Krzysztof Mudryk

Impact of Selected Properties of Raw Material on Quality Features of Granular Fertilizers Obtained from Digestates and ASH Mixtures

Abstract The paper presents the results of research, the objective of which was to determine the impact of particle size distribution and density of digestates and ash on density and tensile strength of granular fertilizer obtained from mixtures of these substrates. Particle size distribution, absolute density, envelope density and porosity of substrates were determined. Granular fertilizers were made of clean substrates and their mixtures. Envelope density of the obtained granulates was within 0.81 - 1.88 g⋅cm-3. The determined compaction degree was within 3.65 - 10.12. While, the compaction index IS of granulates made of mixtures was within 0.5 - 0.55 and was lower in comparison to IS of granulates from digestates (0.6) and ash (0.76).

Influence of Parameters of the Torrefaction Process on the Selected Parameters of Torrefied Woody Biomass

The aim of this study was to determine the effect of time and temperature of torrefaction on selected parameters of torrefied woody biomass. The research material was willow and black locust biomass. First species representing the tree of soft wood and second is representative of hardwood trees. The selected species belong to a group of trees cultivated on energy purposes in so-called short rotation. The biomass samples were dried to a humidity of 10% and then was specified the calorific value, heat of combustion, specific density, ash content and volatiles matter. Characterized samples were subjected to torrefaction process in a special research reactor. In the study was planned the torrefaction temperature range 200–300 °C and the duration of the process in the range of 1–3 h which resulted in products of biomass torrefaction about the different degree of the carbonization, which were characterized by the same parameters as before biomass torrefaction.

Analysis of Impact Of Biomass Added to RDF Oversize Fraction on Properties of Briquettes

Abstract The impact of biomass addition to the RDF oversize fraction on quality parameters obtained from this blend of briquettes produced under semi-industrial conditions was analysed. For the purposes related to the experiment four RDF mixtures with fragmented biomass of common willow Salix viminalis L., differing only with percentage participation of base elements, were prepared. The briquetting process was performed with the use of a semi-industrial briquetting machine at the determined compaction pressure of 47 MPa and a diameter of a sleeve (and a briquette at the same time) of 50 mm. Selected quality parameters of produced briquettes were determined, i.e. density, mechanical strength DU and compression strength. The best parameters were obtained for briquettes produced from the blend with a 50% share of willow (ρ=843.9 kg · m-3, DU=86.1%, Rc=0.46 MPa). The lowest parameters were in case of briquettes without biomass addition. Statistical analysis of research results indicates that biomass additions to RDF significantly affect the improvement of quality parameters of the obtained briquettes.

Agglomeration of Ash-Based Fertilizer Mixtures from Biomass Combustion and Digestate

The production of fertilizers based on high quality waste materials is a highly important problem in environmental protection, mainly due to the protection of natural mineral resources. In addition, the combination of organic and mineral raw materials makes these fertilizers innovative in the fertilizer economy. As the research material unique mixtures of mineral and organic substances mixture were used. The main components were ash from biomass combustion power plant in the Polaniec and the digestate from a biogas plant located in Piekoszow. Sulfur and phosphorite were used as components to enhance the fertilizer value of the tested prototype blends (variant A). There were also blends supplemented with urea (variant B) to add nitrogen to composition. During the tests the energy consumption of the granulation process was determined and the quality of the obtained granules was determined by specifying envelope density, bulk density and mechanical durability.

Innovative Production Technology of High Quality Pellets for Power Plants

The paper presents the results of studies related to the development of quality pellet production technology for the power plants. Presented results shows that the addition of sulfur and kaolinite to the biomass does not significantly affect the basic quality parameters obtained from such pellet mixtures. There is a slight increase in ash value in these pellets, but this is directly related to the fact that kaolinite is a non-combustible mineral material. It has been shown that at the expense of increased ash content in the tested pellets, kaolinite addition virtually eliminates ash slag at all tested incineration temperatures. In the case of pellets from “pure” biomass, this unfavorable phenomenon has already occurred at 1000 °C. The results clearly show that independent of the amount of added sulfur (2 and 5%), the addition of 3% kaolinite effectively prevents ash from slagging in low temperature. Granulation of biomass, supplemented with additive to prevent slagging of ashes, should be regarded as effective and innovative technology of production of granular solid biofuels, which do not cause usual risk of boiler boiler heat exchange surfaces. This technology allows the generation of safe, solid biofuels from a wide range of biomass types available on the market.

Prospects of Growing Miscanthus as Alternative Source of Biofuel

The paper presents the results of research work aimed at determining process parameters for production of quality briquettes from Miscanthus raw material. Raw material was obtained from southern Ukraine from the autumn harvest. The obtained results clearly indicate that adequate grinding, humidity reduction of less than 15% and application of agglomeration pressures above 37 MPa, results in obtaining satisfactory quality briquettes. Compliance with the developed technological assumptions should not in practice lead to technical problems that will have a significant impact on the dissemination of this activity in rural Ukraine.

Characterization of Selected Plant Species in Terms of Energetic Use

The paper presents the characteristics and analysis of the usefulness of selected biomass, obtained from different plant spices (Silphium perfoliatum L., Helianthus salicifolius A. Dietr., Sida hermaphrodita Rusby). The botanical characteristics of the species surveyed from North America was presented. It has been shown that these species meet the requirements for plants intended for so called Energy crops, as they are characterized by high yield, disease and pest resistance and low habitat requirements. The basic physical properties of biomass were determined, like moisture content during harvesting, specific density, ash content, net calorific value. The paper also presents a comparison of the research results obtained by determining the fuel quality indicator. It has been shown that the best parameters are willowleaf sunflower biomass, and the worst is the biomass obtained from cup plant.

Spread Mustard and Prospects for Biofuels

The paper presents research aimed to determine the potential of waste biomass from the processing of mustard. Raw material for research came from the central part of Ukraine. Studies have shown that mustard residues are a valuable raw material for the production of solid biofuels in the form of briquettes or pellets. Values of quality parameters (such as calorific value, durability, density) are comparable to those found in commercial solid biofuels. Analysis of ash content showed an increased content of mineral fractions, which were the source of plant surface impurities applied by atmospheric agents (rain, wind).

Conceptual Design of the RDF Granulation Line

The paper presents a concept of a technological line for the production of granulated fuel from RDF. The main assumption of the line is the complexity of processing a raw RDF with very variable input parameters (morphological and granulometric composition, proportion and type of impurities as well as variable moisture content) to a pellet with high quality parameters (specific density, mechanical durability). Based on an analysis of the raw material characteristics and preliminary research on the RDF granulation process, design guidelines and assumptions were proposed. This allowed to develop a block diagram including all technological operations which must be used to process raw material. For each operation a technical solution was proposed which best fulfills the stated assumptions. A vacuum transport system of raw material has been proposed to reduce the amount of fly dust generated during the production process. This system is equipped with a central filter from which the dust is driven for re-granulation. Such system, reduces production of waste byproducts. As the pelletizing unit, a developed by the authors pelletizer with modified dye was proposed. Thanks to this solution, the granulation process will proceed in the temperature about 100 °C. Beside recommended moisture content and fineness of the raw material, high temperature helps ensure the predetermined quality of pellets.

Influence of Plant Biomass Added to Sewage Sludge on the Product Energy Potential

The authors of this study aimed at evaluating the influence of plant biomass added to sewage sludge on the product energy potential. In order to improve its physical properties, sewage sludge was mixed with wheat straw, sawdust, and bark of conifers. Materials with a natural water content were mixed at 1:1 weight ratio on a dry matter basis. The scheme of the experiment was as follows: sewage sludge without any additions (SS), sewage sludge + wheat straw (SS + WS), sewage sludge + sawdust (SS + S), sewage sludge + bark (SS + B). The moisture of materials, the contents of volatile matter, combined carbon, heat of combustion and calorific value were determined in the study. The addition of plant biomass to sewage sludge reduced the moisture content and increased the volatile matter content compared to sewage sludge without such addition, in which case the variation was relatively low. For the studied mixtures, larger variations were observed in relation to the ash and combined carbon contents. The highest contents of ash and combined carbon were found in the mixture of sewage sludge and bark. The highest value of heat of combustion was determined in the mixture of sewage sludge and sawdust (14,000 J g−1). Calorific values of the mixture of sewage sludge and wheat straw and sewage sludge and bark were 13,640 J g−1 and 11,540 J g−1, respectively, and were higher by more than 40% on the average compared to the calorific value of sewage sludge without any additions.