Multifaceted analysis of products from the intermediate co-pyrolysis of biomass with Tetra Pak waste

Abstract

This study investigates the co-pyrolysis of two types of biomass (pine bark and wheat straw) with Tetra Pak waste (TPW). The experiments were performed using a fixed-bed reactor equipped with an innovative system, where a sample was rapidly heated to 600 °C before being rapidly cooled. The multifaceted analysis included the determination of the i) physical and chemical properties of the feedstocks and chars, ii) aqueous phase, tars, and waxes, iii) char ignition and burnout temperature, iv) chemical composition of gas, and v) distribution of carbon and hydrogen in the obtained products. The results showed that the addition of TPW to the both types of biomass significantly reduced the char mass and aqueous phase, decreased the carbon, hydrogen, and nitrogen contents of the char, and increased the wax and tar yields retained in the water cooler. Different organic compounds such as alkenes, aromatic hydrocarbons, and acids were found in tars and waxes. The chemical composition of the released gases was detected in situ (by a flue-gas analyser) and ex-situ (using gas chromatography). Changes in the concentrations of $H_{2}$, $CH_{4}$, $CO$, $CO_{2}$, and C2–C4 were observed. The addition of Tetra Pak to the two types of biomass had an evident and positive effect on the hydrogen content of the pyrolysis gas.