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This paper aims at developing the potential of cellulose-based energy generation using pyrolysis, gasification, and combustion methods with biodegradable waste media. The cellulose-based material used in this study was sawdust. The sawdust was heated using a biomass stove, which was then analyzed in terms of heat conduction and propagation as well as temperature distribution. To ensure the effectiveness of sawdust as the main material in the biomass stove, sawdust particles were pressed and compacted under various pressure conditions. This experiment was integrated with the Project-Based Learning method through the following steps: (1) determination of projects testing, (2) project design, (3) project implementation schedules, (4) project completion and progress monitoring, (5) reports and presentations of project results, and (6) project evaluation. The results provide new findings that the denser sawdust particles correlate with the greater temperature and propagation rate. This can be obtained from the measured temperature distribution. Areas close to the heat source tend to have the same heat propagation. The density of the sawdust particle is the main key point for producing better pyrolysis and gasification process, in which it correlates with long combustion energy. Integrasi This finding opens a new concept and can be used as a reference for other researchers who develop research related to renewable energy from waste, especially when using a biomass stove. This study also gives ideas for the need for developing project-based learning using the burning of sawdust using biomass stove as a tool for the teaching and learning process.

Erosion of canal and river-shore causes problems on agriculture activities and soil environment. This paper devotes to develop a floating platform to protect the shores. A concrete-reinforced floating platform was designed and fabricated in this study. Mechanical simulation was performed to ensure the design viability. The concrete-reinforced floating platform consists of three main parts: (1) steel structure, (2) foam-cement material, and (3) connecting joints. The dimension of the cement foam floating platform is 1.2 m in width, 3 m in length and 0.4 m in thickness. The cement used in this research is resistant to corrosion of sulfate and chloride from saltwater. Foam with density of 12 kg/m3 is mixed with concrete matrix so that the floating platform can float 60% or 0.16 m above the water surface. The foam cement material has the maximum compression stress of 1,951 kg ± 266.59 kg for the material density of 427.30 kg/m3 ± 19.30 kg/m3. The connecting joint part has the ultimate tensile load of 1,564 kg. The assemble floating platform has the compressive stress of 543.33 kg/m2 with the maximum vertical deformation of samples of 1 mm under the distribution load of 1,571 over the samples. Finally, from simulation with data from the material testing, the designed floating platform had a safety factor 3.46 which was higher than the design criteria of 3.

This study designed and fabricated a novel top-lit downdraft gasifier stove (TLDDGS), which was compared with a traditional top-lit updraft gasifier stove (TLUDGS) in terms of modeling and performance. The experimental and simulation results demonstrated that the novel TLDDGS exhibits a downward-flow configuration. The average fuel consumption measured in the experiments was 4.57 ± 0.933 g/min. The average flame temperature from the experiment was 608 ± 43 °C. The TLDDGS mean flame temperature remained stable throughout the experiment. The O2, H2, CO2, CO, CH4, and N2 in the diluted syngas from the experiment were 16.07, 0.33, 0.66, 2.56, 0.34, and 80.04% by volume, respectively. The total suspended particulates and CO in TLDDGS and TLUDGS were 15 and 28 mg/m3 and 335 and 69 ppm, respectively, which are within the limits specified by the local standard. Thus, the developed TLDDGS is a promising alternative for sophisticated cooking applications because of its superior performance in terms of flame stability.

This paper focuses on a two-dimensional CFD simulation of a downdraft gasifier and a pilot-scale experiment for verification using wood pellet fuel. The simulation work was carried out via the ANSYS-Fluent CFD software package with in-house coding via User Defined Function. Three gasification parameters were taken into account in the simulation and validation to achieve highly accurate results; namely, fuel consumption, temperature profile, and syngas composition. After verification of the developed model, the effects of aspect ratios on temperature and syngas composition were investigated. Results from simulation and experimental work indicated that the fuel consumption rate during the steady state gasification experiment was 1.750 ± 0.048 g/s. The average steady state temperature of the experiment was 1240.32 ± 14.20 K. In sum, the fuel consumption and temperature profile during gasification from modeling and experimentation show an error lower than 1.3%. Concentrations of CO, CO2, H2, and CH4 were 20.42 vol%, 15.09 vol%, 8.02 vol%, and 2.6 vol%, respectively, which are comparable to those of the experiment: 20.00 vol%, 15.48 vol%, 8.00 vol%, and 2.65 vol%. A high concentration of syngas is observed in the outer radial part of the reactor because of the resistive flow of the air inlet and the synthesis gas produced. The average temperatures during the steady state of the gasifier with aspect ratios (H/D) of 1.00, 1.38 (experiment), and 1.82 were 978.77 ± 11.60, 1256.46 ± 9.90, and 1368.94 ± 9.20 K, respectively. The 1.82 aspect ratio reactor has the smallest diameter, therefore the radiative heat transferred from the reactor wall affects the temperature in the reactor. Syngas compositions are comparable. Inverse relationships between the aspect ratios and the syngas LHV, (4.29–4.49 MJ/N m3), cold gas efficiency (29.66% to 31.00%), and carbon conversion (79.59% to 80.87%) are observed.

Activated carbon (AC) was produced from sugarcane bagasse using hydrothermal carbonization (HTC) and steam activation for syrup decolorization. The HTC temperature was 180–240 °C over 30–90 min of holding time and the steam activation temperature was 700–900 °C at 1 h. Results showed that dry-basis AC yield was in the range of 10.4–27.1%. The maximum Brunauer–Emmett–Teller (BET) surface area of the product was 390 m2/g. The average pore size of the AC was 2.2 to 2.5 nm with total pore volume of 0.1–0.25 cm3/g. Decolorization tests showed that the AC produced from low-temperature HTC had better decolorization performance with maximum removal rates of 63.4% and 74% in batch-type and fixed-bed, continuous-flow decolorization, respectively. International Commission for Uniform Methods of Sugar Analysis (ICUMSA) unit reduction of the produced AC was about 62%. This study shows that the AC produced can be used for low-cost preliminary syrup decolorization in sugar mills, offering circular utilization of agricultural residues.

Iron (Fe) migration mechanisms and hydrochar properties in dyeing sludge hydrothermal carbonization (HTC) are important topics in wastewater treatment. HTC treatment of sludge produces wastewater containing Fe so it is necessary to study the migration behavior of Fe during HTC treatment. This study investigated the basic properties and Fe migration behavior of hydrochar during HTC treatment supplemented with nitric acid (HNO

Hydrothermal processing is appraised as one of advanced technologies for wet solid waste handling. In this study, herb residue was subjected to hydrothermal treatment. Calorific value, yield, and also proximate analysis of obtained hydro-char were investigated. A cylindrical reactor with an internal volume of 2.5 Litres made of stainless steel and a low-tech component was used in the experiment. The reactor was equipped with a stirrer to ensure heat transfer took place through the entire parts of the solid-water mixture. Solid products were dried by a microwave oven before analysis. The results show that the final temperature, holding time, and solid-water ratio have various effects on the hydro-char yield, calorific value, and proximate analysis of the hydrothermal products. The hydro-char yield decreased with the increase in final temperature and holding time. Meanwhile, the highest hydro-char yield was obtained at the solid-water ratio of ¼. The hydro-char calorific value increased with the increase in final temperature, holding time, and solid-water ratio. The rise in final temperature, holding time, and solid-water ratio resulted in a lower moisture content and volatile matter but higher fixed carbon. Meanwhile, the ash content increased with the solid-to-water ratio.

This paper studied pyrolysis and catalytic reforming processes of ABS/PC and PCB as representatives of e-waste for possibility of energy and metal recovery. Y-Zeolite (YZ), ZSM-5, biochar (BC), electronic waste char (EWC), iron oxide loaded YZ (Fe/YZ), Fe/ZSM-5, Fe/BC and Fe/EWC were used as catalysts. Pyrolysis and catalytic reforming were performed at 500 °C. Results showed that the ABS/PC had high yield of oil (40–75%) whereas PCB showed limit amount of oil yield (lower than 8%). Catalysts increased single-ring hydrocarbon products in pyrolysis oil of both ABS/PC and PCB. Iron oxide originally in BC and EWC had the debromination effect during catalytic reforming process. Maximum debromination performance for ABS/PC and PCB feedstock was 91% (Fe/BC) and 68% (Fe/EWC), respectively. Metal compound in char was significantly high in case of PCB (16.025 wt%) and relatively low from ABS/PC (1.141 wt%). This research showed that using renewable catalyst precursors such as biochar or char from e-waste itself during pyrolysis and catalytic reforming was a promising method to recover low-bromine oil and metal. This could save cost on catalyst and increase possibility for implementation.

Despite a small proportion of mineral in coal, inherent alkali and alkaline earth metals (AAEM) catalytically affected thermal conversion of coal. The gasification of raw and leached coal char was investigated by using an operando microscopic Raman spectroscopy to explore the effect of content and chemical form of the inherent AAEM on morphology and carbon structure evolution of a single particle during in-situ char gasification. The removal of water-soluble and ion-exchangeable AAEM reduced the R0.5 of SF, NM and YN char by 53.31%, 49.09% and 35.02%, respectively. As a result, the shrinkage of leached coal char progressed slower than that of the raw coal char. Besides, both water-soluble and ion-exchangeable AAEM accelerated char gasification because of an inhibition of the orderly evolution of carbon structure. Higher gasification temperature weakened the catalytic performance of ion-exchangeable AAEM. With the consumption of carbon, carbon microcrystalline structure of the residual char tended to be ordered, which led to a decrease in active free carbon sites for gasification reaction. Kinetic analysis indicated both water-soluble and ion-exchangeable AAEM reduced the activation energy of SF, NM and YN char by 20.97, 20.82 and 9.38 kJ∙mol−1, respectively, and the effect of ion-exchangeable AAEM was more significant.

This paper presents a study on the effect of hydrothermal treatment (HTT) on municipal solid waste (MSW) and mechanical property of fuel pellet. The lab-scale HTT was conducted at the condition of 180–240 °C and 30–90 min. Results showed that the HTT could improve fuel property of MSW including heating value, dewatering and drying performance. The fuel pellet was produced at three different diameters (4, 6, and 8 mm). Tests of mechanical property and water adsorption were performed. Results showed that the fuel pellet was able to withstand the axial load of 19–54 N and the radial load of 72–130 N. The 8-mm pellet exhibited lowest Young’s modulus (18.26 MPa) indicating flexibility and ductility. Durability of the fuel pellet was high (91–94%) while the Hardgrove Grindability Index (HGI) was (57–76) higher than that of the biomass pellet (18–22) and the subbituminous coal (46–49) indicating the ease of grinding. The equilibrium moisture content of the fuel pellet was 5–6%. The small fuel pellet reached adsorption equilibrium faster than the large one. In sum, the fuel pellet produced from HTT showed good fuel property as well as mechanical property for transportation and utilization.

In this study, the activated carbon (AC) derived from oil-palm empty fruit bunches (EFB) for using in effective supercapacitor application was carried out by two main steps namely hydrothermal carbonization and activation with three different activated agents steam, carbon dioxide and potassium hydroxide for increase of the AC’s specific area. The fabricated AC had surface area of 246.9 – 809.7 m2/g which were extremely higher as compared to the non-activated carbon i.e., 1.1 m2/g. It is concluded that the chemically AC afforded the best material and showed the high specific capacitance of 101.1 F/g at the scan rate of 5 mV/s with 1 M Na2SO4 as neutral electrolyte over the three-electrode cell. The study revealed that EFB could be considered as a promising potential electrode for supercapacitor.

This research is intended to study fuel property and thermal decomposition behavior of hydrothermally treated municipal solid waste (HTT-MSW) during combustion. In the experiment, simulated MSW was used as a raw material (Raw-MSW) to produce solid biofuels at the hydrothermal reaction temperature of 180, 200, and 220 oC for 30 min by a lab-scale autoclave. The results showed that the higher reaction temperature in the experiment increased the heating value of the product. Before the HTT process, the Raw-MSW has 20 MJ/kg of heating value, after processed, the energy density was increased to 21.8, 26.4, 31.4 MJ/kg for 180 to 220 oC respectively. From thermogravimetric analysis result (TGA), mass loss profile of Raw-MSW and HTT-MSW showed two major decomposition peaks and the effect of HTT on combustion was that the decomposition profile became smoother. From kinetics study on non-isothermal thermogravimetric data, the activation energy (E) of HTT-MSW was higher than that of the Raw-MSW and the E values were around 35 to 80 kJ/mol for the Raw-MSW and HTT-MSW.

The drying behavior of cassava chips was investigated using two cutting shapes—rectangular and circular—with evaluation under different air temperatures of 60 °C, 80 °C, 100 °C and 120 °C. The results showed that the rectangular chips with a drying air temperature of 100 °C was optimal because they had a soft, white color desirable for cassava flour manufacture and required less drying time compared to the circular chips Four classical drying models—Approximation of Diffusion, Henderson and Pabis, Page, and Verma—were fitted to experimental data and evaluated by comparing the coefficient of determination, reduced chi-square and root mean square error between the experimental and predicted values. The Page model was able to satisfactorily describe the drying behavior of cassava chips. Keywords: Cassava chips, Drying performance, Drying kinetics, Mathematical modeling

To quantitatively emphasize the importance of source separation practice, the difference on the MSW composition of the two areas in Bangkok, namely the community with locally source separated of MSW and the Bangkok’s waste transfer center, was comparatively studied. The possibility of material recycling was discussed based on the observed MSW’s data. Results showed that waste generation per capita at the community was significantly lower (39%) than the official reported value due to source separation practice. The portion of plastic waste at transfer station was 60 and 90% higher than that of the community (where source separation activity has been performed) for weekday and weekend, respectively, while the paper waste of NKC was 147 and 211% higher than that of the community for weekday and weekend, respectively. Potential for plastic and paper recycling was 250 and 150 g per day per capita, respectively, and their potential on economic values were 0.33 and 0.18 baht/person/day, respectively.

The pyrolysis of waste plastic was performed based on the characterization of municipal plastic waste (MPW) from one of Bangkok city's waste transfer station. Results showed that heating value of oil product (49, 47, 43, and 42 MJ/kg, from LDPE, mixture of HDPE and LDPE, PP and HDPE, respectively) was significantly higher than that of the raw plastic waste. Yield of the oil product from the pyrolysis of LDPE was highest (60%). Energy recovery from plastic via pyrolysis was 75%, 59%, 50%, and 49% for LDPE, mixture of HDPE and LDPE, PP, and HDPE, respectively. Results from GC-MS of pyrolysis oil showed that different raw materials produced very different sets of chemical compounds, with alkanes and alkenes found in the pyrolysis oil.

This paper focuses on fiber reinforcement of concrete-foam material (CFM) for floating platform. Oil-palm empty fruit bunch fiber (EFB-F) was selected to mix with CFM. Initially, three composition ratios of CFM were produced and tested to optimize the curing time. Then, the EFB-F was mixed with the optimized CFM. Several ratios of EFB-F and optimized CFM were used to study the effect of fiber reinforcement. Mechanical properties namely, compressive strength and tensile strength from flexural test were investigated. Several designs and compositions of the floating platform were studied to optimize strength and floatability (as composite material density). The research and testing results, it can be concluded that the cement-foam-EFB-F composite material has a higher density, resulting in higher compressive strength and tensile strength. Therefore, Oil-palm empty fruit bunch fiber, a waste material from manufacturing processes, can be utilized as an ingredient to improve the mechanical properties of foam cement for floating platforms.

The NO emission characteristics from both conventional and air-staged combustions of antibiotic mycelial residue were investigated in the temperature range of 1073-1273 K. The effect of hydrothermal treatment (HTT) prior to combustion on the NO emission was clarified. In conventional combustion, the NO emission from combustion of the hydrothermally pretreated antibiotic mycelial residue (HTT-AMR) was 20-30% lower than that from combustion of the directly dried antibiotic mycelial residue (Dried-AMR). By air-staged combustion, the NO emission of HTT-AMR was reduced by about 45% at 1273 K, compared to that by conventional combustion. As a result, the NO emission was largely reduced by 57% by air-staged combustion of HTT-AMR at 1273 K in comparison with conventional combustion of Dried-AMR, showing a significant combining effect of HIT and air-staged combustion on the NO emission. Results of thermogravimetric analysis and X-ray photoelectron spectroscopy revealed that the AMR based fuels have only volatile matters which consist of light and heavy volatiles. Deconvoluting the NO emission curves demonstrated that the reduction in NO emission via HTT mainly resulted from the removal of the nitrogen in the light volatile as the form(s) of amino acid or/and ammonia, while the reduction via air-staged combustion was because air-staged combustion suppressed the formation of NO from the heavy volatile. (C) 2015 Elsevier B.V. All rights reserved.

Fluidized bed co-combustion of raw paper sludge (Raw-PS) and hydrothermally treated paper sludge (HTT-PS) with either low (Lo-Coal) or high reactivity coal (Hi-Coal) was investigated. The paper sludge was treated in a pilot-scale hydrothermal reactor at 197 °C and 1.9 MPa for 30 min. South African bituminous and Thai subbituminous coals were selected as representative of Lo-Coal and Hi-Coal, respectively. A 110-mm bubbling fluidized bed combustor was used in this study. During the steady combustion tests the nominal temperature was 858 °C, the fluidization velocity was 0.5 m/s, and the excess air was varied as 20%, 40%, and 60%. Both single fuel combustion and co-combustion were tested. Co-combustion tests were conducted by feeding the sludge at mixing ratios of 30% and 50% (mass basis) with coal. The main focus of this study was on NO x emissions and unburned carbon performance. Results showed that at 30% mixing ratio using HTT-PS instead of Raw-PS could reduce NO x emission by 3–6% and 9–17% in the case of Lo-Coal and Hi-Coal, respectively, and the loss of unburned carbon could be decreased by 15–18% and 36–53% for Lo-Coal and Hi-Coal, respectively. The particle size distribution of fly ash of all samples was similar regardless of the excess air variation. On the whole, the hydrothermally treated paper sludge showed better performance for co-combustion with coal and would be a better choice compared to the original raw paper sludge.

A combination of experimental techniques was employed to test primary fragmentation and char particle attrition by abrasion during fluidized bed (FB) combustion of raw paper sludge (Raw-PS), hydrothermally treated paper sludge (HIT-PS), and a subbituminous coal (Sub-C), for comparison. The hydrothermal treatment (HIT) was conducted by a pilot-scale reactor at 197 degrees C (1.9 MPa) for 30 min. The results showed that all three samples extensively underwent primary fragmentation. Char attrition tests under inert conditions showed that Sub-C intensely experienced particle rounding off at the beginning, but after that it became very strong against mechanical abrasive attrition, followed by HTT-PS and Raw-PS, respectively. The oxidative char attrition tests showed that Sub-C exhibited an initial low amount of carbon elutriation rate followed by an attrition enhancement effect at later stages of burn-off, whereas for the Raw-PS and HIT-PS attrition was always lower than under inert conditions due to extensive postcombustion of fines. HTT-PS always produced a lower amount of elutriated carbon than Raw-PS and this indicates better combustion performance as well as lower unburned carbon emission. Finally, the Primary Ash Particle Size Distribution (PAPSD) of the three fuels was determined, showing that the paper sludge would contribute much more than coal to the ash bed inventory in a full-scale FB combustor. (C) 2015 Elsevier B.V. All rights reserved.

Steam explosion of coconut mesocarp was performed in lab-scale and pilot-scale experiment. All products, namely, fiber, dust, and liquid phase, were utilized from a single biomass feedstock. Dry basis yield of the fiber product was around 22–51 %. Effects of steam explosion on coconut mesocarp involved partially degradation of hemicellulose and lignin as well as ash removal, particularly K and Cl. Well-oriented cell structure with dense cell wall area were observed in fiber product implied better strength compared to the original fiber. Tensile strength of the coconut fiber produced from lab-scale and pilot-scale steam explosion was in range of 16−23 MPa at 6–12 % breaking elongation and 41 MPa at 4.5 % breaking elongation, respectively. Thermal conductivity coefficient of the fiber sheet was 0.0486 ± 0.012 W/m‧K. The saturated moisture adsorption was 5.6 % after 9 h, lower than the moisture regain of other plant fibers (8.5–14 %). Biomethane potential test showed that the biogas production from liquid product were 446.0 and 457.2 L/kgCOD (methane concentration of 65 %) for FM ratios of 1:2 and 1:3, respectively. This research proposed the concept of coconut mesocarp conversion by steam explosion that the variety of products can be produced without waste generation.

Antibiotic mycelial dreg is a hazardous pollutant that is difficult to deal with because of its high contents of moisture and biomass pectin. Our previous work has demonstrated that the hydrothermal treatment (HTT) provides a feasible way to produce safe solid biofuel by reducing its moisture and nitrogen contents and decomposing its residual antibiotics. This study is devoted to further investigating the HTT through characterizing the HTT produced solid biofuels using oxygen bomb calorimeter, XPS, FTIR, XRF, TGA, DTA and so on. The results showed that the higher heating value (HHV) of the solid biofuel can reach about 26.5kI/g, which was much higher than the HHV of dried raw antibiotic mycelial dreg made by conventional drying (only 19.3 kJ/g). Moreover, the N content was lowered from 7.7 wt.% in the dried raw antibiotic mycelial dreg to 5.6 wt.% in the 200 degrees C HTT produced solid biofuel, while most alkaline metals and chlorine in ash of antibiotic mycelial dreg were leached out with centrifugation after HTT. The atomic ratios of H/C and O/C in the solid biofuels both decreased with increasing the temperature of HTT, indicating the occurrence of dehydration, decarboxylation and hydrolysis of solid matters in the dreg. The HTT also greatly improved the combustion reactivity of the solid matters in the antibiotic mycelial dreg. All of these show that HTT provides indeed an effective way to convert the antibiotic mycelial dreg into high-quality solid biofuel. (C) 2015 Elsevier B.V. All rights reserved.

Fundamental study of an updraft gasification is a key to understanding behaviors and important factors during the process. This paper presents 2-dimensional CFD simulation of updraft gasification. Updraft gasifier in an experiment has a size of 5 kg for biomass fuel per batch and diameter reactor is 160 mm. Updraft gasifier modeling is represented packed bed combustion. The hydrodynamic of packed bed performed by Euler-Granular model. Thermal conversion of solid fuel can be explained by Discrete Phase Model (DPM). The UDF code is developed for control combustion in reactor modeling for the approach to experiment data. The UDF code that is verified can use to predict temperature during startup time when the diameter of the reactor has changed. Temperature prediction of diameter reactor can help design the reactor in term of startup temperature. Three types of fuels have been tested and simulated as well. The effect of fuel can be used to reduce the startup time. In verification of the model, the UDF was used in each fuel and the result of verification was acceptable which can be compared to the temperature during starting, increase and saturation period with the experimental temperature., Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 828-837

The hydrothermal treatment has been utilized to improve solid fuel property of paper sludge. In this study, an investigation on combustion characteristics of the hydrothermally treated paper sludge was performed. The paper sludge was treated at the temperature range of 180–240°C under pressurized conditions with a holding time of 30 minutes by a lab-scale apparatus. After that, the optimized temperature (197°C at 1.9 MPa) was conducted to treat the paper sludge in a pilot plant with the same holding time. The combustion behavior of the products and the reference materials, including cellulose, hemicellulose, and lignin, were studied by the thermogravimetric analysis. The major decomposition of paper sludge was devoted to cellulose. The ignition temperature was originally low around 257–271°C. The burnout temperature was approximately 679–695°C. From the two-stage kinetics study, the activation energy of the treated paper sludge was lower than the original material in range of 113–147 kJ/mol.

This paper aims to investigate the alternative solid fuel production from paper sludge employing hydrothermal treatment (HTT) in a lab-scale facility for implementation of the pilot-scale plant. The paper sludge was subjected to the HTT under subcritical hydrothermal conditions. In the lab-scale experiment, the temperature conditions were 180 °C, 200 °C, 220 °C, and 240 °C, respectively, while it was 197 °C in the pilot plant as the optimum condition. The holding time was 30 min in both cases. The hydrothermally produced solid fuel was evaluated for the fuel property, the water removal performance, and the mass distribution. Furthermore, the energy balance of the process was studied. The higher heating value of the HT pretreated paper sludge was slightly improved. In addition, the produced solid fuel had comparable H/C and O/C atomic ratios with that of coal, indicating the presence of carbonization during the HTT process. Using the mechanical dewatering, only 4.1% of moisture in the raw paper sludge can ...

This work concerns the influence of hydrothermal (HT) pretreatment on sludge drying performance. Sludge was dried in an air duct dryer at a temperature of 30.4 ± 0.4 °C with a constant air velocity of 1.34 ± 0.04 m/s and a relative humidity of about 56%. Drying rate curves, defined as the mass flux (kg/(m2 h)) versus the dry basis moisture content (kg/kg), showed that the drying process mainly took place in the falling rate period. HT pretreatment can improve drying speed and shorten drying time. Six classical semi-theoretical drying models, including Lewis, Page, Logarithmic, Henderson and Pabis, Wang and Singh, and Approximation of Diffusion, were evaluated to represent the experimental results in terms of the coefficient of determination (R2), reduced chi-square (χ2), and root means square error (ERMS). The Approximation of Diffusion model was the best one to reproduce the experimental data with R2 close to 1, χ2 around 0.00001–0.00005, and ERMS of 0.00371–0.00686. The HT pretreatment changed the model...

This paper aims to propose a novel catalytic pyrolytic gasification technology for the in situ conversion of tar and syngas, accompanied by the silica-based nickel nanoparticles generated in situ and the highly dispersed rice husk char (RHC), namely RHC Ni. Partially oxidized nickel oxides (i.e., NiO) in the carbon matrix of biochar can be carbothermally reduced to metallic nickel (Ni0) nanoparticles by reducing gases (e.g., CO) or carbon atoms during biomass pyrolysis. Moreover, due to its strong reducibility, the addition of sodium borohydride (NaBH4) can significantly promote the generation of Ni0 by the reduction of NiO, improving the biochar's catalytic activity. An ultra-low tar yield can be achieved by pyrolysis of RH Ni and RH Ni–B at 750 °C, in terms of the high tar conversion efficiencies of 96.9% and 98.6%, respectively, compared with the pyrolysis of raw RH. It is noteworthy that the condensable tar could be catalytically reformed into the small molecules of non-condensable tar or gases, which contributes to improving the syngas fuel characteristics in the favor of power generation systems, corresponding to the lower heating value (LHV) of syngas increasing from 10.25 to 11.32 MJ m−3. In addition, the increase of the polymolecular Ni0 was most possibly caused by the disproportionation reaction and strong reducibility of NaBH4. In addition, the produced RHC Ni showed a good performance for the catalytic conversion of tar (conversion efficiency, 96.5%) through co-pyrolysis with biomass. After deactivation, the waste RHC Ni might be easily regenerated via thermal treatment or directly catalytically gasified into the applicable syngas, accompanied by the production of the silica-based nickel nanoparticles.

Antibiotic mycelial dreg (AMD) is one of typical industrial wastes with high moisture and nitrogen contents which are difficult to be dealt with. The previous works demonstrated that the hydrothermal pretreatment is feasible for removing moisture and nitrogen contents from AMD so as to upgrade this waste into solid biofuel. Nevertheless, the NO emission characteristics of its combustion are still unknown and needed to be tested. The present work was aimed to clarify this understanding in a laboratory drop tube reactor under the temperature of 1273K. The raw AMD, the hydrothermally pretreated AMD and coal were respectively supplied into the reactor for combustion. The concentration of NO in the flue gas for different samples were measured and compared to evaluate the emission performance of the fuels. Compared to raw AMD, the NO emission of mono-combustion of hydrothermally pretreated AMD was dramatically reduced, whose reduction rate was above 30%. In order to investigate the mechanism of NO reduction, some analyses using Thermo Gravimetric Analyzer (TGA), X-ray Photoelectron Spectroscopy (XPS) and others were performed to reveal the properties of the raw AMD, hydrothermally pretreated AMD and coal. It was shown that the intermediates produced from releasing volatile maters act as reductants for the reduction of NO. The hydrothermal pretreatment can control the NO emission.

This research focused on conversion of high moisture biomass, namely, empty fruit bunch (EFB), trunk of palm (TOP), and frond of palm (FOP) into bio-oil and other valuable byproducts employing non-catalytic and catalytic hydrothermal liquefaction (HTL). The temperature conditions of the HTL were 250, 275, 300 °C and the residence time were 10, 30, and 60 min. Bio-oil was characterized by Gas Chromatography with Mass Spectrometry. Mass and energy consumption of the process have been calculated. Results showed that the yield of bio-oil from the EFB, TOP, and FOP was around 11-23% and the main component was the phenolic compounds followed by ketones. Other substances such as alcohols, aldehydes, and esters were observed. When adding the KOH catalyst, it can be observed that the main component was changed to ketone. Mass balance showed that the amount of the liquid product was the highest due to the high amount of reacting water used in the experiment whereas the yield of bio-oil and bio-char were relatively low. Two-third of energy consumption belonged to the HTL process while one-third of the total energy consumption was used to evaporating the solvent., Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 980-986