Thermal Regeneration of Mineral Sorbent Using Burner Unit

2013 ◽  
Vol 34 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Robert Sekret ◽  
Jan Koldej

This article presents the results of scientific investigations on the thermal regeneration process of a sorbent of mineral origin sorbent using a retort burner. Diesel oil, a petroleum liquid, most often pervades the environment during different catastrophes. The investigated sorbent of mineral origin was used in the standard way that the Fire Service removes such petroleum liquids from the environment during disasters. For research purposes, a regeneration chamber with a retort burner was constructed. The first phase of the investigation was aimed at defining the physico-chemical features of the sorbent after subsequent cycles of the regeneration process. The second phase involved an analysis of the energy and ecological effects of the regeneration process. The results showed that the first three cycles of the regeneration process occurred under low emission conditions. The proposed regeneration method achieved a positive energetic effect with a functional heat stream with an average value of 12.4 kW (average efficiency of the regeneration chamber was 68 %). The method is very efficient, with regeneration rates between 7.2 kg/h and 8.4 kg/h. It requires only a short amount of time for the start-up and extinction of the regeneration chamber, and it is also flexible to changes in the process conditions.

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Johny Anderson Severo ◽  
Regina Célia Espinosa Modolo ◽  
Carlos Alberto Mendes Moraes ◽  
Flávia Schwarz Franceschini Zinani

ABSTRACT Improper disposal of sand used in molding processes after casting increases logistical costs and environmental impact because of the presence of the phenolic resin in its composition. The regeneration process of waste foundry phenolic sand (WFPS) aims to recycle this material. As mechanical regeneration methods are not efficient to guarantee 100% cleaning of the sand grains and their use again in the molding process, this work investigated the efficiency of a method of thermal regeneration of this type of residue that can be employed as a complementary procedure. A laboratory-scale fluidized bed reactor was designed and built to regenerate WFPS that was previously treated by a mechanical method. The methodology used to design and construct the fluidized bed prototype is described, as well as the characterization of the residual, the standard clean sand and the regenerated sand. The results of the thermal regeneration in the fluidized bed were very satisfactory with respect to the regeneration efficiency. For the nine process conditions tested, loss on ignition values were reduced when compared to standard clean sand. This study presents the advantages of a combination of two processes, mechanical and thermal regeneration, which allows to reduce the time and eventual temperature of resin removal due to the partial removal of the resin layer or its weakening during the mechanical regeneration process. Of the nine process conditions tested, six had loss on ignition values below the CSS. Thus, the thermal regeneration in the fluidized bed results was quite satisfactory in relation to the regeneration efficiency.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 444
Author(s):  
Feng Cheng ◽  
Yunlei Wu ◽  
Xiuwei Li

Absorption air-conditioning systems have a great advantage in terms of energy conservation and environmental protection. However, the large amount of energy waste in the thermal regeneration process leads to lower efficiency and impedes its development. To reduce energy loss and improve performance, a local heating regeneration method is proposed in this paper. The main principle is reducing the volume of the liquid participating regeneration. Including the solar steam mode, two modes are introduced and configured. Theoretical and experimental research has been made on the new methods. Models have been developed for comparison analysis. Experiments have been conducted on water and absorbent solution with different modes. Performance has been evaluated based on the experimental data. The results expose the influence of different parameters, like liquid volume and solution concentration, on the regeneration process. The local heating method improved the regeneration efficiency by 40% in the no solar steam mode and the performance tripled in the solar steam mode. The COP (the ratio of cooling load to energy consumption) of the absorption system with the solar steam mode is more than two times of that with the traditional regeneration mode. It shows the local heating regeneration method has good potential in future application.


1986 ◽  
Vol 73 ◽  
Author(s):  
William L. Olson

ABSTRACTAlumina sols derived from aluminum sec-butoxide (Yoldas) were characterized. The distribution of the polymer sizes within the sol, determined by gel filtration chromatography (GFC), was found to be dramatically affected by small changes in the chemical processing or preparative procedure. Aging the sol at room temperature for two weeks produced no significant change in the GFC elution curves of the alumina sol. Sols with a “milky” appearance were found to exhibit a wider distribution of polymers by GFC than transparent sols. Rotary evaporation of the sol followed by redissolution of the residue was found to change the polymer size distribution described by the gel filtration elution curves. These observations coupled with 27Al NMR spectroscopy and viscometry measurements were used to elucidate the effects of process conditions and aging on the molecular structure of the sol.


Author(s):  
Hao Huang ◽  
Abhijit Dasgupta ◽  
Ehsan Mirbagheri ◽  
Srini Boddapati

The focus of this paper is on the stress-strain behavior and creep response of a pressure-sensitive adhesive (PSA) with and without carrier layers. This study consists of two phases. The first phase focuses on understanding of the effects of fabrication profiles, including bonding pressure, bonding temperature, bonding time, and aging time, on the PSA joint strength. This part of the study is used to identify an acceptable bonding and aging conditions for manufacturing a robust PSA bonded assembly. Specimens fabricated with this selected set of bonding process conditions are then used for mechanical characterization. The second phase focuses on the assembly’s mechanical behavior (stress-strain behavior and the creep curves) under different loading conditions, including loading stress, loading rate, and loading temperature. The mechanical behavior of PSA bonded assemblies is affected not only by the loading conditions, but also by the assembly architecture. The mechanical behaviors and failure modes of PSAs with and without carrier layers are compared. The reasons for these differences are also discussed.


2006 ◽  
Vol 50 ◽  
pp. 97-106 ◽  
Author(s):  
Gerard Vignoles

The chemical vapour infiltration (CVI) process is used to fabricate the interphases and matrices of CMCs. This process involves complex physico-chemical phenomena such as the transport of precursor, carrier, and by-product gases in the reactor and inside a fibrous preform, chemical reactions (pyrolysis and deposition), and the structural evolution of the preform. It is able to provide high-quality materials because the process conditions are rather mild with respect to the fibres ; however it is expensive and sometimes difficult to optimize. Many variations of the basic concept have been proposed in the past decades, introducing thermal and pressure gradients, in order to increase the efficiency. This process has been the object of extensive modelling efforts, because of imperative optimization needs. The present work is an attempt to provide a synthetic view of these models, focusing on several features of CVI modelling : i) Modelling CVI requires a multi-scale strategy, with models ranging from process scale down to atomic scale, ii) Original physicochemical couplings are involved, which require the development of adequate treatments, iii) There is a hierarchy of model refinement, ranging from fully detailed models to quasi-analytical predictions.


2013 ◽  
Vol 67 (12) ◽  
pp. 2677-2684 ◽  
Author(s):  
M. Christensson ◽  
S. Ekström ◽  
A. Andersson Chan ◽  
E. Le Vaillant ◽  
R. Lemaire

ANITA™ Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the ‘BioFarm concept’, has been developed in order to decrease the start-up time of new ANITA Mox installations. New ANITA Mox installations are started with typically 3–15% of the added carriers being from the ‘BioFarm’, with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjölunda wastewater treatment plant (WWTP) in Malmö, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m3 d and approximately 90% ammonia removal within 4 months from start-up. This first ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N2O emissions, <1% of the reduced nitrogen and a very stable and robust process towards variations in loads and process conditions. The second ANITA Mox plant, started up at Sundets WWTP in Växjö, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.


2018 ◽  
Vol 64 (No. 3) ◽  
pp. 102-107 ◽  
Author(s):  
Borowik Agata ◽  
Wyszkowska Jadwiga

This study analysed the changes in the development of Avena sativa L. cultivated on soil contaminated with diesel oil (DO; 0, 7, 14 and 21 mL/kg of soil dry matter), and in the microbiological, biochemical, chemical and physico-chemical properties of the soil. In addition to basic fertilisation fulfilling the nutritional needs of the oat plant, finely ground barley straw and finely ground charcoal was also applied. The study revealed a highly toxic effect of DO on the growth and development of Avena sativa L. The uptake of macro- and micronutrients by the tested plant decreased significantly. The active bacteria were identified based on the analysis of 16S rRNA coding sequences. In objects contaminated with DO, a more rapid development of organotrophic bacteria, actinomyces and fungi was observed, as well as higher activity of dehydrogenases, catalase, urease, acid phosphatase, alkaline phosphatase and β-glucosidase. In the soils contaminated with DO, more C<sub>org</sub> and available and exchangeable potassium were found than in the non-contaminated soils. DO did not have such a significant effect on the contents of other elements in the soil. The use of charcoal and straw stimulated both the development of microorganisms and the activity of soil enzymes, yet it did not mitigate the adverse effect of DO on the growth or development of the oat plant.


1993 ◽  
Vol 27 (9) ◽  
pp. 115-123 ◽  
Author(s):  
F. El-Gohary ◽  
R. Abdel Wahaab ◽  
S. El-Hawary ◽  
S. Shehata ◽  
S. Badr ◽  
...  

A study has been conducted to evaluate the performance of an aerated oxidation pond system in a village in Egypt. It comprises an anaerobic pond (AP), an aerated facultative pond (AeP) and a maturation pond (MP). The assessment involved an intensive programme of sampling and analysis of raw wastewater, unit process contents and unit process effluents. Field studies indicated a wide fluctuation in the BOD5 load applied to the STP. It ranged from 64 to 290 g BOD5/m3.d, with an average value of 146 g BOD5/m3.d. This, however, did not affect physico-chemical characteristics of the final effluent. Residual COD, BOD & SS were around 99 mg/l, 32 mg/l & 66 mg/l, respectively. Although faecal coliform removal was around 98.9%, yet residual count was still high. Also, significant decline in both parasitic eggs and protozoal stages has been recorded.


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