| High Density Solid Biofuel (HDSBF) technologies for circular economy Aleksander Pekarez1; Michail Akim2; Svetlana Rogovina3; Aleksander Berlin4; Eduard Akim1; 1SPBSUITD, St. Petersburg, Russian Federation; 2HSE UNIVERSITY, Moscow, Russian Federation; 33SEMENOV FEDERAL RESEARCH CENTER FOR CHEMICAL PHYSICS, RUSSIAN ACADEMY OF SCIENCES,, Moscow, Russia, Russian Federation; 4SEMENOV FEDERAL RESEARCH CENTER FOR CHEMICAL PHYSICS, RUSSIAN ACADEMY OF SCIENCES,, Moscow, Russian Federation; PAPER: 310/AdvancedMaterials/Regular (Oral) SCHEDULED: 15:15/Wed. 30 Nov. 2022/Saitong ABSTRACT: Eduard Akim<sup>1</sup>, Aleksandr Pekaretz<sup>1</sup>, Michael Akim<sup>2</sup>, Svetlana Rogovina<sup>3</sup>, Alersandr Berlin<sup>3</sup> <sup>1</sup>St. Petersburg State University of Industrial Technologies and Design, St. Petersburg, 191186 Russia <sup>2</sup>HSE University, Moscow, 119049, Russia <sup>3</sup>Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119991 Russia Key words: solid biofuels, relaxation state, torrefied briquettes Forests are the main natural sink of greenhouse gases in terrestrial ecosystems in the world while providing the main reproducible resource – wood, which is increasingly used for the production of fuels, according to the international classification, with a zero carbon footprint. In 2020 the global production of solid biofuels (SBF) of the second generation – pellets and briquettes exceeded 50 million tons. Russia exported 2.3 million tons of pellets and briquettes in 2020, while a number of Russian Forestry Companies are implementing ESG programs. The development and widespread use of biofuels is one of the main sustainability trends, particularly in energy sector, but not without criticisms, therefore an effectiveness of biofuel production, logistics and usage is crucial. For instance, excessive cultivation of plants used for biofuel production could exacerbate climate change and destroy the sensitive ecosystems, might contribute to world hunger because land is being used to grow trees, oil palms, soybeans, and sugarcane rather than food. In the context of shrinking global resources with a growing population of the planet, improving the efficiency of wood use, in particular, in the production of SBF of the second generation, is critical. We have developed and implemented a new technology of producing of HDSBF - cellulose composites for energy purposes - wood briquettes with a density of up to 1300-1320 kg/m3. The technology is based on a directed change of relaxation state of polymeric components of wood at the principal stages of HDSBF production [1-3]. The transition to energy-saving technology is carried out at the expense of the brittle destruction of sawdust dried in aerodynamic conditions to practically zero moisture content, and their dispersion - transformation into a powder material. The extrudability of the powder is ensured by subsequent steam humidification. An anomaly of the apparent viscosity of the wood system in the extruder due to the joint action of water vapor, gaseous pyrolysis products, as well as temperature and shear stresses was found. As a result of extrusion wood briquettes with a density up to 1300-1320 kg/m3 are obtained. Having a high density, these briquettes during production can be subjected to torrefication and carbonization with the formation of high-calorie hydrophobic products - torrefied briquettes (TB) and carbonized briquettes (CB), suitable for both combustion and sequestration of carbon [2-5]. At the same time, pellets can be torrefied together with briquettes. TB and pellets are especially in demand for co-firing at coal-fired power plants. Five technological lines have been launched in Russia based on this technology [2-4]. A similar bio-fuel production facility has been established in Riga (Latvia), where a machine-building production according to the EU standard has also been created. The specific features of this technology and arising changes in the polymer structure allows one to use it not only for processing of sawdust, but also for utilization of plastic waste and hydrolytic lignin from dumps. In the latter case HDSBFs with properties corresponding to TB are directly obtained. References: REFERENCES: 1. Akim E.L., Rogovina S.Z., Berlin A.A. Fatigue Strength of Wood and the Relaxation State of Its Polymer Components // Doklady Physical Chemistry. 2020. V. 491. № 2. P. 33-35. 2. Akim E.L., Mandre Yu. G., Pekaretz A.A. Changes in the relaxation state of the polymer components of wood during its high-temperature biorefining // Fibre Chemistry. 2019. V. 51. P. 164-169. 3. Akim E.L., Pekaretz A.A., Rogovina S.Z., Berlin A.A. Relaxation State of Wood and Production of Cellulose Composites for Energy Purposes: Wood Briquettes and Pellets // Polymer Sci. Ser. D. 2021. V. 14. №. 1. P. 102-105. 4. Pekaretz A. Patent RU 2596683; Patent RU 2628602; Patent RU 2653513; Patent RU 2678089. 5. Pekaretz A., Mandre Y., Vinogradov N., Akim E. Biorefining of larch sawdust producing wood and wood-charcoal briquettes: scientific and technological aspects // Proceedings 27th European Biomass Conference and Exhibition, 27-30 May 2019. Lisbon, Portugal. Р. 1887-1889. |
