Recent Innovations in Chemical Engineering (Formerly Recent Patents on Chemical Engineering) - Online First

The aim of this study is to develop mefenamic acid-loaded microspheres using a hydrophilic polymer and a solvent evaporation method for sustained drug release, aiming to reduce the frequency of dosing.

Mefenamic acid is an anti-inflammatory drug commonly used to manage pain, especially menstrual cramps. Microspheres, which are spherical particles ranging from 1 to 1000 micrometres, are effective in enhancing the sustained release of medications. The solvent evaporation method is widely used in the preparation of microspheres to improve drug delivery profiles.

A UV study of mefenamic acid was conducted to analyze all necessary parameters. Mefenamic acid and ethyl cellulose polymer were dissolved and stirred at 700 rpm using the solvent evaporation method. A surfactant-containing aqueous phase was prepared and maintained under stirring, into which the organic phase was introduced and continuously stirred to form microspheres. The formed microspheres were characterized by loading capacity, drug content, entrapment efficiency, and product yield. Scanning Electron Microscopy was used to confirm the spherical shape of the microspheres. An in vitro release study was conducted using a diffusion technique to evaluate the drug release profile.

The microspheres were successfully formed with a spherical shape, as observed in SEM images. The evaluation showed favorable loading capacity, entrapment efficiency, and drug content. The in vitro release study demonstrated a sustained release profile, indicating the effectiveness of the hydrophilic polymer in prolonging drug release.

The developed mefenamic acid-loaded microspheres using a hydrophilic polymer via the solvent evaporation method achieved sustained drug release, potentially reducing the need for frequent dosing. The method and formulation show promise for enhancing the therapeutic efficacy of mefenamic acid.

Centrifugal pumps are key equipment used for fluid transfer in the chemical industry. During the start-up process of high-speed centrifugal pumps, the hydraulic characteristics such as flow rate and head will change significantly, and the optimization of the pump start-up process can improve its stability and service life, which will make centrifugal pumps more efficient in chemical production.

Achieving a fast and stable startup process has always been a goal in the engineering application of high-speed centrifugal pumps.

First, the mathematical relationship between the torque and speed of the centrifugal pump is established. Then, based on the physical characteristics of the DC motor and considering the centrifugal pump torque as the load, a mathematical model of the high-speed DC centrifugal pump is developed. A fuzzy PI controller for the high-speed DC centrifugal pump is designed by integrating traditional PI control methods with fuzzy control theory to manage the startup process. Optimization algorithms are employed to optimize the parameters of the fuzzy PI controller.

Before optimization, the settling time was 0.33 s, the motor speed overshoot was 7.69%, the head overshoot was 3.77%, and the flow rate overshoot was 7.69%. After optimization, the settling time improved to 0.25 s, the motor speed overshoot was reduced to 6.3%, the head overshoot to 3.1%, and the flow rate overshoot to 6.3%.

A comparison of simulation results before and after parameter optimization demonstrates that the optimized fuzzy PI control yields better dynamic performance during the startup process of the high-speed DC centrifugal pump.

The use of bioreactors at sewage treatment plants solves an environmental problem at water utilities in the Udmurt Republic, as sludge beds are overflowing due to the fact that tens of tons of sewage sludge have been stored on sludge beds every day since the 1980s and amount to hectares of land.

The results of experimental studies on the processing of wastewater sludge in the Biotechnology laboratory were analyzed to improve the efficiency of the technological process for the disposal of organic waste using a biogas plant and a process activator.

The methodology for preparing a biogas plant for entering the operating mode and further operation is presented. An algorithm for experimental studies using a biogas plant and obtaining biogas from organic waste is presented.

The article presents an analysis of the results of experimental studies of sewage sludge treatment under periodic psychrophilic and, subsequently mesophilic operating conditions of the bioreactor in relation to the climatic conditions of the Udmurt Republic. The results of experimental studies in the article are presented in the form of graphical dependencies of the volume of produced biogas on the temperature and duration of the process.

The article presents the dynamics of changes in the volume of produced biogas depending on the increase in temperature and duration of the process under the mesophilic operating mode of the bioreactor. On the first day of the experiment under the mesophilic mode in the bioreactor, the volume of produced biogas was 2.15% (7.41 g) at a temperature of 32°C; with increasing temperature, the volume of produced biogas increased. The maximum biogas production was observed on the fifth day of the experiment under the mesophilic mode and amounted to 7.66%, which corresponds to 26.41 g.

The recommended loading volume of biomass into the bioreactor is 80 liters. In accordance with the actual conditions of the sewage treatment facilities, the volume of biogas produced will be 26.000 m³ of methane daily during the period of anaerobic fermentation in the bioreactor. To solve the environmental problem, it is necessary to install a complex of bioreactors at the water utilities of the Udmurt Republic.

Studies using sustainable and environmentally friendly raw materials are prominent among researchers due to rising environmental concerns.

This study aimed to produce epoxidized corn oil using in situ peracid formation, with Amberlite IR-120H as a catalyst, alongside acetic acid and hydrogen peroxide.

Expoxidized corn oil was produced in situ with acetic acid as an epoxidation agent and Amberlite as a catalyst. Results: The results showed that using a 50% concentration of hydrogen peroxide and a 0.5:1 molar ratio of hydrogen peroxide to corn oil achieved the highest Relative Conversion to Oxirane (RCO).

In situ epoxidation resulted in a higher relative conversion to oxirane in reaction time (60 minutes).

Lastly, numerical simulations were executed employing a genetic algorithm, and the outcomes exhibited a noteworthy congruence between the simulated data and the empirical observations.