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: A method is provided for separating a dicarboxylic acid product from a mixture containing such dicarboxylic acids. The method involves: providing a dicarboxylic acid-containing mixture of which at least 35% of the carboxylic acid content of the mixture is a dicarboxylic acid product of interest; running an extraction of said dicarboxylic acid-containing mixture through a chromatographic column configured with an amphoteric resin, such that the dicarboxylic acid product elutes preferentially from the dicarboxylic acid-containing mixture. In certain embodiments, the dicarboxylic acid product of interest can be a glucaric or gluconic acid product from a mixture of either or both of these with still other carboxylic acids.

Abstract: A process is provided for making esters of FDCA, in which an aqueous feed comprising glucaric acid is first reacted with a high boiling first alcohol in the presence of an acid catalyst and with removing water during the reaction, to form a first product mixture comprising a first ester of FDCA and the high boiling first alcohol, then unreacted high boiling first alcohol is removed from the first product mixture. The first ester of FDCA and the high boiling first alcohol is then transesterified with a lower boiling second alcohol selected from the group consisting of methanol, ethanol, isopropanol and n-propanol, to form a second product mixture comprising a second ester of FDCA with the lower boiling second alcohol, and the second ester of FDCA with the lower boiling second alcohol is recovered.

Abstract: A method is provided for separating a dicarboxylic acid product from a mixture containing such dicarboxylic acids. The method involves: providing a dicarboxylic acid-containing mixture of which at least 35% of the carboxylic acid content of the mixture is a dicarboxylic acid product of interest; running an extraction of said dicarboxylic acid-containing mixture through a chromatographic column configured with an amphoteric resin, such that the dicarboxylic acid product elutes preferentially from the dicarboxylic acid-containing mixture. In certain embodiments, the dicarboxylic acid product of interest can be a glucaric or gluconic acid product from a mixture of either or both of these with still other carboxylic acids.

Abstract: A process is provided for making esters of FDCA, in which an aqueous feed comprising glucaric acid is first reacted with a high boiling first alcohol in the presence of an acid catalyst and with removing water during the reaction, to form a first product mixture comprising a first ester of FDCA and the high boiling first alcohol, then unreacted high boiling first alcohol is removed from the first product mixture. The first ester of FDCA and the high boiling first alcohol is then transesterified with a lower boiling second alcohol selected from the group consisting of methanol, ethanol, isopropanol and n-propanol, to form a second product mixture comprising a second ester of FDCA with the lower boiling second alcohol, and the second ester of FDCA with the lower boiling second alcohol is recovered.

Abstract: In the process of distilling a polyol product mixture including one or both of a biobased propylene glycol and a biobased ethylene glycol from the reaction of hydrogen with a biobased feed, it has been discovered that undesirable epoxides can form, and the present invention provides means for guarding against their formation, for removing epoxides which do form by particular methods of distilling, and for removing the epoxides from a finished, otherwise commercially acceptable biobased glycol product.

Abstract: In the process of distilling a polyol product mixture including one or both of a biobased propylene glycol and a biobased ethylene glycol from the reaction of hydrogen with a biobased feed, it has been discovered that undesirable epoxides can form, and the present invention provides means for guarding against their formation, for removing epoxides which do form by particular methods of distilling, and for removing the epoxides from a finished, otherwise commercially acceptable biobased glycol product.

Abstract: In the process of distilling a polyol product mixture including one or both of a biobased propylene glycol and a biobased ethylene glycol from the reaction of hydrogen with a biobased feed, it has been discovered that undesirable epoxides can form, and the present invention provides means for guarding against their formation, for removing epoxides which do form by particular methods of distilling, and for removing the epoxides from a finished, otherwise commercially acceptable biobased glycol product.

Abstract: In the process of distilling a polyol product mixture including one or both of a biobased propylene glycol and a biobased ethylene glycol from the reaction of hydrogen with a biobased feed, it has been discovered that undesirable epoxides can form, and the present invention provides means for guarding against their formation, for removing epoxides which do form by particular methods of distilling, and for removing the epoxides from a finished, otherwise commercially acceptable biobased glycol product.

Abstract: A header box for a heat exchanger assembly and the method of manufacture. The header box has a first header component and a second header component. The first header component has a first corner portion with a first wall and a second wall extending therefrom. The second header component has a second corner portion with a third wall and a fourth wall extending therefrom. Free ends of the first wall and the third wall cooperate to form a first seam which is welded to maintain the first wall in position relative to the second wall. The free ends of the second wall and the fourth wall cooperate to form a second seam which is welded to maintain the third wall in position relative to the fourth wall. The header box, with the first corner portion and the second corner portion, will withstand the stress concentrations associated with a flow of fluid in the header box.

Abstract: A sonde comprising a first sensor and a second sensor adjacent the first sensor, the first sensor including an optical window and a wiper element, the wiper element rotating on a shaft extending from the first sensor so as to clean debris from the window, a brush extending from the wiper element beyond the perimeter of the first sensor such that the brush contacts the adjacent second sensor and removes debris which accumulates on the second sensor.

Abstract: A sonde comprising a first sensor and a second sensor adjacent the first sensor, the first sensor including an optical window and a wiper element, the wiper element rotating on a shaft extending from the first sensor so as to clean debris from the window, a brush extending from the wiper element beyond the perimeter of the first sensor such that the brush contacts the adjacent second sensor and removes debris which accumulates on the second sensor.