1-Butene isomerization and metathesis over Mo/mordenite-alumina: Factors influencing product distribution and induction period

Effects of space velocity, reaction temperature and support acidity on product distribution and induction period in 1-butene isomerization and metathesis over Mo/mordenite-alumina were investigated. As revealed by the catalytic performance results, induction period and objective product were closely related to the reaction conditions. Lower space velocity led to longer induction period and higher propene yield. The optimal reaction temperature for propene production is around 150 ~C and it shifted to 100 ~C for ethene production. 1-Butene auto-metathesis predominated in the reaction network if the support with lower degree of sodium exchanged. And propene gradually became the dominant product upon increasing the support sodium exchange degree. 6Mo/H100Na0M-30A1 catalyst with a support of full sodium exchange degree exhibited the highest propene yield.

Co-feeding with DME:An effective way to enhance gasoline production via low temperature aromatization of LPG

The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reaction conditions the selectivity of alkenes to high-octane gasoline blending components was markedly enhanced and the formation of propane and butanes was greatly suppressed with the addition of DME.It was also found that the distribution of C5+ components was changed a lot with DME addition into the LPG feed.The formation of branched hydrocarbons (mainly C6 C8 i-paraffin) and multi-methyl substituted aromatics,which are high octane number gasoline blending components,was promoted significantly,while the content of n-paraffins and olefins in C5+ components was decreased obviously,indicating that in addition to the oligomerization,cracking,hydrogen-transfer and dehydrogenation-cyclization of alkenes,the methylation of the formed aromatics and olefins intermediates also plays an important role in determining the product distribution due to the high reactivity of surface methoxy groups formed by DME.And this process,in combination with the syngas-to-methanol/DME technology,provides an alternative way to the production of high-octane gasoline from coal,natural gas or renewable raw materials.

Design and Analysis of Transmitter Charge Switch Assembly Load on Weather Radar Test Platform

This paper provides a new method for designing the load of transmitters switch components on provincial radar test platform. Based on the calculation of the specific parameters related to the actual charge switch components, the load-related data model is obtained, the simulation is carried out, and the results are consistent with the actual test results. Through the theoretical numerical analysis of the load of the charging switch components of the transmitter device in the new generation of weather radar maintenance test platform, radar maintenance personnel at all levels can deepen the thorough understanding of the CINRAD/SA transmitter and have some enlightenment and improvement on the maintenance guarantee ability of the new generation of weather radar.

Improvement and Design of Transmitter Modifier Wind Cooling Protection for CINRAD/CB Weather Radar

Doppler weather radar has important applications in measuring the intrinsic factors of cloud, rainfall and various convective weather occurrences. Among them, CINRAD/CB Doppler weather radar is based on the requirements of the China Meteorological Administration and many units have been provided. The modulator is a critical part of the transmitter’s high voltage, where high voltage, high current, and energy conversion are concentrated. It is therefore necessary to redesign the transmitter modulator cooling system protection. This article describes the new design of hardware and software solutions. The fan is a DV5214/2N DC fan from Ebmpapst, Germany. The speed is up to 5000 rpm, the power is 18.5 W, and the single fan current is about 0.8 A. It is powered by 28 V. The protection board uses a DC/DC module to output a 5 V voltage and a 3.3 V voltage adjustment chip LM1117. The embedded web software is based on the TCP/IP protocol stack provided by MICROCHIP. After the cooling system is designed and installed in the radar station in Xi’an, China and other places, after long-term operation, the comprehensive test shows that the system runs well.