Program for North American Mobility in Higher Education Introducing Process Integration for Environmental Control in En

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LEGEND. Go to the web siteGo to next subjectMore data on the same subjectLook for the response to the inquiry. . . . . Level II: Case Study Applications. Level II: Statement of Intent. Level II: Statement of IntentThe reason for this module is to show the utilization of the base assembling ideas utilizing the Thunder Bay and Louisiana-Pacific contextual analyses, and presents the idea

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Program for North American Mobility in Higher Education Introducing Process Integration for Environmental Control in Engineering Curricula Module 3: Environmental Challenges – Pulp & Paper Industry Caroline Gaudreault Created at: École Polytechnique de Montréal & Texas A&M University, 2003

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LEGEND Go to the site Go to next subject More data on a similar subject Look for the response to the question

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Tier II: Case Study Applications

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Tier II: Statement of Intent Tier II: Statement of Intent The motivation behind this module is to d emonstrate the use of the base assembling ideas utilizing the Thunder Bay and Louisiana-Pacific contextual investigations, and presents the ideas of BAT and key arranging. Level II additionally incorporates some chose readings, to help the understudy secure a more profound comprehension of this subject.

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Tier II: Content Tier II is broken into four areas: 2.1 The Thunder Bay contextual analysis 2.2 The Louisiana Pacific Samoa contextual analysis 2.3 Strategic long haul getting ready for kraft factories, innovation guides, and MIM measurements 2.4 Best Available Technologies for the kraft forms At the finish of Tier II, there is a short various answer test

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A Little Bit of History In 1974 , Great Lakes Forest Products Limited (GLFP) chose to assemble a moment kraft line (kraft process B) in their plant situated in Thunder Bay, Ontario. Subsequently, the Ontario Ministry of the Environment (OMOE) requesting that they build an auxiliary treatment of the emanating keeping in mind the end goal to diminish BOD 5 , poisonous components and suspended solids released to the waterway. GLFP considered circulated air through tidal ponds however there was no nearby accessible space to suit it. This is the reason they started to talked about with Howard Rapson at the University of Toronto about the "Shut Cycle Mill" idea. They supported the idea and presented the venture to the OMOE set up of optional treatment.

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A Little Bit of History (Cont'd) The OMOE gave the endorsement for the development of the "nearby cycle" kraft process B, however with the arrangement than by March 1978, GLFP ends up being: operational; To be as proficient as optional treatment and, Following this, GLFP propose to introduce the "close-cycle" framework to the next kraft line (kraft process A). The B process started its operations in 1976 yet the "close-cycle" operations were started just in 1977 after the salt recuperation plant was finished. From 1977 to 1985, the "close-cycle" framework was produced constantly as a team with the University of Toronto too than with different players.

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A Little Bit of History (Cont'd) Pitch stores and scaling issues extremely restricted close-cycle operations, and more particulary amid hardwood preparing. In 1985, the nearby cycle operations were ended for a considerable measure of reasons including: It was conceivable to get a proportionate BOD 5 lessening just by expanding evaporator condensate utilize and recuperation; Operating expenses were high. These expenses incorporate expanded fading compound expenses and high vitality costs for the salt recuperation plant; Heat exchangers in the salt recuperation plant were consumed and it would have been exceptionally costly to supplant/redesign them.

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Information about Kraft Mill B Bleached mash generation of 250 000 ton/year First Canadian "gushing free" mash and paper plant World's first utilization of the Rapson-Reeve shut cycle idea

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Bleach Plant Description A mix of spruce and jackpine chips was encouraged Kamyr nonstop digester . The mash was washed in a two-organize washer. The detergent plant comprise in 5 phases D CEDED : D C: utilization of chlorine dioxide and rudimentary chlorine consecutively in a similar stage, utilizing ClO 2 in substantial amount preceding chlorine in the principal stage will take into consideration a general blanch synthetic diminishment, an expanded yield and a saved mash resistance; E: basic extraction (disintegration of response item with NaOH); D: chlorine dioxide (response with ClO 2 in acidic medium) Whitewater is utilized to wash the mash counter-at present.

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Salt Recovery Process Description Clarified white alcohol from the recausticizing division was moved in an evaporator to build the soluble base substance. Hastened sodium carbonate and burkeite (2Na 2 SO 4 .NACO 3 ) were expelled by illumination and typhoon partition framework. The illuminated concentrated alcohol was reconcentrated in an other evaporator to recuperate more 2Na 2 SO 4 .NACO 3 . The recuperated salt was treated with sodium hypochlorite to oxidize natural polluting influences. At last, after a sand filtration, the salt was utilized as a part of the chlorine dioxide generators.

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Key Features of the "Nearby Cycle" System introduced in Great Lakes Mill The fundamental attributes of the framework were: Dry drum debarkers; Pressure (shut) essential knotters and screens; Use of mash dryer vacuum pump seal water in the wet end of the dryer and utilization of overabundance white water on the last D arrange fade plant washer; Full countercurrent washing in the sanitizer plant; another salt expulsion handle (SRP) in view of dissipation of the white alcohol in two phases to create crystalline sodium chloride; Use of abundance filtrate from the E1 washer to weaken concentrated white alcohol and to wash the unbleached mash; Use of overabundance D  C filtrate after balance with burning or white alcohol for cocoa mash washing and in the lime furnace scrubber, and in this way for noticed dissolving; 70% chlorine dioxide substitution for chlorine in the main stage to limit chloride load to the recuperation framework; A broad spill gathering and recuperation framework; A stripping section to clean the foul condensates.

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Overview of Water Recovery Water ClO 2 Solution Bleach Plant DC Filtrate E 1 Filtrate Brownstock Washers Digesters Evaporators Concentrated White Liquor Recovery Furnace Smelt Dissolver Causticizer White Liquor SRP Process Condensate Salt (Adapted from Springer & al., 2001)

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Expected Benefits from the Close-Cycle Mill Lower steam utilization Greater steam generation Decrease of 1% fiber misfortunes from screening, washing, and so forth. Increment of 1% in faded mash process Lower utilization of fade chemicals, and diminished salt cake and defoamer utilize Elimination of outer waste treatment Reduction in kraft process smell Substantial yearly working cost reserve funds

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Corrosion: High temperature and chloride levels will expand the potential for consumption in the nearby cycle framework. Indeed, even in dying plant gear building material was painstakingly chosen. Early confirmation of erosion was noted. Stores: Hardwood runs were portrayed by stores from wood extractives, buildups from defoamers and different sources which created a great deal of issues: pitch, scale, defoamer buildups and powder/pitch stores stopped washer textures and wires, washer spouts and filtrate lines. Therefore, some filtrate reuse streams were ended amid hardwood runs. Affect on Pulp Mill Operations The Bleach Plant Initial Design Problems: A terrible outline of a portion of the fading tanks occasioned shine issues and an expansion in dying synthetic utilization. Air partition gadgets for the washers was not thoroughly thought out. This brought on frothing issue amid the washing stages. The era limit of ClO2 was lacking to meet the objective of 70% substitution in the chlorination organize. The substitution found the middle value of half. The limit was expanded. There was no cleanse stream in the framework. This brought about an aggregation of Ca thus in extreme scaling issues. And so forth… .

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D  C Closure : Prior to be reused, the filtrate from this stage was killed with NaOH which result in a Ca/lignin/pitch precipitation that kept on texture and wire and in a disabled waste. These store were evacuated utilizing corrosive which result in consumption. Additionally, due to the high natural substance in the reuse stream, there was an expansion in compound utilization for this stage. E 1 Closure: E 1 filtrate was reused to the chestnut decker which brought about poor washing effectiveness and vestige to the D  C arrange with incresed concoction utilization. This was rectified by reusing the E 1 filtrate to washer where the solids content coordinated increasingly the broke down solids in the filtrate. Accessibility of the SRP, pluggage, pitch and scale had additionally extremely hampered E 1 conclusion. Affect on Pulp Mill Operations The Bleach Plant

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Impact on Pulp Mill Operations Monitoring and Control Maintaining water parities was troublesome amid new companies, shutdowns, bombshells and unsettling influences. In view of they were annoying the water equalizations, spill recuperation was not extremely effective.

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Impact on Pulp Mill Operations The Digester No recognizable impact on the digester operations.

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Impact on Pulp Mill Operations The Black Liquor Evaporators Advanced consumption operating at a profit alcohol evaporators decreased their life-time from 25 to 5 years. The mash process operations were confined because of a constrained evaporator limit. The later was expanded yet the spills were never viably recclaimed. half of aggregate BOD 5 of the kraft process B was inferable from the evaporators condensate.

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Impact on Pulp Mill Operations Recovery Boiler Recovery heater consumption brought about noteworthy generation misfortunes and different expenses.

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Impact on Pulp Mill Operations Recausticizing and Lime Kilnb Neutralized D  C filtrate was utilized as a part of the lime furnace scrubber. The filtrate wound up in the powerless wash, green alcohol, and white alcohol. The filtrate hampered leftovers settling in the green alcohol clarifier and lime mud settling in the white alcohol clarifier. A high du