PCDD/F Emissions from Light-Duty Diesel Vehicles Operated under Highway Conditions and a Diesel-Engine Based Power Generator

PCDD/F emissions from three light-duty diesel vehicles–two vans and a passenger car–have been measured in on-road conditions. We propose a new methodology for small vehicles: a sample of exhaust gas is collected by means of equipment based on United States Environmental Protection Agency (U.S. EPA) method 23A for stationary stack emissions. The concentrations of O2, CO, CO2, NO, NO2 and SO2 have also been measured. Six tests were carried out at 90-100 km/h on a route 100 km long. Two additional tests were done during the first 10 minutes and the following 60 minutes of the run to assess the effect of the engine temperature on PCDD/F emissions. The emission factors obtained for the vans varied from 1800 to 8400 pg I-TEQ/Nm3 for a 2004 model year van and 490-580 pg I-TEQ/Nm3 for a 2006 model year van. Regarding the passenger car, one run was done in the presence of a catalyst and another without, obtaining emission factors (330-880 pg I-TEQ/Nm3) comparable to those of the modern van. Two other tests were carried out on a power generator leading to emission factors ranging from 31 to 78 pg I-TEQ/Nm3. All the results are discussed and compared with literature.

Chemical characterization of emissions from a municipal solid waste treatment plant

Gaseous emissions are an important problem in municipal solid waste (MSW) treatment plants. The sources points of emissions considered in the present work are: fresh compost, mature compost, landfill leaks and leachate ponds. Hydrogen sulphide, ammonia and volatile organic compounds (VOCs) were analysed in the emissions from these sources. Hydrogen sulphide and ammonia were important contributors to the total emission volume. Landfill leaks are significant source points of emissions of H2S; the average concentration of H2S in biogas from the landfill leaks is around 1700 ppmv. The fresh composting site was also an important contributor of H2S to the total emission volume; its concentration varied between 3.2 and 1.7 ppmv and a decrease with time was observed. The mature composting site showed a reduction of H2S concentration (<0.1 ppmv). Leachate pond showed a low concentration of H2S (in order of ppbv). Regarding NH3, composting sites and landfill leaks are notable source points of emissions (composting sites varied around 30–600 ppmv; biogas from landfill leaks varied from 160 to 640 ppmv). Regarding VOCs, the main compounds were: limonene, p-cymene, pinene, cyclohexane, reaching concentrations around 0.2–4.3 ppmv. H2S/NH3, limonene/p-cymene, limonene/cyclohexane ratios can be useful for analysing and identifying the emission sources.

Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment. Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 °C. Apart from carbon oxides, HBr was the main decomposition product, followed by high amounts of methane, ethylene, propylene, phenol and benzene. The maximum formation of PAHs was found in pyrolysis at 850 °C, naphthalene being the most abundant. High levels of 2-, 4-, 2,4-, 2,6- and 2,4,6-bromophenols were found, especially at 600 °C. Emissions of PCDD/Fs and dioxin-like PCBs were quite low and much lower than that of PBDD/Fs, due to the higher bromine content of the samples. Combustion at 600 °C was the run with the highest PBDD/F formation: the total content of eleven 2,3,7,8-substituted congeners (tetra- through heptaBDD/Fs) was 7240 and 3250 ng WHO2005-TEQ/kg sample, corresponding to the sample with and without metals, respectively.

Emissions from the Pyrolysis and Combustion of Different Wastes

Paper submitted to the 7th International Symposium on Feedstock Recycling of Polymeric Materials (7th ISFR 2013), New Delhi, India, 23-26 October 2013.

Study of the emissions from pyrolytic and oxidative thermal decomposition of PVC

Polyvinyl chloride (PVC) is one of the plastics most extensively used due to its versatility. The demand of PVC resin in Europe during 2012 reached 5000 ktonnes1. PVC waste management is a big problem because of the high volume generated all over the world and its chlorine content. End-of-life PVC is mainly mixed with municipal solid waste (MSW) and one common disposal option for this is waste-to-energy incineration (WtE). The presence of plastics such as PVC in the fuel mix increases the heating value of the fuel. PVC has two times higher energy content than MSW ‒around 20 MJ/kg vs 10 MJ/kg, respectively. However, the high chlorine content in PVC resin, 57 wt.%, may be a source for the formation of hazardous chlorinated organic pollutants in thermal processes. Chlorine present in the feedstock of WtE plants plays an important role in the formation of (i) chlorine (Cl2) and (ii) hydrochloric gas (HCl), both of them responsible for corrosion, and (iii) chlorinated organic pollutants2. In this work, pyrolytic and oxidative thermal degradation of PVC resin were carried out in a laboratory scale reactor at 500 ºC in order to analyze the influence of the reaction atmosphere on the emissions evolved. Special emphasis was put on the analysis of chlorinated organic pollutants such as polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs) and other related compounds like polychlorobenzenes (PCBzs), polychlorophenols (PCPhs) and polycyclic aromatic hydrocarbons (PAHs). Another objective of this work was to compare the results with those of a previous work3 in which emissions at different temperatures in both pyrolysis and combustion of another PVC resin had been studied; in that case, experiments for PCDD/Fs emissions had been performed only at 850 ºC.

Emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) from a cement kiln using a continuous monitoring system

Resumen de la comunicación presentada en PIC2015 – the 14th International Congress on Combustion By-Products and Their Health Effects, Umeå, Sweden, 14-17 June 2015.

Emissions of Gases, Polycyclic Aromatic Hydrocarbons and Brominated Pollutants during Thermal Degradation of Waste Printed Circuit Boards

Resumen del póster presentado en Symposium on Renewable Energy and Products from Biomass and Waste, CIUDEN (Cubillos de Sil, León, Spain), 12-13 May 2015

Pollutant emissions during the pyrolysis and combustion of flexible polyurethane foam

Thermal decomposition of flexible polyurethane foam (FPUF) was studied under nitrogen and air atmospheres at 550 °C and 850 °C using a laboratory scale reactor to analyse the evolved products. Ammonia, hydrogen cyanide and nitrile compounds were obtained in high yields in pyrolysis at the lower temperature, whereas at 850 °C polycyclic aromatic hydrocarbons (PAHs) and other semivolatile compounds, especially compounds containing nitrogen (benzonitrile, aniline, quinolone and indene) were the most abundant products. Different behaviour was observed in the evolution of polychlorodibenzo-p-dioxins and furans (PCDD/Fs) at 550 °C and 850 °C. At 550 °C, the less chlorinated congeners, mainly PCDF, were more abundant. Contrarily, at 850 °C the most chlorinated PCDD were dominant. In addition, the total yields of PCDD/Fs in the pyrolysis and combustion runs at 850 °C were low and quite similar.