Gasification of Torrefied Sewage Sludge With the Addition of Calcium Carbonate

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Mateusz Wnukowski ◽  
Lukasz Niedzwiecki ◽  
Mateusz Kowal ◽  
Krystian Krochmalny

Abstract Utilization of sewage sludge, in a way friendly to the environment, is still a subject of intensive investigation. One of the possible solutions is the gasification of sewage sludge. Torrefaction and the use of additive can enhance this process. This study presents the results of the gasification of raw and mildly torrefied sewage sludge, as well as mildly torrefied sewage sludge with the addition of calcium carbonate. Overall, the torrefaction in mild conditions had little influence on the composition of the obtained gas. The influence was much more visible when 5% of calcium carbonate was added. The additive caused the increased average concentration of CH4 and decreased average concentration of H2 in the producer gas. The use of additive also improved the kinetics of the gasification of torrefied sewage sludge. Moreover, the tar deposition diagram confirmed that the use of calcium carbonate enhanced the quality of the produced gas by decreasing the content of the compounds, with a melting point higher than 30 °C, thus minimizing the deposition problem.

Author(s):  
M.A. Egyan ◽  

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Meda ◽  
C. Schaum ◽  
M. Wagner ◽  
P. Cornel ◽  
A. Durth

TIn 2004, the German Association for Wastewater, Water and Waste (DWA) carried out a survey about the current status of sewage sludge treatment and disposal in Germany. The study covered about one third of the wastewater treatment plants and about two thirds of the entire treatment capacity (expressed in population equivalents) in Germany. This provides an up-to-date and representative database. The paper presents the most important results regarding sludge treatment, process engineering, current disposal paths and sewage sludge quality.


1998 ◽  
Vol 37 (1) ◽  
pp. 251-257 ◽  
Author(s):  
Torben Larsen ◽  
Kirsten Broch ◽  
Margit Riis Andersen

The paper describes the results of measurements from a 2 year period on a 95 hectare urban catchment in Aalborg, Denmark. The results of the rain/discharge measurements include 160 storm events corresponding to an accumulated rain depth of totally 753 mm. The water quality measurements include 15 events with time series of concentration of SS, COD, BOD, total nitrogen and total phosphorus. The quality parameters showed significant first flush effects. The paper discusses whether either the event average concentration or the accumulated event mass is the most appropriate way to characterize the quality of the outflow.


2010 ◽  
Vol 72 ◽  
pp. 46-52 ◽  
Author(s):  
Laurent Royer ◽  
Stéphane Mathieu ◽  
Christophe Liebaut ◽  
Pierre Steinmetz

For energy production and also for the glass industry, finding new refractory alloys which could permit to increase the process temperatures to 1200°C or more is a permanent challenge. Chromium base alloys can be good candidates, considering the melting point of Cr itself, and also its low corrosion rate in molten glass. Two families of alloys have been studied for this purpose, Cr-Mo-W and Cr-Ta-X alloys (X= Mo, Si..). A finer selection of compositions has been done, to optimize their chemical and mechanical properties. Kinetics of HT oxidation by air, of corrosion by molten glass and also creep properties of several alloys have been measured up to 1250°C. The results obtained with the best alloys (Cr-Ta base) give positive indications as regards the possibility of their industrial use.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ottaviano Allegretti ◽  
Ignazia Cuccui ◽  
Nasko Terziev ◽  
Laerte Sorini

AbstractMass loss (ML) of wood caused by thermal degradation is one of the most important features of the thermal treatments and referred to as an indicator of intensity and quality of the process. The ML is proportional to the quantity of the effective heat power exchanged during the treatment process, represented by the area of the temperature profile versus time during the process. In this paper a model for the ML prediction based on the relative area was discussed. The model proposed an analytical solution to take into account the non-linear trend of ML when plotted versus temperature and time as observed in isothermal experiments. The model was validated comparing calculated and measured final ML of samples treated during thermal modification tests with different temperature profiles. The results showed that the relative area calculated in a transformed time-temperature space improves the correlation with the measured ML.


2017 ◽  
Vol 114 (31) ◽  
pp. 8265-8270 ◽  
Author(s):  
Simon Olsson ◽  
Hao Wu ◽  
Fabian Paul ◽  
Cecilia Clementi ◽  
Frank Noé

Accurate mechanistic description of structural changes in biomolecules is an increasingly important topic in structural and chemical biology. Markov models have emerged as a powerful way to approximate the molecular kinetics of large biomolecules while keeping full structural resolution in a divide-and-conquer fashion. However, the accuracy of these models is limited by that of the force fields used to generate the underlying molecular dynamics (MD) simulation data. Whereas the quality of classical MD force fields has improved significantly in recent years, remaining errors in the Boltzmann weights are still on the order of a few kT, which may lead to significant discrepancies when comparing to experimentally measured rates or state populations. Here we take the view that simulations using a sufficiently good force-field sample conformations that are valid but have inaccurate weights, yet these weights may be made accurate by incorporating experimental data a posteriori. To do so, we propose augmented Markov models (AMMs), an approach that combines concepts from probability theory and information theory to consistently treat systematic force-field error and statistical errors in simulation and experiment. Our results demonstrate that AMMs can reconcile conflicting results for protein mechanisms obtained by different force fields and correct for a wide range of stationary and dynamical observables even when only equilibrium measurements are incorporated into the estimation process. This approach constitutes a unique avenue to combine experiment and computation into integrative models of biomolecular structure and dynamics.


2013 ◽  
Vol 137 ◽  
pp. 239-244 ◽  
Author(s):  
A. Shana ◽  
S. Ouki ◽  
M. Asaadi ◽  
P. Pearce ◽  
G. Mancini

2013 ◽  
Vol 671-674 ◽  
pp. 2736-2741
Author(s):  
Yin An Ming ◽  
Tao Tao

To reuse municipal sewage sludge safely, experiment was carried out on grapefruit trees fertilized with composted sludge from Shiweitou Sewage Treatment Plant in Xiamen City of China, and a method was introduced of how to assess the environmental quality of grapefruit trees soil fertilized with sludge by Set Pair Analysis (SPA) model. The results showed that the soil in the surface layer (0-15cm) and the deeper layer (15-30cm) was less clean, and the environment of soil was not polluted. Thus it was feasible to use sludge as fruit fertilizer. The maximum service life of sludge for continuous land application was estimated by taking Cd as the limiting factor, which would provide scientific guide and technical support for safe land application of sludge.


2004 ◽  
Vol 39 (3) ◽  
pp. 311-317 ◽  
Author(s):  
Luis Rejano ◽  
Antonio de Castro ◽  
Antonio H. Sanchez ◽  
Francisco J. Casado ◽  
Alfredo Montano
Keyword(s):  

1991 ◽  
Vol 24 (2) ◽  
pp. 117-120 ◽  
Author(s):  
W. Stelzer ◽  
J. Jacob

This study is aimed at determining the occurrence of campylobacters in waste water, sewage sludge and in a river system. The selective medium for the isolation of campylobacter consists of blood agar supplemented with the antibiotics vancomycin (10 µg/ml), cephalexin (15 µg/ml), trimethoprim (5 µg/ml), polymycin B (2.5 µg/ml) and rifampicin (5 µg/ml). Raw sewage samples contained about 103 Campylobacter/100 ml while the effluent showed an average concentration of 1.3 × 102/100 ml. Raw sewage from an oxidation pond treatment plant contained an average of 51 Campylobacter/100 ml while none were found in the effluent. No Campylobacter could be found in digested, conditioned sludge. The organism could be detected in 82.1% of river waters examined with the majority showing <10/100 ml. The presence of waterfowl and the faecal contamination from a poultry farm resulted in higher Campylobacter levels. About 50 % of the isolates typed as C. coli were really confirmed as C. jejuni by electrophoretic pattern (whole cell protein profiles).


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