Articles publicats (Grup de Recerca A3 Leather Innovation Center)
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- ItemOpen AccessValorization of tannery-derived FAMEs into bio-based epoxides via chemo-enzymatic synthesis(Elsevier, 2025) Deroncelé, Víctor; Tahmaz , Ismael; Sorolla, Sílvia; Bacardit i Dalmases, AnnaThe urgent transition toward low-carbon chemical manufacturing has prompted the development of renewable alternatives to fossil-based epoxy intermediates. This study presents an integrated and resource-efficient chemoenzymatic route for the synthesis of epoxidized methyl oleate (EMO) from fatty acid methyl esters (FAMEs) derived from tannery waste—a lipid-rich but underutilized industrial residue. A single-step urea complexation achieved 86.7 ± 0.6 % methyl oleate purity with a 38.1 ± 0.9 % recovery yield, while the saturated-rich coproduct (~40 %) exhibited physicochemical properties suitable for biodiesel or lubricant applications. Subsequent epoxidation was carried out using immobilized Candida antarctica lipase B (Novozym® 435) and in situ generated performic acid, yielding an oxirane oxygen content of 6.42 ± 0.14 %, corresponding to >90 % conversion of double bonds under mild conditions. The enzyme retained 72 % of its initial activity after ten reuse cycles, significantly enhancing process circularity and reducing catalytic costs. Green chemistry metrics were favorable: atom economy reached 86 %, solvent recovery exceeded 85 %, and the E-factor remained as low as 0.86 kg waste/kg EMO. A cradle-to-gate life cycle assessment (LCA) estimated a global warming potential (GWP) of 1.92 kg CO₂-eq/kg EMO—representing a 63 % reduction compared to petrochemical benchmarks. Economic analysis at the 1000 t/year scale yielded a production cost of €1.57/kg with an internal rate of return (IRR) of 15 %. Overall, this work demonstrates how lipid-rich industrial residues can be converted into high-value bio-based epoxides through a scalable and environmentally sound chemo-enzymatic route, aligning with circular economy principles and green chemistry targets.
- ItemOpen AccessComparison of the Sustainability of the Vegetable, Wet-White and Chromium Tanning Processes through the Life Cycle Analysis(The American Leather Chemists Association, 2020) Bacardit i Dalmases, Anna; Combalia Cendra, Felip; Font Vallès, Joaquim; Baquero Armans, GrauPublic concerns about the quality of life of human beings as well as the quality of natural environments and ecosystems have led to the increasing importance of sustainability for governments and for all industries, including the leather industry. In this context, more "ecological" leather goods are being demanded. It should be noted that this concept is often used without a scientific study to support it.This concept of sustainable or ecological product in the field of leather goods, are mainly associated with chrome-free tanneries (that is vegetable and wet-white), but this association should be backed up or dismissed by scientific evidence. A complete scientific study is required, which takes into account the different stages of leather production, including also the treatment of water and by-products, analyzing in a scientific and systematic way the environmental impact of each of these tanning processes.This study focuses on the life cycle analysis of the three basic tanning processes: chrome, vegetable and wet-white leather production. It will focus on European manufacturing to have reliable data and reduce uncertainty.In the tanning stage, the process with the greatest impact is the vegetable one, to highlight its high impact on global warming at 100 years (GWP100). This result is due to the energy necessary for the production of mimosa and quebracho in addition to the energy for the processing of the leather in the drums.Wet white tanning with glutaraldehyde has lowest environmental results than vegetable tanning.The chrome tanning process (wet blue) also stands out for its reduced environmental impact.Subsequently, to have a global view of the entire production, the LCA of the post-tanning stages must be performed to evaluate the impact of each of the systems studied.
- ItemOpen AccessDevelopment of a Headspace-Solid Phase Micro Extraction Method for the Analysis of Volatile and Semi-Volatile Organic Compounds from Polyurethane Resins for Leather Finishing(The American Leather Chemists Association, 2021) Flores Reyes, Antonia; Sorolla, Sílvia; Casas, Concepció; Cuadros Domènech, Rosa; Bacardit i Dalmases, AnnaVolatile organic compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs) arise from the chemicals used in the various stages of the leather manufacturing process. An important aim of the tanning industry is to minimize or eliminate VOCs and SVOCs, without lowering the quality of leather.This paper shows the development of a new headspace-solid phase micro extraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) method for the identification of VOCs and SVOCs emitted by newly designed polymers for the leather finishing operation. These new polymers are polyurethane resins designed to reduce the VOC and SVOC concentration. This method enables a simple and fast determination of the qualitative and semi -quantitative content of VOCs and SVOCs in polyurethane type finishing resins. The chemicals that are of concern in this paper are the following: Dipropylene glycol Monomethyl Ether (DPGME), DBE-3 (a mixture of dibasic esters) and Triethylamine (TEA). The test conditions that have been determined to carry out the HS SPME assay are the following: incubation time (2 hours), extraction temperature and time (40 degrees C; 5 minutes) and the desorption conditions (280 degrees C, 50 seconds).Ten samples of laboratory scale resins were tested by HS-SPME followed by gas chromatography (GC-MS). DPGME and DBE-3 (a mixture of dimethyl adipate, dimethyl glutarate and dimethyl succinate) have been identified effectively. The compounds are identified by a quantitative method using external calibration curves for the target compounds. The technique is not effective to determine the TEA compound, since the chromatograms shown poor resolution peaks for the standard.
- ItemOpen AccessA Simple Test to Determine the Propensity of a Fatliquor to Trigger the Formation of Chromium (VI) in Leather(The American Leather Chemists Association, 2022) Compte, Irene; Cuadros Domènech, Rosa; Izquierdo Buera, Francina; Combalia Cendra, Felip; Bacardit i Dalmases, AnnaSince the entry into force of the EU Commission Regulation regarding hexavalent chromium in leather articles in 2014, it is of paramount importance to follow good manufacturing practices to ensure the production of leather not only free of Cr(VI) but with no tendency to its formation. The equilibrium between Cr(III) and Cr(VI) in leather can be disturbed under stressful environmental conditions such as light or heat exposure. These factors could trigger the lipid peroxidation of unprotected unsaturated fatliquoring agents, thus leading to the oxidation of Cr(III) to Cr(VI).Due to the relevance that the oxidation of the fatliquoring agents has in the subsequent Cr(VI) formation, the Propensity Test has been developed and verified as an innovative verifying in-house tool for tanners to verify that each of the fatliquoring agents used in the tannery processes are properly protected against oxidation and thus, that Cr(VI) formation is not triggered.The method has four simple steps and can be easily carried out in the tanneries' pilot plant. It does not require special equipment or specific apparatus because all the necessary instruments are usually available in any tannery and the skills needed to perform the test are the same that leather technicians use in their day-to-day work, so the implementation cost is practically non-existent.This work leads to the conclusion that there is a higher possibility of Cr(VI) formation among sheep skins rather than among calf hides. The rechroming process also presents risks regarding Cr(VI) content in leather, however, in this study it has been shown that rechroming does not increase Cr(VI) formation risks when the fatliquoring agents are properly protected against autoxidation. Therefore, using a well -protected fatliquoring agent is mandatory for the purpose of producing Cr(VI)-free leather despite the type of leather.
- ItemOpen AccessUse of Long-Chain Synthetic Phenolic Antioxidants to Produce Chromium Tanned Leather without Risk of Hexavalent Chromium Formation(The American Leather Chemists Association, 2023) Compte, Irene; Torras, Quim; Izquierdo Buera, Francina; Cuadros Domènech, Rosa; Bacardit i Dalmases, AnnaChromium tanned leather is the widest form of leather tanning across the world, but it might involve a risk of hexavalent chromium formation, which is restricted in leather products above 3 mg/kg. Among other conditions, certain processes might lead to the oxidation of natural fats or fatliquoring agents with unsaturated carbon-carbon bonds, thus generating free radical molecules that can contribute to the Cr(III) oxidation to Cr(VI). The auto oxidation of unsaturated lipids is promoted by exposure to high temperatures and light, specifically UV radiation. Among other relevant manufacturing practices, the addition of synthetic phenolic antioxidants (SPAs) during the synthesis of fatliquoring agents or during leather manufacturing can be a relevant tool for preventing lipid auto-oxidation.The efficiency of the long-chain synthetic antioxidant 1135 (AO1135, CAS RN degrees 125643-61-0) has been assessed for Cr(VI) prevention. The performance of AO1135 has been tested in two different skin types (sheepskin, woolly sheepskin), with two different fatliquoring agents (unprotected and protected against oxidation). The protected fatliquoring agent was formulated with AO1135. Also, two commercial products that contain the AO1135 in its formulation have been applied to leathers. Upon completion of the post-tanning process, the leathers have undergone two different thermal ageing processes.AO1135 has been verified an effective SPA for Cr(VI) prevention and its application during the post-tanning process does not alter the visual aspect of the leathers. Otherwise, if the post-tanning recipe does not contain well-sourced raw materials or Cr(VI) prevention tools, unsaturated fatliquoring agents or natural fats present in the skins can be a cause for Cr(VI) formation.
