Terephthalic Acid Purification Research Articles

Development of a novel “4E” polyethylene terephthalate bio-recycling process with the potential for industrial application: Efficient, economical, energy-saving, and eco-friendly

Recently, clean PET biodegradation has gained widespread attention in tackling white pollution. Nonetheless, the development of industrial biotechnology is still impeded by its contamination susceptibility, high energy input, and consumption of substantial freshwater resources. Thus, a novel PET biodegradation process was developed based on host screening and by-product circulation to address the aforementioned issues. The fast-growth host halophilic Vibrio natriegens (V. natriegens) was used and exhibited an increased protein expression level of 87.3% compared to E. coli. Meanwhile, the new process utilized a seawater-based medium for fermentation under non-sterile conditions, leading to energy-saving (energy reduced by 2.48-fold) and cost-reduction (cost reduced by 47.9%). Moreover, the large amount of saline wastewater from terephthalic acid purification was ingeniously reused for the cultivation of V. natriegens, thereby avoiding resource wastage and secondary pollution. Therefore, an efficient, economical, energy-saving, and eco-friendly process was designed, potentially addressing the industrial bottleneck in PET bio-recycling.

Effects of DTAB on Performance of Nano Pd/C Catalyst for Purification of Terephthalic Acid

The 0.5 wt.% Pd/C catalysts used for purification of terephthalic acid(TA) were prepared, and the effects of dodecyltrimethylammonium bromide(DTAB) concentration on activity and microstructure of catalysts were investigated by means of SEM, TEM, XRD,HPLC,specific surface area(BET) and porosity test. The results show that DTAB can increase the activity of Pd/C catalysts, and the catalytic activity increases with the increase in DTAB concentration and nearly remains constant with further increase after it exceeds 0.5 wt.%.. DTAB can clean the surface of activated carbon and diminish the palladium size of Pd/C catalysts. The addition of DTAB has effects in crystal structure of nano Pd/C catalysts, and the Pd crystal planes of (111) and (200) was replaced by a broad reflections after DTAB added. DTAB tends to form various meta-stable structures(spherical or cylindrical)at the solid-liquid interface that helps finer grain for mation and hinders subsequent coarsening of the palladium particles.

Preparation of Nano Pd/C Catalyst for Purification of Terephthalic Acid by Sol-Gel Method

The traditional method of preparing 0.5 wt.% nano Pd/C catalysts used for pure terephthalic acid(PTA) refining is the precipitate-reduction method, and this paper proposed the sol-gel method, in which the palladium colloid was firstly prepared, and followed by the load process onto the activated carbon. The activity and microstructure of catalysts were investigated by means of SEM, TEM, EDS，XRD and HPLC. It was found that the activity of catalyst with the sol-gel method was much higher than that with precipitate-reduction method. The preparation technology has less effects on the micostructure of Pd/C catalysts, while the palladium particles of catalyst obtained with sol-gel method are much finer and the relatively palladium content is much higher.These two factors contribute to the higher activity of Pd/C catalyst.

Recovery of Terephthalic Acid from Alkali Reduction Wastewater by Cooling Crystallization

AbstractA process for the recovery and purification of terephthalic acid (TA) from alkali reduction wastewater is reported. TA was first precipitated from alkali reduction wastewater by acidification with sulfuric acid, and then the produced crude TA was dissolved in dimethylacetamide (DMA) so that crude TA could be purified from the solution by cooling crystallization. The results indicated that acidification could reduce the chemical oxygen demand of the wastewater by 83 %, and the purity of TA by crystallization could reach 99.91 %. A correlation was proposed in describing the solubility of crude TA in DMA from 303.4 to 358.65 K, which gives a mean relative discrepancy of less than 1.14 %. The cooling rate of the mother liquor had a large influence on the crystal size distribution. At an average cooling rate of 1.18 K min–1, the particle size distribution of TA was narrow and the average size was about 100 μm. In a bench‐scale study, it was demonstrated that the crystallized product can be recycled as the raw material for polyethylene terephthalate production.

Cover Chem. Eng. Technol. 10/2011

AbstractTerephthalic acid recovered from alkali reduction wastewaterA process for the recovery and purification of terephthalic acid (TA) from alkali reduction wastewater was developed. The process consisted of two steps: TA was first precipitated from alkali reduction wastewater by acidification. After that, the crude TA produced was dissolved into dimethylacetylamide and purified by cooling crystallization. The results indicated that acidification could reduce the chemical oxygen demand of the wastewater by 83 %, and the purity of TA by crystallization could reach 99.9 %. Furthermore, at an average cooling rate of 1.18 K min–1, the particle size of TA was uniform and the average size was about 100 µm. The isolated terephthalic acid can be recycled as raw material for polyethylene terephthalate production.S.‐C. Wu, Z.‐M. Cheng*, S.‐D. Wang, X.‐L. ShanChem. Eng. Technol. 2011, 34 (10), 1614–1618.DOI: 10.1002/ceat.201100096

Palladium Catalysts Supported on Fishbone Carbon Nanofibers from Different Carbon Sources

Abstract Pd catalysts (0.5% Pd) supported on fishbone carbon nanofibers (FCNFs) from different carbon sources for terephthalic acid (TA) hydro-purification were prepared and investigated. CNFs from various carbon sources, CO (FCNF-CO), CH 4 (FCNF-C1), and C 2 H 4 (FCNF-C2), have been synthesized and characterized by N 2 adsorption, XRD, and TPD-MS. The results indicated that though they all possess similar fishbone structure, the FCNF from CO has the largest specific surface area, highest graphitization degree, and a large amount of surface groups, while the FCNF from C 2 H 4 has the least specific surface area, lowest graphitization degree, and moderate surface groups. Pd/CNFs were synthesized and characterized by TEM, N 2 adsorption, XRD, and CO chemisorption. The catalytic activity for TA purification follows the sequence Pd/FCNF-CO > Pd/FCNF-C1 > Pd/FCNF-C2, which is in accordance with the sequence of Pd dispersion. It is believed that rather than the graphene arrangement, the synergic support effect of pore structure, crystallinity, and the surface chemistry dictates the Pd dispersion on FCNF and the consequent catalytic activity.

Purification of terephthalic acid by crystal aging

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPurification of terephthalic acid by crystal agingPamela M. Brown, Michael Marquering, and Allan S. MyersonCite this: Ind. Eng. Chem. Res. 1990, 29, 10, 2089–2093Publication Date (Print):October 1, 1990Publication History Published online1 May 2002Published inissue 1 October 1990https://doi.org/10.1021/ie00106a017RIGHTS & PERMISSIONSArticle Views394Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Vapor-phase growth forms and purification of 1,4-benzenedicar☐ylic acid

Telephthalic acid crystals grown by vapor deposition at 160–190 °C and atmospheric pressure assume respectively polygonal, branched and unbranched-dendritic and columnar habits depending on the conditions of the experiments. Preliminary experiments. Preliminary experiments on terephthalic acid purification by vapor-phase recrystallization indicate that the volatile impurities, initially in the terephthalic acid crystal lattice, are preferentially entrained and their concentration (mass fraction) in the deposits is up to 80 times higher than in the source material. About 60% (mass) of the volatile impurity is removed from the crude acid after a 70 min treatment and the purification effects seem independent of the initial impurity loading.