No abstract

No abstract

Carotene and tocopherol are valuable products that exist as minor compounds in palm oil and mostly extracted out during many stages of palm oil processing. Hence, most of it ended up in wastewater or palm oil mill effluent (POME). Fortunately, adsorption is potentially one of the most efficient method as compared to the others. In fact, it is widely studied in laboratory scale, in order to obtain equilibrium data for the steady state system. However, industrial practices are mostly operated in unsteady state in a continuous manner. Consequently, this study is executed to design a recovery process of one of the minor compounds in palm oil mill effluent (POME), which is carotene, using silica gel. It aims to predict the dynamic adsorption of recovery of minor compounds from palm oil mill effluent based on available equilibrium data, investigate the effects of dynamic and physical properties of the system towards the process by analyzing the breakthrough curve and study the feasibility of the scale up process by performing a sensitivity analysis on the system. Then, a base simulation was prepared by using available equilibrium data. Operating and design parameters such as, bed height, inlet flowrate and concentration were manipulated. Consistent with previous packed column studies, increase flow and concentration will reduce the time required for the column to achieve saturation, while increase bed height effects were vice versa. Finally, the last objective to achieve was to study the practicality of the packed bed column and perform a sensitivity on assumptions and predictions such as predicted mass transfer coefficient and isotherm model. It is proven that the selection of isotherm model and prediction in coefficient did not pose a large impact to the breakthrough curve and the average time required for the column of 1.5 m tall and 0.8 in diameter, to reach breakthrough time is 1.7 days. Hence, it can be concluded that adsorption technology using silica gel as its adsorbent can be applied is recovering minor compounds in palm oil mills.

Oxygen, an odorless and colorless gas constituent of the atmosphere, is a vital gas component for the Earth, as it makes up 21% of the composition of the air we breathe. Apart from the importance of oxygen for human breathing, its highly pure form is demanding for industrial applications. As such, several technologies have been established to increase the oxygen purity from 21% to somewhat higher than 95%. One of the competitive technologies for producing this high-purity oxygen from the air is through pressure swing adsorption (PSA), which has the advantages of low cost and energy while being highly efficient. Also, PSA is a simple and flexible system due to its ability to start up and shut down more rapidly since its operation occurs at ambient temperature, which is enabled through the use of adsorbents to bind and separate the air molecules. The enhancement of the PSA’s performances was reported through the modification of PSA step cycles and material (zeolite) tailoring. A simplified complete set of a mathematical model is included for modelling the PSA system, aiming to ease the experimental burden of the process design and optimization of an infinite modification of PSA step cycles. Finally, some technological importance of oxygen production via PSA, particularly for onboard oxygen generation system and oxy-enriched incineration of municipal solid waste, was discussed. Continuous development of PSA will make significant contributions to a wide range of chemical industries in the near future, be it for oxygen production or other gas separation applications.

Plant antibiotics in water are considered an emerging issue due to their interference with human health. Antibiotics protect crops from diseases; however, low levels of antibiotics are found in wastewater due to their incomplete removal. Several treatment methods are available, but with limitations such as high operation and maintenance costs and the formation of toxic by‐products. Antibiotic removal by adsorption is an alternative method, being a low‐energy process with simple operation, mainly if used with carbonaceous adsorbents. Antibiotic removal was fit to a wide variety of isotherm and kinetic models, with the Freundlich isotherm as the most employed one. This paper aims to review the use of the adsorption process in the removal of plant antibiotics from water systems.