Про заміщення вугілля в твердопаливних котельнях бюджетної сфери

Abstract

Purpose. The paper substantiates the need to replace fossil coal in solid fuel local boilers by biochar produced from various types of biomass. Methods. Selection of the best available technology for biochar manufacturing should be based on an integrated assessment including economic, environmental and social aspects. Results. It is noted that direct combustion of agricultural residues does not meet environmental safety standards and also requires significant costs for modernization of existing boiler installations. It is proposed to produce biochar from agricultural residues using modern methods of thermochemical degradation, specifically torrefaction and carbonization. End-products of biomass torrefaction — biochar pellets or briquettes — have high calorific value, low sulfur and heavy metal contents, and low NOx emissions. Conclusions. Biomass carbonization technologies that have been rapidly developing in recent years include hydrothermal carbonization (HTC) and vapor-thermal carbonization methods. In the process of HTC, biomass with up to 80% moisture content and low calorific value is converted into biochar. HTC technologies have the following advantages over other biomass processing technologies: high efficiency; biomass pre-treatment does not require drying and that can significantly reduce the cost of equipment; the possibility to use various types of biomass, including low-grade biomass, which is only suitable for disposal; easy maintenance and low operating costs; eco-friendly technology can help preserve the environment; the possibility to use mixtures of various types of biomass. These advantages make hydrothermal carbonization the best available technology.