Abstract:
A process for recovering and using an organic/carboxylic acid or furanic molecule by means of making an ester of a free carboxylic acid or furanic molecule with an alcohol in carbon dioxide (CO2) without the presence of any other acid catalyst at a reaction temperature and pressure that corresponds to supercritical, critical or near critical conditions for the alcohol and/or CO2 is described. The process can constitute part of a general process of refining carboxylic acids derived from a fermentation broth or use in the production of a variety of chemical compounds, such as C4 platform compounds or polymers.
Abstract:
A process is provided for making isohexides such as isosorbide with reduced color and/or improved color stability on storage, wherein ionic species in the crude dehydration product mixture are chromatographically substantially separated from the remainder of the crude product mixture, then the remainder is refined to yield a finished product for further use or sale.
Abstract:
A process is described for the determination of soluble aldehydes in a composition including one or more of (a) 2,5-furandicarboxylic acid (FDCA), (b) terephthalic acid (TPA), (c) an ester of 2,5-furandicarboxylic acid and (d) an ester of terephthalic acid. The process can indicate the presence in the composition of even those very low levels of such soluble aldehydes that have been associated with the development of unacceptable color in a) the composition, b) some portion of the composition or c) a prepolymer, oligomer or polymer prepared, directly or indirectly, at least in part from the composition or some portion of the composition, so that mitigating or corrective measures can be undertaken in response.
Abstract:
Methods are disclosed for the purification of crude compositions comprising 2,5-furandicarboxylic acid, dimethyl ester (FDME) or other diester derivatives (e.g., dialkyl ester derivatives) of 2,5-furandicarboxylic acid (FDCA), by crystallization. In this regard, certain solvents, and classes of solvents, have been discovered to promote the selective crystallization of FDME over impurities often generated in its production by FDCA esterification and other upstream processing steps. Importantly, certain impurities that are selectively removed include those that would otherwise be detrimental to the color and/or color stability of the purified composition. Other improvements in crystallization reside in the use of techniques such as liquid-liquid extraction and pre-treatment of the crystallization solution by contact with a solid medium.
Abstract:
A process for recovering and using an organic/carboxylic acid or furanic molecule by means of making an ester of a free carboxylic acid or furanic molecule with an alcohol in carbon dioxide (CO2) without the presence of any other acid catalyst at a reaction temperature and pressure that corresponds to supercritical, critical or near critical conditions for the alcohol and/or CO2 is described. The process can constitute part of a general process of refining carboxylic acids derived from a fermentation broth or use in the production of a variety of chemical compounds, such as C4 platform compounds or polymers.
Abstract:
Reduced color and improved color stability isohexide products are enabled through adding one or more antioxidants to a crude dehydration product mixture from an acid-catalyzed dehydration of a corresponding hexitol.
Abstract:
A process is described for making isohexides, comprising dehydrating one or more hexitols with an acid catalyst to form a crude dehydration product mixture including one or more isohexides, further processing the mixture to separate out one or more fractions of a greater purity or higher concentration of at least one of the isohexides, and hydrogenating at least one of a) the crude dehydration product mixture, b) a neutralized crude dehydration product mixture, following a neutralization of the crude dehydration product mixture, c) the product mixture following a neutralization step and further following a step to remove ionic species therefrom, d) a greater purity or higher concentration fraction, and e) a lesser purity or concentration fraction, by reaction with a hydrogen source in the presence of a hydrogenation catalyst. Hydrogenation improves the color and/or color stability of the material, especially of a finished isohexide product.
Abstract:
An improved process and catalyst are provided for making an FDCA diester monomer product with improved productivity compared to an autocatalyzed esterification but with comparable or at least not greatly diminished color properties compared to the FDCA diester monomer product that would be produced autocatalytically, wherein a heterogeneous tin (II) catalyst is employed to make an esterification product comprising a diester of FDCA with an alcohol, the catalyst being in either a bulk, unsupported form or in the form of a supported tin (II) catalyst, in particular, using a hygroscopic support such as a gamma alumina, a zeolite or a silica, or using a carbon support.
Abstract:
Compositions and methods are provided for the production of bio-based polymers (e.g., polymers made from glucose), including polyesters, as well as end products resulting from such production, in which one or more color stabilizing additive compounds is utilized. The additive(s) may be used in the stabilization of a monomer or prepolymer that is reacted in such production methods, prior to obtaining the polymer. Particular bio-based polymers are those having furandicarboxylate moieties or residues in their backbone structure, with poly(alkylene furan dicarboxylate) polymers, such as polyethylene furan dicarboxylate) (PEF) and poly(trimethylene furan dicarboxylate) (PTF) being representative.
Abstract:
A process for making esters from organic acids by means of reacting a carboxylic acid with dialkylcarbonate in an alcohol-containing solvent without any extrinsic acid or base catalyst is described. A benefit of the preparation process is that it can make the separation and extraction of ester products simpler and more facile vis-a-vis conventional isolation techniques.