04816naa a2200325 a 450000100080000000500110000800800410001902200140006002400360007410000200011024501310013026000090026130000100027052039120028065000130419265000110420565000190421665000130423565300130424865300130426165300170427465300140429170000190430570000290432470000220435370000220437570000230439770000170442077300530443721396922023-02-10       2021    bl uuuu     u00u1 u    #d  a2045-23227 a10.1038/s41598-021-95043-12DOI1 aSILVA, J. E. da  aColored cotton wastes valuation through thermal and catalytic reforming of pyrolysis vapors (Py-GC/MS).h[electronic resource]  c2021  a10 p.  aBrazil is a major producer of cotton, accounting for approximately 11% of world production with 64,519.67 thousand tons, behind only countries such as the United States, China and India. The cultivation of colored fber cotton has stood out in recent years due to the sustainability of the production process of the fabric that does not require dyeing, reducing water consumption, cost, and treatment steps of the generated efuents. The fabric made with naturally colored fbers, in addition to contributing to the environment, has been shown to be an alternative for people who are allergic to the dyes used in the coloring of white cotton fabrics. In addition, the elimination of the dyeing process can save up to one half of the cost of preparing textiles and also saves on disposal costs for toxic dye waste The naturally colored cotton cultivars of Brazil have been developed by EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária), vary between green, red and light brown colors and are called by Brazil of seeds (BRS) as BRS-Verde, BRS-Rubi, BRS-Topázio and BRS-Jade, and are low-cost produced consistently in semi-arid regions in northeast Brazil. Te Brazilian agricultural production of this type of cotton generates tons of underutilized waste annually, approximately 2 times greater than the production of fibers. These residues could be used for energy generation, but their main destination is direct landfll. However, this practice demands a high amount of energy and, in some cases, degrades the soil structure. The use of cultural residues from naturally colored cotton becomes interesting for the generation of distributed energy or chemical products, considering that diferent cultivars are being developed and that the parts (stalks and shell) have similar energy potentials, according to a reported study by Silva et al. Energy could be generated with agricultural waste from colored cotton (17 GJ ton-1), and a way to take advantage of this energy potential is through the pyrolysis process, especially catalytic fash pyrolysis for the production of biofuels and/or bioproducts of greater added-value. Catalytic fash pyrolysis has been successfully used to deoxygenate bio-oil and improve its energy properties, in addition to increasing the yield of aromatic compounds, such as benzene, toluene, ethylbenzene and xylene (BTEX), which are high-valued compounds obtained mainly from the oil industry. The use of zeolites ZSM-5 and HZSM-5 in the catalytic fash pyrolysis process has been consolidating, with emphasis on HZSM-5, which has shown good efciency in the production of deoxygenated hydrocarbons. The high specifc area and acidity of these catalysts are indispensable to promote the deoxygenation reactions of the pyrolysis products leading to renewable chemicals of industrial interest. Hu et al. studied the best pore size for deoxygenation of biomass pyrolysis products, showing the HZSM-5 efectivity in deoxygenating the products. Liu et al. also showed the efciency in promoting monocyclic aromatics when using HZSM-5 and modifed HZSM-5 catalysts. Barbosa et al. conformed the high deoxygenation performance of a low-cost synthesized HZSM-5 at the catalytic pyrolysis of pineapple crown leaves, with high production of BTEX compounds. Therefore, the objective of this work is to evaluate the production of renewable aromatic compounds through the fash pyrolysis of naturally colored cotton waste through thermal and catalytic cracking of pyrolysis vapors, using ZSM-5 and HZSM-5 at 300 and 500 °C, and also to evaluate the activity of these catalysts. The valorization of naturally colored cotton wastes is presented in this study as an alternative for the production of energy, biofuels and value-added bioproducts. In this study it is presented the energetic potential of the biomass, fash pyrolysis and its upgrading through two routes: thermic and catalytic reforming.  aBiofuels  aCotton  aNatural fibers  aAlgodão  aBRS Jade  aBRS Rubi  aBRS Topázio  aBRS Verde1 aCALIXTO, G. Q.1 aMEDEIROS, R. L. B. de A.1 aMELO, M. A. de F.1 aMELO, D. M. de A.1 aCARVALHO, L. P. de1 aBRAGA, R. M.  tScientific Reportsgv. 11, 16087, p. 1-10, 2021.