Ethanol removal processes

Figure 9.7 Dry grind ethanol process with GSH enzymes and in situ ethanol removal process (removing substrate and product inhibition).

The term folded oils refers to concentrated oils. This typically involves a distillation process however, alcohol washing can also be used. Alcohol washing is based on the insolubility of d-limonene in 60% to 70% ethanol. These processes predominately remove terpene compounds, although aldehydes (octanal) are also reduced. Oils that are more than 20-fold concentrated are called terpeneless oils and are more stable. Distillation is predominately used by flavor houses. Flavor houses purchase cold-pressed oil, which is concentrated and fractionated. These fractionated portions are sold for flavorings or flavor precursors. 

Biofiltration can be used to remove volatile organic compounds, including odors, from waste air.295 Pseudomonas spp. can remove toluene, and Bacillus spp., ethanol. The process is suitable for use on food-processing plants, public treatment works, and others, to control odors. The cost can be quite a bit lower than that of incineration or adsorption on carbon. A biofilter with Nitrosomonas eu ropaea immobilized in calcium alginate removed 97.5% of ammonia from air.296... 

For the ethanol-water separation, the requirement of thorough removal of ethanol from the recycled CO2 represents a technical challenge that increases the complexity and cost of the process relative to the simplified diagram shown in figure 8.10. The reasons for the increased complexity are explained below. Figure 8.13 illustrates the ethanol extraction process in the instance where the recycled CO2 has an ethanol concentration of 0.1 wt%. At the raffinate section of the extractor the ethanol concentration in the water-rich phase is now dictated by considerations of equilibrium and by the value of the distribution coefficient. The limitation attributed to equilibrium is indicated by the... 

In this study, we reported the preparation of mesoporous Ti02 materials via the sol-gel method involving a co-assembly of titanium (IV) isopropoxide and mainly neutral soluble starch CTMACl is used only for comparative reason. Ethanol and cyclohexane were used as solvents. The effect of key parameters, including surfactant removal process either by washing and/or by calcination and the solvent nature are discussed. Ti02 samples were characterized by means of N2 adsorption-desorption experiments, X-ray Diffraction analysis, UV-vis spectrophotometer. Scanning Electron Microscopy and Atomic Force Microscopy. 

While it is therefore more like ethanol and isopropanol, which require the addition of an entrainer to dry them by distillation, sec-butanol is not very hydrophilic and LLE can be linked to distillation in water removal processes. 

Gusmao, V.R. Martins, T. H. Chinalia, F.A. Sakamoto, I.K Thiemann, O.H. Varesche, M.B. (2006). BTEX and ethanol removal in horizontal-flow anaerobic immobilized biomass reactor, under denitrifying condition. Process Biochemistry, Vol.41, No.6, pp. 1391-1400... 

Recently, a quite different use for an inert-purge cycle has emerged the removal of large amounts (up to and exceeding 20 wt. %) of water from organic streams. Thus, inert-purge adsorption can now compete directly with azeotropic and extractive distillation and other means for a number of azeotrope-breaking separations, the most common of which is the production of dry ethanol. The process, as depicted in Fig. 

The polymer was precipitated by pouring the aqueous solution into ethanol and the resultant fine powder was recovered by filtration and washed with ethanol. This process was repeated twice to remove excess sodium hydroxide. NMR spectroscopy showed that the polymer has been totally converted, evidenced by the complete disappearance of the ethyl group. 

As the ethanol produced in fermentation acts as an inhibitor for the process, continuous ethanol removal is generally used to improve the productivity/ yield of the fermentation process. Garhyan and Elnashaie (8) modeled a continuous-membrane fermentor with in situ removal of ethanol produced using a sweep liquid as shown in Figure P6.21. The rate of ethanol removal is considered to be proportional to the ethanol concentration gradient across the membrane and area of permeation. 

For the ethanolic extraction process, macerate 100 g of minced tissue with 200 ml of 95 per cent ethanol and sufficient tartaric acid to give an acid reaction. Mix this mass with another 300 ml of ethanol, filter and wash with ethanol the filtrate should be clear although coloured. Mix each volume with four volumes of 5 per cent aqueous trichloroacetic acid solution and filter to remove proteins. If aqueous acid extraction is employed, macerate 100 g of minced tissue with 200 ml of 10 per cent trichloroacetic acid solution, filter and wash with more of the acid. Mix with an equal volume of water and to each 100 ml of diluted solution add 25 ml of 95 per cent ethanol. For adsorption, adjust the pH to between 8 0 and 9 0 with dilute sodium hydroxide solution and pass through a 10-cm column of Florisil retained between cotton wool (previously cleaned by refluxing for two hours with a mixture of formic acid 1 volume, ethanol 2 volumes and ethyl acetate 2 volumes) and then wash with 250 ml of water followed by 50 ml of 20 per cent aqueous ethanol. 

Schmolzer, K., Madje, K., Nidetzky, B., and Kratzer, R. (2012) Bioprocess design guided by in-situ substrate supply and product removal process intensification for synthesis of (S)-l-(2-chlorophenyl) ethanol. Bioresour. Technol., 108, 216-223,... 

Removal of alcohol from the fermentation broth in ethanol fermentation process (silicone capillaty membranes)... 

Esterifica.tlon. The process flow sheet (Fig. 4) outlines the process and equipment of the esterification step in the manufacture of the lower acryflc esters (methyl, ethyl, or butyl). For typical art, see References 69—74. The part of the flow sheet containing the dotted lines is appropriate only for butyl acrylate, since the lower alcohols, methanol and ethanol, are removed in the wash column. Since the butanol is not removed by a water or dilute caustic wash, it is removed in the a2eotrope column as the butyl acrylate a2eotrope this material is recycled to the reactor. 

Supercritical Extraction. The use of a supercritical fluid such as carbon dioxide as extractant is growing in industrial importance, particularly in the food-related industries. The advantages of supercritical fluids (qv) as extractants include favorable solubiHty and transport properties, and the abiHty to complete an extraction rapidly at moderate temperature. Whereas most of the supercritical extraction processes are soHd—Hquid extractions, some Hquid—Hquid extractions are of commercial interest also. For example, the removal of ethanol from dilute aqueous solutions using Hquid carbon dioxide... 

Precipitation was the principal protein separation technology initially chosen for the development of an industrially suitable fractionation process. Ethanol [64-17-5] (qv) was selected as the precipitation reagent because of its volatility. It can be subsequently removed using available drying technology... 

Pig. 4. Batch process for producing phosphatidylcholine fractions. 1, Ethanol storage tank 2, deoiled lecithin 3, solubiHzer 4, blender 5, film-type evaporator 6, ethanol-insoluble fraction 7, ethanol-soluble fraction 8, aluminum oxide 9, mixer 10, decanter 11, dryer 12, aluminum oxide removal 13, phosphatidylcholine solution 14, circulating evaporator 15, cooler 16, dryer and 17, phosphatidylcholine. 

A schematic diagram of the polymer precipitation process is shown in Figure 8. The hot polymer solution is cast onto a water-cooled chill roU, which cools the solution, causing the polymer to precipitate. The precipitated film is passed through an extraction tank containing methanol, ethanol or 2-propanol to remove the solvent. Finally, the membrane is dried, sent to a laser inspection station, trimmed, and roUed up. The process shown in Figure 8... 

Pervaporation is a relatively new process with elements in common with reverse osmosis and gas separation. In pervaporation, a liquid mixture contacts one side of a membrane, and the permeate is removed as a vapor from the other. Currendy, the only industrial application of pervaporation is the dehydration of organic solvents, in particular, the dehydration of 90—95% ethanol solutions, a difficult separation problem because an ethanol—water azeotrope forms at 95% ethanol. However, pervaporation processes are also being developed for the removal of dissolved organics from water and the separation of organic solvent mixtures. These applications are likely to become commercial after the year 2000. 

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