Ethanol process, novel

A. K. Jain, R. K. Srivastava, M. K. Gupta, S. K. Das. A novel technique in membrane separation processes Electroosmotic separation of benzene in ethanol solution. J Memb Sci 75 53, 1993. 

The catalytic alcohol racemization with diruthenium catalyst 1 is based on the reversible transfer hydrogenation mechanism. Meanwhile, the problem of ketone formation in the DKR of secondary alcohols with 1 was identified due to the liberation of molecular hydrogen. Then, we envisioned a novel asymmetric reductive acetylation of ketones to circumvent the problem of ketone formation (Scheme 6). A key factor of this process was the selection of hydrogen donors compatible with the DKR conditions. 2,6-Dimethyl-4-heptanol, which cannot be acylated by lipases, was chosen as a proper hydrogen donor. Asymmetric reductive acetylation of ketones was also possible under 1 atm hydrogen in ethyl acetate, which acted as acyl donor and solvent. Ethanol formation from ethyl acetate did not cause critical problem, and various ketones were successfully transformed into the corresponding chiral acetates (Table 17). However, reaction time (96 h) was unsatisfactory. 

Adrian et al. (2000) have reported a novel high-pressure liquid-liquid extraction process with reference to processing in biotechnology the example of cardiac glycosides (digitoxin and digoxin) is cited. A completely miscible, binary system of water and a hydrophobic organic solvent like ethanol can split into two liquid phases when a near-critical gas (e.g. CO2) is added. The near-critical C02/water/l-propanol system is reported, for which possibilities for industrial exploitation exist. 

Partial oxidation is also mentioned as a process to convert ethanol to hydrogen.124 Another novel technology for ethanol to hydrogen has been described by Toci and Modica.125 It is based on cracking ethanol vapors by "cold-plasma-chemical processing" in the presence of a Ni-based catalyst. 

The alternative pathway is the biochemical route. It processes starches/sugars into ethanol, a standard technology with installations world-wide, but in a biorefinery the start is the whole-plant material or biomass residues containing hemicel-lulose, which is broken into sugars that then can be fermented to ethanol and/or other alcohols such as butanol. As mentioned before, there is the need to develop novel and/or improved biocatalysts for alternative organic fuels, such as biobutanol, by fermentation processes. 

The fifth paper, "A Separative Bioreactor Direct Product Capture and pH Control," presented by Seth Snyder of the Argonne National Laboratory, reviewed development and performance of a novel bioreactor incorporating electrodeionization to simultaneously produce and separate products from both enzymatic and microbially mediated reactions. The sixth paper, " Optimization of Xylose Fermentation in Spent Sulfite Liquor by Saccharomyces cerevisiae 259ST," presented by Steven Helle of the University of British Columbia, provided an overview of an approach to fermentation optimization utilized to identify key process variables limiting use of the SSL for commercial ethanol production. 

As it is well known, fermentation processes generally produce aqueous solutions of ethanol, the separation of which necessitates a series of distillation processes. Distillation, however, is a very expensive operation and in addition, ethanol-water mixture forms an azeotrope which further increases the cost of purification. Therefore, novel separation methods must be investigated to make the process more feasible and economical. 

Camptothecin (43) was first isolated by Monroe Wall and Mansukh Wani in 1966, after ethanolic extracts of Camptotheca acuminata, a tree native to China, showed unusual and potent antitumor activity (63). Starting with 19 kg of dried wood and bark. Wall and Wani painstakingly purified the principal active component with a combination of hot solvent extraction, an 11-stage Craig countercurrent partition process, silica gel chromatography, and crystallization. Camptothecin was characterized as a novel pentacyclicalkaloid, present as j ust 0.01 % w/w of the stem bark of C ax umi-... 

In 1989, a novel, electrochemical process developed jointly with the Max-Planck-Institut fiir Kohlenforschung at Miilheim/Ruhr (Germany) went into operation. The process is based on earlier work of Lehmkuhl and Eisenbach [7] and follows eq. (4). An iron anode is first used to form the reactive intermediate iron(II) ethoxide Fe(OC2H5)2 as an ethanol adduct. (The ethanol serves as solvent and reactant.) Due to the Lewis-basic ethoxy ligands, (monomeric) cyclopentadiene is deprotonated under mild conditions to form high-purity ferrocene directly. This process has the advantage that the iron(II) precursor compound is not to be synthesized but is rather formed in situ without further purification. Typical conditions of electrolysis are 120 A at 13 V at 0.8 m X 10 mm iron anodes. A pilot plant converts 2.5 kg of iron per day. The working temperature is 60 °C. 

SSFSE process, the ethanol production can be enhanced when compared to a batch process. For all these reasons, in this work a novel adaptive control scheme for a fed-batch SSFSE process is proposed, which due to its simplicity is suitable for industrial applications. 

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