Boilers slagging when burning wood pellets

A promising trend for upgrading wastes from timber cutting, processing and treatment is their granulation. It allows to increase their specific heats of combustion by 2.5– 3.5 times and their portability characteristics by 3–4 times, to reduce transportation costs by 6– 10 times and to improve all the operations stages. The construction and commissioning of boiler facilities operating on refined biofuel made it possible to form a stable domestic market for wood pellets. However, 0.5 – 1.5 MW nominal capacity hot water boilers equipped with furnaces and profiled burners at the bottom, in cold seasons had fast accumulation of focal residues deposits in the burners and on the furnace chambers lining. The process was complicated by these deposits hardening due to their melting and sintering. These circumstances cause a decrease in the energy and environmental performance of heat-generating installations and their reliability, and also leads to the unplanned shutdowns to clean the boiler furnaces. To find out the reasons for these negative phenomena and to develop recommendations for their elimination, a set of research operations was carried out with wood pellets shipped by the manufacturer and supplied to the burners of the boilers under the analyses; with focal residues accumulated in the burners and on the lining of the furnace chambers; as well as an analysis of the heat generating facilities operation modes. The studies carried out made it possible to identify the main factors that caused these negative phenomena and to develop the recommendations for their elimination.

Combustion of wood pellets with a high amount of fines

A comprehensive study of the efficiency of the 1.5 MW Arimax Bio Energy hot water boiler operating on wood pellets with a high amount of fines has been carried out. Fuel characteristics and its compliance with the quality requirements of Russian and European standards have been investigated. The components of the heat balance and emission of harmful substances have been determined. Thermovision study of the boiler was carried out. The comprehensive study showed that the boiler provides sufficiently high technical and economic performance and minimal emissions of nitrogen oxides and carbon monoxide. However, the high amount of fines in the pellets significantly increases the emissions of particulate matter and especially black carbon into the environment.

Design and Feasibility Study of Biomass-Driven Combined Heat and Power Systems for Rural Communities

Meeting energy demands at crucial times can often be jeopardized by an unreliable power supply from the grid. Local, on-site power generation, such as combined heat and power (CHP) systems, may safeguard against grid fluctuations and outages. CHP systems can provide a more reliable and resilient energy supply to buildings and communities while it can also provide energy-efficient, cost-effective, and environmentally sustainable solutions compared to centralized power systems. With a recent increased focus on biomass as an alternative fuel source, biomass-driven CHP systems have been recognized as a potential technology to bring increased efficiency of fuel utilization and environmentally sustainable solutions. Biomass as an energy source is already created through agricultural and forestry by-products and may thus be efficient and convenient to be transported to remote rural communities. This paper presents a design and feasibility analysis of biomass-driven CHP systems for rural communities. The viability of wood pellets as a suitable fuel source is explored by comparing it to a conventional grid-connected system. To measure viability, three performance parameters – operational cost (OC), primary energy consumption (PEC), and carbon dioxide emission (CDE) – are considered in the analysis. The results demonstrate that under the right conditions wood pellet-fueled CHP systems create economic and environmental advantages over traditional systems. The main factors in increasing the viability of bCHP systems are the appropriate sizing and operational strategies of the system and the purchase price of biomass with respect to the price of traditional fuels.

Portuguese Wood Pellets Market: Organization, Production and Consumption Analysis

Wood pellets are a form of energy that can be seen as an alternative to fossil fuels, thus contributing to the reduction of greenhouse gas emissions. In other words, wood pellets can be considered a solution contributing to the mitigation of climate change. The use of wood pellets has grown significantly in recent years, with different markets emerging, such as Portugal, both from production and consumption perspectives. The wood pellet industry in Portugal began its development about 15 years ago, with the companies installed in the country initially almost exclusively dedicated to the production of wood pellets for export to central and northern European markets. However, over the years, the domestic market, initially considered insignificant, began to develop; it recently reached a considerable consuming share of the national production. This study presents an analysis of the Portuguese wood pellet market using data collected on the sector, and specifically on producers and consumers. The information was gathered using surveys presented directly to consumers and producers and through interviews with other stakeholders in the sector. From the analysis of the information, it was possible to understand the market’s dynamics, its current evolution and its prospects for the upcoming years, since it can already be considered mature and consolidated.

The current state and prospects for the development of Russian Federation green energy exports

Renewable energy is obtained from sustainable sources, which in particular include solar and wind energy, geothermal and hydroelectric energy, biomass, tidal energy. The Russian Federation has a significant potential for the development of “green” energy, is among the leaders in terms of export potential in this area. The article considers the export potential of fuel wood pellets. The European sales market, problems and prospects of entering it were studied as priority areas. The purpose of this study is to assess the export potential of the Russian Federation for “green” energy products, using the example of the group of HS 4401310000 Wood pellets. Within the framework of the study, the following tasks were solved: the importance of export relations in the framework of the development of “green” energy directions was studied, the market of wood pellets of the Russian Federation was studied and the export potential of the country for this group of goods was determined. As a result of the conducted research, the authors concluded that the development of the export of wood fuel pellets is of high importance for strengthening the country’s position in the market of foreign trade in renewable energy sources.

Mobile Power Generation System Based on Biomass Gasification

Disaster-hit and/or un-electrified remote areas usually have electricity accessibility issues and an abundance of plant-derived debris and wood from destroyed wooden structures; this can be potentially addressed by employing a decentralized ultra-small biomass-fed gasification power generating system. This paper presents an assessment of the technical viability of an ultra-small gasification system that utilizes densified carbonized wood pellets/briquettes. The setup was run continuously for 100 hours. A variety of biomass was densified and carbonized by harnessing fugitive heat sources before charging into the reactor. Carbonized briquettes and furnished blends exhibited inferior gasification performance compared to the carbonized pellets. In the absence of tar blockage problems, steady-state conditions were achieved when pre-treated feedstock was used. Under steady-state conditions for carbonized pellets gasification operated at an equivalence ratio of 32%, cold gas efficiency, and carbon conversion of 49.2%, and 70.5% was achieved, respectively. Overall efficiency and maximum power output of 20.3% and 21 kW were realised, respectively. The results indicate that the proposed compact ultra-small power generation system is a technically feasible approach to remedy power shortage challenge.

Determination of Length of Individual Pellets and Pellets’ Lengths Distribution

A form and dimensions of fuel particles influence the intensity of their burning and approaches to the mathematic description of the process. Known methods do not allow correctly measuring all pellets’ lengths and describing pellets’ lengths distribution. The purpose of the study is to substantiate method for determining the individual pellet length and to specify statistical characteristics of pellets’ lengths distribution. The purpose was achieved by applying the proposed method of indirect determination of the length of each pellet by weighing it, followed by calculation of the equivalent length and modal cluster analysis of the distribution of pellets by length, based on the probability density distribution. The most noteworthy results are that the experimental calculation of the equivalent length gives results that coincide with direct measurements for pellets of the correct shape, but in contrast to direct measurements can also be used to determine the equivalent lengths of irregularly shaped pellets and their fragments. Clustering allowed grouping pellets around objectively existing local maxima in the probability density distribution, which can be identified at intervals of pellet lengths not exceeding 2 mm. The importance of the obtained results is that the indirect method of determining the length of pellets allows replacing the measurement of pellet lengths by their weighing, which eliminates subjective factors when measuring the length of irregularly shaped pellets and their fragments. Clustering characterised the granulometric composition of pellets with histograms of probability, mass fraction, and average length by clusters. Upon using proposed approaches, granulometric composition of industrially produced pellets was specified and increased probabilities were noted for 8 mm pellets in clusters of smaller lengths, compared to 6 mm pellets; while straw pellets are characterised by a higher probability in clusters with shorter lengths compared to wood pellets