添加剂在玉米芯酸催化水解制备糠醛过程中的应用

糠醛是一种重要的基础化学品。以糠醛为原料,可以生产糠醇、四氢糠醇、四氢呋喃和呋喃等1 600多种化工产品。糠醛生产原理为植物半纤维素中的聚戊糖水解为戊糖后进一步脱水生成糠醛。我国采用玉米芯在稀硫酸中水解制取糠醛,工艺简单,技术成熟,但是目前工业中糠醛产率较低,仅为50%～60%,且三废污染严重。糠醛收率较低的因素主要有工业生产中拌酸温度低、玉米芯浸酸不均匀、高温下发生焦化、反应过程中发生多种副反应等。为有效抑制过程中的副反应,提高糠醛的收率,本实验首先对稀硫酸水解制备糠醛工艺进行优化,重点考察了反应温度、液固比及硫酸浓度对糠醛收率的影响;其次,在优化的基础上,选用添加剂抑制糠醛副反应,以进一步..

三苯基磷在玉米芯制备糠醛中的应用

研究了三苯基磷在稀硫酸法水解玉米芯制备糠醛中的应用。在三苯基磷用量占玉米芯总量的0.05%～0.5%范围内,考察了三苯基磷的量对糠醛收率的影响。实验结果表明:随着三苯基磷用量的增加,糠醛收率明显提高,当三苯基磷加入量为玉米芯总量的0.25%时,糠醛收率升至86.0%,同传统工艺相比,糠醛收率提高20%～25%。由此可见,通过添加三苯基磷的途径可大幅度提高糠醛收率,在稀硫酸法水解玉米芯制备糠醛工艺中将具有良好的应用前景

三苯基磷在玉米芯制备糠醛中的应用

研究了三苯基磷在稀硫酸法水解玉米芯制备糠醛中的应用。在三苯基磷用量占玉米芯总量的0.05%～0.5%范围内,考察了三苯基磷的量对糠醛收率的影响。实验结果表明：随着三苯基磷用量的增加,糠醛收率明显提高,当三苯基磷加入量为玉米芯总量的0.25%时,糠醛收率升至86.0%,同传统工艺相比,糠醛收率提高20%～25%。由此可见,通过添加三苯基磷的途径可大幅度提高糠醛收率,在稀硫酸法水解玉米芯制备糠醛工艺中将具有良好的应用前景

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies