Separation of ethanol/water azeotrope using compound starch-based adsorbents

Wang, Yanhong; Gong, Chunmei; Sun, Jinsheng; Gao, Hong; Zheng, Shuai; Xu, Shen

doi:10.1016/j.biortech.2010.02.102

Cited by 44 publications

(33 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4.16 (b) shows that the breakthrough time decreased from 42 to 31 min and the bed saturated faster as the superficial velocity was increased. The results conformed to the ones obtained by Wang et al, (2010), where an increase in the vapor superficial velocity led to a decrease in concentration of ethanol in the product. In addition, curves became sharper which may be explained by the fact that film mass transfer resistance decreases by increasing flow rate (Simo et al, 2009).…”

Section: Superficial Velocity Effectsupporting

confidence: 78%

“…Sowerby and Crittenden (1988) explained that the reason for this observation was that the adsorbent was subjected to more adsorbate per unit time. Wang et al, (2010) studied the effect of feed concentration on separation of ethanol/water azeotrope using compound starch-based adsorbents. They found that as the feed concentration was increased from 82.1 to 92.5 wt% EtOH, the concentration of ethanol in the product significantly increased and the curve plateau length became longer.…”

Section: Effect Of Vapor Feed Concentrationmentioning

confidence: 99%

“…They found that palm gave the best results in separation of ethanol-water mixture compared to natural corncobs, activated palm stone, oak, and activated oak. Wang et al, (2010) used gravimetric method to investigate the water vapor isotherms on 3A zeolite, potato starch, corn starch, cassava starch, and cellulose at room temperature. Their results indicated that at relative pressure of 0.6, the highest value of water-ethanol adsorption ratio was achieved for potato starch (64.2).…”

Section: Bio-adsorbentsmentioning

confidence: 99%

See 2 more Smart Citations

Ethanol Dehydration in a Pressure Swing Adsorption Process Using Canola Meal

2013

View full text Add to dashboard Cite

Canola meal was used as an adsorbent in a pressure swing adsorption (PSA) apparatus for ethanol dehydration. The experiments were conducted at different pressures, temperatures, vapor superficial velocities, vapor concentrations and particle sizes. Adsorption experiments were performed at equilibrium and breakthrough points. The results demonstrated that canola meal can break the azeotropic point 95.6 wt% and produce over 99 wt% ethanol. At elevated temperature, feed water concentration, and vapor superficial velocity, it was found that the mass transfer rate increased. In addition, the mass transfer rate decreases when either the total pressure or the size of the adsorbent particles are increased. Breakthrough curves were simulated and the overall mass transfer resistance was evaluated at all experimental runs. The internal mass transfer resistance was identified as the relevant mass transfer mechanism.For canola meal, the equilibrium water/ethanol uptake was achieved at 100, 105, and 110˚C. The Frenkel-Halsey-Hill (FHH) and Guggenheim-Andrson-de-Boer (GAB) models perfectly simulated the water adsorption isotherms. By applying Dubinin-Polanyi model to the experimental data, canola meal was identified as a large pore (non-porous) material.The heat of adsorption on canola meal with particle size of 0.43-1.18 mm was determined to be -32.11 kJ/mol. The result confirms that the adsorption process is an exothermic phenomenon and is of physical type due to the fact that the value obtained as the heat of adsorption is negative and its magnitude is within the range 20-80 kJ/mol. The equilibrium water uptake on canola meal was similar to that reported for other starchy and cellulosic adsorbents, while the ethanol uptake was higher.Water saturated canola meal was successfully regenerated by passing nitrogen at 110˚C which is lower than that for molecular sieves commonly used in industry for bioethanol dehydration. The canola meal bio-adsorbent was re-used for more than 32 cycles and no significant change in adsorption capacity was observed.iii ACKNOWLEDGEMENTS

show abstract

Section: Superficial Velocity Effectsupporting

confidence: 78%

Section: Effect Of Vapor Feed Concentrationmentioning

confidence: 99%

Section: Bio-adsorbentsmentioning

confidence: 99%

See 1 more Smart Citation

Ethanol Dehydration in a Pressure Swing Adsorption Process Using Canola Meal

2013

View full text Add to dashboard Cite

show abstract

“…The screened formula presented in previous research was used here to prepare the adsorbent (Wang et al, 2010). Based on the previous research (Bushuk and Winkler, 1957;Hong et al, 1982;Pirzada, 1984) and the mechanism of adsorption of water, five typical biomass materials, which were purchased commercially, were selected and appraised to prepare ZSG-1.…”

Section: Preparation Of Zsg-1 and Reagentmentioning

confidence: 99%

“…In a recent successful undertaking, the authors formulated a compound adsorptive biomass known as agent ZSG-1 (Wang et al, 2010), which consists of corn, sweet potatoes, and a foaming agent, to dehydrate ethanol=water systems. This work further investigates ZSG-1 and shows that it can dehydrate aqueous isopropanol (IPA), which forms a homogeneous azeotrope at 87.4-87.7 wt.% under atmospheric pressure (Kirk and Othmer, 1968).…”

Section: Introductionmentioning

confidence: 99%

Characterization of Biomass Adsorbent ZSG-1 through Isopropanol and Water Azeotrope Dehydration

Gao

Sun

et al. 2014

Chemical Engineering Communications

Self Cite

View full text Add to dashboard Cite

In this work, a compound starch-based adsorbent material known as ZSG-1, which was formulated in a previous work for high-capacity, low-cost ethanol dehydration, was thermodynamically assessed through dehydration of azeotropic aqueous isopropanol. Comparisons of the retention times, heats of adsorption (DH s ), and Gibbs free energies (DG) of isopropanol and water confirmed the feasibility of using ZSG-1 in this dehydration process. Retention data were obtained by inverse gas chromatography and revealed the heat of adsorption DH s to be À55.73 kJ=mol, demonstrating that water entrapment in ZSG-1 is an exothermic physisorption process. After SEM observation, the inner micrographic pore size and surface area of ZSG-1 were calculated and estimated using an approach that combines nitrogen adsorption and mercury porosimetry. Through tests in a fixed-bed column under conditions determined by orthogonal experiment design, the optimal adsorption conditions were determined from breakthrough curves at different bed depths, bed temperatures, and kettle temperatures.

show abstract

Adsorption

Venkatesan

2013

Separation and Purification Technologies in Biorefineries

View full text Add to dashboard Cite

Separation of ethanol/water azeotrope using compound starch-based adsorbents

Cited by 44 publications

References 19 publications

Ethanol Dehydration in a Pressure Swing Adsorption Process Using Canola Meal

Ethanol Dehydration in a Pressure Swing Adsorption Process Using Canola Meal

Characterization of Biomass Adsorbent ZSG-1 through Isopropanol and Water Azeotrope Dehydration

Adsorption

Contact Info

Product

Resources

About