scholarly journals Hydrothermal Carbonization of Spent Coffee Grounds

2021 ◽  
Vol 11 (14) ◽  
pp. 6542
Author(s):  
Hyeok-Jin Kim ◽  
Sea-Cheon Oh
Keyword(s):  
Carbon Content ◽  
Reaction Temperature ◽  
Hydrothermal Carbonization ◽  
Reaction Products ◽  
Spent Coffee Grounds ◽  
Fixed Carbon ◽  
Heating Value ◽  
Coffee Grounds ◽  
Fuel Characteristics ◽  
Fixed Carbon Content

With increasing coffee production and consumption, the amount of coffee by-product is also increasing. Therefore, there is growing worldwide interest in using these by-products as a renewable energy source. In this study, hydrothermal carbonization was conducted with subcritical water to improve the fuel characteristics of spent coffee grounds. The water content was varied, with the mass ratio between the dry sample and water set to 1:1.5 and 1:4. The reaction temperature was increased by 10 °C from 180 to 250 °C. The fuel and thermal characteristics of the reaction products were investigated through mass and energy yields, elemental, proximate, and heating value analysis. In analysis results, as the reaction temperature increased, carbon and fixed carbon content increased, and oxygen and volatile matter content decreased, resulting in an increase in calorific value. Thermogravimetric analysis, derivative thermogravimetry, and Fourier transform infrared spectroscopy were also conducted on the reaction products. To investigate their storage characteristics, chemical oxygen demand analysis was conducted. The results showed that with increasing reaction temperature, the fixed carbon content and heating value increased; also, the fuel characteristics became similar to those of coal. In addition, the reaction products became more hydrophobic as the reaction temperature increased.

scholarly journals Alternative Fuels from Forestry Biomass Residue: Torrefaction Process of Horse Chestnuts, Oak Acorns, and Spruce Cones

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2468 ◽  
Author(s):  
Arkadiusz Dyjakon ◽  
Tomasz Noszczyk
Keyword(s):  
Carbon Content ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Energy System ◽  
Hard Coal ◽  
Energy Yield ◽  
Fixed Carbon ◽  
Heating Value ◽  
Wide Range ◽  
Fixed Carbon Content

The global energy system needs new, environmentally friendly, alternative fuels. Biomass is a good source of energy with global potential. Forestry biomass (especially wood, bark, or trees fruit) can be used in the energy process. However, the direct use of raw biomass in the combustion process (heating or electricity generation) is not recommended due to its unstable and low energetic properties. Raw biomass is characterized by high moisture content, low heating value, and hydrophilic propensities. The initial thermal processing and valorization of biomass improves its properties. One of these processes is torrefaction. In this study, forestry biomass residues such as horse chestnuts, oak acorns, and spruce cones were investigated. The torrefaction process was carried out in temperatures ranging from 200 °C to 320 °C in a non-oxidative atmosphere. The raw and torrefied materials were subjected to a wide range of tests including proximate analysis, fixed carbon content, hydrophobicity, density, and energy yield. The analyses indicated that the torrefaction process improves the fuel properties of horse chestnuts, oak acorns, and spruce cones. The properties of torrefied biomass at 320 °C were very similar to hard coal. In the case of horse chestnuts, an increase in fixed carbon content from 18.1% to 44.7%, and a decrease in volatiles from 82.9% to 59.8% were determined. Additionally, torrefied materials were characterized by their hydrophobic properties. In terms of energy yield, the highest value was achieved for oak acorns torrefied at 280 °C and amounted to 1.25. Moreover, higher heating value for the investigated forestry fruit residues ranged from 24.5 MJ·kg−1 to almost 27.0 MJ·kg−1 (at a torrefaction temperature of 320 °C).

scholarly journals Determination of Relationship between Higher Heating Value and Atomic Ratio of Hydrogen to Carbon in Spent Coffee Grounds by Hydrothermal Carbonization

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6551
Author(s):  
Jung Eun Park ◽  
Gi Bbum Lee ◽  
Cheol Jin Jeong ◽  
Ho Kim ◽  
Choong Gon Kim
Keyword(s):  
Preliminary Investigation ◽  
Hydrothermal Carbonization ◽  
Atomic Ratio ◽  
Proximate Analysis ◽  
Spent Coffee Grounds ◽  
Capillary Suction ◽  
Heating Value ◽  
Coffee Grounds ◽  
Optimum Reaction

This study was a preliminary investigation of solid recovered fuel production from spent coffee grounds using the hydrothermal carbonization (HTC) technique. The spent coffee grounds (SCGs) were subjected to HTC at 170 to 250 °C. The biochar was characterized by proximate analysis, ultimate analysis, capillary suction time, time to filter, suspended solids, and particle size distribution. The biochar yields decreased with increasing HTC temperature and time. However, the higher heating value (HHV) of biochar increased with the HTC temperature and time. The H/C slop relative to the O/C atomic rate of spent coffee grounds was 0.10 with low decarboxylation selectivity. Considering the HHV of biochar and dehydration capacity depend on ratio of H/C vs. O/C, the optimum reaction temperature of HTC was 200 °C, and the biochar from SCGs is an attractive biochar.

scholarly journals Performance Optimisation of Fuel Pellets Comprising Pepper Stem and Coffee Grounds through Mixing Ratios and Torrefaction

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4667
Author(s):  
Sunyong Park ◽  
Hui-Rim Jeong ◽  
Yun-A Shin ◽  
Seok-Jun Kim ◽  
Young-Min Ju ◽  
...  
Keyword(s):  
Calorific Value ◽  
Basic Information ◽  
Spent Coffee Grounds ◽  
Mixing Ratios ◽  
Moisture Contents ◽  
Fuel Pellets ◽  
Coffee Grounds ◽  
Coffee Ground ◽  
Fuel Characteristics ◽  
By Products

Agricultural by-products have several disadvantages as fuel, such as low calorific values and high ash contents. To address these disadvantages, this study examined the mixing of agricultural by-products and spent coffee grounds, for use as a solid fuel, and the improvement of fuel characteristics through torrefaction. Pepper stems and spent coffee grounds were first dried to moisture contents of <15% and then combined, with mixing ratios varying from 9:1 to 6:4. Fuel pellets were produced from these mixtures using a commercial pelletiser, evaluated against various standards, and classified as grade A, B, or Bio-SRF. The optimal ratio of pepper stems to spent coffee grounds was determined to be 8:2. The pellets were torrefied to improve their fuel characteristics. Different torrefaction temperatures improved the mass yields of the pellets to between 50.87% and 88.27%. The calorific value increased from 19.9% to 26.8% at 290 °C. The optimal torrefaction temperature for coffee ground pellets was 230 °C, while for other pellets, it was 250 °C. This study provides basic information on the potential enhancement of agricultural by-products for fuel applications.

Research on Purification Technology of Ultra-Large Flake Graphite Based on Alkali-Acid Method

2021 ◽  
Vol 1036 ◽  
pp. 104-113
Author(s):  
Hong Fei Guo ◽  
Bao Chao ◽  
Zeng Qi Zhao ◽  
Ding Nan
Keyword(s):  
Carbon Content ◽  
High Purity ◽  
Raw Materials ◽  
Acid Leaching ◽  
Flake Graphite ◽  
Fixed Carbon ◽  
Fusion Temperature ◽  
Acid Method ◽  
Fixed Carbon Content ◽  
Flake Structure

Graphite is a strategically scarce resource, and the preparation of high-purity graphite is the prerequisite and basis for the application of graphite. In order to determine the optimal purification technology parameters of an ultra-large flake graphite mine pneumatic separation ore with a fixed carbon content of 77.69%, a particle size of mainly 10 to 40 mesh, and main impurities of calcium carbonate, iron oxide and silica , two additional experiments of acid method and alkali method were added on the basis of alkali-acid method, to investigate the purification effect of different technological processes and acid leaching times on graphite raw materials, as well as to analyze the retention extent of different methods and alkali fusion temperature on graphite ultra-large flake structure. The results show that all three methods can increase the fixed carbon content of graphite to above 99%. However, compared with the acid method and the alkali method, the alkali-acid method can obtain high-purity graphite while also better protecting the graphite's ultra-large flake structure. The optimal fusion temperature is 400 °C, the optimal acid leaching time is 30% sulfuric acid thrice and 5% hydrofluoric acid once. After purification, the fixed carbon content of the product exceeds 99.97%.

scholarly journals ENERGY PROPERTIES OF WOOD PARTICLES TORREFIED AT DIFFERENT TEMPERATURES

2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Carlos Miguel Simões da Silva ◽  
Benedito Rocha Vital ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Aylson Costa Oliveira ◽  
Solange Oliveira Araújo ◽  
...  
Keyword(s):  
Untreated Wood ◽  
Control Group ◽  
Fixed Carbon ◽  
Final Temperature ◽  
Heating Value ◽  
Physical Chemical ◽  
Wood Particles ◽  
Different Temperatures ◽  
Fixed Carbon Content ◽  
Positive Effect

ABSTRACT The objective of this study was to evaluate the effect of the final torrefaction temperature on the energy properties of wood. It was applied four treatments with three replicates, consisting of untreated wood particles and particles torrefied at temperatures of 170, 220 and 260ºC. Better physical, chemical and thermal properties of the particles were observed as a function of the torrefaction temperature. Comparing with the control group, the particles torrefied at the highest final temperature (260ºC) showed significant differences in bulk density - from 239 to 396kg/m3; the equilibrium moisture content changed from 12.3 to 5.7%; fixed carbon content - from 13.0 to 24.8%; heating value - from 4,465 to 4,945kcal/kg; and energy density - from 882 to 1,727Mcal/m3. It was concluded that torrefaction had a positive effect on the energy properties of the wood.

scholarly journals Characterization of hydrochars produced by hydrothermal carbonization of rice husk

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 477-483 ◽  
Author(s):  
D. Kalderis ◽  
M. S. Kotti ◽  
A. Méndez ◽  
G. Gascó
Keyword(s):  
Surface Area ◽  
Hydrothermal Carbonization ◽  
Aqueous Environment ◽  
Residence Times ◽  
Fixed Carbon ◽  
Heating Value ◽  
Carbon Recovery ◽  
Set Up ◽  
Technical Terms

Abstract. Biochar is the carbon-rich product obtained when biomass, such as wood, manure or leaves, is heated in a closed container with little or no available air. In more technical terms, biochar is produced by so-called thermal decomposition of organic material under limited supply of oxygen (O2), and at relatively low temperatures (< 700 °C). Hydrochar differentiates from biochar because it is produced in an aqueous environment, at lower temperatures and longer retention times. This work describes the production of hydrochar from rice husks using a simple, safe and environmentally friendly experimental set-up, previously used for degradation of various wastewaters. Hydrochars were obtained at 200 °C and 300 °C and at residence times ranging from 2 to 16 h. All samples were then characterized in terms of yield, surface area, pH, conductivity and elemental analysis, and two of them were selected for further testing with respect to heating values and heavy metal content. The surface area was low for all hydrochars, indicating that porous structure was not developed during treatment. The hydrochar obtained at 300 °C and 6 h residence times showed a predicted higher heating value of 17.8 MJ kg−1, a fixed carbon content of 46.5% and a fixed carbon recovery of 113%, indicating a promising behaviour as a fuel.

scholarly journals Energetic potential of bamboo culms for industrial and domestic use in Southern Brazil

2016 ◽  
Vol 46 (11) ◽  
pp. 1963-1968 ◽  
Author(s):  
Ailton Leonel Balduino Junior ◽  
Thalles Yurgen Balduino ◽  
Gustavo Friederichs ◽  
Alexsandro Bayestorff da Cunha ◽  
Martha Andreia Brand
Keyword(s):  
Chemical Composition ◽  
Carbon Content ◽  
Calorific Value ◽  
Energy Generation ◽  
Extractive Content ◽  
Fixed Carbon ◽  
Gross Calorific Value ◽  
Bambusa Vulgaris ◽  
Domestic Use ◽  
Fixed Carbon Content

ABSTRACT: This study aimed to determine the energetic quality of the Bambusa vulgaris culms for combustion (in natura) and as a charcoal. Five individuals (culms) of Bambusa vulgaris of 3 years of age were analyzed, gathered in the city of Florianópolis, Santa Catarina. In the in natura culms it was determined the moisture content freshly gathered (39%); basic density (0.624gcm-3); the chemical composition (total extractive content (16.26%) and lignin content (25.76%)); the proximate chemical composition (volatiles content (82.25%); fixed carbon content (15.26%) and ash (2.49%)) and gross calorific value (4571kcalkg-1). In the charcoal, produced in the laboratory, the determined properties were the gravimetric yield (36.40%);the apparent density (0.372gcm-3); volatiles content (27.55%); fixed carbon content (67.32%); ash (5.12%) and gross calorific value (7431kcalkg-1). The Bambusa vulgaris species has potential for use in the energy generation either in natura, as chips for burning in boilers or in the charcoal form for domestic use, it can be used to broaden the base of biomass for energy generation and to replace the timber species of Pinus and Eucalyptus gender used for this purpose in the Southern region of Brazil.

scholarly journals Pemanfaatan Limbah Kulit Kakao Menjadi Briket Arang sebagai Bahan Bakar Alternatif dengan Penambahan Ampas Buah Merah

2019 ◽  
Vol 13 (1) ◽  
pp. 57
Author(s):  
Syarifhidayahtullah Syarif ◽  
Rochim Bakti Cahyono ◽  
Muslikhin Hidayat
Keyword(s):  
Moisture Content ◽  
Carbon Content ◽  
Calorific Value ◽  
Ash Content ◽  
Fruit Pulp ◽  
Volatile Content ◽  
Fixed Carbon ◽  
Shell Waste ◽  
Cocoa Shell ◽  
Fixed Carbon Content

A B S T R A C TThe conversion of cocoa shell waste into char briquettes has been carried out through various methods. However, the product characteristics do not meet the SNI briquettes requirements. Therefore, it is necessary to improve process engineering by mixing cocoa peel waste with red fruit pulp to get char briquettes in order to improve quality of briquette products. This research was carried out through pyrolysis process with temperthwatures up to 500 oC and held for 4 hours. The research objective was to produce char briquettes from cacao pod shell waste with the addition of red fruit pulp and its characteristic test. The study was designed with 2 variables, namely independent variables in the form of char raw material powder that passed 50 mesh sieve, weight ratio of cocoa shell char powder and red fruit pulp char powder (100:0, 70:30, 50:50, 30:70, and 0%:100%), pressure (100 kg/cm2), 10% starch adhesive from raw materials, and briquette diameter of 40 mm. Whereas the dependent variables are the moisture content (%), volatile content (%), ash content (%), fixed carbon content (%), and calorific value (cal/g). The results showed that the process of pyrolysis of char briquettes waste cocoa shell with red fruit pulp can increase its calorific value. The best characteristics of briquette were obtained from mixed briquettes (composition of 30%:70%) with moisture content of 5.63%, volatile content of 18.65%, ash content of 9.45%, fixed carbon content of 66.27%, and calorific value of 6422 cal/g.A B S T R A KPemanfaatan limbah kulit buah kakao menjadi briket arang telah banyak dilakukan melalui berbagai metode tetapi belum memenuhi persyaratan SNI briket arang. Oleh karena itu, perlu diupayakan untuk mendapatkan briket arang yang memenuhi persyaratan SNI. Salah satunya dengan cara mencampurkan limbah kulit kakao dengan ampas buah merah karena ampas buah merah memiliki nilai kalor yang cukup tinggi. Penelitian ini dilakukan melalui proses pirolisis dengan suhu sampai dengan 500 oC  dan ditahan selama 4 jam. Tujuan penelitian untuk memproduksi briket arang dari limbah kulit buah kakao dengan penambahan ampas buah merah serta uji karakteristiknya. Penelitian dirancang dengan 2 variabel, yaitu variabel bebas (independent variable) berupa ukuran serbuk bahan baku arang yang lolos saringan  50 mesh, rasio massa campuran serbuk arang kulit kakao dengan serbuk arang ampas buah merah (100:0, 70:30, 50:50, 30:70, dan 0%:100%), tekanan pengempaan (100 kg/cm2), perekat kanji 10% dari bahan baku, dan diameter briket 40 mm. Variabel terikat (dependent variable) yang diukur yaitu kadar air (%), kadar zat mudah menguap (%), kadar abu (%), kadar karbon terikat (%), dan nilai kalor (kal/g). Hasil penelitian menunjukkan bahwa, dengan melalui proses pirolisis briket arang limbah kulit kakao dengan ampas buah merah dapat meningkatkan nilai kalor-nya. Karakteristik briket terbaik diperoleh dari briket komposisi campuran (30%:70%) dengan kadar air 5,63 %, kadar zat mudah menguap 18,65 %, kadar abu 9,45 %, kadar karbon terikat 66,27 %, dan nilai kalor 6422 kal/g.

scholarly journals THE EFFECT OF BINDER RATIO ON THE PHYSICAL AND COMBUSTION CHARACTERISTICS OF CARBONIZED RICE STALK BRIQUETTES

2020 ◽  
pp. 221-229
Author(s):  
Rapheal Ige ◽  
Elinge Ogala ◽  
Cosmos Moki ◽  
Abdulrahman Habeeb
Keyword(s):  
Moisture Content ◽  
Carbon Content ◽  
Calorific Value ◽  
Volatile Matter ◽  
Ash Content ◽  
Hot Water ◽  
High Concentration ◽  
Fixed Carbon ◽  
Binder Ratio ◽  
Fixed Carbon Content

The selection or choice of agro-waste briquettes for domestic and industrial cottage applications depends on the fuel properties. In this study, the briquette was produced by carbonizing the rice stalk followed by crushing and sieving, the binder was prepared by dissolving the starch in hot water, then mixed with the sieved carbonized rice stalk and then the briquette was produced using the briquetting machine. Proximate analyses, viability, characteristics and combustion were determined to know the average composition of their constituents. From the results obtained it was observed that ash content, moisture content, after glow and ignition propagation decrease as the binder ratio increase while fixed carbon content, volatile matter, calorific value, density and compressive strength increase. The results of this work indicate that briquettes produced using high concentration of the binder would make good biomass fuels. However, it has a high moisture content of 25.00%, high ash content of 23.00%, moderate volatile matter of 44.80%, low fixed carbon content of 32.20%, moderate calorific value of 13.86 MJ/Kg and high density of 0.643g/cm3. The results obtained for all the parameters showed that rice stalks briquettes produced with high concentration of the binder (starch) had a better performance based on their combustion profile.

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