Conversion of end-of-life cotton banknotes into liquid fuel using mini-pyrolysis plant. (10th September 2020) - Yousef, Samy
Abstract: End-of-life cotton banknotes (ELCBs) is lignocellulosic waste rich in cellulose and usually disposed of by combustion or incineration. In order to change these useless policies and integrate ELCBs into the circular economy strategy, this research aims to convert ELCBs into high value-added energy products that could be used to achieve self-sufficiency from energy in some sectors of the banknote industry. Pyrolysis was used to achieve this goal and the experiments were performed on the basis of the concept of Technology Readiness Levels (fundamentals and pilot level). The fundamental pyrolysis was performed in nitrogen in the different heating scope of 5–30 °C/min using Differential thermal analysis/Thermogravimetric analysis/3D-Fourier-Transform Infrared spectroscopy in order to determine thermal decomposition, chemical decomposition, and pyrolysis reaction kinetics of ELCBs. The kinetic parameters were estimated using model-free methods, including Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), and Friedman method. The pilot pyrolysis experiments were implemented in a mini pyrolysis power plant built especially for this purpose under the conditions that achieve maximum activation energy (25 °C/min) up to 500, 600, and 700 °C. The built plant had a capacity of 250 g and consisted of three integrated units: conversion pyrolysis reactor, gas collection and purification, and gas monitoring. XRD, Gas chromatography-mass spectrometry, and SEM-EDS were used to analyze and examine the feedstock and obtained energy products. The fundamental results showed that the maximum thermal decomposition of ELCBs is located in the range 383–410 °C with mass loss 70 wt% and maximum activation energy 250 kJ/mol at 25 °C/min, while the pilot results under the optimum conditions showed that the suggested strategy can be generated pyrolysis product yield; 40% of bio-oil, 44% of bio-gases, and 17.8% of char from ELCBs with conversion rate 82.2%. Graphical abstract: Image 1 Highlights: Pyrolysis was used to treat end-of-life cotton banknotes on lab and pilot scale. The kinetic parameters were estimated using model-free methods. Mini-pyrolysis plant was built to simulate the pilot scale. The yield of the obtained bio-oil was estimated by 40% at 500 °C. The developed technology successfully converted more than 82% of banknotes waste.