The Evaluation of Torrefaction Efficiency for Lignocellulosic Materials Combined with Mixed Solid Wastes

Abstract

The paper presents the results of research aimed at evaluating the possibility of using selected biomass wastes to produce solid biofuels. In this work, the thermochemical properties of two lignocellulosic biomasses, namely, miscantshus (Miscanthus × Giganteus) and hops (Humulus lupulus), and non-lignocellulosic biomass, namely, municipal solid waste, and their mixtures (micanthus + municipal solid waste and hops + municipal solid waste) were studied using the torrefaction process as the main method for investigation. The effects of various torrefaction temperatures (250, 300, and 350 °C) and times (30 and 60 min) were evaluated. Proximate and ultimate analyses were performed on the torrefied samples. The following can be stated: as the torrefaction temperature and time increased, mass and energy yields decreased while the higher heating values (HHVs) and fuel ratios (FRs) increased, together with carbon contents (C). In addition, energy on return investment (EROI) was studied; the maximum EROI of 28 was achieved for MSW biochar at 250 °C for 30 min. The results of studying greenhouse gas emissions (GHGs) showed a reduction of around 88% when using torrefied biochar as a substitute for coal. In sum, this study shows that torrefaction pre-treatment can improve the physicochemical properties of raw biomasses to a level comparable with coal, and could be helpful in better understanding the conversion of those biomasses into a valuable, solid biofuel.

Enhanced Torrefied Oil-Palm Biomass as an Alternative Bio-Circular Solid Fuel: Innovative Modeling of Optimal Conditions and Ecoefficiency Analysis

“…The energy density in terms of the energy efficiency of the torrefied products increased with increasing torrefying temperature, while the mass yield decreased with increasing torrefying temperature. The results were in good agreement with the other study [47]. Thus, from an economic point of view, optimal temperatures should be taken into consideration for large-scale production to achieve not only the desired energy efficiency but also a high mass yield of the torrefied products.…”

Recent Advances in Miscanthus Macromolecule Conversion: A Brief Overview

“…A great many works worldwide have been focused on the miscanthus processing. Some applications employ all fractions of the miscanthus biomass, for example, incineration for power generation [ 36 , 37 , 38 ] or pyrolysis for the production of bio-oil [ 39 , 40 ], biochar [ 41 , 42 ], hydrochar [ 43 , 44 ] and graphene oxide [ 45 ], for biopolyol synthesis [ 27 ] and for the production of composite materials [ 46 , 47 , 48 ], concrete [ 49 ], miscanthus-based mortar [ 50 ], fiber-reinforced screed [ 51 ] and bio-based PET [ 52 ].…”

The Economic and Environmental Aspects of Miscanthus × giganteus Phytomanagement Applied to Non-Agricultural Land

“…However, gasification has become preferable, demonstrating greater efficiency, higher pollution-emission standards [20], and an advantage in generating gas to be converted into heat, electricity, biofuels, or platform chemicals [21]. Various input materials can be utilised in gasification, including the biomass of energy crops or their mixture with wood and agricultural residues [22][23][24][25].…”