Tar-free and hydrogen-rich syngas from Euro cotton banknotes using gasification-catalytic reforming process and its life cycle assessment

Recently, oxygen gasification technology has been used to convert Euro cotton banknote waste (BW) into hydrogen-rich synthetic gas (19 vol%), but the tar content is still above standard values and should be removed for future marketing. In this regard, this research was developed to study the possibility of using a catalytic reforming process to remove the tar content from syngas produced by BW gasification and enhance hydrogen (H₂) content in its composition. The life cycle assessment (LCA) of the proposed strategy and typical gasification of BW was also investigated according to ISO 14040/44 standard and ReCiPe 2016 pathway, and then compared to its incineration. The experiments were carried out using an updraft gasifier reactor (for production of syngas) connected in series with a catalytic reactor for upgrading reason. The untreated syngas of different compositions were prepared at different temperatures (700–900 °C) and equivalent air-fuel ratios (0.19–0.29), and then soot was separated from it using a ceramic filter. While the upgrading process of tar-laden syngas was carried out at 900 °C over Ni/Mg-porous clay heterostructure catalyst in a steam atmosphere. The results showed that the catalytic reforming process was very successful in removing tar (up to 99.98 %), resulting in an increase in the upgraded syngas production rate by 11–32 % with HHV = 9695 kJ/kg. In addition to its contribution to significantly enhancing H₂ content (53 vol%) and reducing CO and CH₄ content by 75.5 % and 96.6 % respectively. Meanwhile, the LCA showed a high potential in this strategy in reduce many environmental burdens compared to gasification combined with reforming process process with a significant reduction in the ranges of 73–99 % (gasification) and 68–99 % (gasification-catalytic reforming). Accordingly, gasification combined with catalytic reforming process can be considered as a promising eco-friendly technology to convert BW into tar-free and H₂-rich syngas.