scholarly journals Proof-of-Concept of High-Pressure Torrefaction for Improvement of Pelletized Biomass Fuel Properties and Process Cost Reduction

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4790
Author(s):  
Bartosz Matyjewicz ◽  
Kacper Świechowski ◽  
Jacek A. Koziel ◽  
Andrzej Białowiec

This paper provides a comprehensive description of the new approach to biomass torrefaction under high-pressure conditions. A new type of laboratory-scale high-pressure reactor was designed and built. The aim of the study was to compare the high-pressure torrefaction with conventional near atmospheric pressure torrefaction. Specifically, we investigated the torrefaction process influence on the fuel properties of wooden-pellet for two different pressure regimes up to 15 bar. All torrefaction processes were conducted at 300 °C, at 30 min of residence time. The initial analysis of the increased pressure impact on the torrefaction parameters: mass yields, energy densification ratio, energy yield, process energy consumption, the proximate analysis, high heating value, and energy needed to grind torrefied pellets was completed. The results show that high-pressure torrefaction needed up to six percent less energy, whereas energy densification in the pellet was ~12% higher compared to conventional torrefaction. The presence of pressure during torrefaction did not have an impact on the energy required for pellet grinding (p < 0.05).

2018 ◽  
Vol 37 (1) ◽  
pp. 544-557 ◽  
Author(s):  
Alejandra Saffe ◽  
Anabel Fernandez ◽  
Germán Mazza ◽  
Rosa Rodriguez

The use of energy from biomass is becoming more common worldwide. This energy source has several benefits that promote its acceptance; it is bio-renewable, non-toxic and biodegradable. To predict its behavior as a fuel during thermal treatment, its characterization is necessary. The experimental determination of ultimate analysis data requires special instrumentation, while proximate analysis data can be obtained easily by using common equipment but, the required time is high. In this work, a methodology is applied based on thermogravimetric analysis, curves deconvolution and empirical correlations for characterizing different regional agro-industrial wastes to determine the high heating value, the contents of moisture, volatiles matter, fixed carbon, ash, carbon, hydrogen, oxygen, lignin, cellulose and hemicellulose. The obtained results are similar to those using standard techniques, showing the accuracy of proposed method and its wide application range. This methodology allows to determine the main parameters required for industrial operation in only in one step, saving time.


2013 ◽  
Vol 39 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Michał Wichliński ◽  
Rafał Kobyłecki ◽  
Zbigniew Bis

Abstract This paper presents the results of the investigation associated with the determination of mercury content in Polish hard coal and lignite samples. Those coals are major fuels used for electricity generation in Poland. The results indicated that the average content of mercury in the coal samples was roughly about 100 ng/g. Apart from the determination of the mercury contents a detailed ultimate and proximate analysis of the coal samples was also carried out. The relationships between the mercury content and ash, as well as fixed carbon, volatile matter, sulfur, and high heating value of the coal samples were also established. Furthermore, the effect of coal enrichment was also investigated, and it was found that the enrichment process enabled the removal of up to 75% of the coal mercury from the samples.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2984
Author(s):  
Anna Partridge ◽  
Ekaterina Sermyagina ◽  
Esa Vakkilainen

Upgrading biomass waste streams can improve economics in wood industries by adding value to the process. This work considers use of a hydrothermal carbonization (HTC) process for the residual feedstock after lignin and hemicelluloses extraction. Batch experiments were performed at 200–240 °C temperatures and three hours residence time with an 8:1 biomass to water ratio for two feedstocks: Raw spruce and spruce after lignin extraction. The proximate analysis and heating value showed similar results for both feedstocks, indicating that the thermochemical conversion is not impacted by the removal of lignin and hemicelluloses; the pretreatment processing slightly increases the heating value of the treated feedstock, but the HTC conversion process produces a consistent upgrading trend for both the treated and untreated feedstocks. The energy yield was 9.7 percentage points higher for the treated wood on average across the range temperatures due to the higher mass yield in the treated experiments. The energy densification ratio and the mass yield were strongly correlated with reaction temperature, while the energy yield was not. Lignocellulosic composition of the solid HTC product is mainly affected by HTC treatment, the effect of lignin extraction is negligible.


2018 ◽  
Vol 6 ◽  
pp. 1-8
Author(s):  
Anu Radha Baral ◽  
Krishna Raj Shrestha

Biomass is the most utilized primary energy source in context of Nepal. Briquetting of pine needles can be an option for natural resource management. This research work was carried out to quantify the amount of pine needles during the fall season and to study the combustion properties, performance and emission of the briquette produced. The study was carried out in Hattiban Community Forest of Kathmandu district. In order to quantify the pine needle, simple random sampling was used. The average weight of needles in field was observed to be 751g m-2. Altogether, four types of briquettes and two types of pellets were produced using different binders and various briquetting technologies. Proximate analysis was carried out following the Japanese Industrial Standards (JIS 8812) and the calorific value test was done using Toshniwal Digital Bomb Calorimeter. The result from the proximate analysis showed higher (32.93%) amount of ash content of beehive briquette. Calorific value test of the fuel showed that high pressure pellets had the higher heating value (5555.1 kcal kg-1) and beehive had the lower heating value (3801.4076 kcal kg-1). The water boiling test reveals that thermal efficiency of the stove was highest (39.1%) when operated with high pressure pellet and low (24.76%) for charcoal pellets. Except high pressure pellets, other briquettes and pellets exceeded the safe limit of carbon monoxide and particulate matter emission given by National Indoor Air Quality Standard. Fuel characteristics like high thermal efficiency, high calorific value and proximate value obtained from present analysis shows pine needles can be used as appropriate and sustainable source of energy.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 858 ◽  
Author(s):  
Nepu Saha ◽  
Akbar Saba ◽  
Pretom Saha ◽  
Kyle McGaughy ◽  
Diana Franqui-Villanueva ◽  
...  

Each year the pulp and paper industries generate enormous amounts of effluent treatment sludge. The sludge is made up of various fractions including primary, secondary, deinked, fiber rejects sludge, etc. The goal of this study was to evaluate the fuel properties of the hydrochars produced from various types of paper mill sludges (PMS) at 180 °C, 220 °C, and 260 °C. The hydrochars, as well as the raw feedstocks, were characterized by means of ultimate analysis, proximate analysis, moisture, ash, lignin, sugar, and higher heating value (HHVdaf) measurements. Finally, combustion indices of selected hydrochars were evaluated and compared with bituminous coal. The results showed that HHVdaf of hydrochar produced at 260 °C varied between 11.4 MJ/kg and 31.5 MJ/kg depending on the feedstock. This implies that the fuel application of hydrochar produced from PMS depends on the quality of feedstocks rather than the hydrothermal carbonization (HTC) temperature. The combustion indices also showed that when hydrochars are co-combusted with coal, they have similar combustion indices to that of coal alone. However, based on the energy and ash contents in the produced hydrochars, Primary and Secondary Sludge (PPS2) could be a viable option for co-combustion with coal in an existing coal-fired power plant.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2484
Author(s):  
Tomasz Turzyński ◽  
Jacek Kluska ◽  
Mateusz Ochnio ◽  
Dariusz Kardaś

This paper describes characteristics of the combustion of sunflower husk (SH), sunflower husk pellets (SHP), and, for comparison, hardwood pellets (HP). The experiments were carried out using a laboratory-scale combustion reactor. A proximate analysis showed that the material may constitute an alternative fuel, with a relatively high heating value (HHV) of 18 MJ/kg. For SHP, both the maximum combustion temperatures (TMAX = 1110 °C) and the kinetic parameters (temperature front velocity vt = 7.9 mm/min, combustion front velocity vc = 8 mm/min, mass loss rate vm = 14.7 g/min) of the process were very similar to those obtained for good-quality hardwood pellets (TMAX = 1090 °C, vt = 5.4 mm/min, vc = 5.2 mm/min, vm = 13.2 g/min) and generally very different form SH (TMAX = 840 °C, vt = 20.7 mm/min, vc = 19 mm/min, vm = 13.1 g/min). The analysis of ash from SH and SHP combustion showed that it has good physicochemical properties (ash melting point temperatures >1500 °C) and is safe for the environment. Furthermore, the research showed that the pelletization of SH transformed a difficult fuel into a high-quality substitute for hardwood pellets, giving a similar fuel consumption density (Fout = 0.083 kg/s·m2 for SHP and 0.077 kg/s·m2 for HP) and power output density (Pρ = MW/m2 for SHP and 1.5 MW/m2 for HP).


2020 ◽  
Vol 187 ◽  
pp. 03009
Author(s):  
Natthanant Bangkha ◽  
Wanphut Saechua ◽  
Tharathip Nuamyakul ◽  
Jiraporn Sripinyowanich Jongyingcharoen

The aim of this research was to investigate the effect of torrefaction temperature on 4 energy properties as high heating value (HHV), enhancement factor, solid yield, and energy yield of spent coffee ground (SCG). Four different torrefaction temperatures (200, 250, 300, and 350°C) were selected. Torrefaction process was conducted at the heating rate of 10°C/min. HHV and enhancement factor were the highest when SCG was torrefied at the highest temperature of 350°C. However, at this temperature, solid and energy yields were the lowest. Torrefaction temperature highly affected these four energy properties with R of higher than 0.9. Regression models representing the relationship between torrefaction temperature and HHV and energy yield were HHV = 0.0519T+15.917, R2 = 0.9483 and energy yield = -0.2743T+155.1, R2 = 0.9976. These models are helpful for prediction of the energy properties of SCG undergoing torrefaction process in the studied temperature range.


2018 ◽  
Vol 5 (10) ◽  
pp. 181126 ◽  
Author(s):  
Fangyu Fan ◽  
Zongling Yang ◽  
Han Li ◽  
Zhengjun Shi ◽  
Huan Kan

Macadamia nut shell (MNS) is a type of waste lignocellulose obtained from macadamia nut production processing. Large MNS wastes caused serious resource waste and environmental pollution. So, preparation of hydrochars from MNS via hydrothermal carbonization (HTC) is of great significance. HTC of MNS was conducted to study the effect of process parameters, including HTC temperature (180–260°C) and residence time (60–180 min) on the properties of hydrochars. Results showed that the increase in HTC temperature and residence time decreased the mass yield of hydrochars and increased the high heating value of hydrochars. Furthermore, the C content of hydrochars increased, whereas the H and O contents decreased. Mass yield of hydrochar is 46.59%, energy yield is 64.55% and the higher heating value is 26.02 MJ kg −1 at a temperature of 260°C and time of 120 min. The surface structure of hydrochars was rougher compared with that of MNS as observed via scanning electron microscopy. The chemical and combustion behaviour of MNS and hydrochars was analysed by Fourier transform infrared spectroscopy, and thermogravimetric analysis indicated that decarboxylation and dehydration reactions were the predominant pathways during the HTC process. Results showed that HTC can facilitate the transformation of MNS into solid fuel.


2020 ◽  
Vol 11 (1) ◽  
pp. 20
Author(s):  
Leonel J. R. Nunes ◽  
João C. O. Matias ◽  
Liliana M. E. F. Loureiro ◽  
Letícia C. R. Sá ◽  
Hugo F. C. Silva ◽  
...  

The use of residual forms of biomass, resulting from processes of transformation of the agri-food and/or forest industries, presents itself as an alternative with high potential for energy recovery, given the existing availability, both from the perspective of quantities, but also from the perspective of geographic distribution. In this work, samples of four by-products originating from the agri-food industry were collected, namely coconut shells, sugarcane bagasse, cashew nutshells, and palm kernel shells, which were characterized in the laboratory by determining their Thermogravimetric and Elemental analysis, subsequently calculating the High Heating Value, Low Heating Value, Hardgrove Grindability Index, Mass Yield, Energy Yield, and Energy Densification Ratio. The values obtained show the potential to optimize logistical operations related to transportation, demonstrating that energy densification operations, especially if associated with physical densification processes, enable the use of these residual forms of biomass in the replacement of fossil fuels, such as coal.


2020 ◽  
Vol 143 (2) ◽  
Author(s):  
S. Kerdsuwan ◽  
K. Laohalidanond ◽  
K. Gupta Ashwani

Abstract Landfill resource reclamation or landfill mining offers an attractive option to harvest the primary materials remaining behind in landfills or open dump sites. After reclamation, the major fractions left after removing soil-like material are paper and plastic fractions, which can be used transformed to refuse-derived fuel (RDF) as a fuel. However, the variation of constituents in RDF causes to low-quality fuel derived from the reclaimed landfill. The torrefaction process is proposed here to upgrade the fuel properties in terms of heating value, energy density ratio, and hydrophobicity. A torrefaction oven was used to torrefy RDF from reclaimed landfill at a controlled temperature of 250, 300, and 300 °C and a residence time of approximately 30 min in an inert environment using Nitrogen gas. The experiment results showed an optimum torrefaction temperature of 250 °C, which resulted in the improved heating value of RDF by up to 14.12%, an increased energy yield of 107.78%, and an energy density ratio of 1.14. These results demonstrated greater energy yield from the torrefied RDF compared with raw RDF. The hydrophobic property of torrefied RDF was also improved with the torrefaction process due to low water adsorption capability of torrefied RDF that was evaluated to be only one-half of that of raw RDF. The fuel upgrading of RDF from reclaimed landfill achieved via the torrefaction process improved the fuel properties that offers its direct use or, in conjunction with other coal fuels, for power generation.


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