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1.
A 92–95% conversion of high fructose corn syrup (HFCS) or crystalline D -fructose to 5-chloromethylfurfuraldehyde (CMF) was achieved using 300 mol% of concentrated hydrochloric acid in chlorobenzene, under a nitrogen atmosphere, a reaction temperature of 75°C and a reaction time of 1–2 h. Constant high-speed stirring was essential for high yields and purity of CMF. Inferior yields of CMF were obtained from glucose and starch. Saccharine, phenyl sulphone and thiuronium derivatives were prepared and characterised. The use of surfactants did not improve the yields of CMF.  相似文献   

2.
Saccharomyces cerevisiae ATCC 36859 preferentially consumes glucose from glucose–fructose mixtures. Synthetic media and complex media containing high fructose corn syrup supplemented with Jerusalem artichoke juice were used for the production of pure fructose syrup by the conversion of glucose to ethanol. Fructose was not converted in these processes. Increasing the concentration of Jerusalem artichoke juice increased the yields of ethanol and biomass and decreased the process time. A similar effect was obtained at a low juice concentration when a larger amount of biomass was used for the inoculum. The product from this process contained only fructose and ethanol. Use of food-grade materials results in a pure fructose syrup that is suitable for human consumption.  相似文献   

3.
5-Hydroxymethyl-2-furfural (HMF) was prepared with high fructose corn syrup (HFCS) manufactured directly from industry. Equipped industrial process and cheaper availability considered HFCS-90 as a competitive starter for production of HMF. Readily evaporable solvent, 1,4-dioxane was found as a promising reaction media from the screening of various solvents and readily available cation exchange resin, Amberlyst-15 was used as a solid acid catalyst. Parametric variation studies including amount of catalyst, concentration of HFCS-90, and reaction temperature were performed to achieve a maximum HMF yield of 80% at 100 °C within 3 h. In particular, use of readily evaporable solvent and heterogeneous catalyst allowed highly practical purification of HMF, which still remains as a major obstacle to the commercialization of HMF. With filtration, evaporation, and extraction, HMF was simply isolated in 72% yield and 1H NMR spectra of the isolated HMF confirmed that its purity was sufficient for use in next step of reactions. In addition, all solvents could be recycled with distillation and catalyst was reused up to 5 cycles without a significant loss of activity.  相似文献   

4.
ABSTRACT: BACKGROUND: The replacement of sucrose with HFCS in food products has been suggested as playing a role in the development of obesity as a public health issue. The objective of this study was to examine the effects of four equally hypocaloric diets containing different levels of sucrose or high fructose corn syrup (HFCS). METHODS: This was a randomized, prospective, double blind trial, with overweight/obese participants measured for body composition and blood chemistry before and after the completion of 12 weeks following a hypocaloric diet. The average caloric deficit achieved on the hypocaloric diets was 309 kcal. RESULTS: Reductions were observed in all measures of adiposity including body mass, BMI, % body fat, waist circumference and fat mass for all four hypocaloric groups, as well as reductions in exercise only group for body mass, BMI and waist circumference. CONCLUSIONS: Similar decreases in weight and indices of adiposity are observed when overweight or obese individuals are fed hypocaloric diets containing levels of sucrose or high fructose corn syrup typically consumed by adults in the United States.  相似文献   

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玉米淀粉胶粘剂的研制   总被引:3,自引:1,他引:3  
黄向红  刘海飞 《粘接》2001,22(4):15-17
采用高锰酸钾作氧化剂,经氧化,糊化,交联等步骤,可于室制备出一种粘度适中,粘性,流动性及稳定性好的玉米淀粉胶粘剂。通过实验,确定了高锰酸钾,氢氧化钠,硼砂的最佳用量分别为0.8-1.6,10,0.5-1.0份(100份淀粉中加入量),水与淀粉的最佳质量比为6:1-6.5:1。  相似文献   

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研究以玉米芯为原料,十二烷基本磺酸钠为改性剂制取玉米芯活性炭的最佳工艺条件。通过单因素实验和正交试验得出玉米芯活性炭的最佳条件是:振荡温度为35℃,振荡时间为3h,玉米芯与十二烷基本磺酸钠的料液比为1:6,十二烷基本磺酸钠质量分数为9%,各因素的影响顺序为振荡温度料液比LAS质量分数振荡时间,并对普通玉米芯及市售活性炭吸附性能的对比进行了一定的探讨。  相似文献   

9.
以果糖为原料,二甲基亚砜为溶剂,接枝铝的SBA-15分子筛为催化剂,在探针超声辐照下进行果糖脱水反应合成5-羟甲基糠醛。结果表明,施加超声明显提高了5-羟甲基糠醛产率。在单因素实验基础上,采用响应面法优化合成工艺,得到探针超声600 W强化果糖催化水解制备5-羟甲基糠醛的最佳工艺为:催化剂10-Al/S用量0.1 g/g,反应温度151℃和反应时间1.6 h(即96 min)。此条件下,合成5-羟甲基糠醛的产率为69.4%。  相似文献   

10.
离子液体中果糖脱水制5-羟甲基糠醛   总被引:3,自引:0,他引:3  
以阳离子相同(1-丁基、3-甲基咪唑、[Bmim] )、阴离子不同(Cl-、Br-、[CF3COO]-、[BF4]-、[H2SO4]-和[H2PO4]-)的6种离子液体为溶剂和催化剂,研究反应时间(15~180 min)、反应温度(80~120℃)和离子液体种类对果糖脱水制5-羟甲基糠醛(5-HMF)过程的影响.结果表明,随着时间延长和温度升高,果糖转化率和5-HNF产率增大,但是长时间和高温会降低反应选择性;L酸性的离子液体比B酸性的有利于催化果糖脱水,Cl-离子的存在可抑制分子间缩聚,提高反应选择性.以[Bmim]Cl离子液体为溶剂和催化剂,在120℃和120min条件下,果糖转化率达94.4%,5-HNF产率为70.8%.  相似文献   

11.
A semi-continuous counter current chromatographic refiner, developed in this department, was used to produce high fructose syrup from an industrial barley syrup containing 42% fructose, 52% glucose and 6% maltose and oligosaccharides. The chromatographic refiner consisted of twelve 5.4 cm i.d. columns, each packed to a height of 65.5 cm with KORELA VO7C calcium charged resin, with a particle size range 150–300 μm. At a throughput of 32.1 kg sugar solids/m3 resin/h, the fructose rich product obtained was 95% pure and had a concentration of 11.3% w/v, while the glucose rich product contained only 4.5% fructose and had a concentration of 22.56% w/v.  相似文献   

12.
《应用化工》2022,(1):128-132
以果糖为原料,二甲基亚砜为溶剂,接枝铝的SBA-15分子筛为催化剂,采用超声强化催化果糖脱水制备5-羟甲基糠醛(5-HMF)。研究了超声功率、反应时间、催化剂硅铝摩尔比和催化剂用量对5-HMF合成的影响,并对这个反应的动力学进行了研究。结果表明,合适的反应条件是:0.3 g果糖,超声功率800 W,反应时间3 h,催化剂硅铝摩尔比为10,催化剂用量0.03 g。在此条件下,5-HMF产率为46.2%。动力学实验表明,超声能加快果糖脱水转化5-HMF的反应速率,并降低该反应的活化能,反应过程符合一级反应动力学方程。  相似文献   

13.
制备了一种磺酸化的磁性碳质固体酸催化剂PCM-SO_3H,用于催化糖类制备液态生物燃料5-乙氧基甲基糠醛(EMF),考察了二甲亚砜在溶剂中的含量对糖类转化和产物分布的影响。结果表明,该催化剂不仅能催化5-羟甲基糠醛(HMF)的醚化,EMF产率高达85.6%,也能在乙醇-二甲亚砜双溶剂体系下一锅法催化果糖制备EMF,反应温度100℃,反应时间10 h,催化剂加入量45 mg,溶剂(DMSO 1.5 m L和乙醇3.5 m L)时,EMF的收率达61.8%。反应结束后,该催化剂可以在外部磁场条件下从反应混合物中重新获得,且重复使用多次依然保持高的活性。  相似文献   

14.
制备了一种磺酸化的磁性碳质固体酸催化剂PCM-SO_3H,用于催化糖类制备液态生物燃料5-乙氧基甲基糠醛(EMF),考察了二甲亚砜在溶剂中的含量对糖类转化和产物分布的影响。结果表明,该催化剂不仅能催化5-羟甲基糠醛(HMF)的醚化,EMF产率高达85.6%,也能在乙醇-二甲亚砜双溶剂体系下一锅法催化果糖制备EMF,反应温度100℃,反应时间10 h,催化剂加入量45 mg,溶剂(DMSO 1.5 m L和乙醇3.5 m L)时,EMF的收率达61.8%。反应结束后,该催化剂可以在外部磁场条件下从反应混合物中重新获得,且重复使用多次依然保持高的活性。  相似文献   

15.
采用浸渍法制备氧化铌负载氧化钨固体酸催化剂,用XRD、EDS、TEM、NH3-TPD、Py-IR、BET、BJH对催化剂的结构、组分、形貌、酸性、比表面积及孔径等进行表征;并将其用于催化果糖转化为5-羟甲基糠醛( HMF) 反应,对氧化钨负载量、反应时间、反应温度、催化剂用量等影响因素进行考察。结果表明,氧化钨负载量对催化剂结构、酸性以及催化活性均有影响:随着WO3负载量的增加,氧化钨分子从表面分散的非晶态WO3转变为结晶WO3,且Nb2O5上适量的WO3产生大量强酸位点,使催化剂的Brønsted酸含量增加,从而使果糖的转化率得到提高;但结晶WO3却不利于HMF的生成。当氧化钨的负载量为5%时 ,在催化剂加入量为100mg,170 ℃条件下反应1 h,HMF选择性 较高为85.4%,收率可达49.6%。  相似文献   

16.
采用浸渍法制备五氧化二铌(Nb2O5)负载三氧化钨(WO3)固体酸催化剂,用XRD、EDS、TEM、NH3-TPD、Py-IR、BET、BJH对催化剂的结构、组分、形貌、酸性、比表面积及孔径等进行表征;并将其用于催化果糖转化为5-羟甲基糠醛(HMF)的反应,对WO3负载量、反应时间、反应温度、催化剂用量等影响因素进行考...  相似文献   

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18.
Qian Zhao  Shengtian Wang 《Fuel》2011,90(6):2289-2293
A clean, facile, economical, and environmental friendly method for converting fructose into 5-hydroymethylfurfural (HMF) has been developed, in the presence of a solid heteropolyacid Cs2.5H0.5PW12O40 catalyst in a biphasic system. A 5-HMF yield of 74.0% and a higher selectivity of 94.7% were obtained in 60 min at 388 K. More importance is that this catalyst is tolerant to high concentration feedstocks (50 wt.% fructose) and it can be recycled.  相似文献   

19.
Spruce budworm larvae reared on an artificial diet were tested for preference of twelve carbohydrates over a water control. A strong preference for sucrose was seen, followed by fructose, inositol, and glucose. Male and female larvae do not differ in their responses to sucrose. The behavioral threshold for sucrose is at 10–4 to 10–3 M, with a peak response in the range of 0.01 to 0.05 M sucrose. Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae).Work leading to this publication was funded in part by a USDA Forest Service sponsored program entitled Canada/United States Spruce Budworms Program (grant 23–352), and in part by the National Sciences and Engineering Council of Canada (operating grant A9723), and in part by the Whitehall Foundation.  相似文献   

20.
5-羟甲基糠醛(5-HMF)是美国能源部认定的来源于生物质的重要平台化合物之一。研究表明5-HMF可通过催化葡萄糖和果糖水解制备,但与葡萄糖相比,果糖具有转化效率高等优点,被认为更适合转化合成平台化合物。固体酸作为催化剂因具有产物易分离、回收和不腐蚀设备等优点,近年来被广泛应用于催化领域。主要就近年来固体酸催化果糖合成5-HMF方面的研究进展加以综述,重点概述了固体酸催化果糖制备5-HMF机理,种类及催化性能,并对其未来的发展前景进行了展望。  相似文献   

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