scholarly journals Issues related to waste sewage sludge drying under superheated steam

2015 ◽  
Vol 17 (4) ◽  
pp. 5-14 ◽  
Author(s):  
Ihsan Hamawand ◽  
Wilton Pereira da Silva ◽  
Friederike Eberhard ◽  
Diogenes L. Antille
Keyword(s):  
Particle Size ◽  
Sewage Sludge ◽  
Moisture Content ◽  
Superheated Steam ◽  
Final Particle ◽  
Screw Feeder ◽  
Rotary Drum ◽  
Sludge Drying ◽  
Dried Sludge ◽  
Mesh Sieve

Abstract Sewage sludge was dried in a rotary drum dryer under superheated steam. Particle size and moisture content were shown to have significant influences on sticking and agglomeration of the materials. Pouring partially dried sludge (70–80% moisture content, wet basis) directly into the screw feeder of the drum dryer resulted in a significant sticking to the surface of the drum and the final particle size of the product was greater than 100 mm in diameter. The moisture content of this product was slightly less than its initial value. To overcome this issue, the sludge was mixed with lignite at variety ratios and then chopped before being introduced to the feeding screw. It was found that mixing the sludge with lignite and then sieving the chopped materials through a four millimetre mesh sieve was the key to solve this issue. This technique significantly reduced both stickiness and agglomeration of the material. Also, this enabled for a significant reduction in moisture content of the final product.

Hydrogen-Rich Gas Production from Microwave Pyrolysis of Sewage Sludge at High Temperature

2012 ◽  
Vol 610-613 ◽  
pp. 2302-2306
Author(s):  
Wen Yi Deng ◽  
Xiao Lei Wang ◽  
Wei Chao Yu ◽  
Ya Xin Su
Keyword(s):  
Particle Size ◽  
Sewage Sludge ◽  
Moisture Content ◽  
Single Mode ◽  
Gas Production ◽  
Pyrolysis Gas ◽  
Microwave Pyrolysis ◽  
Co Concentration ◽  
Gas Products ◽  
Fixed Structure

Microwave pyrolysis of sewage sludge was conducted in a single-mode microwave oven. The influencing effects of experimental factors, including particle size and moisture content of sewage sludge, pyrolysis temperature, and shape of microwave adsorber, on concentration of pyrolysis gas products were studied. The results indicated that with the decrease of particle size, the H2 concentration increased from 31 vol.% to 34 vol.%, and CO concentration increased from 17 vol.% to 22 vol.%. When the moisture content of sewage sludge increased from 0 to 83 wt.%, the H2 concentration increased from 32 vol.% to 42 vol.%, and the CO concentration increased from 20 vol.% to 31 vol.%. Compared with microwave adsorber in powder phase, the microwave adsorber in fixed structure can transform more volatile compounds to uncondensable gas, and the concentrations of H2 and CO were also slightly increased.

scholarly journals Municipal Sewage Sludge Drying Treatment by an Composite Modifier

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Na Wei
Keyword(s):  
Sewage Sludge ◽  
Moisture Content ◽  
Portland Cement ◽  
Uniform Design ◽  
Cement Clinker ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Curing Time ◽  
Material Content ◽  
Sludge Drying

A sludge composite modifier (SCM) which comprises a mixture of three cementitious components was proposed for sludge drying and stabilization. Effect of SCM components on sludge moisture content was analyzed using uniform design and the optimum composition of SCM was determined by computer-aided modeling and optimization. To compare the drying effect of SCM, quicklime, and Portland cement, the effects of material content and curing time on moisture content of sludge were also studied. The results showed that the optimum ratio of modifier component was slag/cement clinker/dihydrate gypsum = 0.64/0.292/0.068 and the moisture content of SCM-stabilized sludge decreased with the increasing material content and extending curing time. Besides, the experimental results showed that optimized SCM behaved better than quicklime and Portland cement in sludge semi-drying and XRD analysis revealed that the main hydrated product of stabilization was ettringite, which played an important role in the effective drying process. Sewage sludge stabilized using SCM could be used as an effective landfill cover.

scholarly journals Integrating sludge drying in biomass fueled CHP plants

2020 ◽  
Author(s):  
Jinshan Wang ◽  
Chaudhary Awais Salman ◽  
Bin Wang ◽  
Hailong Li ◽  
Eva Thorin
Keyword(s):  
Moisture Content ◽  
Flue Gas ◽  
Feeding Rate ◽  
Waste Heat ◽  
Thermal Conversion ◽  
Water Evaporation ◽  
Drying Process ◽  
Sludge Drying ◽  
Dried Sludge ◽  
Downstream Processes

Abstract Handling sludge through thermal conversion is environmentally friendly, which, however, requires sludge drying. This work proposed to use the waste heat of flue gas (FG) to dry sludge. The integration of sludge drying in biomass fueled combined heat and power (CHP) plants can clearly affect the performance of downstream processes in FG cleaning, such as flue gas quench (FGQ) and flue gas condenser, and further affect the energy efficiency of CHP. In order to understand the influence, a mathematical model and an Aspen PLUS model were developed to simulate the drying process and the CHP, respectively. Based on simulations, it is found that the increase of feeding rate of sludge and the moisture content of sludge after drying can decrease the water evaporation in FGQ. An increase in the feeding rate of sludge in combination with a drop of moisture content of sludge after drying can decrease the heat recovery from FG. When using dried sludge to replace biomass, the amount of saving could be influenced by the moisture content after drying and the flow rate of sludge. Simulation results show that drying sludge to a moisture content of 40% leads to the maximum biomass saving.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

EFFECT OF MOISTURE AND PARTICLE SIZE ON THE COMBUSTION CHARACTERISTICS OF SEWAGE SLUDGE IN A FIXED BED

2018 ◽  
Author(s):  
Joana Freitas Campana ◽  
Kaio Pandolfi Pessotti ◽  
Carlos Eduardo Silva Abreu ◽  
Patrick de Jesus
Keyword(s):  
Particle Size ◽  
Sewage Sludge ◽  
Fixed Bed ◽  
Combustion Characteristics ◽  
Effect Of Moisture

Estimation of Energy Saving for Melting Process on Sewage Sludge

1991 ◽  
Vol 23 (10-12) ◽  
pp. 2011-2018 ◽  
Author(s):  
T. Murakami ◽  
K. Sasabe ◽  
K. Sasaki ◽  
T. Kawashima
Keyword(s):  
Sewage Sludge ◽  
Moisture Content ◽  
Energy Saving ◽  
Fuel Consumption ◽  
Melting Process ◽  
System Operation ◽  
Operational Conditions ◽  
Volatile Solids ◽  
Cake Moisture ◽  
Very High

The possible volume reduction and stabilization of the sewage sludge associated with the melting process are expected to be greater than with the incineration process. In addition, melted slag can be utilized. However, since the melting process requires a very high temperature to melt inorganics (ash) in the sludge, the technologies to minimize energy consumption, to establish system operation and to prolong durability of facilities should be developed. This paper discusses the auxiliary fuel consumption as follows.(1)Preparation of a model that provides the auxiliary fuel consumption of the melting system on the basis of the mass and heat balances.(2)Evaluation of the auxiliary fuel consumption in the above model using the cake moisture content, the volatile solids of the cake, the dried cake moisture content and the melting temperature as parameters.(3)Examination of the operational conditions for an energy saving melting system based on the results of (1) and (2) above.

scholarly journals Wheat Grinding Process with Low Moisture Content: A New Approach for Wholemeal Flour Production

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 32
Author(s):  
Waleed H. Hassoon ◽  
Dariusz Dziki ◽  
Antoni Miś ◽  
Beata Biernacka
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Average Particle Size ◽  
Average Particle ◽  
Grinding Process ◽  
Mixing Properties ◽  
New Approach ◽  
Grain Moisture ◽  
Flour Production ◽  
And Storage

The objective of this study was to determine the grinding characteristics of wheat with a low moisture content. Two kinds of wheat—soft spelt wheat and hard Khorasan wheat—were dried at 45 °C to reduce the moisture content from 12% to 5% (wet basis). Air drying at 45 °C and storage in a climatic chamber (45 °C, 10% relative humidity) were the methods used for grain dehydration. The grinding process was carried out using a knife mill. After grinding, the particle size distribution, average particle size and grinding energy indices were determined. In addition, the dough mixing properties of wholemeal flour dough were studied using a farinograph. It was observed that decreasing the moisture content in wheat grains from 12% to 5% made the grinding process more effective. As a result, the average particle size of the ground material was decreased. This effect was found in both soft and hard wheat. Importantly, lowering the grain moisture led to about a twofold decrease in the required grinding energy. Moreover, the flour obtained from the dried grains showed higher water absorption and higher dough stability during mixing. However, the method of grain dehydration had little or no effect on the results of the grinding process or dough properties.

scholarly journals Functional Properties and Molecular Degradation of Schizostachyum Brachycladum Bamboo Cellulose Nanofibre in PLA-Chitosan Bionanocomposites

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2008
Author(s):  
Samsul Rizal ◽  
N. I. Saharudin ◽  
N. G. Olaiya ◽  
H. P. S. Abdul Khalil ◽  
M. K. Mohamad Haafiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Moisture Content ◽  
Polymeric Materials ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Thickness Swelling ◽  
Compression Moulding ◽  
Ft Ir ◽  
Degradation Properties

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.

scholarly journals A thermodynamic assessment of precipitation, growth, and control of MnS inclusion in U75V heavy rail steel

2021 ◽  
Vol 40 (1) ◽  
pp. 178-192
Author(s):  
Wen-Qiang Ren ◽  
Lu Wang ◽  
Zheng-Liang Xue ◽  
Cheng-Zhi Li ◽  
Hang-Yu Zhu ◽  
...  
Keyword(s):  
Particle Size ◽  
Rail Steel ◽  
Solidification Process ◽  
Segregation Ratio ◽  
Two Phase ◽  
Final Particle ◽  
Solid Liquid ◽  
And Control ◽  
Heavy Rail ◽  
Heavy Rail Steel

Abstract Thermodynamic analysis of the precipitation behavior, growth kinetic, and control mechanism of MnS inclusion in U75V heavy rail steel was conducted in this study. The results showed that solute element S had a much higher segregation ratio than that of Mn, and MnS would only precipitate in the solid–liquid (two-phase) regions at the late stage during the solidification process at the solid fraction of 0.9518. Increasing the cooling rate had no obvious influence on the precipitation time of MnS inclusion; however, its particle size would be decreased greatly. The results also suggested that increasing the concentration of Mn would lead to an earlier precipitation time of MnS, while it had little effect on the final particle size; as to S, it was found that increasing its concentration could not only make the precipitation time earlier but also make the particle size larger. Adding a certain amount of Ti additive could improve the mechanical properties of U75V heavy rail steel due to the formation of TiO x –MnS or MnS–TiS complex inclusions. The precipitation sequences of Ti3O5 → Ti2O3 → TiO2 → TiO → MnS → TiS for Ti treatment were determined based on the thermodynamic calculation.

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