Research on the Production of Composite Fuel on the Basis of Fine-Grained Coal Fractions and Biomass—The Impact of Process Parameters and the Type of Binder on the Quality of Briquettes Produced

Michał Rejdak,Piotr Fudała,Karina Ignasiak,Jolanta Robak,Agata Czardybon

doi:10.3390/min10010031

Michał Rejdak, Piotr Fudała + Show 3 more

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https://doi.org/10.3390/min10010031

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Abstract

This paper presents the partial results of a study on obtaining compacted fuel from fine-grained coal fractions and biomass. The aim of the study was to determine the impact of selected parameters of the extrusion process and the applied binder (mechanical durability and density of the products). The fuels were formulated using the extrusion process. Raw materials used in the research were: Fine-grained coal (flotation concentrates), biomass (hydrolytic lignocellulose), and a wide spectrum of organic and mineral binders and their compositions. During the investigations, the variable factors were the following: Extrusion pressure, preparation of the mixtures for extrusion (mixing time and temperature of the mixture), composition of the extruded mixtures (share of fine-grained coal and biomass and type of binder). It was found that it is possible to extrude mechanically durable briquettes from mixtures containing fine-grained coal products and biomass. Under the conditions of the experiment, the most favorable mechanical durability was characterized by briquettes containing in their composition 90% of coal and 6% of biomass (in relation to the dry state). The briquettes with the most favorable physico-mechanical properties were obtained using organic binders—Starch (based on wheat and potato starch) and cellulose derivatives.

Highlights

During the heating season, especially in the winter, there is an increase in air pollution which is associated with the burning of fossil fuels in heating devices in the individual heating sector
The reason for smog formulation is primarily the combustion of low-quality fuels and the use of low-class chamber boilers with manual dosing of fuel
From year to year, there has been an increase in public awareness concerning the phenomenon described, which is mainly related to the intensity of media reports and the dissemination of reports of institutions dealing with the issues of environmental protection and preventive care

Summary

Introduction

Especially in the winter, there is an increase in air pollution which is associated with the burning of fossil fuels in heating devices in the individual heating sector (formation of smog as a result of the so-called low-stack emission). The reason for smog formulation is primarily the combustion of low-quality fuels (flotation concentrates and coal sludges) and the use of low-class chamber boilers with manual dosing of fuel. In November of the following year, the Regulation of the Minister of Energy of 27 September 2018 regulated the quality requirements for solid fuels [2], the requirements for fuels introduced to the market and used in households and combustion plants with a nominal thermal power lower than 1 MW. The quoted legal provisions in practice mean the elimination of flotation concentrates and coal sludges from the market, and from the primary market of boilers—Devices that do not meet the requirements for class 5 boilers in accordance with standard PN-EN 303-5:2012 [4] (practically: Manual feed boilers)

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