Industrial & Engineering Chemistry Research最新文献

The experimental and simulative methods were used to study the hydrodynamic characteristics of gas–solid two-phase flow and particle erosion in a codirectional swirling spouted bed (CSSB). The four-zone flow of particles was found in the filling zone: separation zone, convergence zone, re-separation zone, and particle accumulation zone. The internal reinforced structure effectively strengthened the radial velocity of particles in the cylinder. In addition, the two serious erosion zones on the axial swirl vane were, respectively, in the convergence zone and particle accumulation zone, and the erosion heights were, respectively, roughly 0.045 m on the A-face and 0.076 m on the B-face. The erosion heights on the cylinder internal walls were basically 0.15 m with the increase of the inlet velocity. By comparing the axial swirling spouted bed, integrated multinozzle swirling spouted bed, and CSSB, it was found that CSSB had a better swirling effect and smaller intensity of particle erosion.

Silicone rubber bonding structure is widely used in prominent fields such as aviation matter and aerospace, the performance changes of which are of great concern and the occurrence of joint failure can have serious consequences, so it is crucial to assess the failure mechanism and storage life of bonding structures. In this paper, it is suggested that oxygen and water molecules diffused at the interface further break and cross-link with molecular chains, and the interfacial failure occurs for all three kinds of bonding specimens under the artificial accelerated aging conditions of both thermal and hygrothermal aging. By means of molecular dynamics simulation, the diffusion of molecules in different environments at the interface was investigated, further revealing the aging mechanism of the adhesive structure. The parameters describing bonding structures, interfacial binding energy (E) and diffusion coefficient (D), were calculated to construct the storage life prediction model conforming to the adhesive structure, which supports the use of a silicone rubber adhesive structure.

Sand, a naturally occurring granular material primarily composed of SiO₂, serves as a common proppant in hydraulic fracturing operations. Proppants play a crucial role in maintaining fractures open, allowing hydrocarbon production by withstanding reservoir closure stresses and ensuring high conductivity. Despite its abundance and cost-effectiveness, natural sand must meet stringent criteria to withstand the harsh downhole conditions. For polycrystalline sand particles containing high in situ impurities, a strengthened coating is essential to enhance crush resistance. This coating prevents microparticles from being crushed under higher closure stress. In the context of fracturing a single well with multiple stages, several thousand tons of proppants are required. Therefore, the strengthening technology must be both cost-competitive and economically viable for scaling up from laboratory to industrial production. In this study, we present a cost-competitive nanocomposite resin coating technology scaled up from laboratory to industrial scale. This technology combines a novel nanomaterial-based reinforcing agent with a surface wettability-altering agent. The resulting coated sand exhibits improved crush resistance strength, API (American Petroleum Institute) conductivity, chemical resistance, and durability. The development process began in the laboratory, where we optimized the technology using batch sizes ranging from 150 g to 1 kg. Subsequently, we conducted pilot production in an industrial proppant coating plant, coating 48000 kg of sand with an approximate batch size of 1100 kg. Finally, we successfully produced 6250 US tons of coated sand using a larger batch size of 1360 kg. Throughout the entire scale-up process, the performance of the coated sand remained consistent. The synergistic effects introduced by the nanoreinforcing, and wettability-altering agents contributed to its robustness, making it suitable for practical application in hydraulic fracturing.

The continuous Pasteurian chiral resolution of (±)-ibuprofen by using diastereomers with S-α-methylbenzylamine appears to be prone to encrustation. This comes from the necessity of operating under high supersaturation in order to obtain an acceptable yield. A kind of dead zone growth appears when the two diastereomeric salts coexist. Several remedies have been contemplated. The best solution led to design a setup of four CT crystallizers in parallel. Each reactor would be periodically disconnected from the system to undergo a preventive antifouling cleaning procedure, including temperature cycling and pure solvent circulation. A recycling stream could be implemented to recover the cleaning liquors. Finally, to better control the crystallization process, each CT crystallizer would have the possibility of performing an axial and radial temperature gradient.