The Use of Wood Pellets in the Production of High Quality Biocarbon Materials

Abstract

Biomass is one of the most important sources of renewable energy. One of the most widely used biomass biofuels is wood pellets. It is an economical, homogeneous and easy-to-use raw material. Biomass is used to generate low-emission energy utilizing the pyrolysis process. Pyrolysis allows for higher energy efficiency with the use of commonly available substrates. This thesis presents the results of research on the possibility of using the pyrolysis process to produce high-energy biocarbons from wood pellets. Data on basic energy parameters and explosivity of biocarbon dust were compiled as criteria for the attractiveness of the solution in terms of energy utility. The research used pellets made of oak, coniferous, and mixed sawdust, which were subjected to a pyrolysis process with varying temperature and time parameters. Carbon, ash, nitrogen, hydrogen, volatile substances, heavy metals, durability and calorific value of the tested materials were carried out. The highest increase in calorific value was determined to be 63% for biocarbons obtained at 500 ℃ and a time of 15 min, compared with the control sample. The highest calorific value among all analyzed materials was obtained from coniferous pellet biocarbon at 31.49 MJ kg−1. Parameters such as maximum explosion pressure, Pmax, maximum pressure increase over time, (dp/dt)max, and explosion rates, Kst max, were also analyzed. It was noted that biomass pyrolysis, which was previously pelletized, improved the energy parameters of the fuel and did not increase the risk class of dust explosion. The lowest and highest recorded values of Kst max for the analyzed materials were 76.53 and 94.75 bar s−1, respectively. The study concluded that the process used for processing solid biofuels did not affect the increase in the danger of dust explosion. The results presented in this article form the basis for further research to obtain detailed knowledge of the safety principles of production, storage, transport and use of these new fuels.

Pyrolysis as a Method for Processing of Waste from Production of Cultivated Tobacco (Nicotiana tabacum L.)

“…The analyses showed no content of total nitrogen in the samples assessed, and the processes of pyrolysis did not produce any change in this parameter. Similar conclusions were reported by Yuan et al, who investigated materials obtained from sewage sludge [48], and by Saletnik et al, who did not find a relationship between pyrolysis and changes in this parameter in biochar produced from pellets [64]. In the case of pyrolysis conducted at 400-500 • C for a duration of 5-15 min, a significant increase in carbon contents was observed in the samples, with the highest value of 63.16% obtained as a result of pyrolysis conducted at a temperature of 500 • C for a duration of 15 min.…”

“…The best values of this parameter were also observed in the case of pyrolysis conducted at 500 • C for a duration of 15 min. Similar results were reported by Saletnik et al (2022) [64] in a study assessing such materials as wood, bark, brushwood, leaves and acorns subjected to pyrolysis to produce biochar. The authors observed that the changes in the contents of volatile substances were related to the pyrolysis method applied [48].…”

Oak Biomass in the Form of Wood, Bark, Brushwood, Leaves and Acorns in the Production Process of Multifunctional Biochar

“…Saletnik et al classified the thermally unprocessed oak, coniferous pellets and their mixture, as well as the thermally processed forms obtained from them, into the first class of dust explosion hazard (St1)—a material not susceptible to explosiveness. Scientists noticed in-crease in this parameter for the obtained biocarbons with an increase of the temperature range and the duration of the pyrolysis process [ 144 ]. The present study shows that modifications of raw biomass required for the production of fuels with better quality parameters do not in-crease the risk of explosion.…”

Biochars from wood biomass as effective methylene blue adsorbents

“…Wood waste, including the forest waste (wood, branches, bark and sawdust), accounts for a significant proportion of wood industry waste. However, the plant biomass is quite difficult to use as a fuel and requires proper treatment because this is a heterogeneous, contaminated material, often damp and with a low energy potential (Saletnik et al, 2022). Traditionally, wood biomass was used as a fuel in energy processes, however, through innovative approaches, wood waste can be turned into a valuable resource, not only reducing waste, but also producing biochar, a greatly efficient material with adsorption properties, commonly used for the environmental management applications that include soil remediation (Ding et al, 2016;Bianco et al, 2021), carbon sequestration (Lal, 2004;Woolf et al, 2010;Tenenbaum, 2013) or adsorption of heavy metals and other impurities, and many others (Kookana, 2010;Mohan et al, 2014;Liang et al, 2006;Chen and Pilla, 2022;Jedynak and Charmas, 2021;Wiśniewska et al, 2022;Szczęśniak et al, 2020;Skubiszewska-Zięba et al, 2017;Gusiatin et al, 2023).…”