{"id":1103,"date":"2025-01-17T10:50:18","date_gmt":"2025-01-17T10:50:18","guid":{"rendered":"https:\/\/www.espindesa.es\/tecnologias\/azeotropic-nitric-acid\/"},"modified":"2025-03-12T15:28:26","modified_gmt":"2025-03-12T15:28:26","slug":"azeotropic-nitric-acid","status":"publish","type":"page","link":"https:\/\/www.espindesa.es\/es\/tecnologias\/azeotropic-nitric-acid\/","title":{"rendered":"\u00c1cido N\u00edtrico Azeotr\u00f3pico"},"content":{"rendered":"<div class=\"wpb-content-wrapper\"><p>[vc_row full_width=\u00bbstretch_row_content_no_spaces\u00bb][vc_column]\n    <section class=\"tr-mod mod-cabecera_tercer_nivel padding-80 bg-full\" style=\"background: url(https:\/\/www.espindesa.es\/wp-content\/uploads\/2025\/02\/03_ficha-HNO3-AZEOTROPIC-1.jpg);\">\n      <div class=\"container\">\n        <a href=\"\/\">\n          <div class=\"go-back\">\n            <span>Volver<\/span>\n            <i class=\"tr-icon i-arrow-slim\"><\/i>\n          <\/div>\n        <\/a>\n        <div class=\"row\">\n          <div class=\"col-md-6\">\n          <div class=\"breadcrumbs\"><ul><li><span class=\"current\">P\u00e1gina<\/span><\/li><\/ul><\/div>\n            <h1>\n              FERTlLlZERAND AZEOTROPIC GRADES\n            <\/h1>\n          <\/div>\n        <\/div>\t\n      <\/div>\n    <\/section>[\/vc_column][\/vc_row][vc_row css=\u00bb.vc_custom_1737025291657{margin-top: 50px !important;}\u00bb][vc_column][vc_row_inner][vc_column_inner width=\u00bb1\/2&#8243;]<section class=\"tr-mod mod-texto_titulo_pretitulo \">\n          <h3 class=\"pretitle\">\n                  Overview\n          <\/h3>\n          <h2>\n              ESPINDESA leaded the European high pressure process in the 70\u2019s and since then has continuously updated this technology to deal with the most severe environmental regulations and high cost of energy.\n          <\/h2>\n          <p class=\"p1\">NITRlC ACID is manufactured from Ammonia in the form of a solution of HNO<span class=\"s2\">3 <\/span>in water. Concentrations of 55-60% HNO<span class=\"s2\">3 <\/span>are used in the Fertilizer lndustry while azeotropic concentrations (68% HNO<span class=\"s2\">3<\/span>) are required by various procedures in the Chem\u00edcal Industry, mainly organic nitrations.<\/p>\n<p class=\"p1\">ESPINDESA leaded the European high pressure process in the 70&#8217;s and since then has continuously updated this technology to deal with the most severe environmental regulations and the high cost of energy. Plants for the Fertilizer Industry are still being designed by ESPINDESA with this technology.<\/p>\n\n      <\/section>[\/vc_column_inner][vc_column_inner width=\u00bb1\/2&#8243;][vc_single_image image=\u00bb419&#8243; img_size=\u00bbfull\u00bb css=\u00bb\u00bb][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text css=\u00bb\u00bb]<\/p>\n<p class=\"p1\"><strong>In the last years the Industry demands giant plants and, in some <span class=\"s3\">cases, azeotropic concentration. Early in the 2000&#8217;s ESPINDESA <\/span>dual pressure process achieves:<\/strong><\/p>\n<p>[\/vc_column_text][\/vc_column][vc_column width=\u00bb1\/4&#8243;]\n      <section class=\"tr-mod mod-icono_texto \">\n        <img decoding=\"async\" class=\"icon\" src=\"https:\/\/www.espindesa.es\/wp-content\/uploads\/2025\/01\/energia-sostenible.svg\">\n        <p>Acid concentrations ranging 60 to 68% (azeotropic)<\/p>\n      <\/section>\n      [\/vc_column][vc_column width=\u00bb1\/4&#8243;]\n      <section class=\"tr-mod mod-icono_texto \">\n        <img decoding=\"async\" class=\"icon\" src=\"https:\/\/www.espindesa.es\/wp-content\/uploads\/2025\/01\/nitrogen.svg\">\n        <p>Low N20 and NOx tail gas emissions<\/p>\n      <\/section>\n      [\/vc_column][vc_column width=\u00bb1\/4&#8243;]\n      <section class=\"tr-mod mod-icono_texto \">\n        <img decoding=\"async\" class=\"icon\" src=\"https:\/\/www.espindesa.es\/wp-content\/uploads\/2025\/01\/raw.svg\">\n        <p>Extremely efficient raw material and energy consumptions<\/p>\n      <\/section>\n      [\/vc_column][vc_column width=\u00bb1\/4&#8243;]\n      <section class=\"tr-mod mod-icono_texto \">\n        <img decoding=\"async\" class=\"icon\" src=\"https:\/\/www.espindesa.es\/wp-content\/uploads\/2025\/01\/polution.svg\">\n        <p>Pollution prevention at start up and shutdown<\/p>\n      <\/section>\n      [\/vc_column][vc_column offset=\u00bbvc_hidden-lg vc_hidden-md vc_hidden-sm vc_hidden-xs\u00bb][vc_empty_space]\n        <section class=\"tr-mod mod-boton_descarga \">\n          <a class=\"d-flex align-items-center\" href=\"#\" target=\"_blank\">\n            <i class=\"tr-icon i-download\"><\/i>\n            <span>Download technical sheet<\/span>\n          <\/a>\n        <\/section>\n    [vc_empty_space][\/vc_column][\/vc_row][vc_row full_width=\u00bbstretch_row_content_no_spaces\u00bb][vc_column][vc_empty_space]<section class=\"tr-mod mod-cita_pequena padding-80 bg-blue\">\n        <div class=\"container\">\n          <img decoding=\"async\" class=\"quotes\" src=\"\/wp-content\/themes\/tr\/assets\/images\/comillas_light.png\" alt=\"Comillas\">\n          <p >\n            In the last years the Industry demands giant plants and, in some cases, azeotropic concentration.\n          <\/p>\n        <\/div>\n      <\/section>[\/vc_column][\/vc_row][vc_row][vc_column][vc_empty_space]\n    <section class=\"tr-mod mod-titulo_separador \">\n      <h4>\n        Process Description\n      <\/h4>\n    <\/section>[vc_column_text css=\u00bb\u00bb]<\/p>\n<p class=\"p1\"><strong>Ammonia oxidation<\/strong><\/p>\n<p class=\"p1\">The process air is filtered and compressed up to 3-4 bar in the first stage of the compressor set.<\/p>\n<p class=\"p1\">The evaporated ammonia is reheated, filtered and mixed with process air before entering the ammonia burner where Pt-Rh catalyst and getter gauzes are placed. The temperature reaches 870\u00b0 C. The reactor can include a N,0 abatement catalyst to reduce N,0 to levels lower than 50 ppm in the tail gas.<\/p>\n<p class=\"p1\">The heat of the process gas is recovered in a series of heat exchangers, where the temperature decreases from 870\u00b0C to 145\u00b0C. At this point the gases enter the low-pressure cooler-condenser, which cools them below the dew point, so most of the water produced in the ammonia oxidation reaction condenses in the form of a 30% nitric acid stream.<\/p>\n<p class=\"p1\">This is separated from the gas and pumped to the appropriate tray of the absorber.<\/p>\n<p class=\"p1\"><strong>Process gas compression and cooling<\/strong><\/p>\n<p class=\"p1\">The dry cool process gases are mixed with the secondary air after it has been used in the bleaching tower to strip out most of the free NOX remaining in the product acid. Then are compressed to 8-11 bar what rises the temperature up to 200\u00b0 C.<\/p>\n<p class=\"p1\">In the ducts downstream the compressor, the NO contained in the process gas reacts with the oxygen of the secondary air and is oxidized to NO,. Two further heat exchangers lower the temperature of the process gases to 50\u00b0 C and enters the absorption tower.<\/p>\n<p class=\"p1\"><strong>Absorption<\/strong><\/p>\n<p class=\"p1\">By the time the gases reach the inlet of the absorption tower the oxidation of <span class=\"s3\">NO<\/span><\/p>\n<p class=\"p1\">to NO<span class=\"s1\">2<\/span> has already been completed. The internals of the absorber are a set of sieve trays with integral cooling coils. The number of trays depends on the tail gas NOx content permitted in the exhaust gas. The absorber could be designed <span class=\"s3\">toa<\/span> <span class=\"s3\">NOx content<\/span> <span class=\"s3\">in<\/span> <span class=\"s3\">tail<\/span> <span class=\"s3\">gas<\/span> <span class=\"s3\">below<\/span> <span class=\"s3\">200<\/span> <span class=\"s3\">ppmv.<\/span> <span class=\"s3\">To<\/span> <span class=\"s3\">reduce<\/span> <span class=\"s3\">below<\/span> <span class=\"s3\">50<\/span> <span class=\"s3\">ppmv,a<\/span> <span class=\"s3\">catalyst<\/span> for DeNOx abatement may be advisable.<\/p>\n<p class=\"p1\"><span class=\"s1\">The<\/span> <span class=\"s1\">acid<\/span> <span class=\"s1\">leaving<\/span> <span class=\"s1\">the<\/span> <span class=\"s1\">bottom<\/span> <span class=\"s1\">of<\/span> <span class=\"s1\">the<\/span> <span class=\"s1\">absorption<\/span> <span class=\"s1\">column<\/span> <span class=\"s1\">isa<\/span> <span class=\"s1\">reddish<\/span> <span class=\"s1\">colour<\/span> <span class=\"s1\">due<\/span> <span class=\"s1\">to<\/span> <span class=\"s1\">the<\/span> presence of dissolved free NO<span class=\"s4\">2<\/span>. This is removed by countercurrent contact with the secondary air <span class=\"s6\">in<\/span> a small sieve tray column. After bleaching, the acid is colourless and contains less than 20 ppm NO<span class=\"s4\">2.<\/span><\/p>\n<p class=\"p2\"><span class=\"s1\">The<\/span> <span class=\"s1\">tail<\/span> <span class=\"s1\">gas<\/span> <span class=\"s1\">leaves<\/span> <span class=\"s1\">the<\/span> <span class=\"s1\">absorption<\/span> <span class=\"s1\">tower<\/span> <span class=\"s1\">at<\/span> <span class=\"s1\">10-11<\/span> <span class=\"s1\">bars<\/span> <span class=\"s1\">and<\/span> <span class=\"s1\">30\u00baC<\/span> <span class=\"s1\">and<\/span> <span class=\"s1\">is<\/span> <span class=\"s1\">reheated<\/span> <span class=\"s1\">to<\/span> 420\u00baC in three heat exchangers. The gases are <span class=\"s8\">sent <\/span>to the gas turbine, which recovers 70% of the power needed to drive the compressor set. The rest of the power is provided by the steam turbine.<\/p>\n<p class=\"p3\">Azeotropic acid can only be produced directly if the NOx partial pressure at the inlet of the absorption tower is above1 bar and the water balance is very carefully <span class=\"s1\">controlled.<\/span><\/p>\n<p class=\"p4\"><span class=\"s1\">The<\/span> <span class=\"s1\">first<\/span> <span class=\"s1\">condition<\/span> <span class=\"s1\">is<\/span> <span class=\"s1\">fulfilled<\/span> <span class=\"s1\">fairly<\/span> <span class=\"s1\">easily<\/span> <span class=\"s1\">by<\/span> <span class=\"s1\">ensuring<\/span> <span class=\"s1\">that<\/span> <span class=\"s1\">the<\/span> <span class=\"s1\">NO<\/span> <span class=\"s1\">is<\/span> <span class=\"s1\">fully<\/span> <span class=\"s1\">oxidized<\/span> <span class=\"s1\">to<\/span> NO<span class=\"s4\">2<\/span> and by performing the absorption under a sufficiently high total pressure, <span class=\"s8\">which<\/span> increases the NO<span class=\"s4\">2<\/span> partial pressure. The water balance is rather more critical in hot and humid conditions. ESPINDESA dries the process air by cooling it with chilled water and condensing its moisture content. Not only this removes extraneous moisture from the plant; it also improves the efficiency of the air compressor because water vapour is excluded and cool air is denser than ambient air.<\/p>\n<p class=\"p5\">65-71% HNO<span class=\"s4\">3<\/span> acid is produced in the bottom of the <span class=\"s1\">Absorber.<\/span><\/p>\n<p class=\"p1\"><strong>Operating consumptions<\/strong><\/p>\n<p class=\"p1\">The following table summarizes the main specific materials and utilities consumption per ton of HNO, for a 1,000-t\/d plant.<\/p>\n<ul>\n<li class=\"p1\"><span class=\"s1\">Ammonia<\/span> \u00a0<span class=\"s1\">281.5 kg<\/span><\/li>\n<li>Steam (export) <span class=\"s4\">650 mg<\/span><\/li>\n<li class=\"p1\">Catalyst, net (as Pt) <span class=\"s4\">30g<\/span><\/li>\n<li>Electric power 10 kW\/h<\/li>\n<\/ul>\n<p class=\"p7\">[\/vc_column_text]\n    <section class=\"tr-mod mod-titulo_separador \">\n      <h4>\n        Process Flow Diagram\n      <\/h4>\n    <\/section>[vc_single_image image=\u00bb421&#8243; img_size=\u00bbfull\u00bb css=\u00bb\u00bb][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n<p>[\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>[vc_row full_width=\u00bbstretch_row_content_no_spaces\u00bb][vc_column][\/vc_column][\/vc_row][vc_row css=\u00bb.vc_custom_1737025291657{margin-top: 50px !important;}\u00bb][vc_column][vc_row_inner][vc_column_inner width=\u00bb1\/2&#8243;][\/vc_column_inner][vc_column_inner width=\u00bb1\/2&#8243;][vc_single_image image=\u00bb419&#8243; img_size=\u00bbfull\u00bb css=\u00bb\u00bb][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text css=\u00bb\u00bb] In the last years the Industry demands giant plants and, in some cases, azeotropic concentration. Early in the 2000&#8217;s ESPINDESA dual pressure process achieves: [\/vc_column_text][\/vc_column][vc_column width=\u00bb1\/4&#8243;][\/vc_column][vc_column width=\u00bb1\/4&#8243;][\/vc_column][vc_column width=\u00bb1\/4&#8243;][\/vc_column][vc_column width=\u00bb1\/4&#8243;][\/vc_column][vc_column offset=\u00bbvc_hidden-lg vc_hidden-md vc_hidden-sm vc_hidden-xs\u00bb][vc_empty_space][vc_empty_space][\/vc_column][\/vc_row][vc_row full_width=\u00bbstretch_row_content_no_spaces\u00bb][vc_column][vc_empty_space][\/vc_column][\/vc_row][vc_row][vc_column][vc_empty_space][vc_column_text css=\u00bb\u00bb] Ammonia oxidation The process air is filtered and compressed [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1011,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-1103","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/pages\/1103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/comments?post=1103"}],"version-history":[{"count":2,"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/pages\/1103\/revisions"}],"predecessor-version":[{"id":1127,"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/pages\/1103\/revisions\/1127"}],"up":[{"embeddable":true,"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/pages\/1011"}],"wp:attachment":[{"href":"https:\/\/www.espindesa.es\/es\/wp-json\/wp\/v2\/media?parent=1103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}