Retort-heating carbonisation of almond (Terminalia catappa) leaves and LDPE waste for biochar production: evaluation of product quality

Abstract

The aim of this study was to utilise a top-lit updraft biomass conversion reactor with retort heating for the production of biochar from dry almond (Terminalia catappa) leaves and Low-Density Polyethylene (LDPE) waste (biomass-plastic mass ratio of 35:1). The feedstock was chosen to serve as a typology of each of the two major constituents of municipal solid waste (MSW). The study was done to examine the process performance and product yield and quality. A yield of 28.57 wt% for the biomass biochar and 71.43 wt% for the hybrid biochar was achieved at a peak temperature of 494°C and 362°C respectively in 90 minutes. The products were characterised using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Branueur–Emmett–Teller (BET) analyses. The biomass biochar and the hybrid biochar have a specific surface area of 450.2 m2/g and 296.8 m2/g respectively and both products was mesoporous. It is observed that retort heating carbonisation can be used to convert almond leaves and LDPE waste to biochar usable as an adsorbent. The work is of benefit in converting MSW to a useful product. These are helpful in waste minimisation, environmental protection.

Keywords

• almond
• biomass
• biochar
• ldpe
• waste