Design the mechanical–chemical reactor for oily wastewater treatment

This study explains the mechanical design of a mixer with a focus on the fluid forces generated by the fluid continuum in the mixing reactor on the impellers. The research demonstrates that the forces are caused by transient asymmetries in fluid flow that act on the mixing impeller. The mixer shaft and gear reducer receive these dynamic loads from the impeller blades. A general equation for the fluid force behavior can be developed. The research also stresses on the significance of the mechanical interaction of the mixing process with the mixing vessel and impeller. Four parameters were measured; impeller speed for coagulation and flocculation, mixing time for coagulation, and flocculation. The experimental results in the final section will explain that impellers with four blades provide higher oil removal than impellers with two blades in oily wastewater treatment

A fuel gas waste heat recovery-based multigeneration plant integrated with a LNG cold energy process, a water desalination unit, and a CO2 separation process

Development of the multigeneration plants based on the simultaneous production of water and energy can solve many of the current problems of these two major fields. In addition, the integration of fossil power plants with waste heat recovery processes in order to prevent the release of pollutants in the environment can simultaneously cover the environmental and thermodynamic improvements. Besides, the addition of a carbon dioxide (CO2) capturing cycles with such plants is a key issue towards a sustainable environment. Accordingly, a novel waste heat recovery-based multigeneration plant integrated with a carbon dioxide separation/liquefaction cycle is proposed and investigated under multi-variable assessments (energy/exergy, financial, and environmental). The offered multigeneration system is able to generate various beneficial outputs (electricity, liquefied CO2 (L-CO2), natural gas (NG), and freshwater). In the offered system, the liquified natural gas (LNG) cold energy is used to carry out condensation processes, which is a relatively new idea. Based on the results, the outputs rates of net power, NG, L-CO2, and water were determined to be approximately 42.72 MW and 18.01E+03, 612 and 3.56E+03 kmol/h, respectively. Moreover, the multigeneration plant was efficient about 32.08% and 87.72%, respectively, in terms of energy and exergy. Economic estimates indicated that the unit product costs of electricity and liquefied carbon dioxide production, respectively, were around 0.0466 USD per kWh and 0.0728 USD per kg-CO2. Finally, the total released CO2 was about 0.034 kg per kWh. According to a comprehensive comparison, the offered multigeneration plant can provide superior environmental, thermodynamic, and economic performances compared to similar plants. Moreover, there was no need to purchase electricity from the grid

The effect of initial temperature and oxygen ratio on air-methane catalytic combustion in a helical microchannel using molecular dynamics approach

In industrial environments where combustion (Com.) is widely carried out, such as steam power plants, gas turbines, etc., the most common way to express the amount of oxygen consumption is its excess percentage in addition to the stoichiometric ratio, and the nearness of a catalyst causes combustion to happen at a high ratio. There are different influential factors in catalytic combustion, such as initial temperature (IT). The current study uses the molecular dynamics (MD) method to examine how the IT and oxygen ratio affect air-methane catalytic combustion in a helical microchannel. The LAMMPS package was used to conduct this investigation. This study examines how simulated structures function during burning in excess oxygen (EO) and oxygen deficiency (OD). Furthermore, palladium was used as a catalyst with an atomic ratio of 4 %. The findings show that raising the IT may enhance its atomic behavior (AB) and thermal performance (TP). The maximum velocity (MV) and maximum temperature (MT) increased from 0.26 Å/ps and 1617 K to 0.45 Å/ps and 1891 K in EO as IT increased from 300 to 700 K. By accelerating the particle velocity, it is anticipated that the catalytic combustion process would proceed more quickly. As a result, after increasing the IT to 700 K, the heat flux (HF), thermal conductivity (TC), and combustion efficiency (CE) increase to 2101 W/m2, 1.23 W/m. K, and 93 %, respectively. On the other hand, the results show that increasing IT affects combustion performance in the presence of OD. In the presence of OD, the MV and CE converge to 0.38 Å/ps and 94 % at 700 K. Therefore. It can be concluded that the atomic ratio of oxygen and the IT can significantly affect combustion process