Incomplete Combustion Processes Research Articles

Investigation on effects of thickness on ignition characteristics and combustion process of the oil-impregnated transformer insulating paperboard

Effects of thickness on ignition characteristics and combustion process of the oil-impregnated transformer insulating paperboard were investigated experimentally by cone calorimeter. Five thicknesses of transformer insulating paperboard, including 0.5, 1.0, 1.5, 2.0 and 3.0 mm were taken into account together with five radiation intensities between 25 and 80 kW m−2. According to the experimental results on ignition characteristics, the 0.5-mm paperboard for all radiation intensities and the 1.0-mm paperboard with the radiation heat flux less than 35 kW m−2 were thermal thin material. The 1.0-mm paperboard under higher radiation intensities and the paperboard with the thicknesses of 1.5, 2.0 and 3.0 mm were thermal thick material. The heat release rate (HRR) of oil-impregnated transformer insulating paperboard decreased with its thickness. Due to the different pyrolysis processes, the number of HRR peaks increased with the thickness of paperboard. The CO and CO2 production rate and the O2 consumption rate were all decreased with the paperboard thickness basically. There was an increase in the CO production rate at the end of fire duration, since the incomplete combustion process occurred at this stage. The increase in the CO production rate was more obvious in the experiments under lower external radiation heat fluxes.

New protocol based on high-volume sampling followed by DLLME-GC-IT/MS for determining PAHs at ultra-trace levels in surface water samples

Polycyclic Aromatic Hydrocarbons (PAHs), ubiquitous compounds coming from incomplete combustion processes, are very toxic species and can cause serious effects on the human health. At authors' knowledge, studies on PAHs levels in surface waters are scarce: the main problem regards the analytical implications due to analyzing such compounds at very low levels. This paper would like to present a new extraction protocol based on Dispersive Liquid-Liquid MicroExtraction (DLLME) procedure followed by GC-IT/MS for simultaneous determination of nine PAHs in surface water. Iso-octane is used as extraction solvent whereas no dispersive solvent is involved. An important issue regarded the procedure to obtain the emulsion without dispersive solvent but using ultrasounds; the other important novelty of this method of extraction regards the enrichment factors, that were demonstrated to be significantly high (up to 100,000). Methodological parameters such as the volume of surface water sample, the extraction solvent and relative volume, the time required for breaking emulsion and the salting-out effect have been investigated. Under the optimum experimental conditions (1L-volume of surface water sample, 300μL of isooctane as extraction solvent, 2min-ultrasound for the emulsion and 10minutes-agitation for breaking the emulsion, nitrogen stream for concentrating up to 10μL, analysis by GC-IT/MS) the method provides very good correlation coefficients (R2>0.99) in the range investigated, LODs and LOQs able to analyze such compounds in any water matrix (0.001–0.009pgμL−1 and 0.003–0.022pgμL−1, respectively), recoveries ranging 97–108%, inter- and intra-day precisions below 6.0% and 8.2%, respectively, for all PAHs. A comparison with other methods reported in literature demonstrates the reliability of such easy, cost-effective and reproducible methods. Finally, applications to nine different water samples are reported and discussed.

Neurotoxicity of alkylated polycyclic aromatic compounds in human neuroblastoma cells

ABSTRACTPolycyclic aromatic compounds (PAC) are ubiquitous environmental pollutants originating from incomplete combustion processes. While the toxicity of parent PAC such as benzo[a]pyrene (BaP) is well characterized, effects of other alkyl-PAC dibenzothiophene (DBT) and retene (Ret) are not well established. The aim of this study was to examine the underlying relative neurotoxic mechanisms attributed to BaP (parent PAH), DBT and Ret (alkyl-PACs) using human neuroblastoma SK-N-SH cells. The lethal concentrations (LC10 and LC20) were found at approximately 10 µM and 40 µM, respectively after 24-h exposure of SK-N-SH cells. It was hypothesized that PAC trigger reactive oxygen species (ROS) production, leading to activation of apoptotic signaling pathways. Differentiated neuronal cells were treated with three compounds at (0.5–40 µM) for 24 h. There was a significant concentration-dependent increase in levels of ROS, even at sub-lethal levels of 1 µM Ret. The mitochondrial membrane potential (MMP) was significantly decreased. Real-time RT-PCR results showed up-regulation of pro-apoptotic genes and down-regulation of antioxidative genes expression in BaP-, DBT-, and Ret-treated SK-N-SH cells. Cytochrome c protein levels and lipid peroxidation (LPO) were also significantly elevated in a concentration-related manner. Data demonstrated that BaP-, DBT-, or Ret-induced neuronal cell damage involved oxidative stress generation through mitochondria-mediated apoptosis pathway. Alkyl-PAC also exhibited higher potency in ROS induction and reduction of MMP than parent PAC. These findings may be important for environmental risk assessment attributed to exposure to PAC.

A numerical study on combustion process in a small compression ignition engine run dual-fuel mode (diesel-biogas)

In order to reduce the consumption of fossil fuel of a compression ignition (CI) engines which is usually used in transportation and heavy machineries, it can be operated in dual-fuel mode (diesel-biogas). However, the literature reviews show that the thermal efficiency is lower due to incomplete combustion process. In order to increase the efficiency, the combustion process in the combustion chamber need to be explored. Here, a commercial CFD code is used to explore the combustion process of a small CI engine run on dual fuel mode (diesel-biogas). The turbulent governing equations are solved based on finite volume method. A simulation of compression and expansions strokes at an engine speed and load of 1000 rpm and 2500W, respectively has been carried out. The pressure and temperature distributions and streamlines are plotted. The simulation results show that at engine power of 732.27 Watt the thermal efficiency is 9.05%. The experiment and simulation results show a good agreement. The method developed in this study can be used to investigate the combustion process of CI engine run on dual-fuel mode.

Investigating repetitive reaction pathways for the formation of polycyclic aromatic hydrocarbons in combustion processes

Repetitive hydrogen-abstraction and methyl- and acetylene-addition reaction sequences that contribute to the formation and growth of polycyclic aromatic hydrocarbons (PAHs) during incomplete combustion processes have been analyzed in flame-sampled electron ionization mass spectra. Specifically, we analyzed the range from C6H6 to C16H10 in the mass spectra obtained from atmospheric-pressure opposed-flow flames fueled by n-butane, i-butane, and i-butene, with conditions identical to those chosen by Schenk et al. [PAH formation and soot morphology in flames of C4 fuels, Proc. Combust. Inst. 35 (2015)1761-1769]. To assist the interpretation of the complex flame-sampled mass spectral data, this work elucidates the possibility for providing mechanistic insights from a simple analysis approach that does not convert the mass spectral data into isomer-resolved mole fraction profiles but solely is based on signal strength and ratios. While such an approach has not been exploited before, it is shown in this work that the repetitive nature of the observed quantitative signal ratios in the methyl- and acetylene-addition reaction sequences provides interesting insights into the overall features of flame-sampled mass spectra and the growth chemistry of PAHs. For the flames studied here, the similarity between the spectra obtained from the three different flames suggests that the signal ratios in the covered range are not fuel-structure dependent and that it is possible to draw mechanistic conclusions without knowing the isomer-specific chemistry. For example, the chemical growth pathways supported by this work suggest that other isomers besides pyrene contribute to the measured signal at m/z = 202u (C16H10), a result that adds concern regarding the general validity of the assumption of pyrene dimerization as the particle inception step.

Adaptive upregulation of DNA repair genes following benzo(a)pyrene diol epoxide protects against cell death at the expense of mutations.

A coordinated and faithful DNA damage response is of central importance for maintaining genomic integrity and survival. Here, we show that exposure of human cells to benzo(a)pyrene 9,10-diol-7,8-epoxide (BPDE), the active metabolite of benzo(a)pyrene (B(a)P), which represents a most important carcinogen formed during food preparation at high temperature, smoking and by incomplete combustion processes, causes a prompt and sustained upregulation of the DNA repair genes DDB2, XPC, XPF, XPG and POLH. Induction of these repair factors on RNA and protein level enhanced the removal of BPDE adducts from DNA and protected cells against subsequent BPDE exposure. However, through the induction of POLH the mutation frequency in the surviving cells was enhanced. Activation of these adaptive DNA repair genes was also observed upon B(a)P treatment of MCF7 cells and in buccal cells of human volunteers after cigarette smoking. Our data provide a rational basis for an adaptive response to polycyclic aromatic hydrocarbons, which occurs however at the expense of mutations that may drive cancer formation.

Atmospheric PAHs in North China: Spatial distribution and sources

Polycyclic aromatic hydrocarbons (PAHs), formed through incomplete combustion process, have adverse health effects. To investigate spatial distribution and sources of PAHs in North China, PAHs with passive sampling in 90 gridded sites during June to September in 2011 were analyzed. The average concentration of the sum of fifteen PAHs in North China is 220±14ng/m3, with the highest in Shanxi, followed by Shandong and Hebei, and then the Beijing-Tianjin area. Major sources of PAHs are identified for each region of North China, coke process for Shanxi, biomass burning for Hebei and Shandong, and coal combustion for Beijing-Tianjin area, respectively. Emission inventory is combined with back trajectory analysis to study the influence of emissions from surrounding areas at receptor sites. Shanxi and Beijing-Tianjin areas are more influenced by sources nearby while regional sources have more impact on Hebei and Shandong areas. Results from this study suggest the areas where local emission should be the major target for control and areas where both local and regional sources should be considered for PAH abatement in North China.

Load-Dependent Emission Factors and Chemical Characteristics of IVOCs from a Medium-Duty Diesel Engine

A detailed understanding of the climate and air quality impacts of mobile-source emissions requires the characterization of intermediate-volatility organic compounds (IVOCs), relatively-low-vapor-pressure gas-phase species that may generate secondary organic aerosol with high yields. Due to challenges associated with IVOC detection and quantification, IVOC emissions remain poorly understood at present. Here, we describe measurements of the magnitude and composition of IVOC emissions from a medium-duty diesel engine. Measurements are made on an engine dynamometer and utilize a new mass-spectrometric instrument to characterize the load dependence of the emissions in near-real-time. Results from steady-state engine operation indicate that IVOC emissions are highly dependent on engine power, with highest emissions at engine idle and low-load operation (≤25% maximum rated power) with a chemical composition dominated by saturated hydrocarbon species. Results suggest that unburned fuel components are the dominant IVOCs emitted at low loads. As engine load increases, IVOC emissions decline rapidly and become increasingly characterized by unsaturated hydrocarbons and oxygenated organics, newly formed from incomplete combustion processes at elevated engine temperatures and pressures. Engine transients, including a cold-start ignition and engine acceleration, show IVOC emission profiles that are different in amount or composition compared to steady-state combustion, underscoring the utility of characterizing IVOC emissions with high time resolution across realistic engine operating conditions. We find possible evidence for IVOC losses on unheated dilution and sampling surfaces, which need to be carefully accounted for in IVOC emission studies.

Can positive matrix factorization help to understand patterns of organic trace gases at the continental Global Atmosphere Watch site Hohenpeissenberg?

Abstract. From the rural Global Atmosphere Watch (GAW) site Hohenpeissenberg in the pre-alpine area of southern Germany, a data set of 24 C2–C8 non-methane hydrocarbons over a period of 7 years was analyzed. Receptor modeling was performed by positive matrix factorization (PMF) and the resulting factors were interpreted with respect to source profiles and photochemical aging. Differing from other studies, no direct source attribution was intended because, due to chemistry along transport, mass conservation from source to receptor is not given. However, at remote sites such as Hohenpeissenberg, the observed patterns of non-methane hydrocarbons can be derived from combinations of factors determined by PMF. A six-factor solution showed high stability and the most plausible results. In addition to a biogenic and a background factor of very stable compounds, four additional anthropogenic factors were resolved that could be divided into two short- and two long-lived patterns from evaporative sources/natural gas leakage and incomplete combustion processes. The volume or mass contribution at the site over the entire period was, in decreasing order, from the following factor categories: background, gas leakage and long-lived evaporative, residential heating and long-lived combustion, short-lived evaporative, short-lived combustion, and biogenic. The importance with respect to reactivity contribution was generally in reverse order, with the biogenic and the short-lived combustion factors contributing most. The seasonality of the factors was analyzed and compared to results of a simple box model using constant emissions and the photochemical decay calculated from the measured annual cycles of OH radicals and ozone. Two of the factors, short-lived combustion and gas leakage/long-lived evaporative, showed winter/summer ratios of about 9 and 7, respectively, as expected from constant source estimations. Contrarily, the short-lived evaporative emissions were about 3 times higher in summer than in winter, while residential heating/long-lived combustion emissions were about 2 times higher in winter than in summer.

Analysis of the Effect of Preheating System to Improve Efficiency in LPG-fuelled Small Industrial Burner

Abstract Nowadays, industries have been using combustion system as one of energy supply in their utility system. However, incomplete combustion process often takes place in the process, which resulted in several disadvantages for the industry such as less energy efficiency, higher CO emission and higher production cost. The aimed of this study was to understand characteristics and increasing combustion efficiency in fuel preheating system technology and to find out the effect of various initial temperature of LPG to combustion efficiency and CO emission. Results showed that increasing initial temperature of LPG from 28 °C to 50 °C would raise efficiency of the burner up to 6.75% while CO emissions decreased 49.06%. Furthermore, if the temperature increased up to 100 °C the burner efficiency would raise significantly and CO emissions considerably decreased.

Measurement of atmospheric black carbon in the Vaal Triangle and Highveld Priority Areas

Atmospheric black carbon is an important atmospheric pollutant; it has impacts on human health and a strong climate impact. Black carbon particles are functionally defined by their optical properties (viz. characteristics in light absorption). As a result, black carbon particles are derived from a wide range of sources, but are largely the result of incomplete combustion processes. In order to quantify the atmospheric load of black carbon particles, multi angle absorption photometer (MAAP) instruments have been installed in 8 of the ambient air quality monitoring stations in the Vaal Triangle and Highveld Priority areas. Three of the instruments have been in operation since 2012 and the other 5 were installed in August 2013. This paper presents an analysis of the initial black carbon monitoring data. The impacts of seasonality and meteorological conditions as well as the relationship of the black carbon concentration to PM10 and PM2.5 concentrations are discussed.

Formation of Oxygenated and Hydrocarbon Intermediates in Premixed Combustion of 2-Methylfuran

Abstract This paper focuses on the combustion chemistry of 2-methylfuran (2-MF), a potential biofuel, and it is built on the previous work of Tran et al. [Combust. Flame 161 (2014) 766]. In their work, they had combined detailed flame chemistry modeling with flame speciation data based on flame-sampling molecular beam mass spectrometry (MBMS) with electron ionization and gas chromatography with MS detection. In this work, we significantly extend those previous studies by in-situ isomer-resolving species identification and quantification. Specifically, we have determined the detailed chemical structure of a premixed laminar 2-MF flame using flame-sampling high-resolution MBMS with synchrotron-generated vacuum-ultraviolet radiation. Mole fraction profiles of 60 intermediate, reactant, and product species were measured in order to assess the pollutant potential of this possible next-generation biofuel. Special emphasis is paid towards the fuel's ability to form aromatic and oxygenated intermediates during incomplete combustion processes, with the latter species representing a variety of different classes including alcohols, ethers, enols, ketones, aldehydes, acids, and ketenes. Whenever possible the experimental data are compared to the results of model calculations using the 2-MF combustion chemistry model of Tran et al., but it should be noted that many newly detected species are not included in the calculations. The experimental data presented in this work provides guidance towards to development of a next-generation 2-MF combustion chemistry model.

Optimization of aircraft fuel consumption and reduction of pollutant emissions: Environmental impact assessment

Environmental impact of aircraft emissions can be addressed in two ways. Air quality impact occurs during landings and takeoffs while in-flight impact during climbs and cruises influences climate change, ozone and UV-radiation. The aim of this paper is to investigate airports related local emissions and fuel consumption (FC). It gives flight path optimization model linked to a dispersion model as well as numerical methods. Operational factors are considered and the cost function integrates objectives taking into account FC and induced pollutant concentrations. We have compared pollutants emitted and their reduction during LTO cycles, optimized flight path and with analysis by Dopelheuer. Pollutants appearing from incomplete and complete combustion processes have been discussed. Because of calculation difficulties, no assessment has been made for the soot, <TEX>$H_2O$</TEX> and <TEX>$PM_{2.5}$</TEX>. In addition, because of the low reliability of models quantifying pollutant emissions of the APU, an empirical evaluation has been done. This is based on Benson's fuel flow method. A new model, giving FC and predicting the in-flight emissions, has been developed. It fits with the Boeing FC model. We confirm that FC can be reduced by 3% for takeoffs and 27% for landings. This contributes to analyze the intelligent fuel gauge computing the in-flight fuel flow. Further research is needed to define the role of <TEX>$NO</TEX><TEX>_x$</TEX> which is emitted during the combustion process derived from the ambient air, not the fuel. Models are needed for analyzing the effects of fleet composition and engine combinations on emission factors and fuel flow assessment.

On-Roadway In-Cabin Exposure to Particulate Matter: Measurement Results Using Both Continuous and Time-Integrated Sampling Approaches.

The Atlanta Commuters Exposure (ACE) Study was designed to measure in-cabin exposure to roadway particulate pollution and acute health response in a panel of adults with and without asthma following a 2-h scripted route along major highways in Atlanta. This article focuses on methods and results of both continuous and integrated approaches used to measure the concentration of PM2.5 mass, particle number concentration (PNC), black carbon (BC) mass, and particle-bound PAHs, in-cabin noise, PM elemental composition, elemental carbon, organic carbon, water-soluble organic carbon (WSOC) content, and speciation of a broad range of organic compounds including alkanes, hopanes, and PAHs. Speciated PM data indicates that in-cabin particles derive from three non-co-varying processes: the resuspension of road dust containing crustal elements and previously-deposited brake pad residue with a contribution of normal fuel combustion, incomplete combustion processes producing PAHs and carbon particles, and particles ablated from brake pads that have not previously deposited to the roadside environment. Most in-cabin pollutants were elevated during the warm season with the notable exception of PNC. PNC was not found to be correlated with most other pollutants. In-cabin concentrations were marginally higher when windows were open.

Investigation of Thermoelectric Power Generation Module on Waste Heat Recovery in a Downdraft Gasifier

In this study, the thermoelectric power generation (TEG) module is used to recover waste heat from a downdraft gasifier. The performance and optimal operating temperature of TEG module are studied at different locations on the surface wall of catalyst reactor. The simulation model of downdraft gasifier is performed by using the Fire Dynamics Simulator (FDS), its appropriate for the low-speed, thermally-driven flow simulation with an emphasis on incomplete combustion process. The results demonstrate that the simulation temperature of catalyst reactor surface is around 200°C~300°C which is used to convert heat into electricity by TEG module. In summary, the TEG modulus power per unit area can reach 857W/m2 with temperature difference of 140°C and output power attain at least 2.04kW if TEG modulus is applied on the improved downdraft gasifier system (IDGS).

Risk assessment and spatial chemical variability of PM collected at selected bus stations

The chemical characterization of particulate matter inside and outside of confined bus shelters has been discerned for the first time. Transit patrons are at risk due to the close vicinity of densely trafficked areas resulting in elevated pollution footprints. Incomplete combustion processes, as well as exhaust and wear and tear emissions from public and personal transportation vehicles, are key contributors to degraded urban air quality and are often implicated as causal to various diseases in humans. Urban planning, therefore, includes efficient public transport systems to mitigate the effect. The bus rapid transit system was inaugurated in Curitiba to ensure dedicated traffic lanes, major bus interchanges and semi-confined bus stops called “tube stations”. To assess the chemical risk that the passengers are exposed to, an investigation of the aerosol inside and outside five of these tube stations was launched. Electron probe X-ray micro-analysis and X-ray fluorescence were used to determine the elemental composition of individual and of bulk particle samples. An aethalometer quantified the black carbon. Elemental concentrations inside the shelters were in general higher than outside, especially for traffic-related elements. The lead concentration exceeded the NAAS standard at times, although the average was below the guideline. The biogenic, organic and soot clusters showed the highest abundance for the city centre sites. The overall carcinogenic risk could be classed as moderate, and the risk was significant at two sites during one of the sampling campaigns. The non-carcinogenic risk is well below the significant value.

Exclusive prenatal exposure to a 16 PAH mixture does not impact anxiety-related behaviours and regional brain metabolism in adult male rats: A role for the period of exposure in the modulation of PAH neurotoxicity

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants originating from incomplete combustion processes. Humans are mainly exposed through contaminated food ingestion. PAHs are neurotoxic compounds both for human and rodents, and may be found in placenta, umbilical cord blood and breast milk, suggesting that early exposure may impact developing central nervous system.In a previous study we showed that PAH exposure during both gestation and lactation periods in rats increased anxiety-related behaviours and decreased cerebral metabolism in several key structures linked to the limbic system on male pups at the adult stage. The aim of the present study was to assess the effects of an exclusive gestational PAH exposure on the same aspects of brain functionality. Female rats were exposed through diet to a 16 PAH mixture at doses of 2μg/kg/day or 200μg/kg/day during gestation. Late neurotoxic effects were evaluated by carrying out behavioural and cognitive tests and histochemical analyses using cytochrome oxidase activity as a cerebral metabolism marker in different brain areas.The results of this study revealed that behaviour and cerebral metabolism on prenatally PAH exposed adult rats was not significantly affected by the exposure to these pollutants.Finally this work highlights that the exposure period to pollutants such as PAHs at very early stages of development play a key role on the neurological impairment induced.

Establishment of a cell‐free bioassay for detecting dioxin‐like compounds

Dioxins are byproducts from incomplete combustion processes and belong to a group of mostly toxic chemicals known as persistent organic pollutants, and 2, 3, 7, 8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is considered to be the most toxic species of all dioxin‐like compounds. Analytical chemical processes are employed to determine the specific dioxin content in environmental samples. However, cost‐ineffectiveness and excess time consumption limit their routine utilization. The aryl hydrocarbon receptor (AhR) is the major TCDD receptor. Upon binding to dioxin, the AhR dissociates from Hsp90 and other cofactors. TCDD‐bound AhR subsequently translocates to the nucleus and interacts with the AhR nuclear translocator (Arnt) to induce signal transduction. Here, we describe a highly sensitive and cost‐effective alternative assay based on detecting stability of bioluminescence signals. We generated AAPA cells that stably coexpress Renilla luciferase tagged‐AhR (AhR‐RL), Ah receptor‐interacting protein (AIP), p23 and yellow fluorescent protein‐tagged Arnt (Arnt‐YFP). Treatment with 3‐methylcholanthrene (3MC), a dioxin agonist, enhanced the interaction between AhR and Arnt and avoided proteosomal degradation. In addition, treatment with 3MC and TCDD stabilized Renilla luminescence in AhR‐RL of AAPA cell‐free extracts in a concentration‐dependent manner. The TCDD detection limit in this cell‐free system was as low as 10−18 M. These results highlight the potential of AAPA cell‐free extracts to detect dioxin‐like pollutants.

Establishment of a cell-free bioassay for detecting dioxin-like compounds

Dioxins are byproducts from incomplete combustion processes and belong to a group of mostly toxic chemicals known as persistent organic pollutants, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is considered to be the most toxic species of all dioxin-like compounds. Analytical chemical processes are employed to determine the specific dioxin content in environmental samples. However, cost-ineffectiveness and excess time consumption limit their routine utilization. The aryl hydrocarbon receptor (AhR) is the major TCDD receptor. Upon binding to dioxin, the AhR dissociates from Hsp90 and other cofactors. TCDD-bound AhR subsequently translocates to the nucleus and interacts with the AhR nuclear translocator (Arnt) to induce signal transduction. Here, we describe a highly sensitive and cost-effective alternative assay based on detecting stability of bioluminescence signals. We generated cells that stably co-express Renilla luciferase tagged-AhR (AhR-RL), Ah receptor-interacting protein (AIP), p23 and yellow fluorescent protein-tagged Arnt (Arnt-YFP) (AAPA cells) for detection of dioxin-like compounds. Treatment with 3-methylcholanthrene (3MC), AhR agonist, enhanced the interaction between AhR and Arnt and avoided proteosomal degradation. In addition, treatment with 3MC or TCDD stabilized Renilla luminescence from AhR-RL of AAPA cell-free extracts in a concentration-dependent manner. The TCDD detection limit in this cell-free system was as low as 10−18 M. These results highlight the potential of AAPAA cell-free extracts to detect dioxin-like pollutants.

Removal of formaldehyde by adsorption and plasma treatment of mineral adsorbent

Formaldehyde is a harmful ambient air pollutant which can be produced by incomplete combustion processes, e.g. in power plants or automobiles. In this work a cycled adsorption and discharge process using mineral granulate in a packed bed dielectric barrier discharge plasma reactor was applied for formaldehyde (99 ppm) removal from gas streams. The mineral granulate used consisted of 80% halloysite and showed a good adsorption capacity for formaldehyde. In the discharge step, the adsorbed formaldehyde molecules were decomposed to COx and hydrocarbons in a N2 plasma at a low input discharge power of 2.2 W. The decomposition performance on adsorbed formaldehyde molecules was studied depending on space–time, a specific oxygen fraction of the carrier gas and the influence of temperature. With rising N2 space times in the discharge area, the total amount of decomposed formaldehyde molecules increased and the decomposition reaction mechanism shifted to CO2 formation. An oxygen fraction in the carrier gas further raised the oxidized amount of formaldehyde to CO2. The mineral granulate showed satisfied regeneration ability during the cycled plasma process.