• 제목/요약/키워드: Chlorine Bleaching

검색결과 44건 처리시간 0.023초

대나무화학펄프의 다단표백에 관한 연구 (Studies on the Multistage Bleaching of Bamboo Chemical Pulps)

  • 강진하;박성종
    • 펄프종이기술
    • /
    • 제33권4호
    • /
    • pp.49-54
    • /
    • 2001
  • This study was carried out to acquire basic data for the bleaching of bamboo chemical pulp. Bamboo chemical pulps (alkaline sulfite (AS)-anthraquinone (AQ) pulp, Kraft pulp) were bleached with two kinds of multistage bleaching methods (CEDED, PDED) using the various kinds of bleaching agents. And, physical properties of bleached pulps were investigated. The conclusions obtained from the results were as follows; The yield of AS-AQ pulp bleached with four-stages bleaching method using the hydrogen peroxide and chlorine dioxide as a bleaching agents was higher than the other bleached pulps. The brightness of kraft pulp bleached with five-stages bleaching method using the chlorine and chlorine dioxide as a bleaching agents was higher than the other bleached pulps. The physical properties of kraft pulp bleached with four-stages bleaching method using the hydrogen peroxide and chlorine dioxide as a bleaching agents was higher than the other bleached pulps.

  • PDF

이산화염소 표백조건에 따른 삼 인피섬유의 표백효과 (Bleachability of Hemp Bast Fiber by Chlorine Dioxide)

  • 김준규;최경화;서진호;이명구
    • 펄프종이기술
    • /
    • 제47권4호
    • /
    • pp.109-114
    • /
    • 2015
  • In this study, the effects of chlorine dioxide (D) bleaching conditions on the delignification of hemp bast fiber were elucidated. Chlorine dioxide bleaching was carried out through three stages (DED) and five stages (DEDED), respectively. Applied amounts of chlorine dioxide at $D_1$ and $D_2$ stages were varied to find the optimum bleaching condition. It was found that the optical properties of its handsheet as well as the delignification of hemp bast fiber increased as the concentration of chlorine dioxide at $D_1$ stage increased. It was also notable that the bleachability of the DEDED bleaching stages was slightly more effective than that of the DED bleaching stages. The burst index of the handsheets made with bleached hemp bast fiber was higher than that of the unbleached samples, but the burst index of these samples decreased as their delignification increased. These results indicated that the higher concentration of chlorine dioxide at $D_1$ stage was major factor to improve the bleaching efficiency of hemp bast fiber.

볏짚화학펄프의 표백에 관한 연구 (Studies on the Bleaching of Rice-Straw chemical Pulp(I))

  • 강진하;박성종
    • 펄프종이기술
    • /
    • 제32권3호
    • /
    • pp.65-74
    • /
    • 2000
  • This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulps(alkaline sulfite-Na2S2O4 pulp) were bleached with the various kinds of bleaching agents. And physical properties of bleached pulps were tested. The results of this study were as follows; 1, The proper conditions of chlorine sequence were determined to be 4% concentration of chlorine 25$^{\circ}C$ of reaction temperature and 50 minutes of reaction time. 2. For calcium hypochlorite sequence the proper conditions of chemical concentration reac-tion temperature and reaction time were 3% 25$^{\circ}C$ and 20 minutes respectively. 3. For chlorine dioxide sequence the proper conditions were 1% concentration of chlorine dioxide 70$^{\circ}C$ of reaction temperature and 2hr. of reaction time. 4. The proper conditions of hydrogen peroxide sequence were 1.5% concentration of hydro-gen peroxide 70$^{\circ}C$ of reaction temperature and 1hr. of reaction time respectively. 5. When the rice-straw chemical pulp were bleached with four kinds of bleaching agents methioned above in the proper conditions respectively brightnesses were the order of chlorine dioxide calcium hypochlorite, chlorine, hydrogen peroxide. And strengthes of pulps bleached with chlorine dioxide and hydrogen peroxide were higher than those of pulps bleached with other bleaching agents.

  • PDF

오존을 이용한 신갈나무 크라프트펄프의 무염소표백 (Non-chlorine Bleaching of Oak Kraft Pulp by Ozone)

  • 김동호;백기현
    • 펄프종이기술
    • /
    • 제29권2호
    • /
    • pp.36-45
    • /
    • 1997
  • Newly bleaching sequence using oxygen, ozone and hydrogen peroxide has introduced to avoid pollution hazards from chlorinated organic compounds, because chlorine dioxide substitution bleaching was produced a little chlorinated organic substance. Oxygen-type chemicals replaced for chlorine has attracted much research attention. Bleachability of ozone was improved at low temperature and high pulp consistency. In third bleaching followed OZ bleaching, addition of O2 and NaBH4 in alkali extraction was effective than only alkali extraction. Bleachability of pulps in ozone bleaching(Z) was improved at higher consistency and lower temperature The addition O2 and NaBH4 in alkali extraction after OZ bleaching sequence improved brightness, when compared to those obtained by only alkaline extraction. Pulps bleached by ECF bleaching sequences such as OZEoD and OZEopD was obtained by 90% ISO brightness. The brightness of pulp bleached by TCF sequences with the ozone dosage of 1.6% was approached to target brightness (88~90%ISO). Pulps bleached Z stage combined bleaching sequence was reduced the viscosity to a little greater extent. However, physical properties of pulps was not great different compared to those bleached by conventional bleaching sequences. A pollution index of bleaching effluente by ozone combined bleaching sequences was lower than by conventional bleaching sequence, but somewhat higher than multistage bleaching sequences combined C/D stage.

  • PDF

pH와 첨가제에 의한 이산화염소의 분해율 및 펄프표백 효과(1)-표백 중에서 이산화염소의 분해와 Chlorate의 생성- (Pulp Bleaching Effect and Ionization Rate of Chlorine Dioxide by Additives and Various pH Conditions(I)-Ionization of ClO$_2$ and Formation of Chlorate in Pulp Bleaching-)

  • 윤병호;;김용식
    • 펄프종이기술
    • /
    • 제30권3호
    • /
    • pp.1-6
    • /
    • 1998
  • Elementally Chlorine Free (ECF) bleaching will be superior than Totally Chlorine free (TCF) bleaching, not only because they have no significant difference in effluent toxicity, but also those pulps bleached by ECF have higher brightness, strength, yield, etc., over those by TCF. With this belief, this paper focused on the chemistry of chlorine dioxide decomposition and ionization, both in water solution and in pulp slurry. Special attention was paid to chlorate ion because there have been controversies as how it is formed and what its behavior to the end pH of pulp bleaching is. As a result, during ionization of chlorine dioxide with water, both chlorate and chlorite were found to increase with increasing pH, but during ionization with pulp, chlorite was found to increase with end pH while chlorate decreased with increasing end pH. In the case of ionization with water, the disproportion equation $2CIO_2 + OH^{-} \lightarrow H_2O + CIO_3^{-} + CIO_2^{-}$ was thought to become the main reaction with the increasing pH, while in the case of ionization with pulp, the reaction $HCIO + CIO_2^{-}\lightarow H^{+} + Cl^{-} + CIO_3^{-}$ was the main reaction contributing to the formation of chlorate. Based on this above opinion, the contrary results of chlorine dioxide ionization from different researchers were discussed and explained.

  • PDF

Analysis of Chlorine Species in Chlorine Dioxide Bleaching Liquor and Generation Process by UV-VIS Spectroscopy

  • Wang, Li-Jun;Lee, Seon-Ho;Yoon, Byung-Ho
    • 한국펄프종이공학회:학술대회논문집
    • /
    • 한국펄프종이공학회 1999년도 춘계학술발표논문집
    • /
    • pp.78-83
    • /
    • 1999
  • In this paper the extinction coefficients of molecule chlorine ($Cl_2$), chlorine dioxide (ClO$_2$), hypochlorous acid (HClO), chlorous acid ($HClO_2$$_2$) were determined using a PDA UV-VIS spectrophotometer. Based on these, the concentrations of $Cl_2$, $ClO_2$, and HClO in general chlorine dioxide bleaching liquor can be measured. The concentrations of $Cl_2$, $ClO_2$ and $HClO_2$ produced during the generation of methanol based chlorine dioxide generator can also be determined use the same method. The method was thought to be able to give more information in chlorine dioxide bleaching chemistry if combine its use with titration and ion chromatography.

  • PDF

Studies on the Bleaching Efficiency in Newsprint Using Formamidine Sulfinic Acid

  • Choi, Won-Jung;Kim, Hyoung-Jin
    • 한국펄프종이공학회:학술대회논문집
    • /
    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
    • /
    • pp.381-386
    • /
    • 2006
  • Many different types of bleaching chemicals and processes have been globally used for deinked pulp. Besides chlorine-free bleaching chemicals, hydrogen peroxide, and sodium dithionite that could be used without restriction for almost all types of fibers, chlorine-containing chemicals such as chlorine dioxide and sodium hypochlorite have also used throughout the world. Even though hydrogen peroxide is commonly used in newsprint, it could not effectively increase brightness. Experimental evaluation on the possibility of using formamidine sulfinic acid (FAS), a reducing agent, for bleaching a wood-containing deinked pulp has been carried out in this study. The effect of bleaching efficiency for FAS on operational conditions and chemical concentrations compaired to hydrogen peroxide in one and two stages was studied. FAS bleaching showed higher brightness at high temperature and low consistency, and vice versa for peroxide one. Bleaching with sodium silicate and DTPA in FAS and peroxide stage showed better results than cases without them. Sodium silicate and chelant seemed minimize the influence of transition metal ions, including manganese and iron ions, which induce both bleaching agents to decompose. As a result, FAS as a reducing agent seems more effective than hydrogen peroxide for increasing brightness and reducing yellowness. FAS and FAS sequence seemed more efficient than the other two stages of bleaching sequences with regard to the best brightness level obtained. When bleaching was conducted with FAS, COD load was just about one-third compared to peroxide, and brightness stability of the bleached pulp appeared better than peroxide after UV light irradiation.

  • PDF

사탕수수 부산물 펄프의 DEDP 표백 시 킬레이트 전처리가 표백 효율에 미치는 영향 (Effect on Bleaching Efficiency by Chelating Treatment in Sugarcane Bagasse DEDP Bleaching Process)

  • 이재성;송우용;박종문;신수정
    • 펄프종이기술
    • /
    • 제47권4호
    • /
    • pp.81-87
    • /
    • 2015
  • Soda-AQ pulp made from sugarcane bagasse (SCB) were bleached in element chlorine free (ECF) sequence. To reduce chlorine dioxide use, final peroxide bleaching was introduced. Prior to peroxide bleaching, different chelating chemicals were applied for comparative analysis in ISO brightness and viscosity. When using equal total chlorine dioxide usage (4.5%), bleached SCB pulp using chelate and hydrogen peroxide (DEDQP) was reached 86.8% (DTPA), 86.4% (EDTA) ISO brightness, whereas bleached pulp using only hydrogen peroxide (DEDP) reached at 81.2% ISO brightness. Viscosity of DEDQP bleached pulp was 25.6 cPs (DTPA), 25.2 cPs (EDTA), And DEDP bleached pulp was shown 18.0 cPs viscosity. Decreasing of transition metal by chelate process led to improvements in final brightness along with higher viscosity. Due to EDTA is 5-7 times cheaper than DTPA, EDTA is recommended as chelating chemical prior to peroxide bleaching.

맹종죽(Phyllostachys pubescens)의 소다 안트라퀴논 펄핑 특성 및 이산화염소 표백 특성 (Soda-Anthraquinone Pulping and Chlorine Dioxide Bleaching Properties from Moso Bamboo (Phyllostachys pubescens))

  • 이규성;송우용;신수정
    • 펄프종이기술
    • /
    • 제48권2호
    • /
    • pp.13-19
    • /
    • 2016
  • Moso Bamboo was investigated as the a raw material for pulp and paper industry. Soda-Anthraquinone (Soda-AQ) pulping, elemental chlorine free bleaching was applied. Yield of soda or soda-AQ pulp was 29.3-31.7% with Kappa number 33.0-22.8 with different cooking time or anthraquinone addition at 20% active alkali. In soda or soda-AQ pulping, 81-86% of xylan was removed, which was the main reason for lower pulp yield than hardwood species. Average fiber length of Moso Bamboo soda-AQ pulp was 1.36 mm with $15.5{\mu}m$ fiber width. Soda-AQ pulp from Moso Bamboo (P-3, lowest Kappa pulp) was bleached with 5.5-6.5% of chlorine dioxide charge as D0ED1 bleaching sequence. In 3-stages ECF bleaching, final brightness of 85.3% ISO was achieved with total chlorine dioxide 6.5%.

효소를 이용한 크라프트펄프의 무감소표백-신갈나무 크라프트펄프- (Elemental Chlorine free Bleaching of Kraft Pulps with Enzymes( I )-Oakwood Kraft Pulp-)

  • 강진하;박성종;임현아
    • 펄프종이기술
    • /
    • 제30권1호
    • /
    • pp.44-58
    • /
    • 1998
  • This study was carried out to bleach the Oakwood kraft pulp without the elemental chlorine using the xylanase or wastewater(We : wastewater enzymes) effluented from the submerged biofilter reactor containing the fungi, Phanerorhaete sordida YK-624. So in this research, the proper treatment conditions (pH, temperature, dosage and time) were investigated respectively. And after the various kinds of multistage bleaching of pulps, the properties of pulps were tested. From the experimental results, we can conclude as follows. In the treatments of Oakwood kraft pulps with xylanase, the proper pH, temperature, enzyme dosage and time were 8.0, $35^{\circ}C$ , 400 EXU/kg and 1 hr. respectively. And in the case of treatment with a wastewater(We) effluented from the submerged biofilter reactor, the proper pH, temperature and time were 5.5, $37^{\circ}C$ and 2 hr. respectively. On the other hand, Oakwood kraft pulps were bleached by the method of a multistage bleaching using xylanase or We instead of elemental chlorine Consequently the strengthes and brightnesses of pulps bleached by the method mentioned above were lower than those of pulp bleached by the conventional method using the elemental chlorine. But it is possible to improve the brightnesses through the increase of chlorine dioxide dosage or use of hydrogen peroxide in the final bleaching stage.

  • PDF