Performance and Emissions Control of Commercial-Scale Biochar Production Unit

2018 ◽  
Vol 34 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Mark A. Severy ◽  
David J. Carter ◽  
Kyle D. Palmer ◽  
Anthony J. Eggink ◽  
Charles E. Chamberlin ◽  
...  

Abstract.Two commercial biochar production machines – a single-auger unit and a larger dual-auger version – were operated to evaluate feedstock specifications, biochar quality, throughput rates, and emissions profiles. Biochar was produced from woody biomass feedstocks of various species, contamination levels, comminution methods, and moisture contents. Feedstocks with ash content exceeding 15% dry basis or moisture content exceeding 25% wet basis were observed to decrease fixed carbon content of biochar and to increase the labor effort required to operate the machine. The dual-auger version of the machine was able to process 380 kg h-1 of biomass feedstock (dry basis) to produce 63 kg h-1 of biochar with a mean electricity demand of 4.5 kW. Average CO, propane, NOx, and SO2 emission rates from the flare of this machine were measured to be 160, 120, 51, and 43 g h-1, respectively, with total particulate matter (PM), PM10, and PM2.5 emission rates of 380, 40, and 4.5 g h-1, respectively. Results from these experiments indicate that high-quality biochar can be produced from a variety of feedstocks, including forest residuals, as long as the ash and moisture content are within the specifications. Future research and development should focus on increasing the throughput of the machine, implementing an automated control system to reduce the operational effort, and improving safety and product consistency. Keywords: Biochar, Biomass, Biomass conversion technology, Carbon sequestration, Forest residuals, Gasification, Pyrolysis.

Holzforschung ◽  
2004 ◽  
Vol 58 (3) ◽  
pp. 274-279 ◽  
Author(s):  
J. Cao ◽  
D.P. Kamdem

Abstract The fractal-geometry approach was used to calculate the thermodynamic properties of moisture sorption by wood from the adsorption isotherms in this study. The results were compared with those from an isosteric approach and a calorimetric approach. The adsorption isotherms of Southern yellow pine (Pinus spp.) were measured at 4, 15, 30, and 40°C to provide source data for the calculation of both fractal-geometry and isosteric approaches. The results show that the fractal dimensions of the internal surfaces of wood vary between 2.4 and 2.5. The curves of the differential heat of adsorption −∆H against moisture content from the fractal-geometry approach are similar to those from calorimetric measurements in previous research. The −∆H values from the isosteric approach increased with moisture content within a moisture content range up to 3%. And, at moisture contents higher than 3%, the −∆H values from this method are much higher than those from the fractal-geometry approach and calorimetric approach. As a result, the fractal-geometry approach is applicable to calculate the differential thermodynamic properties of moisture sorption by wood in future research.


Author(s):  
Matthew Brzowski ◽  
Dan Nathan-Roberts

This systematic review summarizes current measurements of trust in human-automation interaction. A total of 217 articles were found, and it was determined that 44 articles contained relevant information and met inclusion criteria. The results of the review showed that 75% ( n = 33) of articles used subjective measures of trust only, and 41% ( n = 18) used researcher-defined methods of measuring trust instead of peer-reviewed and validated scales. Of 10 defined industries, the highest number of articles ( n = 14) were assigned to the automotive industry, followed by aviation, military, and security ( n = 6). The automated systems studied in relevant articles were decision aids, automated control and navigation systems, and process control systems. This review showed that research of trust in human-automation interaction (1) has the tendency to use subjective measures of trust as the primary or only measure, (2) has the tendency to individually define trust and how it is measured, and (3) is heavily composed of research on automotive automation. Best practices and future research are discussed.


2020 ◽  
pp. 1-11
Author(s):  
Giulia Forlati ◽  
Paul Shepley

Sinkholes in clay soils can be considered as the collapse of a soil layer previously bridging a void. Here, flexural deformation in the clay drives the formation of tensile cracks from the lowest surface of the layer and the consequent soil collapse is from crack propagation. Considering a simplified model of the sinkhole geometry, this paper aims to describe the tensile and fracture behaviour of clay soils with different plasticity indices. Speswhite kaolin, London, and Durham clays were tested using direct tensile and bending tests. Moderate- and high-plasticity clays showed a nonlinear fracture response with increasing moisture content, while low-plasticity clays demonstrated a linear response. Bending tests confirmed the importance of the moisture content while the plasticity index confirmed the difference in ductile or fragile collapse for fracture propagation. To assess the results, elasto-plastic fracture mechanics (EPFM) theory was applied to clays with appropriate modifications. The analysis demonstrated that EPFM theory provides a good baseline for predicting tensile fracture behaviour in clay soils, which can be extended in future research.


2021 ◽  
Vol 11 (1) ◽  
pp. 111-132
Author(s):  
Muhammad Usman ◽  
Shuo Cheng ◽  
Jeffrey Scott Cross

Many tropical islands, including Aruba, Seychelles, Mauritius, and Pacific Island countries, are entirely dependent on importing fossil fuels to meet their energy demands. Due to global warming, improving energy use efficiency and developing regionally available renewable energy resources are necessary to reduce carbon emissions. This review analyzed and identified biomass feedstocks to produce liquid biofuels targeting tropical islands, particularly focusing on Hawaii as a case study. Transportation and energy generation sectors consume 25.5% and 11.6%, respectively, of Hawaii's imported fossil fuels. Various nonedible feedstocks with information on their availability, production, and average yields of oils, fiber, sugars, and lipid content for liquid biofuels production are identified to add value to the total energy mix. The available biomass conversion technologies and production costs are summarized. In addition, a section on potentially using sewage sludge to produce biodiesel is also included. Based on a comparative analysis of kamani, croton, pongamia, jatropha, energycane, Leucaena hybrid, gliricidia, and eucalyptus feedstock resources, this study proposes that Hawaii and other similar tropical regions can potentially benefit from growing and producing economical liquid biofuels locally, especially for the transportation and electricity generation sectors


2021 ◽  
Vol 5 (2) ◽  
pp. 9-16
Author(s):  
Imron Rosyadi ◽  
Ni Ketut Caturwati ◽  
Ahmad Fauzi

The increase in the population of Indonesia is proportional to the increase in the amount of waste produced. Municipal solid waste (MSW) especially organic waste, can be used as solid fuel by means of the torefaction process. Torefaction is a thermo-chemical heat treatment method for biomass conversion that takes place at a temperature of 200oC to 300oC under conditions of atmospheric pressure and in the absence of oxygen. The purpose of this study was to determine the effect of moisture content on calorific, proximate and ultimate values ​​of torefaction samples using municipal solid waste. Setting the water content in the mixed sample (30% rice + 70% wood) with variations in moisture content of 30%, 40%, and 50%; and rice and wood samples with variations in moisture content of 40% and 50%. The torefaction was carried out at a temperature of 300oC for one hour and  inert gas  N2. Torefaction products have been tested contain of the calorific value, proximate testing, and ultimate testing. The results obtained were the best calorific value in the rice sample, the moisture content of 40% was 6351.1 cal / g or equivalent to sub-bituminous coal. The proximate and ultimate results of the best heating value are rice samples with 40% moisture content, fixed carbon 62.95%, volatile matter 27.85%, moisture 7.06%, ash 2.14%, carbon 71.85%, hydrogen. 2.80%, nitrogen 3.17%, and sulfur 0.05%. The calorific value calculation method that is almost close to the test results is the Dulong method, with an average error percentage of 1.63%.


2019 ◽  
Vol 13 (1) ◽  
pp. 57
Author(s):  
Syarifhidayahtullah Syarif ◽  
Rochim Bakti Cahyono ◽  
Muslikhin Hidayat

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.


Author(s):  
Rapheal Ige ◽  
Elinge Ogala ◽  
Cosmos Moki ◽  
Abdulrahman Habeeb

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.


2018 ◽  
Vol 34 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Heesung Woo ◽  
Han-Sup Han

Abstract. The most commonly traded forms of biomass energy feedstock are chipped (wood chips) and ground (hog fuel) materials. Of these two feedstocks, particle size distribution is one of the key characteristics that affect efficient feedstock handling and biomass conversion. This paper compares productivity and effectiveness of star screener and deck screeners in separating chipped and ground material. Both machines were set up to separate feedstock into three different size categories: unders (<10 mm), accepts (10-51 mm), and overs (>51 mm). Results from the study indicated that the star screener (62.61 and 50.95 tons/h) was more productive than the deck screener (26.80 and 15.63 tons/h) when separating wood chips and hog fuel. Also, there was additional cost to apply screening systems to distribute the size of the materials; $3.53/ton and $6.05/ton for deck screen with wood chips and hog fuel and $1.61/ton and $1.98/ton for star screen with wood chips and hog fuel. For size distribution of screened materials, the 13-mm size materials had the highest portion of the accept size class, and the 25-mm size materials were primarily found in the oversize class, and pan size materials (e.g., sawdust) had the highest portion of the under size class. The feedstock materials screened using star and deck screening machines still had size variations exceeding over or under sizes in the under, accept, and over size classes. To improve the quality of screened materials, definitions of the size (under, accept, and over) should to be further refined. Keywords: Biomass feedstock, Deck screen, Hog fuel, Size distribution, Star screen, Wood chips.


2009 ◽  
Vol 60 (12) ◽  
pp. 1117 ◽  
Author(s):  
M. D. Le Lagadec

The incidence of kernel brown centres in macadamia (Macadamia integrifolia and M. tetraphylla and hybrids) has increased substantially in Australia. Although the defect amounts to only ~1% of all kernels processed in Australia, it costs the macadamia industry over AU$2 million per annum. Little formal research has been conducted, although the defect is mentioned widely in informal grower journals. Possible causal factors are reviewed in this article. Evidence suggests that kernel brown centres may be associated with exposure of enzymes in cell membranes and are also associated with incorrect nut-in-shell drying regimes. There appears to be an interaction among nut-in-shell moisture content, nut drying regime, and the incidence of brown centres. There is some indication that storage of wet nuts in poorly ventilated silos increases the potential for developing kernel brown centres. It is recommended that future research focusses on these issues.


2021 ◽  
Vol 11 (1) ◽  
pp. 111-132
Author(s):  
Muhammad Usman ◽  
Shuo Cheng ◽  
Jeffrey Scott Cross

Many tropical islands, including Aruba, Seychelles, Mauritius, and Pacific Island countries, are entirely dependent on importing fossil fuels to meet their energy demands. Due to global warming, improving energy use efficiency and developing regionally available renewable energy resources are necessary to reduce carbon emissions. This review analyzed and identified biomass feedstocks to produce liquid biofuels targeting tropical islands, particularly focusing on Hawaii as a case study. Transportation and energy generation sectors consume 25.5% and 11.6%, respectively, of Hawaii's imported fossil fuels. Various nonedible feedstocks with information on their availability, production, and average yields of oils, fiber, sugars, and lipid content for liquid biofuels production are identified to add value to the total energy mix. The available biomass conversion technologies and production costs are summarized. In addition, a section on potentially using sewage sludge to produce biodiesel is also included. Based on a comparative analysis of kamani, croton, pongamia, jatropha, energycane, Leucaena hybrid, gliricidia, and eucalyptus feedstock resources, this study proposes that Hawaii and other similar tropical regions can potentially benefit from growing and producing economical liquid biofuels locally, especially for the transportation and electricity generation sectors


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