scholarly journals Semi-Batch Gasification of Refuse-Derived Fuel (RDF)

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 343
Author(s):  
Juma Haydary ◽  
Patrik Šuhaj ◽  
Michal Šoral

Gasification is a promising technology for the conversion of mixed solid waste like refuse-derived fuel (RDF) and municipal solid waste (MSW) into a valuable gas consisting of H2, CO, CH4 and CO2. This work aims to identify the basic challenges of a single-stage batch gasification system related to tar and wax content in the producer gas. RDF was first gasified in a simple semi-batch laboratory-scale gasification reactor. A significant yield of tars and waxes was received in the produced gas. Waxes were analyzed using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectrometry. These analyses indicated the presence of polyethylene and polypropylene chains. The maximum content of H2 and CO was measured 500 sec after the start of the process. In a second series of experiments, a secondary catalytic stage with an Ni-doped clay catalyst was installed. In the two-stage catalytic process, no waxes were captured in isopropanol and the total tar content decreased by approximately 90 %. A single one-stage semi-batch gasification system is not suitable for RDF gasification; a large fraction of tar and waxes can be generated which can cause fouling in downstream processes. A secondary catalytic stage can significantly reduce the tar content in gas.

2021 ◽  
Vol 21 (13) ◽  
pp. 10589-10608
Author(s):  
Yubo Cheng ◽  
Yiqiu Ma ◽  
Di Hu

Abstract. Here we conducted comprehensive chemical characterization and source apportionment of 49 PM2.5 samples collected in Hong Kong. Besides the major aerosol constituents, 39 polar organic species, including 14 secondary organic aerosol (SOA) tracers of isoprene, monoterpenes, β-caryophyllene, and naphthalene, were quantified using gas chromatography–mass spectrometry (GC–MS). Six factors, i.e., SOA, secondary sulfate (SS), biomass burning (BB)/SOA, sea salt, marine vessels, and vehicle emissions, were apportioned by positive matrix factorization (PMF) as the major sources of ambient organic carbon (OC) in Hong Kong. The secondary formation, including OC from SOA, SS, and aging of BB plume, was the leading contributor to OC (51.4 %, 2.15 ± 1.37 µg C m−3) throughout the year. We then applied a tracer-based method (TBM) to estimate the SOA formation from the photo-oxidation of four selected precursors, and monoterpene SOA was the most abundant. A Kintecus kinetic model was used to examine the formation channels of isoprene SOA, and the aerosol-phase ring-opening reaction of isoprene epoxydiols (IEPOXs) was found to be the dominant formation pathway. Consistently, IEPOX tracers contributed 94 % to total GC–MS-quantified isoprene SOA tracers. The TBM-estimated secondary organic carbon (SOCTBM) and PMF-apportioned SOC (SOCPMF) showed similar temporal trends; however, SOCTBM only accounted for 26.5 % of SOCPMF, indicating a large fraction of ambient SOA was from other reaction pathways or precursors. Results of Pearson's R and multivariate linear regression analysis showed that NOx processing played a key role in both daytime and nighttime SOA production in the region. Moreover, sulfate had a significant positive linear relationship with SOCPMF and SS-related SOC, and particle acidity was significantly correlated with SOC from the aging of BB.


2020 ◽  
Vol 24 (3) ◽  
pp. 112-118
Author(s):  
Dace Âriņa ◽  
Rūta Bendere ◽  
Gintaras Denafas ◽  
Jānis Kalnačs ◽  
Mait Kriipsalu

AbstractThe authors determined the morphological composition of refuse derived fuel (RDF) produced in Latvia and Lithuania by manually sorting. The parameters of RDF (moisture, net calorific value, ash content, carbon, nitrogen, hydrogen, sulphur, chlorine, metals) was determined using the EN standards. Comparing obtained results with data from literature, authors have found that the content of plastic is higher but paper and cardboard is lower than typical values. Results also show that the mean parameters for RDF can be classified with the class codes: Net heating value (3); chlorine (3); mercury (1), and responds to limits stated for 3rd class of solid recovered fuel. It is recommended to separate biological waste at source to lower moisture and ash content and increase heating value for potential fuel production from waste.


2019 ◽  
Vol 11 (3) ◽  
pp. 935 ◽  
Author(s):  
Andrzej Białowiec ◽  
Monika Micuda ◽  
Antoni Szumny ◽  
Jacek Łyczko ◽  
Jacek Koziel

The torrefaction of municipal solid waste is one of the solutions related to the Waste to Carbon concept, where high-quality fuel—carbonized refuse-derived fuel (CRDF)—is produced. An identified potential problem is the emission of volatile organic compounds (VOCs) during CRDF storage. Kinetic emission parameters have not yet been determined. It was also shown that CRDF can be pelletized for energy densification and reduced volume during storage and transportation. Thus, our working hypothesis was that structural modification (via pelletization) might mitigate VOC emissions and influence emission kinetics during CRDF storage. Two scenarios of CRDF structural modification on VOC emission kinetics were tested, (i) pelletization and (ii) pelletization with 10% binder addition and compared to ground (loose) CRDF (control). VOC emissions from simulated sealed CRDF storage were measured with headspace solid-phase microextraction and gas chromatography–mass spectrometry. It was found that total VOC emissions from stored CRDF follow the first-order kinetic model for both ground and pelletized material, while individual VOC emissions may deviate from this model. Pelletization significantly decreased (63%~86%) the maximum total VOC emission potential from stored CDRF. Research on improved sustainable CRDF storage is warranted. This could involve VOC emission mechanisms and environmental-risk management.


1977 ◽  
Vol 36 (3) ◽  
pp. 314-327 ◽  
Author(s):  
R. Fred Rolsten ◽  
Leon Glaspell ◽  
J. P. Waltz

Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Rei Makino ◽  
Seiji Ohara ◽  
Koh Hashida

Abstract The object of this study was to elucidate the relationship between the chemical structure of purified condensed tannin polymers from tree species and their radical scavenging characteristics. By means of 13C-NMR spectrometry and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), four kinds of proanthocyanidins were identified: prorobinetinidins, profisetinidins, procyanidins, and prodelphinidins. The tannins were submitted to radical scavenging assays with DPPH and galvinoxyl radicals and from the time-course of the reactions was concluded: 1) Tannins with pyrogallol type B-ring scavenge radicals in the beginning faster than those with catechol type B-ring. 2) Tannins with catechol type B-ring needs more time to scavenge the same amount of radicals as those with pyrogallol type B-ring. 3) The IC50 values of tannins with catechol type B-ring decrease after longer reaction times with the galvinoxyl radical. 4) Radical scavenging with DPPH radical proceeds faster than that for the galvinoxyl radical.


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