Engineering characteristics of liquid–liquid microflow and its advantages in chemical reactions.

Searching for new additives to enhance the alkylation of isobutane and butene in H 2 SO 4 has attracted the interest of academic as well as industrial researchers since the process was introduced to produce high-quality oil product on a large scale. This research focused on alkylation of isobutane and butene with caprolactam as an additive in H 2 SO 4 . With the new additive of caprolactam, the selectivity of C8 was obviously improved due to the improved solubility of isobutane in H 2 SO 4 and the decreased acidity. Different additive amounts of caprolactam were tested, showing that 1.0 wt % is optimal and that the selectivity of alkane C8 can be improved from nearly 80% to 88%. The effects of stirring speed, reaction temperature, acid to hydrocarbon volume ratio, isobutane to butene molar ratio, reaction time, and variety of olefin were also studied carefully and respectively. Extended duration runs were practiced, which has demonstrated that the system was stable. This new additive has potential to be applied in large-scale industrial processes to improve the quality of alkylation.

To realize process intensification of clean fuel production is becoming a hot topic for sustainable development. This work presents a new intensification technology of sulfuric acid alkylation of isobutane and butene using a microstructured chemical system. A microstructured chemical system has been designed and constructed. The reaction performance was determined, and the effect of acid concentration, phase ratio, reaction temperature, and ratio of isobutane to butene (I/O) were investigated carefully. The results show that the microsturctured chemical system could obviously improve the quality of alkylates with much smaller size reactor and much shorter reaction time for better transport performances. The conversion of olefin could be as high as 100% within 30 s. The selectivity of C8 was 71% with a research octane number (RON) 94.4 under the 94 wt % H2SO4. No obvious changes of H2SO4 concentration was observed after several cycles, indicating that the acid consumption could be effectively reduced in this microreaction process.