1-Propanol recovery

Propanol recovery solution To prepare 10 ml, mix 6 ml 2-propanol with 4 ml 0.1% trifluoroacetic acid solution. 

Pollution Control Pervaporation is used to reduce the organic loading of a waste stream, thus effecting product recovery and a reduction in waste-treatment costs. An illustration is a waste stream containing II percent (wt) n-propanol. The residue is stripped to 0.5 percent and 96 percent of the alcohol is recovered in the permeate as a 45 percent solution. This application uses a hydrophobic, rubbery membrane. The residue is sent to a conventional waste-treatment plant. 

Applications Caceres et al. [114] compared various methods for extraction of Tinuvin 770 and Chimas-sorb 944 from HDPE pellets, namely room temperature diffusion in CHC13 (20 % extraction), ultrasonica-tion (20% extraction), Soxtec extraction with DCM (nonsolvent) (50 % extraction), dissolution (dichloroben-zene)/precipitation (2-propanol) (65-70% recovery) and boiling under reflux with toluene (solvent) at 160 °C (95 % extraction). By changing conditions (nature of solvent, T, t) similar comparisons do not have much added value. Table 3.6 compares the results of reflux extraction and MAE for additives in LDPE [115]. 

Production of chemicals became increasingly important. The recovery of oxygenates from the Fischer-Tropsch aqueous product was expanded to include niche chemicals, such as 1-propanol.45 Ethylene and propylene extraction was increased and even supplemented by the addition of a high-temperature catalytic cracker.46 Linear a-olefin extraction units for the recovery of 1-pentene, 1-hexene, and 1-octene were added to the refinery,45-47 and a new facility for the extraction of 1-heptene and its... 

Many extraction solvents have been used, of which the more polar protic solvents are found to perform best. While Soxhlet recoveries for NPEO are reported at 70% using pentane [13], and 80% using acetone/ hexane [13], solvents like propanol or methanol yield higher recoveries, especially for the higher ethoxylates. 

In our previous paper we have reported that silica MCM-41 exhibits a large amount of reversible adsorption, high thermal and hydrothermal stabilities, and little catalytic acidity and is an excellent adsorbent in PSA process for recovery of 2-propanol and toluene vapors [1]. Here we present the results of PSA of butanone on silica MCM-41 and discuss the effect of pretreatment temperatures on adsorption properties of MCM-41. 

Agbaba et al. [56] developed an HPTLC method for the determination of omeprazole, pantoprazole, and their impurities omeprazole sulfone and N-methylpantoprazole in pharmaceutical. The mobile phase chloroform-2-propanol 25% ammonia-acetonitrile (10.8 1.2 0.3 4), enables good resolution of large excesses of the drugs from the possible impurities. Regression coefficients (r > 0.998), recovery (90.7-120.0%), and detection limit (0.025-0.05%) were validated and found to be satisfactory. The method is convenient for quantitative analysis and purity control of the compounds. 

Aqueous samples are extracted with methylene chloride. If the sample is not clean or if the presence of organic interference is suspected, a solvent wash should be performed. For this, the pH of the sample is adjusted to 12 or greater with NaOH solution. The sample solution made basic is then shaken with methylene chloride. Organic contaminants of basic nature and most neutral substances partition into the methylene chloride phase, leaving phenols and other acidic compounds in the aqueous phase. The solvent layer is discarded. The pH of the aqueous phase is now adjusted to 2 or below with H2S04, after which the acidic solution is repeatedly extracted with methylene chloride. Phenols and other organic compounds of acidic nature partition into the methylene chloride phase. The methylene chloride extract is then concentrated and exchanged into 2-propanol for GC analysis. For clean samples, abasic solvent wash is not necessary however, the sample should be acidified before extraction. It may be noted that basic solvent wash may cause reduced recovery of phenol and 2,4-dimethylphenol. 

When using propanols for esterification, the alcohol and water form azeotropes making necessary secondary recovery and recycling of alcohol. An industrial process that is conducted in this way makes use of homogeneous catalyst (para-toluene sulfonic acid) lost after reaction [5]. A more efficient solution can found by employing an entrainer for breaking the azeotrope water/alcohol and superacid solid catalyst. Besides, the entrainer has a beneficial effect on the reaction rate, by increasing the amount of alcohol recycled to the reaction space [3]. 

The method of Lentz (35,36) was adopted for trimethylsilylation of the aqueous silicate solutions. The mixture of cone, hydrochloric acid, water, 2-propanol and hexamethyldisiloxane was used as the trimethylsilylating reagent. Trimethylsilylated derivatives obtained were adaptable to gas-phase analysis. The distribution of silicate species in solutions, which was analyzed quantitatively by the trimethylsilylation technique combined with gas-liquid chromatography, was expressed as the Si(>2 recovery, that is, the percentage of silica as a silicate species in total silica component in the solutions. 

Methanol is often used in PLE. It was found to be a better solvent than acetonitrile, or a mixture of methanol and propanol, to extract tocols from cereals (Bustamante-Rangel et al., 2007). Extraction was carried out at 50 °C and a pressure of 110 bar with one extraction cycle of 5 min, because higher extraction temperatures and longer times did not improve analyte recoveries. The same conditions were used to extract tocols from infant formulas (Delgado-Zamarreno et al., 2006). Intra-day and inter-day precisions were very good, being < 10%, and the recoveries... 

Fischer and co-workers undertook a LCA of the 26 organic solvents which they had already assessed in terms of EHS criteria (see above).They used the Eco-solvent software tool (http //www.sust-chem.ethz.ch/tools/ecosolvent/), which on the basis of industrial data considers the birth of the solvent (its petrochemical production) and its death by either a distillation process or treatment in a hazardous waste incineration plant. For both types of end-of-life treatment, environmental credits were granted where appropriate, e.g. solvent recovery and reuse upon distillation. The results of this assessment are shown in Figure 1.2. From an LCA perspective, tetrahydrofuran (THF), butyl acetate, cyclohexanone and 1-propanol are not good solvents. This is primarily due to the environmental... 

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