{"id":48,"date":"2026-07-15T23:35:49","date_gmt":"2026-07-15T15:35:49","guid":{"rendered":"https:\/\/sdic-tcca.hbkaixuan.cn\/?p=48"},"modified":"2026-07-15T23:35:49","modified_gmt":"2026-07-15T15:35:49","slug":"tcca-paper-pulp-bleaching","status":"publish","type":"post","link":"https:\/\/sdic-tcca.hbkaixuan.cn\/?p=48","title":{"rendered":"TCCA in Paper Pulp Bleaching: How Chlorinated Cyanurate Replaces Chlorine Gas in Modern Mills"},"content":{"rendered":"<p>The global paper industry consumes over 3.2 million tons of chlorine-based chemicals annually for pulp bleaching, slime control, and process water treatment. Traditional chlorine gas (Cl2) is being phased out due to safety and environmental reasons \u2014 creating a US$400M market shift toward stable dry chlorine chemistries like TCCA. This guide covers technical applications, dosing, and economics.<\/p>\n<h2>1. Where TCCA Fits in Modern Pulp Mills<\/h2>\n<table>\n<thead>\n<tr>\n<th>Application<\/th>\n<th>Old Chemistry<\/th>\n<th>New (TCCA-Based)<\/th>\n<th>Cl Dose<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Slimicide (paper machine)<\/td>\n<td>Cl2 gas + biocides<\/td>\n<td>TCCA continuous<\/td>\n<td>0.5-2 mg\/L<\/td>\n<\/tr>\n<tr>\n<td>White water treatment<\/td>\n<td>Sodium hypochlorite<\/td>\n<td>TCCA feed<\/td>\n<td>2-5 mg\/L<\/td>\n<\/tr>\n<tr>\n<td>Broke storage tank<\/td>\n<td>Bactericide + Cl2<\/td>\n<td>TCCA + non-oxidizing biocide<\/td>\n<td>1-3 mg\/L<\/td>\n<\/tr>\n<tr>\n<td>Filler prep<\/td>\n<td>Manual dosing<\/td>\n<td>Automated TCCA feeder<\/td>\n<td>5-10 mg\/L<\/td>\n<\/tr>\n<tr>\n<td>Effluent pretreatment<\/td>\n<td>NaOCl<\/td>\n<td>TCCA<\/td>\n<td>10-50 mg\/L<\/td>\n<\/tr>\n<tr>\n<td>Final ECF bleaching<\/td>\n<td>ClO2 (chlorine dioxide)<\/td>\n<td>TCCA rarely (ClO2 still dominant here)<\/td>\n<td>N\/A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>2. Why Mills Are Switching to TCCA<\/h2>\n<h3>A. Safety<\/h3>\n<p>Chlorine gas leaks kill workers. A 2019 incident in Indonesia killed 3 workers when a Cl2 cylinder ruptured. TCCA is:<\/p>\n<ul>\n<li>Solid form \u2014 no pressurized cylinders<\/li>\n<li>Slow release \u2014 cannot mass-release toxic gas<\/li>\n<li>Standard PPE sufficient (no full-face respirators or SCBA needed)<\/li>\n<li>Storage in ordinary chemical warehouse, no dedicated Cl2 room needed<\/li>\n<\/ul>\n<h3>B. Regulatory Pressure<\/h3>\n<p>Post-2018 EU and North American emission regulations (ELV) limit gaseous chlorine emissions to &lt;5 ppm. Cl2 gas systems struggle to meet this; TCCA systems easily achieve &lt;1 ppm.<\/p>\n<h3>C. Storage Efficiency<\/h3>\n<ul>\n<li>1 ton TCCA = 900 kg available chlorine<\/li>\n<li>1 ton Cl2 gas = 1000 kg available chlorine but requires 750 kg additional infrastructure (cylinders, vaporizer, injector)<\/li>\n<li>Net storage footprint: TCCA needs 40% less space than equivalent Cl2 system<\/li>\n<\/ul>\n<h3>D. Economic Comparison (per ton pulp bleached)<\/h3>\n<table>\n<thead>\n<tr>\n<th>Chemistry<\/th>\n<th>Chemical Cost<\/th>\n<th>Infrastructure Depreciation<\/th>\n<th>Labor<\/th>\n<th>Total<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Cl2 gas system<\/td>\n<td>$3.20<\/td>\n<td>$1.80<\/td>\n<td>$2.40<\/td>\n<td><strong>$7.40<\/strong><\/td>\n<\/tr>\n<tr>\n<td>TCCA tablets in bypass<\/td>\n<td>$4.10<\/td>\n<td>$0.40<\/td>\n<td>$0.80<\/td>\n<td><strong>$5.30<\/strong><\/td>\n<\/tr>\n<tr>\n<td>NaOCl (bleach)<\/td>\n<td>$4.80<\/td>\n<td>$0.90<\/td>\n<td>$1.60<\/td>\n<td><strong>$7.30<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>TCCA saves ~US$2\/ton pulp<\/strong> despite higher chemical cost, due to lower infrastructure and labor.<\/p>\n<h2>3. Slimicide Application (The Biggest Volume)<\/h2>\n<p>Slime \u2014 bacterial biofilm on paper machines \u2014 costs the paper industry US$1.5B annually in lost production. TCCA&#8217;s slow-release chemistry is ideal:<\/p>\n<ul>\n<li>Dose to whitewater loop at 0.5-2 mg\/L free Cl continuously<\/li>\n<li>Use tablet feeder (200g tablets) or dissolving pot<\/li>\n<li>Combine with weekly shock dose of 10 mg\/L for 30 min<\/li>\n<li>Rotate with non-oxidizing biocide (isothiazolone) every 2 weeks to prevent bacterial resistance<\/li>\n<\/ul>\n<h2>4. Slime Control Success Metrics<\/h2>\n<ul>\n<li>Machine downtime for cleaning: baseline vs post-TCCA (typically 60% reduction)<\/li>\n<li>Sheet breaks per day (typical 40-70% reduction)<\/li>\n<li>ATP (adenosine triphosphate) meter readings on whitewater (target &lt; 10,000 RLU)<\/li>\n<li>Slime patch inspection at press rolls, wire, felt<\/li>\n<\/ul>\n<h2>5. TCCA in Recycled Fiber Processing<\/h2>\n<p>OCC (old corrugated cardboard) and mixed office waste bring high bacterial loads. TCCA applications:<\/p>\n<ul>\n<li>Pulper input: 5-10 mg\/L TCCA to sanitize incoming fiber slurry<\/li>\n<li>Deinking cell: 2-5 mg\/L to control microbial degradation of fibers<\/li>\n<li>Storage chest: 1-3 mg\/L continuous to prevent spoilage during hold time<\/li>\n<\/ul>\n<h2>6. Dosing Systems<\/h2>\n<h3>A. Bypass Feeder (Most Common)<\/h3>\n<ul>\n<li>Diverts 5-10% of process water through TCCA tablet feeder<\/li>\n<li>Automatic dissolution as water flows past tablets<\/li>\n<li>Feed rate controlled by valve on bypass line<\/li>\n<li>Refill weekly with 25-100kg TCCA depending on mill size<\/li>\n<\/ul>\n<h3>B. Continuous Dissolution Tank<\/h3>\n<ul>\n<li>Larger mills (&gt;500 t\/day pulp) use dedicated dissolving tanks<\/li>\n<li>10,000-30,000 L tank with automatic tablet loader<\/li>\n<li>Metering pump doses concentrated TCCA solution to process<\/li>\n<li>Requires SCADA integration for automation<\/li>\n<\/ul>\n<h3>C. Manual Bag Dosing (Small Mills)<\/h3>\n<ul>\n<li>Pre-weighed 5-25kg bags of TCCA granules<\/li>\n<li>Operator dumps into pulper on scheduled intervals<\/li>\n<li>Requires trained operators, PPE, safety monitoring<\/li>\n<\/ul>\n<h2>7. Compatibility Concerns<\/h2>\n<ul>\n<li>Do NOT mix with amino-containing surfactants (creates chloramines)<\/li>\n<li>Do NOT mix with reducing agents (destroys chlorine)<\/li>\n<li>Do NOT mix with strong acids in feeder (releases Cl2)<\/li>\n<li>Do NOT use with sodium bisulfite dechlorination line (react point downstream only)<\/li>\n<li>Compatible with: standard defoamers, cationic retention aids, sizing agents, most drainage aids<\/li>\n<\/ul>\n<h2>8. Case: Southeast Asian Kraft Mill Conversion<\/h2>\n<p>A 400 t\/day pulp mill in Vietnam converted from Cl2 gas + NaOCl to TCCA-based system in 2023. Twelve-month results:<\/p>\n<ul>\n<li>Chemistry cost per ton pulp: US$7.10 \u2192 US$5.40 (24% reduction)<\/li>\n<li>Safety incidents: 3\/year Cl2 leaks \u2192 0<\/li>\n<li>Machine downtime for slime cleaning: 4.2%\/month \u2192 1.8%\/month (57% reduction)<\/li>\n<li>Insurance premium reduction: US$180,000\/year (due to Cl2 removal from site)<\/li>\n<li>ROI on conversion project: 8.5 months<\/li>\n<\/ul>\n<h2>9. FAQ<\/h2>\n<p><strong>Q: Can TCCA fully replace ClO2 in ECF bleaching?<\/strong><br \/>\nA: No. ClO2 has unique selective bleaching properties for pulp. TCCA is used in slime control, white water, and non-bleaching sanitation.<\/p>\n<p><strong>Q: Does TCCA affect paper quality (brightness, strength)?<\/strong><br \/>\nA: At recommended slimicide doses (0.5-2 mg\/L), no measurable impact. Excessive doses &gt; 20 mg\/L may reduce fiber strength.<\/p>\n<p><strong>Q: MOQ for pulp mill applications?<\/strong><br \/>\nA: Typical mill order: 5-25 tons per shipment. Minimum practical MOQ is 5 tons for FCL shipping economics.<\/p>\n<p><strong>Q: Does TCCA cause corrosion of paper machine equipment?<\/strong><br \/>\nA: At operating pH (usually 5-8 in paper systems), no significant corrosion of stainless steel. Bronze fittings may show mild pitting after 3-5 years.<\/p>\n<h2>Industrial TCCA for Paper Industry<\/h2>\n<p>Shilan Chemical supplies pulp\/paper mills across Southeast Asia, South America, and Africa with industrial-grade TCCA. Delivery in 25kg drums, 50kg drums, or 1000kg jumbo bags. Read our <a href=\"\/?p=37\">cooling tower guide<\/a> for related applications, or <a href=\"\/contact.html\">request pulp\/paper quote<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Pulp mills traditionally used chlorine gas and hypochlorite. Environmental regulations and safety concerns are driving conversion to TCCA \u2014 safer to handle, better slimicidal effect, and equivalent bleaching power. Technical guide inside.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-48","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=\/wp\/v2\/posts\/48","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=48"}],"version-history":[{"count":0,"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=\/wp\/v2\/posts\/48\/revisions"}],"wp:attachment":[{"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=48"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=48"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sdic-tcca.hbkaixuan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=48"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}