Feed Plate and Feed Adsorbent Temperature Optimisation of Distillation – Adsorption Process to Produce Absolute Ethanol

Abstract

Two subsequent separation processes are required to produce absolute ethanol (at least purity of 99.5% v/v),namely the distillation and adsorption processes. Thus, it is important to find the optimum operation conditionfor those following processes. The aims of the present study are to optimize the feed plate of distillation and thetemperature of feed adsorbent. This study is conducted using a continuous sieve tray distillation system with thenumber of 16 trays, the length-diameter ratio of 80.64, the reflux ratio of 3.5, and the feed with ethanol contentof 10 % v/v ethanol, which is produced via the fermentation process of molasses. To conduct the first aim of thisstudy, the feed enters the distillation column with several of variable feed plate, i.e. 12, 13, 14, and 15. This feedplate location is calculated from the top of the column. On the other hand, the second aim of this study, isconducted using the subsequent combination of distillation and adsorbent columns, where the distillate (purity ofethanol around 95% v/v) from the distillation column is then flowed into the adsorbent column with various feedadsorbent temperature, i.e. 80 °C, 90 °C, 100 °C, and 110 °C, to be purified as an absolute ethanol. Here theadsorbent column is designed as a fix bed adsorption column with a molecular sieve of 3A (zeolite) is used as anadsorbent for that purification process. Our results showed that the optimum feed plate is 14, because at thisplate the ethanol distillate has the highest content among those various variables. Meanwhile, the optimumtemperature of feed adsorbent is 90° C, which requires the least energy for the distillation - adsorption process,i.e. at 18691 kJ/kg absolute ethanol. This primary study is expected to be an alternative way to optimize theoperating condition of the sieve tray distillation-molecular sieve adsorption system by means of acquiring aminimum energy involving in the process to achieve the highest purity of ethanol.

Ethanol Recovery From Propolis Production Waste Using Adsorption Distillation Method

“…Based on analysis with the GC-FID instrument, the percentage of ethanol content that has been recycled by the adsorption distillation process using synthetic zeolite 3A adsorbent has increased when compared to the percentage of initial ethanol content. In addition, this study is more better if compared with previous studies, where pure ethanol concentration increased from 92% to 99.5% [31]. The GC-FID analysis results are in line with the test results using the GC/MS instrument, where the impurities are successfully absorbed by the adsorbent so that the recycled ethanol constituent components are detected less when compared to the initial constituent components and cause an increase in the percentage of ethanol content.…”

Modelling of Adsorptive-distillation of Ethanol-water Using Natural and Synthetic Zeolites as Adsorbent

“…21 As a result, the molecular sieve 3Å adsorbent is widely used in ethanol purification. 15 According to Chopade et al, zeolite is a mineral consisting of SiO 2 .AlO 2 groups and alkali-ions. 22 In its complex crystal structure, zeolite is capable of adsorbing water vapour.…”

“…With the assumption that C AN+1,j = C AN , j (no adsorption beyond the adsorbent bed), the ethanol concentration at i = N can be expressed as Equation 15:…”

“…12 This method is more economical and efficient than others. [13][14][15] The latter workers used inorganic adsorbents such as molecular sieves, lithium chloride, silica gel and activated alumina. 4,9,14,16,17 In addition, synthetic zeolites 3Å is better than natural ones for removing and purifying ethanol from an ethanol-water mixture in gas phase.…”

The Influence of Activated Carbon as Adsorbent in Adsorptive – Distillation of Ethanol–Water Mixture

“…ASTM D4806 regulates that bioethanol used as fuel must have a maximum water content of 426 The Influence of Activated Carbon as Adsorbent in Adsorptive -Distillation of Ethanol-Water Mixture 1%, requiring further purification. Simple distillation is commonly used, but it cannot surpass the azeotropic point above 95% (Taufanny et al, 2015). Therefore, a method is needed to surpass the azeotropic point and obtain ethanol concentrations higher than 95%.…”