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1.
Epoxy resin and polyetheretherketone (PEEK) resin were decomposed into their monomers such as phenol, cresols, and their analogues by thermal treatment in sub- and supercritical water in a 10-ml tubing bomb reactor. The addition of basic compounds such as Na2CO3 was effective in promoting the decomposition reaction of the resins. In the reaction of epoxy resin, the yield of identified products reached 10% for the reaction at 703K over 1h. In the reaction of PEEK resin, the total yield of phenol and dibenzofuran reached 88% for the reaction at 703K over 3h. Chemical participation of water in the decomposition reaction was confirmed by the reaction of dinaphthylether. 相似文献
2.
Hajime Yasuda Tohru Kamo Mariko Adachi Satoshi Sajima Hideki Nakagome 《Journal of Material Cycles and Waste Management》2010,12(2):123-127
The rapid hydropyrolysis of model compounds for epoxy resin oligomers and biomass tar was carried out in a hydrogen atmosphere
at 1073 K and 973 K. The assumed oligomers were partially pyrolyzed epoxy resin with biomass tar as solvent for the resin.
The product distributions obtained from rapid hydropyrolysis of phenol and bisphenol-A are shown. We also discuss the effects
of reaction temperature and hydrogen partial pressure on the product yield. In particular, more phenol was produced from bisphenol-A
at 973 K than at 1073 K. The yield of methane, which was the final hydropyrolysis product, increased with increasing hydrogen
partial pressure, whereas benzene and phenol were believed to behave as intermediate products in the hydropyrolysis reaction.
The results suggest that phenol could be obtained with high selectivity from tar by optimizing the reaction conditions. 相似文献
3.
Haihong Huang Yanzhen Yin Huanbo Cheng Zhipei Zhao Baoyu Zhang 《Journal of Polymers and the Environment》2017,25(2):115-125
CF/EP (carbon fibre/epoxy resin) composites were degraded by supercritical n-butanol with alkali additive KOH in a batch reactor. The catalytic degradation mechanism of the composites was investigated based on the analysis of liquid phase products by GC–MS and solid phase products by FTIR. The results indicate that alkali additive (KOH) can promote Guerbet reaction and increase hydrogen donor capability of supercritical n-butanol. The H· can combine promptly with the free radical formed by the scission of linear and crosslinked chains in epoxy resin to generate the liquid products, including phenol, 4-isopropylphenol, 4-(2-methylallyl)phenol and other derivatives of benzene and phenol. The combination of supercritical n-butanol with alkali additive is an effective way to degrade and recycle CF/EP composites. 相似文献
4.
Shin'ya Hayashi Kanemasa Nomaguchi Tsutomu Okusawa Osamu Yokomizo Yukio Ishigaki Hitoshi Ishimaru 《Journal of Material Cycles and Waste Management》2000,2(1):57-62
Fiber-reinforced plastics (FRP) were first used as a material for boats and bath tubs about 40 years ago. Because of their
great durability, wastes including FRP products are increasing. In addition, since the FRP resin is synthesized from expensive
reactants, material recycling is highly desirable. Recycling using supercritical water is one solution; however, the cost
of producing the high pressure and temperature needed to produce supercritical water prevents the concept from being realized.
Therefore, we proposed a system concept based on dual waste-plastics recycling. A numerical survey of the results confirmed
that our concept was feasible and would contribute to resource recycling as we expected.
Received: January 6, 1998 / Accepted: July 23, 1999 相似文献
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The recycling of waste plastics is important for the prevention of the exhaustion of fossil resources. In this paper, recycling techniques of carbon fiber-reinforced plastic (CFRP) using supercritical and subcritical fluids were reviewed. The matrix resin of CFRP such as epoxy resin or resol resin was decomposed by supercritical and subcritical fluids, and the carbon fiber without thermal damage was recovered from CFRP. Mainly, water or alcohol was used as decomposition medium. 相似文献
7.
以废弃线路板热解油为原料,采用碱溶—中和—萃取工艺提取其中以苯酚为主的粗酚,并合成改性酚醛树脂。合成硼酸改性酚醛树脂的优化工艺条件为n(粗酚)∶n(外加苯酚)=2∶3,n(粗酚+外加苯酚)∶n(甲醛)∶n(NaOH)∶n(硼酸)=1∶1.5∶0.15∶0.17;合成有机硅改性酚醛树脂的优化工艺条件为n(粗酚)∶n(外加苯酚)=2∶3,n(粗酚+外加苯酚)∶n(甲醛)∶n(NaOH)∶n(正硅酸乙酯)=1∶1.3∶0.1∶0.1。所合成的硼酸改性和有机硅改性酚醛树脂的主要性能指标均满足YB/T4131—2005《耐火材料用酚醛树脂》中牌号为PFn-5301的热固性液体树脂性能的要求。 相似文献
8.
Destruction of PAHS from soil by using pressurized hot water extraction coupled with supercritical water oxidation 总被引:4,自引:0,他引:4
Chemical processes utilizing water both as extraction solvent and reaction medium are promising "Green Chemistry" alternatives to conventional techniques. Equipment for on-line coupled hot water extraction and supercritical water oxidation was constructed to extract polyaromatic hydrocarbons and toluene from sea sand followed by oxidation using hydrogen peroxide. The effectiveness of the technique is based on the physico-chemical properties of heated and pressurized water. Extraction efficiency increased with temperature and time; the best results were obtained at 300 degrees C with 40 min extraction time. In the oxidation stage, conversion of the PAHs increased with reaction time and oxidant concentration and the best conversion (97.0-99.9%, depending on the compound) was obtained at 425 degrees C with 43 s reaction time. Benzaldehyde and benzoic acid were the most abundant reaction intermediates in the oxidation process. In addition, phenol, p-cresol, and benzyl alcohol were found as intermediates. The intermediates originated mainly from toluene, which was present in much greater concentration than PAHs in the reaction medium. 相似文献
9.
Masaru Watanabe Shuhei Sawamoto Tadafumi Adschiri Kunio Arai 《Journal of Material Cycles and Waste Management》2001,3(2):99-102
This paper gives the results of partial oxidation experiments of polyethylene (PE) in supercritical water (SCW). The experiments
were carried out at a reaction temperature of 693K and a reaction time of 30 min using 6 cm3 of a batch-type reactor. The loaded sample weight was 0.3 g and there was 2.52 g water (0.42 g/cm3). The ratio of oxygen atoms to carbon atoms was 0.3. The results show a significant CO formation in O2–SCW, and the 1-alkene/n-alkane ratio in partial oxidation was higher than that in SCW pyrolysis. These results suggest the possibility of the hydrogenation
of hydrocarbon through partial oxidation followed by a water–gas shift reaction.
Received: July 19, 2000 / Accepted: September 28, 2000 相似文献
10.
采用二次缩合反应预处理高浓度酚醛树脂生产废水。一次反应的最佳工艺条件为:甲醛加入量0.010 0 mL/mL,Ba(OH)2加入量0.005 g/mL,反应时间3 h,反应温度85 ℃。最佳工艺条件下的一次反应COD去除率为 52.9%。二次反应中,当反应温度为80 ℃、反应时间为3 h、尿素加入量为3 g/L时,二次反应COD去除率最高,为31.5%。COD=85 000 mg/L、ρ(挥发酚)= 12 000 mg/L、ρ(甲醛)=6 740 mg/L的废水经两次缩合反应处理后,出水中COD=27 400 mg/L,COD的总去除率为67.8%;ρ(挥发酚)=2 400 mg/L,挥发酚的总去除率达80.0%;ρ(甲醛)= 980 mg/L,甲醛的总去除率达84.9%。处理1 t废水还可回收酚醛树脂6.75 kg。 相似文献
11.
采用HZ-16型大孔树脂对含三(三溴苯氧基)三嗪(RDT-8)废水进行吸附及脱附处理。实验结果表明:在废水流量为4.0 BV/h的条件下,树脂最佳吸附工艺条件为出水体积88.0 BV,此条件下出水COD小于291 mg/L,挥发酚质量浓度小于0.08 mg/L;在脱附液流量为0.5 BV/h的条件下,树脂最佳脱附工艺条件为脱附液体积3.0 BV,此条件下脱附液中挥发酚质量浓度为30.6 mg/L,挥发酚脱附率高达76.4%。在最佳吸附-脱附工艺条件下,连续进行10次动态吸附-脱附实验,吸附出水中COD为137~294 mg/L,COD去除率为72.5%~89.1%,挥发酚质量浓度稳定在0.05 mg/L以下,挥发酚去除率为99.8%~100%,说明HZ-16型大孔树脂的吸附-脱附性能稳定。 相似文献
12.
Yan Wang Guanyi Chen Yanbin Li Beibei Yan Donghui Pan 《Waste management (New York, N.Y.)》2013,33(11):2408-2415
Environment-friendly treatment of sewage sludge has become tremendously important. Conversion of sewage sludge into energy products by environment-friendly conversion process, with its energy recovery and environmental benefits, is being paid significant attention. Direct liquefaction of sewage sludge into bio-oils with supercritical water (SCW) was therefore put forward in this study, as de-water usually requiring intensive energy input is not necessary in this direct liquefaction. Supercritical water may act as a strong solvent and also a reactant, as well as catalyst promoting reaction process. Experiments were carried out in a self designed high-pressure reaction system with varying operating conditions. Through orthogonal experiments, it was found that temperature and residence time dominated on bio-oil yield compared with other operating parameters. Temperature from 350 to 500 °C and reaction residence time of 0, 30, 60 min were accordingly investigated in details, respectively. Under supercritical conversion, the maximum bio-oil yield could achieve 39.73%, which was performed at 375 °C and 0 min reaction residence time. Meanwhile, function of supercritical water was concluded. Fuel property analysis showed the potential of bio-oil application as crude fuel. 相似文献
13.
选择性吸附-高效生物降解法处理含硝基苯与苯酚混合废水 总被引:1,自引:0,他引:1
结合NDA-150型树脂(简称树脂)选择性吸附和生物降解的优点,对含硝基苯和苯酚的模拟混合废水(简称混合废水)进行处理。通过树脂的选择性吸附,使混合废水中的硝基苯和苯酚分离,随后用高效菌对树脂所吸附的硝基苯进行生物降解,同时实现树脂的再生。实验结果表明:通过调节混合废水的pH,树脂可有效地将混合废水中的硝基苯和苯酚进行选择性吸附分离;树脂对硝基苯的吸附是可逆的;树脂的再生程度受微生物对可利用硝基苯质量浓度的下限(1.2mg/L)限制;吸附-生物再生循环实验结果表明,该树脂可有效抵抗微生物的生物降解与破坏。 相似文献
14.
Akio Kamimura Eisuke Konno Shigehiro Yamamoto Takeru Watanabe Kazuo Yamada Fumiaki Tomonaga 《Journal of Material Cycles and Waste Management》2009,11(1):38-41
To develop a new method for the chemical recycling of plastics, we examined the formation of recycled polymers from the recovered
monomeric materials of solubilized waste fiber-reinforced plastics (FRP) under supercritical alcoholic conditions. Treatment
of waste FRP with supercritical MeOH resulted in the formation of monomeric organic compounds that mainly contained dimethyl
phthalate (DMP) and propylene glycol. The presence of these materials was confirmed by gas chromatography and nuclear magnetic
resonance analyses and they were mixed with new DMP and glycols in various ratios to form unsaturated polyesters. The polymerization
progressed successfully for all mixing ratios of the recovered and new DMP. Hardness tests on these recycled polymers indicated
that the polymer made from a 1:1 mixture of recovered and new dimethyl phthalate had almost the same level of hardness as
the polymers made from new materials. We also examined the formation of recycled FRP by using glass fibers and monomeric materials
recovered through the present depolymerization method.
Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6 相似文献
15.
Tadeusz Spychaj Ewa Fabrycy Stanislawa Spychaj Michal Kacperski 《Journal of Material Cycles and Waste Management》2001,3(1):24-31
This paper describes the chemical degradation of waste poly(ethylene terephthalate) (PET) with polyamines or triethanolamine,
the characteristics of the products, and a search for ways to use these products. Solvolysis of the polymer ester bonds was
caused by diethylenetriamine, triethylenetetramine, and their mixtures, as well as mixtures of triethylenetetramine and p-phenylenediamine or triethanolamine. Products of aminolysis or aminoglycolysis of PET obtained in reactions performed at
200–210°C (with a molar ratio of the recurrent polymer unit to amine of 1 : 2) have been characterized using nuclear magnetic
resonance (NMR). Viscosity and hydroxyl number measurements have been done for PET/triethanolamine products. Substances from
aminolytical reactions with polyamines were tested as hardeners for liquid epoxy resins, and the product of polymer aminoglycolysis
with triethanolamine was tested as an epoxy resin hardener, e.g., for water-borne paints, and a polyol component for rigid
polyurethane foams. The compositions of epoxy resin hardeners have been characterized using DSC and rheometry. Comparative
analyses of the hardened epoxy materials have been done on the basis of glass temperature and mechanical properties data,
as well as some specific properties of the coating materials and rigid polyurethane foams.
Received: September 15, 2000 / Accepted: September 21, 2000 相似文献
16.
Osamu Sawai Teppei Nunoura Kazuo Yamamoto 《Journal of Material Cycles and Waste Management》2014,16(1):82-92
Sewage sludge, a byproduct of municipal wastewater treatment, was gasified by supercritical water using a bench-scale batch reactor. Configuration of bench-scale batch reactor and operation procedures are discussed in detail. Experience and challenges that arose during the experiment are also shared. Using the bench-scale reactor under the condition of 600 °C, 23 MPa, and a reaction time of 60 min without catalyst presence, a total gas yield of 9.8 mol/(kg-sewage sludge) was obtained. Furthermore, investigations on operational parameters were conducted. Extension of reaction time up to 60 min increased the gasification, reaching a plateau thereafter. Investigation on pressure indicated the superiority of supercritical pressure. The addition of Ni as a catalyst also promoted gasification, although inorganic salts and char seemed to cover the catalyst surface. With regard to the prospect of future operation at a municipal waste water treatment plant, the effect of operational parameters on heavy metal concentration in the liquid phase is also discussed. 相似文献
17.
To apply PET depolymerization in supercritical methanol to commercial recycling, the benefits of supercritical methanol usage in PET depolymerization was investigated from the viewpoint of the reaction rate and energy demands. PET was depolymerized in a batch reactor at 573 K in supercritical methanol under 14.7 MPa and in vapor methanol under 0.98 MPa in our previous work. The main products of both reactions were the PET monomers of dimethyl terephthalate (DMT) and ethylene glycol (EG). The rate of PET depolymerization in supercritical methanol was faster than that of PET depolymerization in vapor methanol. This indicates supercritical fluid is beneficial in reducing reaction time without the use of a catalyst. We depicted the simple process flow of PET depolymerization in supercritical methanol and in vapor methanol, and by simulation evaluated the total heat demand of each process. In this simulation, bis-hydroxyethyl terephthalate (BHET) was used as a model component of PET. The total heat demand of PET depolymerization in supercritical methanol was 2.35 x 10(6)kJ/kmol Produced-DMT. That of PET depolymerization in vapor methanol was 2.84 x 10(6)kJ/kmol Produced-DMT. The smaller total heat demand of PET depolymerization in supercritical methanol clearly reveals the advantage of using supercritical fluid in terms of energy savings. 相似文献
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废印制线路板真空热解产物分析 总被引:1,自引:0,他引:1
在自行设计的间歇式固定床真空热解装置中热解废印制线路板(PCB),对热解产物进行了分析.在热解温度为550 ℃、热解压力为20 kPa、恒温时间为60 min的条件下,得到的热解产物质量分数为:热解渣70%;热解油3%~4%;不可冷凝热解气26%~27%.经气相色谱-质谱联用(GC-MS)分析,热解油经常压蒸馏后得到的低沸点液态油中含有29种化合物,主要有苯酚、对异丙基酚、3-乙基酚、4-甲酚及2-溴苯酚,还含有少量含溴化合物和含氯化合物.热解油经简单的蒸馏就可达到回收酚类化合物的目的.热解渣经风选可实现铜与黏附有碳黑的玻璃纤维的分离,其中铜质量分数约30%,黏附有碳黑的玻璃纤维质量分数约70%. 相似文献