Ruoqian Xu

High energy density materials (HEDM) are the subject of an extensive research effort in relation to the use of these compounds as components of rocket propellants, powders, and formulations of high-performance explosives. Hexanitrohexaazaisowurtzitane (HNIW, i.e., CL-20) has received much attention in these research fields for its specific impulse, burning rate, ballistics, and detonation velocity. In this paper, the development and performances of the explosives from the first to the fourth generation are briefly summarized, and the synthesis status of the fourth-generation explosive, HNIW, is reviewed. The key issues that restrict the development of industrial amplification synthesis of HNIW are analyzed, and the potential directions of development are proposed. It is pointed out that to synthesize new and efficient catalysts is the key to making the cost-effective manufacturing of CL-20 a reality.

The block copolymer of 3,3’‐bis(azidomethy) oxetane and glycidyl azide polymer (p(BAMO)‐b‐GAP) is an ideal energetic binder for solid propellants. In this work, the enthalpy of formation of p(BAMO)‐b‐GAP was first investigated by the heat of combustion experimental method and group additivity method. Meanwhile, the energetic characteristics of solid propellants based on the copolymer were systematically calculated. The results proved that the Δ_fH of p(BAMO)‐b‐GAP could be estimated accurately by two methods and the positive Δ_fH values were obtained. Dual‐oxidant formulas were designed in which AP was replaced gradually by some chlorine‐free high‐energy materials. The calculation results showed when AP was gradually replaced by RDX or HMX, the energy level of propellants based on p(BAMO)‐b‐GAP was improved first but then decreased with AP content further decreased, indicating there was an optimum ratio between AP and its alternative. However, when AP was replaced by CL‐20 or ADN, the values of I_sp were improved steadily. When less than 40 % AP was replaced, the contribution to the energy level of propellant by RDX or HMX was even more than that by CL‐20.

The demand for transportation diesel fuels has been increasing in most countries for the last decade. As is one of the primary sources for diesel distillates, light cycle oil (LCO), having the advantages of inheriting similar density and boiling point range to diesel fuels, but high contents of aromatics, sulfur, and nitrogen, needs to be upgraded before being utilized. This work reports a trinary porous SiO₂–Al₂O₃–TiO₂ (SAT) synthesized by sol–gel method and used as the NiMo catalyst support for the LCO hydro-upgrading. NiMo/Al₂O₃-zeolite (AZ) was used as a reference to evaluate the performances of the NiMo/SAT. The catalysts were characterized by XRD, BET, Pyridine-FTIR, and TEM; and evaluated in a 20-mL fixed-bed microreactor using a Fluid Catalytic Cracking LCO as feedstock. It was found that the SAT support possessed a high surface area, high pore volume, and good acid properties. The NiMo/SAT catalyst exhibited even better hydrodesulfurization, hydrodenitrogenation, and hydrodearomatization performances than NiMo/AZ when the reaction was performed at 375 °C and 1100 psi. Compared with the zeolite addition catalyst, the SAT catalyst has the advantages of simple synthesis procedures and low input cost.

The roles of catalyst acidity and basicity playing in catalytic conversion of oleic acid were studied in a fixed-bed micro-reactor at atmospheric pressure. The chemical compositions of the petroleum-like products were obtained and the reaction pathways of different catalysts are discussed. The metal oxides are suitable for upgrading oleic acid into organic liquid products (OLPs). Over 98% oxygen was removed when CaO, MgO, and TiO₂ were implemented, whereas a minimum oxygen removal lower than 20% was obtained by using quartz. The oxygen removal was 73% by alumina; however, the light oil yield (to feed) and the valuable product yield received were the highest in all investigated catalysts. The hydrocarbons in OLPs, overwhelmingly presenting in the product, were found to be alkenes and cycloalkenes, followed by saturated hydrocarbons, and then aromatics lower than 4%. For Lewis acidic catalysts, higher acidity of the catalyst is beneficial to deoxygenation but also secondary cracking. CaO has higher dehydrogenation capability than MgO does.