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... ignition reactor is used to determine the ignition behaviour of fuels. In this equipment a powdered sample mass of approx. 300 mg is burnt in a pre-heated reactor up to a temperature of 1100 °C. Through an optical sensor and an installed thermal element, the temperature distribution over the current flow can be ascertained. With a laboratory thermo balance (Fig 1) the ignition and combustion behaviour under different Temperature-Time conditions, varied gas atmosphere, kinetic reaction constants etc, for samples (max is 1 g) can be determined. Since the samples amount is small, homogenisation is hence necessary and a major that is major difficulty for RDF. The running of industrial processes (e.g. rotary kiln, combustion chamber) can be simulated [7]. The technical thermo balance can weigh samples up to a size of 3 kg, and hence can suitable for investigating heterogeneous lumpy samples. It is therefore used to supplement the laboratory thermal balance. The batch reactor is utilised for the determination of kinetic data for the solid material conversion on the packed bed or in a fluidized bed (ignition and burnt out behaviour) [4], [8], [9], [12]. The specifications of the Batch reactor are summarised in Table 3. Fig 4 and Fig 5 show a schematic diagram and a photo of the batch reactor. With parameter variation, grate firing and fluidised bed reactor systems can be ...
Citations
... NaCl, KCl and MgCl 2 vapour pressures investigated by Beckmann & Ncube (2007) (Beckmann and Ncube) shows that P(NaCl) and P(KCl) equal 1 bar around 1400 • C and 10 − 2 bar around 900 • C and that P(KCl) > P(NaCl) and P(MgCl 2 ) > P(NaCl) for this later temperature. ...
... A positive correlation between size and total chlorine was also obtained (r = 0.255, Fig. 5 Organic matter content of biodegradable size fractions regarding the income levels p < 0.1). It was reported that the organic-bound chlorine is generally caused by high plastic content (mostly PVC) in refuse derived fuel (RDF) [62]. That's why the average chlorine content of the Bio-MSW was calculated by using the data obtained for size fractions and its correlation with the share of plastics in wet waste was determined separately. ...
Background:
Waste composition and characteristics are determinative in selecting technological alternatives to develop waste management strategies that can meet legislative requirements. The aim of this study is to identify the major factors influencing the municipal solid waste (MSW) composition and the properties of its biodegradable fraction in İzmir city, Turkey.
Methods:
MSW composition was determined in samples collected from different income level areas of the city. Water and organic matter contents, calorific value, and the total chlorine levels in seven biodegradable waste (Bio-MSW) size fractions (between >120 mm and > 10 mm) and in the fine fraction (<10 mm) were analyzed. The data on waste components and Bio-MSW properties were statistically investigated.
Results:
The average shares of biodegradables and recyclables in MSW were found as 50.2 and 40.3%, respectively. The organic matter content of Bio-MSW increased with waste size (r = 0.313, p < 0.05) and its calorific value were in the range of 2310-3686 kcal/kg. A link between the plastics' share in MSW and the Bio-MSW chlorine levels was recognized (r: 0.666, p < 0.1). PCA analysis identified the main factors degrading the Bio-MSW quality as the cross contamination due to the mixed collection (30.8%), compaction applied in waste trucks (27.5%), and the inert broken materials trapped in larger fractions (21.3%).
Conclusion:
Strong negative impact of mixed collection on Bio-MSW quality indicated that implementation of source separated collection of MSW is crucial for Izmir city in order to develop an integrated waste management system that meets the legal requirements by means of end product quality.
In the past several decades, refuse-derived fuels (RDFs) have been widely applied in industrial combustion processes, for instance, in cement production. Since RDF is composed of various waste fractions with complex shapes, its flight and combustion behaviors can be relatively complicated. In this paper, we present a novel plenoptic camera-based spatial measurement system that uses image processing approaches to determine the dwell time, the space-sliced velocity in the depth direction, and the ignition time of various applied RDF fractions based on the obtained images. The image processing approach follows the concept of tracking-by-detection and includes a novel combined detection method, a 2.5D multiple particle tracking algorithm, and a postprocessing framework to tackle the issues in the initial tracking results. The thereby obtained complete spatial fuel trajectories enable the analysis of the flight behaviors elaborated in the paper. The acquired particles' properties (duration, velocity, and ignition time) reversely prove the availability and applicability of the developed measurement system. The adequacy and accuracy of the proposed novel measurement system are validated by the experiments of detecting and tracking burning and nonburning fuel particles in a rotary kiln. This new measurement system and the provided experimental results can benefit a better understanding of the RDF's combustion for future research.
India had the second largest population in the world in 2017 with 1.34 billion inhabitants, and its population-specific CO2 emissions rose from 0.98 in 2000 to 1.73 tons per capita in 2014 (The World Bank 2018). Indian urban areas generated 62 million tons of municipal solid waste (MSW) in 2011 (Planning Commission 2014). While 50 to 90 wt.-% of MSW are collected, in average almost 87 wt.-% is disposed on landfills without further processing or treatment (PIB 2016; CPCB 2016; Banerjee 2016; Mani and Singh 2016). A review of urban MSW in India shows that approx. 51 wt.-% (±12.4) are comprised of organic materials, whereas plastics and papers contributed in average 6.7 (±4.4) and 7.7 (±5.5) wt.-% respectively (Speier et al. 2018b).
The impact of biomass addition to the RDF oversize fraction on quality parameters obtained from this blend of briquettes produced under semi-industrial conditions was analysed. For the purposes related to the experiment four RDF mixtures with fragmented biomass of common willow Salix viminalis L., differing only with percentage participation of base elements, were prepared. The briquetting process was performed with the use of a semi-industrial briquetting machine at the determined compaction pressure of 47 MPa and a diameter of a sleeve (and a briquette at the same time) of 50 mm. Selected quality parameters of produced briquettes were determined, i.e. density, mechanical strength DU and compression strength. The best parameters were obtained for briquettes produced from the blend with a 50% share of willow (ρ=843.9 kg · m
In the current work the co-combustion of Solid Recovered Fuels’ (SRFs’) with brown coal in large scale pulverised coal boilers under different operational conditions is numerically investigated. In order to overcome the difficulty of the complex, inhomogeneous nature of waste recovered fuels, SRF is modelled as a mixture of two different fractions, the biogenic and the plastic one. For each fraction different combustion mechanisms are presented, whilst for the first time the proposed combustion mechanism of the plastic fraction is incorporated in a commercial CFD code and validated against available experimental data. A 600 MWe brown coal boiler is simulated as a reference and its operational characteristics are compared with parameterised scenarios of SRF co-firing conditions. Based on the numerical results, the optimum co-firing concepts regarding the more efficient operation of the boiler (hot spots and fuel’s burnout) are identified, decreasing the environmental impact of the boiler’s emissions.
