Importance of Initial Moisture Content and Bulking Agent for Biodrying Sewage Sludge

Wastewater treatment plants produced large amounts of municipal dewatered sewage sludge with about 80wt% moisture content. High moisture content is the bottleneck of sludge treatment and disposal. Hydrothermal treatment could economically disrupt sludge cells, release bound water and finally improve sludge dewaterability instead of thermal drying technology with high energy consumption. In this paper, hydrothermal treatment experiments were carried out and the combustion performance of the original sewage sludge and the hydrothermal treatment sewage sludge was analyzed to verify the possibility of burning after sludge hydrothermal treatment. The results show that the optimal reaction temperature, initial moisture content, pressure and time are 170°C, 87wt%, 0.9MPa and 40min, respectively, obtaining a final moisture content lower than 50wt% by centrifugation. Total Organic Carbon (TOC) results show that higher temperature and pressure, as well as longer reaction time are of benefit to the hydrothermal treatment of the municipal sewage sludge. Furthermore, Thermal Gravimetric Analysis (TGA) of the original sewage sludge and the hydrothermal treatment sewage sludge shows that a hydrothermal treatment can improve the combustion performance of the sludge, which is beneficial to the subsequent incineration process.

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Examination of Tobacco Hygroscopicity / Über die Hygroskopizität des Tabaks

Beiträge zur Tabakforschung International/Contributions to Tobacco Research ◽

10.2478/cttr-2013-0092 ◽

1965 ◽

Vol 3 (1) ◽

Author(s):

L. Hübschen

Keyword(s):

Moisture Content ◽

Sorption Isotherm ◽

Initial Moisture Content

AbstractThe present paper shows the detectable factors on which a sorption isotherm depends. Even if it is well-known that a sorption isotherm is most essentially conditioned by influences of the respective tobacco variety, other factors, such as temperature, initial moisture content, or fibre dimension, play a part as well. In general, a sorption isotherm constitutes a ''summation'' of such factors and, in the end, a combination of desorption and adsorption if the tobacco is dried or moistened from the average commercial moisture content. The tobacco hysteresis is experimentally investigated and discussed

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Pengeringan Biji Kakao dengan Pengering Surya Tipe Terowong Berpenggerak Sel Fotovoltaik di Manokwari

Agrotek ◽

10.30862/agt.v2i6.540 ◽

2018 ◽

Vol 2 (6) ◽

Author(s):

Wilson Palelingan Aman

Keyword(s):

Moisture Content ◽

Performance Test ◽

Initial Moisture Content ◽

Maximum Temperature ◽

Photovoltaic Module ◽

Cocoa Beans ◽

Drying Time ◽

Tunnel Dryer ◽

Heat Collector ◽

New Construction

<em>A research about cocoa beans drying used solar tunnel dryer with photovoltaic module driven have conducted in Manokwari. Solar tunnel dryer used in this research adapted from type Hohenheim with photovoltaic module and integrated air heat collector has been installed at the Department of Agricultural Technology, Papua State University Manokwari to dried cocoa beans. The objectives of this research were to design solar tunnel dryer and evaluate it�s performance in dryed cocoa beans. The result obtained was a new construction of solar tunnel dryer for cocoa beans with dimensions 6 m of length and 0,9 m of wide. The dryer completed with photovoltaic module to drive the blowers of hot drying air. �Performance test of the dryer showed that drying of 10 kg of cocoa beans with initial moisture content about 70% wet basis needed 13 hours of drying time to achieved final moisture content about 7,17% wet basis. The drying time achieved was faster compared than traditional solar drying that needed 20 hours of drying time. The maximum temperature achieved in drying chamber was 60 <sup>o</sup>C.</em>

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Estimation of Energy Saving for Melting Process on Sewage Sludge

Water Science & Technology ◽

10.2166/wst.1991.0657 ◽

1991 ◽

Vol 23 (10-12) ◽

pp. 2011-2018 ◽

Cited By ~ 2

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.

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Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽

10.3390/en12091590 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1590 ◽

Cited By ~ 9

Author(s):

Angelo Del Giudice ◽

Andrea Acampora ◽

Enrico Santangelo ◽

Luigi Pari ◽

Simone Bergonzoli ◽

...

Keyword(s):

Moisture Content ◽

Power Plants ◽

Black Locust ◽

Thermal Power ◽

Initial Moisture Content ◽

Wood Chip ◽

Wood Chips ◽

Cocurrent Flow ◽

Drying Process ◽

Rotary Dryer

Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kgdry solids−1 (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

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Effects of microwave irradiation on the moisture content of various wood chip fractions obtained from different tree species

Journal of Wood Science ◽

10.1186/s10086-021-01958-8 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Monika Aniszewska ◽

Krzysztof Słowiński ◽

Ewa Tulska ◽

Witold Zychowicz

Keyword(s):

Moisture Content ◽

Microwave Irradiation ◽

Microwave Power ◽

Irradiation Time ◽

Initial Moisture Content ◽

Radiant Energy ◽

Wood Chip ◽

Wood Chips ◽

Chip Size ◽

Drying Rates

AbstractThe paper proposes the use of microwave irradiation to lower the initial moisture content of wood chips. The study involved willow and fir chips fractionated by means of a sieve separator and unfractionated ash chips. The wood chips were exposed to a constant microwave power of 800 W for 30 s, 60 s, 120 s and 180 s. The chips were weighed before and after irradiation to measure loss of moisture. It was found that the decline in moisture content increased with wood chip size for a given irradiation time and microwave power. The initial moisture content of wood chips was not found to significantly affect loss of moisture as the drying rates of wood chips with higher and lower moisture content exposed to microwaves were not statistically different. The results showed that irradiation intensity increased with the time of exposure to microwaves and unit radiant energy per unit of evaporated moisture decreased with increasing wood chip size in the 3.15–31.50 mm range.

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Cherry Tomato Drying: Sun versus Convective Oven

Horticulturae ◽

10.3390/horticulturae7030040 ◽

2021 ◽

Vol 7 (3) ◽

pp. 40

Author(s):

Vincenzo Alfeo ◽

Diego Planeta ◽

Salvatore Velotto ◽

Rosa Palmeri ◽

Aldo Todaro

Keyword(s):

Moisture Content ◽

Initial Moisture Content ◽

Drying Process ◽

Drying Time ◽

Oven Drying ◽

Sun Drying ◽

Different Temperatures ◽

Final Water Content ◽

Drying Curves ◽

Drying Conditions

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.

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