{"id":3202,"date":"2026-08-28T00:01:56","date_gmt":"2026-08-27T22:01:56","guid":{"rendered":"https:\/\/gekkophotonics.com\/case-study\/stezenie-mocznika-i-azotanu-amonu-w-nawozie-saletrzano-mocznikowym-rsm\/"},"modified":"2026-08-28T00:12:53","modified_gmt":"2026-08-27T22:12:53","slug":"stezenie-mocznika-i-azotanu-amonu-w-nawozie-saletrzano-mocznikowym-rsm","status":"publish","type":"case-study","link":"https:\/\/gekkophotonics.com\/en\/case-study\/urea-ammonium-nitrate-fertilizer-inline-composition-control\/","title":{"rendered":"Urea and ammonium nitrate concentration in urea-ammonium nitrate fertilizer (UAN): inline composition control"},"content":{"rendered":"
\n
\n
Industry<\/dt>\n
Produkcja ciek\u0142ych nawoz\u00f3w azotowych (RSM\/UAN)<\/dd>\n<\/div>\n
\n
Scope<\/dt>\n
Inline control of urea and ammonium nitrate concentration<\/dd>\n<\/div>\n<\/dl>\n

Client context<\/h2>\n

UAN is a solution of urea and ammonium nitrate in water, with a total nitrogen content of 28\u201332%, one of the most commonly used liquid nitrogen fertilizers in the EU and the USA. The customer decides on the fertilizer type depending on the required properties.<\/p>\n

Production involves continuously mixing a urea stream, an ammonium nitrate solution stream, and water. Control is based on flow rates and density, so fluctuations in the concentrations of the input streams propagate directly to the final composition, and during a grade change the installation produces material that meets neither the previous nor the new specification for a certain period of time.<\/p>\n

Challenge.<\/h2>\n
    \n
  • The deviation works in both directions, and both are costly. Below the declaration \u2013 a complaint and the risk of product conformity being challenged. Above the declaration \u2013 nitrogen given to the customer for free, in every tonne.<\/li>\n
  • A grade change on a continuous installation generates transitional material. The longer it takes to reach the new window, the greater its volume, and this is tonnage to be reclassified or recycled, counted directly in the duration of the transition.<\/li>\n
  • The laboratory is faced with a choice: speed or resolution. Total nitrogen is determined by the combustion method in a few minutes, but as a single aggregate number that says nothing about the ratio of components. Separating the nitrogen forms \u2013 nitrate, ammonium, and amide \u2013 requires a wet determination with nitrate reduction before mineralization, and therefore time.<\/li>\n
  • Regardless of the choice, each laboratory method describes a single sampled point of a continuous stream. Between samples, the line keeps producing, and during a grade change it is precisely the segment between samples that matters.<\/li>\n<\/ul>\n

    Solution<\/h2>\n

    Spectrally\u2122 X1 in an inline configuration measures urea concentration and ammonium nitrate concentration directly in the mixing line, continuously and without sample extraction. Both components produce distinct, distinguishable signals in solution, so the composition is available as two independent quantities rather than a single aggregate number.<\/p>\n

    The advantage is not that the laboratory cannot cope \u2013 it copes well. The advantage is the removal of the trade-off between speed and resolution, and continuity: the measurement describes the stream also between samples, and during a grade change it shows the approach to the new window in real time, instead of confirming it after the fact.<\/p>\n

    Water gives a weak analytical signal in Raman spectroscopy, so it does not overwhelm the analyte signal in aqueous solution \u2013 this is a general physical property of the method. The measurement requires no sample preparation.<\/p>\n

    Scope and limitations<\/h3>\n

    The measured quantities are urea and ammonium nitrate concentrations. Total nitrogen content is derived from them by calculation, from the stoichiometry of both components.<\/p>\n

    The measurement is sensitive to stream temperature. The range of conditions within which it remains reliable is established in a feasibility study and is not declared in advance.<\/p>\n

    With regard to homogeneity \u2013 UAN is a single-phase solution, so the subject of the measurement is the detection of incomplete mixing at the mixer outlet, not the assessment of homogeneity of the finished product.<\/p>\n

    The measurement does not replace a release determination or the conformity documentation required for placing the product on the market.<\/p>\n

    Compliance<\/h2>\n

    Regulation (EU) 2019\/1009 opens the path to CE marking for EU fertilizer products; it is optional alongside national routes. If your product is subject to conformity assessment under a module based on internal production control, the evidence of conformity is documented process control \u2013 not a single certificate of analysis. An in-line measurement is then not only a control tool but also the record on which that control is based.<\/p>\n

    Configuration<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n
    Position<\/th>\nConfiguration<\/th>\n<\/tr>\n<\/thead>\n
    Measured quantities<\/td>\nurea and ammonium nitrate concentration, and solution homogeneity<\/td>\n<\/tr>\n
    Measurement mode<\/td>\ninline in the mixing line<\/td>\n<\/tr>\n
    Excitation wavelength<\/td>\n785 nm<\/td>\n<\/tr>\n
    Single measurement time<\/td>\nup to 1 min<\/td>\n<\/tr>\n
    Reference methods<\/td>\nnitrogen forms per EN 15604; total nitrogen per EN 15750 or by the combustion method, density and stream temperature<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    How we verify feasibility on your stream<\/h2>\n

    We do not provide accuracy figures from other implementations here. It depends on the composition range and stream temperature \u2013 a figure from someone else's installation is not transferable to your line. The number that matters to you is generated in a feasibility study on your samples.<\/p>\n

    We conduct the study as follows:<\/p>\n

      \n
    • The reference point is your requirement \u2013 the permissible error of determination of both concentrations, derived from the specification window and the tolerance of the declared nitrogen content.<\/li>\n
    • Together with you, we prepare a set of reference samples covering the composition range of the types you produce and the process parameters, e.g., temperature.<\/li>\n
    • The report provides: the achieved accuracy relative to your reference methods, the covered composition and temperature range, and the areas that could not be covered.<\/li>\n<\/ul>\n

      The report also provides the result when it does not meet your requirement\u2014along with the magnitude of the discrepancy. The decision on implementation is yours and should be based on numbers, not on declarations.<\/p>\n

      What this means for your process<\/h2>\n

      If you produce UAN or other liquid nitrogen fertilizers, an in-line measurement in the mixing line allows you to see both concentrations separately and continuously, rather than inferring composition from a single aggregate number between successive samples:<\/p>\n

        \n
      • correct stream ratios when input raw material concentrations deviate from nominal values,<\/li>\n
      • shorten the transition during grade changes,<\/li>\n
      • detect a raw material mix-up that density will not reveal.<\/li>\n<\/ul>\n

        Commercially, this translates into two things: less transitional tonnage at every grade change, and less nitrogen given away above the declaration in every tonne of steady-state production.<\/p>\n

        The most reliable way to verify on a specific stream is a short feasibility study on real samples.<\/p>","protected":false},"excerpt":{"rendered":"

        The plant produces UAN 28, 30, or 32 to customer order on a single continuous mixing line. Hitting the specification window for the selected grade and reaching it quickly during grade changes determine the amount of transitional material and the nitrogen above declaration. We demonstrate how to control composition directly in the mixing line.<\/p>","protected":false},"author":1,"featured_media":3211,"menu_order":0,"comment_status":"closed","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","industry-grid":""},"class_list":["post-3202","case-study","type-case-study","status-publish","format-standard","has-post-thumbnail","hentry"],"blocksy_meta":[],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/case-study\/3202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/case-study"}],"about":[{"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/types\/case-study"}],"author":[{"embeddable":true,"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/comments?post=3202"}],"version-history":[{"count":1,"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/case-study\/3202\/revisions"}],"predecessor-version":[{"id":3212,"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/case-study\/3202\/revisions\/3212"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/media\/3211"}],"wp:attachment":[{"href":"https:\/\/gekkophotonics.com\/en\/wp-json\/wp\/v2\/media?parent=3202"}],"curies":[{"name":"entry","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}