • Last Update: 2022-01-17
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com

    1 Scope

    1.
    1 This standard specifies the
    Karl Fischer coulometric method and hygrometer method for the determination of trace water in
    ethylene and propylene
    .
    This standard Karl Fischer coulometric method for the determination of content of not less than 1mg / kg traces of water, hygrometer method is suitable for determination of content of not less than 1 mL / m
    .
    3
    traces of water
    .

    1.
    2 This standard is not intended to describe all safety issues related to its use

    .
    Therefore, users of wooden standards should be responsible for establishing appropriate safety and protection measures in advance, and determining appropriate rules and regulations

    .

    2 Normative references

    The clauses in the following documents have become clauses of this standard after being quoted in this standard
    .
    For dated reference documents, all subsequent amendments (excluding errata content) or revisions do not apply to this standard.
    However, all parties that have reached an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used

    .
    For undated reference documents, the latest version is applicable to this standard

    .

    GB/T 2366-1986 Determination of water content in chemical products by gas chromatography

    GB/T8170-1987 Numerical Rounding Rules

    GB/T13289-1991 Industrial ethylene liquid and gas sampling method

    GB/T13290-1991 Industrial Propylene and Butadiene Liquid Sampling Method

    3 Karl Fischer Coulomb Method

    3.
    1 Method summary

    When the measured gas passes through the electrolytic cell of the Karl Fischer coulometric analyzer, the water in the gas and the iodine and sulfur dioxide in the Karl Fischer reagent will react in the presence of organic bases (such as pyridine) and methanol :

    H 2 O+I 2 +SO 2 +CH 3 OH+3RN→(RNH)SO 4 CH 3 +2(RNH)I

    The consumed iodine is electrolytically supplemented by the anolyte containing iodide ions:

    2I - → the I 2 + 2E

    The amount of iodine required for the reaction is directly proportional to the amount of electricity passing through the electrolytic cell.
    Therefore, the amount of electricity consumed by electrolysis is recorded, and the water content in the sample can be obtained according to Faraday's law of electrolysis

    .

    3.
    2 Apparatus and equipment

    3.
    2.
    1 Karl Fischer Coulometer: The detection limit should not be higher than 10ug:

    3.
    2.
    2 Electronic balance:

    a) The sensing capacity is 0.
    1g or 0.
    01g, and the weighing range should meet the requirements of 3.
    2.
    5 and 3.
    2.
    6 for the weighing of steel cylinders;

    b) Sensitivity 0.
    1mg, weighing range (0~160)g;

    3.
    2.
    3 Blast drying box;

    3.
    2.
    4 Water bath;

    3.
    2.
    5
    Ethylene injection cylinder: 1000mL, in line with GB/T13289: the inner wall should be polished, and the outlet end is equipped with a pressure gauge with a range (0~16) MPa;

    3.
    2.
    6 Propylene injection cylinder: 1000mL, in line with GB/T13290 regulations, the inner wall should be polished

    .

    3.
    3 Reagents and materials

    3.
    3.
    1 Elastic quartz capillary tube:

    a) Inner diameter (0.
    25±0.
    01)mm, length (2.
    0±0.
    1)m, used for propylene analysis;

    b) Inner diameter (0.
    15±0.
    01)mm, length (3.
    0±0.
    1)m, used for ethylene analysis;

    3.
    3.
    2 Micro syringe: 100uL;

    3.
    3.
    3 Medical injection needle: No.
    9;

    3.
    3.
    4 Tighten the nut;

    3.
    3.
    5 Stainless steel ferrule: the middle hole, the diameter of 1.
    5mm;

    3.
    3.
    6 Gasket: Silicone rubber;

    3.
    3.
    7 Plastic septa:
    PTFE , with a hole in the middle, with a diameter of 1.
    5mm;

    3.
    3.
    8 Benzene-water balance solution: prepared according to 5.
    2.
    1 of GB/T2366-1986;

    3.
    3.
    9 Karl Fischer Coulometric electrolyte (catholyte, anolyte);

    3.
    3.
    10 Ethylene glycol: the mass fraction of water is not more than 0.
    05%;

    3.
    3.
    11 Nitrogen: The volume fraction is not less than 99.
    999%, and the water content is not higher than 3mL/m
    3
    .

    3.
    4 Sampling

    Steel cylinders (3.
    2.
    5, 3.
    2.
    6) should be kept clean and dry before sampling

    .
    Collect liquid samples according to the technical requirements of GB/T13289-1991 and GB/T13290-1991

    .

    Note: The cleaned and dried cylinders can be placed in a blast drying box at a temperature of 110°C, and nitrogen gas (3.
    3.
    11) for 30 minutes to obtain a better drying effect

    .

    Related Links: Electrochemical Method for Determination of Trace Oxygen in Industrial Ethylene and Propylene (3)

     

     

    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Related Articles

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.