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Air separation processes are time‐consuming and energy‐intensive. Most of the energy used in air separation unit (ASU) is used for air compression. During the air compression process, some energy is lost, which is converted into waste heat. This wasted energy is used to warm liquefied natural gas (LNG). At some point, LNG ships will dock at an LNG regasification facility. Here, LNG is converted back to gas and supplied to the distribution and transmission systems. During the regasification process, cryogenic LNG has a huge opportunity for cold energy recovery. An innovative air separation process that is integrated with the cold utilization of LNG is presented in this study along with a thorough conceptual design and analysis. The results of this study show that producing high‐purity oxygen and nitrogen, respectively, requires 0.28 kWh kg−1 and 0.06 kWh kg−1 of specific energies. Prior to integration with cold utilization of natural gas, 25 141.6 kW is needed for air compression. However, following integration, 10 554.6 kW of energy is needed, resulting in a 58.01 % energy savings. Exergy destruction as well as efficiency have been calculated for the primary components of the system. Sensitivity analysis is carried out to examine the effects of LNG streams on important parameters. In conclusion, a cryogenic ASU is integrated with an LNG‐direct expansion cycle‐organic Rankine cycle power cycle to supply the necessary power for operation and reduce extraneous power inputs. Overall, this integrated approach increases efficiency, lowers costs, benefits the environment, allows for flexibility and adaptability, and raises system dependability. [ABSTRACT FROM AUTHOR]

The effectiveness of low‐cost fly ash geopolymer (FAGP) adsorbents synthesized from biomass fly ash in lead removal from aqueous solution was studied. The synthesized FAGP was characterized by the Brunauer‐Emmett‐Teller method and energy dispersive spectroscopy. The adsorption experiments were performed in batch mode under various conditions, and the maximum removal efficiency and uptake were found at an optimum time of 120 min and pH 5. Adsorption isotherm studies confirmed that lead removal is best fitted by both Langmuir and Freundlich isotherms. A kinetic analysis showed that pseudo‐second‐order kinetics governs lead adsorption. Lead adsorption was determined to be an endothermic, spontaneous process through thermodynamic analysis. [ABSTRACT FROM AUTHOR]

This work investigated the potentiality of Hypnea musciformis algae as a biosorbent for the removal of indigo carmine dye from synthetic solution. The sorption experiments were performed in batch mode under different parametric conditions like pH, contact time, the average particle size of biosorbent and its dosage, dye solution initial concentration, and temperature. The experimental results confirmed the optimum contact time is at least 25 min and favorable pH of 5 for the biosorption of carmine dye. Langmuir, Freundlich, and Temkin isotherms have been used to test the equilibrium data and found the best fit with the Freundlich isotherm with a regression coefficient (R2) of 0.992 followed by Langmuir (R2 = 0.979) and Temkin isotherm (R2 = 0.94). The analysis of kinetic data revealed Pseudo first order as the best fit. The thermodynamic parameter evaluated confirmed the endothermic nature of indigo carmine dye biosorption process. [ABSTRACT FROM AUTHOR]

Considering the toxicity, the removal of heavy metals from the liquid effluent is of great significance. This article addresses the impact of the adsorbent bed height and flowrate on the adsorption performance and breakthrough curves in column studies. To explore the potential of Liagora viscida biosorbent, adsorption experiments were conducted in a packed column at various bed heights in the range of 2 to 6 cm and flow rates in the range of 10 to 20 ml/min. The maximum uptake of 53.90 mg/g has been achieved at the flow rate of 20 ml/min for an initial metal solution concentration of 20 ppm and pH and bed height of 6 and 2 cm, respectively. In the current study, the breakthrough (tb) and exhaust times (ts) correspond to 0.1 and 0.9, respectively. To predict the breakthrough characteristics, the experimental data were tested using Bohart‐Adam (B‐A), Bed Depth Service Time (BDST), Thomas, and Yoon‐Nelson (Y‐N) models. The experimental results confirmed that all three models except the Bohart‐Adams model were suitable for the experimental data with a good correlation coefficient. [ABSTRACT FROM AUTHOR]

The present article addresses the effect of various parameters on batch biosorption of nickel using an inexpensive Liagora viscida algae as a biosorbent. The experimental studies revealed that for an initial metal solution concentration of 20–200 ppm, the equilibrium is achieved after 50 min and the maximum sorption at a pH of 5. Isotherms such as Temkin, Freundlich, and Langmuir were examined. The data are well suitable by using the Langmuir isotherm with a sorption uptake of 22.77 mg/g, confirming that L. viscida can be considered as a low‐cost biosorbent. The dynamic experimental data were represented well by pseudo‐first‐order kinetics. The thermodynamic study revealed that the biosorption of nickel on to L. viscida was endothermic and spontaneous. [ABSTRACT FROM AUTHOR]