Potential of Integrated Emissions Reduction ... - ACS Publications

May 25, 2017 - ABSTRACT: Firewood combustion is the main renewable heating source for households in Europe and is responsible for a certain share of ...
0 downloads 14 Views 2MB Size
Subscriber access provided by CORNELL UNIVERSITY LIBRARY

Article

Potential of integrated emissions reduction systems in a firewood stove under real life operation conditions Marius Wöhler, Dirk Jaeger, Stefan K. Pelz, and Harald Thorwarth Energy Fuels, Just Accepted Manuscript • Publication Date (Web): 25 May 2017 Downloaded from http://pubs.acs.org on May 27, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Energy & Fuels is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Potential of integrated emissions reduction systems in a firewood stove under real life operation conditions Marius Wöhler†‡, Dirk Jaeger‡, Stefan K. Pelz†, Harald Thorwarth†* †

University of Applied Forest Sciences Rottenburg, Schadenweilerhof, 72108 Rottenburg am

Neckar, Germany ‡

University of Freiburg, Chair of Forest Operations, Werthmannstraße 6, 79085 Freiburg im

Breisgau, Germany

Abstract Firewood combustion is the main renewable heating source for households in Europe and responsible for a certain share of harmful emissions such as particle matter. Common wood combustion appliances in households are firewood stoves. Forced by stringent limits of European emission control legislations, the stove industry developed a wide variety of new pollution control technologies which can be integrated into firewood stoves. The aim of this study was to evaluate the performance of three emission control systems to be applied in firewood stoves which were a foam ceramic element, a catalytic active coated foam ceramic element and a

ACS Paragon Plus Environment

1

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 29

honeycomb catalyst. Combustion tests with these devices and dummies under real life operation conditions were conducted which included starting phases and stove operation in nominal and partial load. Particulate and gaseous emissions were measured and emission conversion rates were calculated. Results showed no significant emission reduction rates for the foam ceramic element. The catalytic active coated foam ceramic element reduced the emissions considerably in nominal and partial load operation up to 32% for carbon monoxide, 61% for organic gaseous carbon and up to 41% for particulate matter. However, emission reduction rates were rather low in the starting phase. The honeycomb catalyst showed the highest emission reduction potential of all systems in the study. The reduction rates were significant in all combustion phases and were up to 73% for carbon monoxide, 58% for organic gaseous carbon and up to 33% for particulate matter.

1. Introduction Wood combustion is the main sustainable energy source for residential heating in Europe 1. The main advantage of using sustainable produced wood is the substitution of fossil fuels and consequently a reduction of greenhouse gas emissions into the atmosphere. However, emissions from wood combustion have become one of the major sources for particulate matter (PM) especially in winter time in urban areas 2–11. Various studies showed that PM emissions and also gaseous emissions such as polycyclic aromatic hydrocarbons (PAH), soot and tar from wood combustion can seriously affect public health.

11–17

. The most common wood combustion

appliances in households are small-scale residential wood combustion (RWC) units. The majority of these units are firewood stoves and they are mainly used as direct room heaters (i.e. without a water jacket). The stock of these appliances is estimated to be higher than 25 million in Europe 18.

ACS Paragon Plus Environment

2

Page 3 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

In general, emissions from wood combustion vary widely due to the type of combustion technology (e.g. automatically and manually stoked combustion systems) and type of fuel (e.g. firewood, wood chips, wood pellets)

15,19–21

.

Batch wise firewood stoves are mainly

characterized by a natural convection driven combustion. Thus, the combustion quality is limited compared to automatically controlled systems such as firewood or pellet boilers

21–26

. In

principle, the performance (i.e. emissions and efficiency) of firewood stoves depend on many factors such as combustion technology user behavior

33,37–39

27–29

, installation conditions

30–33

, fuel quality

34–36

and

. In recent years, emission control legislation with more stringent limits

forced the European stove industry to develop advanced firewood stoves with reduced emissions and increased efficiency 40. For this reason, a wide variety of new pollution control technologies are available on the market. In general, pollution control technologies in combustion units can be assigned to primary measures which influence the combustion directly and secondary measures which reduce emissions after the combustion. In the case of natural-draught driven firewood stoves secondary measures may influence the gas flow and pressure conditions in the combustion chamber and therefore they have a primary and secondary effect on emissions

41

. One market

available technology for emission reduction in firewood stoves are foam ceramic elements which are installed at the upper end of the combustion chamber instead of a deflection plate. These foam ceramic elements are available with and without catalytic active coating and they may have primary and secondary effects on the combustion in firewood stoves catalysts are used for emission reduction in firewood stoves

44,45

42,43

. Also honeycomb

. They are normally assigned to

secondary emission reduction measures due to their low flow resistance and integration after the combustion chamber.

ACS Paragon Plus Environment

3

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 29

In Europe, stoves and secondary pollution control technologies have to be tested according to testing standards (e.g. EN 13240

46

) prior commercial launch. However, such testing differs

considerably from real life operation of stove users

31,37,38,47

and therefore a different emission

composition can be assumed. Till now, the performance of the aforementioned integrated air pollution control devices (APCDs) has not been evaluated under real life operation conditions. Therefore, the aim of this study was to evaluate the performance of integrated foam ceramic elements, catalytic active coated foam ceramic elements and a honeycomb catalyst in a firewood stove under real life operation conditions.

2. Material and Methods 2.1. Test facility All combustion tests were performed with an 8 kW firewood stove which is sold under the brand name “Hark 44 GT ECOplus” from the company Hark GmbH & Co. KG, Germany. The stove was purchased in April 2016 and installed at the combustion facility of the University of Applied Sciences Rottenburg (Germany). The manually loaded stove is certified to fulfill the current German emission standard (Federal emission control act - 1. BImSchV). The stove provides combustion air staging with separate manually controlled primary and secondary air. The primary air enters the combustion chamber through a grate on the bottom and the secondary air via 15 nozzles on the back wall of the combustion chamber. In the original version of the stove, approximately 50% of the upper end of the combustion chamber was covered by a ceramic foam element. The element consisted of two ceramic foam plates which are placed obliquely on top of the combustion chamber with bypasses between the plates and the supporting points (see Figure 1).

ACS Paragon Plus Environment

4

Page 5 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Figure 1 Picture of upper combustion chamber part and detailed view on bypasses (marked with red arrows) 2.2. Test set up The combustion test set up followed a method described in 47 which differed slightly from the common European standard EN 13240

46

. Figure 2 shows the test set up which consisted of a

measurement section which was installed above the stove. The draught of the measurement section was constantly controlled to 12 ± 2 Pa for all test runs. For online gas sampling the measurement section was equipped with a suction probe and a centrally placed K-type thermocouple (Emko) for a temperature measurement of the flue gas (TFG). A multi-gas analyzer (Uras26 NDIR photometer, ABB Ltd.) was used for carbon monoxide (CO) and carbon dioxide (CO2) measurement. Oxygen (O2) was measured with a paramagnetic oxygen analyzer (Magnos 206, ABB Ltd.). Organic gaseous carbon (OGC) was measured with a flame ionization detector (Fidas24, ABB Ltd.). The emissions of OGC are presented in methane equivalents. The tube between the measurement section and the gas analyzers was heated to 180°C to avoid condensation of hydrocarbons. Emissions and temperatures were determined continuously over the test period with a time resolution of one second in the undiluted flue gas. Calibrations of the

ACS Paragon Plus Environment

5

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 29

gas measurement devices were done prior to every test day by built-in calibration cells for the multi-gas analyzer and test gas for the O2 and OGC analyzers. The measuring range and accuracy of the gas analyzers are given in Table 1. PM was measured gravimetrically by using out-stack filtration in an undiluted flue gas stream. A filter was heated to 180°C and sampling was conducted by using a sampling nozzle of 12 mm inner diameter and a constant sampling rate of 10 l/min (STP). The micro-glass filters (Munktell MG 160) which were used were thermally treated for one hour at 200°C before and at 180°C after each measurement and equilibrated in the desiccator with silica gel for 12 hours. The total sampled mass was determined by weighting the filter with an analytic balance (Sartorius CPA124S, readability 0.1 mg) before and after sampling.

ACS Paragon Plus Environment

6

Page 7 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Figure 2 Sketch of test set up

2.3. Test procedure For combustion experiments two test cycles were defined which considered combustion phases in typical real life operation

47

. The long test cycle consisted of eight consecutive combusting

batches and the short test cycle consisted of five consecutive combusting batches. The batches were attributed to starting phase, nominal load and partial load operation. Figure 3 shows the sequence of batches, the used amount of fuel and the positions of the primary (PA) and secondary (SA) combustion air valves for the long test cycle (above) and the short test cycle (below). Two long cycles and one short cycle were conducted for the ceramic foam element

ACS Paragon Plus Environment

7

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 29

(CFE) and the honeycomb catalyst (HC) configuration. The catalytic ceramic foam element (CCFE) configuration was tested with two long cycles. One test day started with batch one and ended after the last batch. The instant of fuel refilling at the end of the batch and after the last batch was defined when CO2 level dropped below 3 vol.%. Gaseous and PM emission measurement started immediately after lighting the first fuel batch or fuel refilling. PM stopped three minutes before refilling (i.e. to change the filter) and gaseous emissions were measured online during the entire batch.

Figure 3 Sequence of batches during long test cycle (above) and short test cycle (below) 2.4. Tested Air Pollution Control Devices In this study combustion tests with three APCDs were performed. For the evaluation of the emission reduction rates comparative baseline test results were needed. In the case of the used firewood stove (with integrated foam ceramic) combustion tests without any integrated element were not possible due to the considerable change of the primary combustion conditions (i.e. flow

ACS Paragon Plus Environment

8

Page 9 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

resistance). Therefore dummies were prepared for the baseline tests which offered similar flow resistance compared to the ceramic foam elements. To evaluate the flow resistance of the baseline dummy and the APCDs a measurement device was used. It consists of an airtight box with one open side and a connection hose to the leakage tester Wöhler DP 600 (Wöhler Technik GmbH). The leakage tester provides an adjustable airflow and a pressure measurement. For testing, the filter plates were placed in the open top of the box (i.e. on holders) and a defined airstream was blown into the box while the pressure was measured within the box. Figure 4 shows the results of the flow resistance tests.

Figure 4 Results of flow resistance tests 2.4.1. Ceramic foam element (CFE) The provided ceramic element which was installed in the original version of the stove was used. This device consists of two uncoated open-celled ceramic plates (20x20x2.5 cm). For comparative measurements a dummy (DYI) was prepared. It consists of two vermiculite plates

ACS Paragon Plus Environment

9

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 29

with drilled holes which provide a similar flow resistance like the CFE (see Figure 4). The dummy was integrated in the same way (i.e. with the same bypasses) as the CFE (see Figure 5).

Figure 5 Ceramic foam filter (left) and corresponding dummy (right) 2.4.2. Catalytic ceramic foam element (CCFE) The element consists of an open-celled ceramic with a catalytic coating which contains platinum, palladium and rhodium. The system is sold under the brand name “OfenKAT®” from the company Linder-Katalysatoren GmbH. For combustion tests the CCFE was integrated instead of the original foam ceramic plates according to the manufacturer specifications which included the bypasses of the original stove version. In addition a dummy (DYII) with similar flow resistance was prepared (see Figure 6).

Figure 6 Foamed ceramic catalyst (left) and corresponding dummy (right)

ACS Paragon Plus Environment

10

Page 11 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

2.4.3. Honeycomb catalyst (HC) The catalyst with the brand name “ENVICAT Longlive PLUS” is produced from the company CLARIANT INTERNATIONAL LTD and consists of a stainless round (18 cm in diameter) honeycomb shaped stainless carrier with a catalytically noble metal coating. The catalyst was integrated downstream of the stove’s heat exchanger before the exhaust gas outlet without a bypass (see Figure 7); the dummy (DYI) which offers similar flow resistance conditions like the original stove was installed. Due to the integration position of the HC no primary effect on the combustion can be assumed (i.e. low flow resistance). Therefore no dummy tests were conducted and results were compared with the baseline tests with the DYI dummy.

Figure 7 Integrated honeycomb catalyst 2.5. Fuel Beech firewood according to EN ISO 17225-5 class A1

48

was used for all combustion tests.

The firewood was produced from two trees of the same tree population in Southern Germany in cooperation with a forest company (Brennholz Zentrum Bickelsberg). The firewood was first technically dried (i.e. in a drying chamber) and afterwards stored under a roof outside for several weeks to equilibrate the water content. Table 2 shows the relevant fuel parameters.

2.6. Data evaluation

ACS Paragon Plus Environment

11

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

CO emissions, heat output and efficiency evaluation were done according to EN 13240 OGC were evaluated according to CEN/TS 15883

50

Page 12 of 29

49

.

. All presented results are arithmetic mean

values and they were calculated for standard conditions for temperature and pressure (STP i.e. 273 K and 1013 hPA) and normalized to volumetric oxygen content (O2 ref) of 13 vol.-% in the flue gas. Time weighted results were evaluated separately for the starting phase, nominal load, partial load and for all test batches. The performance evaluation of the integrated air pollution control devices were done by calculation of the emission conversion rates (ECR). Therefore the results gained with the dummy were compared to the results with the integrated reduction systems according to Equation 1. Equation 1 Calculation of emission conversion rate

 =

 −  × 100 [%] 

CD Emission concentration with integrated dummy CC Emission concentration with integrated converter

Student’s t-test was used to identify statistical differences between the emission values of the different stove configurations (α=0.05). In this paper the following interpretations are used for the p values resulting by Student´s t-tests: p < 0.01

highly significant difference or correlation

p < 0.05

significant difference or correlation

0.32 ≤ p ≥ 0.05

no significance, but a clear trend of difference or correlation

p > 0.32

no significance and no trend of difference or correlation

3. Results and Discussion

ACS Paragon Plus Environment

12

Page 13 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

The results of the combustion tests were evaluated separately for the used APCDs. Figure 11 shows all results in a graphical overview. 3.1. Ceramic foam element (CFE) The conversion rates of the CFE were evaluated by comparison of the combustion tests results with the results of the dummy (DYI) tests. Table 3 shows the combustion results of the CFE and the results of the corresponding dummy. The results showed similar values for residual oxygen, flue gas temperature and heat output in both stove configurations. This indicates that comparable combustion conditions during tests in both stove configurations were achieved due to the use of a dummy with similar flow resistance properties. Figure 8 shows the emission conversion rates of the CFE for CO, OGC and PM emissions in the different combustion phases and for all batches. The values showed partly negative conversion rate (i.e. for CO and OGC) which implements higher emissions in operation with the CFE compared to dummy operation. The highest emission conversion rates are seen in partial load operation. In the evaluation of all batches, the conversion rates for CO (-7%) and OGC (24%) were negative. Only for PM the conversion rate was positive with 3%. However, in the evaluation of all batches the CFE did not reduced CO, OGC and PM emissions significantly (CO: p=0.93; OGC: p=0.64; PM: p=0.84).

ACS Paragon Plus Environment

13

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 29

Figure 8 Conversion rate of ceramic foam element Based on available studies

51,52

the expected effect of the integration of a ceramic foam

element in a firewood stove is the reduction of PM by filtration. However, results indicated that this filtration mechanism did not work in the tested firewood stove and CFE combination which is in line with results of Hartmann et al.

53

. The gained results could be explained by a limited

flow through the ceramic foam element due to the integration position with bypasses. Furthermore, due to the fact that there are no catalytic active centers on the surface of the CFE, also no surface related catalyzed chemical reaction is to be expected. 3.2. Catalytic ceramic foam (CCFE) The conversion rates of the CCFE were evaluated by comparison of the combustion tests results with the results of dummy (DYII) tests (see Table 4). Also in this stove configuration comparable combustion conditions were achieved which is indicated by the similar values for residual oxygen, flue gas temperature and heat output.

ACS Paragon Plus Environment

14

Page 15 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

The CCFE showed different conversion rates in the different combustion phases (see Figure 9). In the evaluation of all batches the conversion rate for CO was 20% and the differences were highly significant (p=0.02). For OGC the conversion rate of all batches was 31% and a statistical clear trend was observed (p=0.06). The PM conversion rate was 29% and the results were also significantly different from the dummy results (p=0.02). In total the CCFE showed a considerable emission reduction especially in nominal and partial load operation which is in line with other studies

53

. The measured emission reduction rate can be explained by the basically

known effect of catalysts on the emissions of wood combustion appliances 45,54. In the case of the CCFE, catalytic supported gas reactions can be assumed even on the surface of the whole element. Therefore a gas flow through the element which is limited due to the bypasses is not necessarily required for emission reduction. An additional filtration effect of the CCFE on PM emissions cannot be separately measured by the used testing method.

Figure 9 Conversion rate of foamed ceramic catalyst 3.3. Honeycomb catalyst (HC)

ACS Paragon Plus Environment

15

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 29

The results for the combustion tests with the HC are given in Table 5. The conversion rates were calculated in combination with the results of the DYI dummy (see Table 3). The CO conversion rate calculated for all batches was 70% and highly significant (p= 0.00). The conversion rate for OGC was 55% for all batches and also highly significant (p=0.00). For PM for all batches the conversion rate was 27% which was significant (p=0.04). However, the reduction rate for PM was slightly lower compared to the CCFE values. The integration of the HC showed the highest emission reduction rates of all APCDs. The measured CO conversion rate is in the range of other wood combustion studies 54,55.

Figure 10 Conversion rate of honeycomb catalyst

ACS Paragon Plus Environment

16

Page 17 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Figure 11 Results of combustion tests

ACS Paragon Plus Environment

17

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 29

Table 6 shows the p-values for the different combustion phases of all tested APCDs.

The total view on all combustion test results show a considerably influence of the combustion phases on the emissions. The highest PM emissions were measured in the starting phases and the gaseous emissions were comparably high in the starting and nominal load operation which is in line with other studies 56–58. These differences are related to varying combustion conditions such as temperature, condition of the firebed (i.e. amount of ember) and different air-fuel ratios

59

.

The aim of the integration of APCDs should be to reduce emissions especially in the combustion phases with high emissions. The two functional APCDs of this study (CCFE and HC) showed different emissions reduction potential in the starting phase. The CCFE showed very low PM conversion rates in the starting phase (2%) while the HC showed the highest conversion rate in this phase (33%). These differences may be explained by different gas flow behaviors (e.g. due to bypasses) and heating-up rates of the different carrier materials which influence the catalytic reaction

60

. Further research is needed to verify the different functionality of the APCDs in the

high emission phases. Therefore also current type testing standards for firewood stoves should be reconsidered which requires tests exclusively in nominal load heating operation. New type testing methods which reflect real life operation (i.e. including starting phase) would trigger research and industry to continue research and development towards stoves and APCDs with low emissions also in real life operation. The functionality of the CCFE and HC is based on a catalytic active coating. In this study the emission reduction rates were measured with new devices. However, the performance of catalysts is not stable and may change after a certain period of operation. Bindig et al. (2012) measured reduced reduction rates of total hydrocarbons, methane and acetylene of a catalyst after

ACS Paragon Plus Environment

18

Page 19 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

16 hours of use in a firewood stove 61. In this study the CCFE and HC were used for around 12 to 16 hours without changes of the CO, OGC and PM reduction rates. However, further long-term experiments are needed to verify the reduction performance of several heating seasons. These tests should consider the user behavior in real life operation such as varying fuel quality, insufficient ignition material (e.g. newspapers) and user maloperation. The integration of the APCDs in this study was different in terms of bypasses. The CFE and CCFE were installed according to the manufacturer requirements with a considerable number of bypasses. The HC was installed without any bypass. It can be assumed that the integration situation influence the emission reduction rates due to different gas flow and temperature behavior. However, the integration without any bypasses may cause the risk of clogging the system in long term operation. Therefore further long-term research is needed.

4. Conclusion This paper presents the results of the evaluation of three air pollution control devices which were integrated into an 8 kW firewood stove. Therefore combustion tests with an integrated foam ceramic element, a catalytic active coated foam ceramic element and a honeycomb catalyst under real life operation conditions were conducted.

Tests were evaluated for different

combustion phases (i.e. starting phase, nominal and partial load) which were characterized by different emissions levels. The results showed no significant CO, OGC and PM reduction rates for the foam ceramic element which may be caused by the limited flow through the device due to the integration position with bypasses and the missing catalytic active surface. The tested catalytic active ceramic foam element showed a significant emission reduction potential by evaluation of all test batches and in nominal and partial load operation. This effect can be

ACS Paragon Plus Environment

19

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 29

assigned to catalytic supported gas reactions on the surface which not necessarily requires a gas flow through the element. However, the reduction was limited in the starting phase which is characterized by comparably high emissions. Therefore, further development with a focus on emission reduction in the starting phase is needed. In total, the honeycomb catalyst showed the highest emission reduction potential of all systems in the study. These results can also be assigned to catalytic gas reactions on the catalyst surface which was supported by the integration position without bypasses. The reduction rates were measured in all combustion phases which imply a significant emission reduction in the real life operation of the firewood stove which should be the goal of such emission reduction systems. In summary, the presented results show an emission reduction potential of two catalytic based APCDs and an existing foam ceramic element that was insignificant in terms of its air pollution control functionality. Based on the given results further research in terms of long-term stability of catalytic systems, potential risk of clogging and possible impact on emission properties (e.g. particle size distribution, chemical composition) should be investigated. Based on the given results and further development steps APCDs may help the industry to provide in future firewood stove with low emission and high efficiency combustion in real life operation.

5. Acknowledgments The authors gratefully acknowledge the support of the LUBW Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg.

ACS Paragon Plus Environment

20

Page 21 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Table 1 Technical specifications of gas analyzers Analyzer

Measuring range

Accuracy

CO low: 0…1,000 ppm Uras26 NDIR

≤ 1% of measuring range

CO high: 0…20,000 ppm

(automatic measurement range adaptation)

CO2: 0…20% Magnos 206

O2: 0…25%

≤ 0.5% of measuring range

FID low: 0…100 mg/m³

≤ 2% of measuring range

FID high: 0…10,000 mg/m³

(automatic measurement range adaptation)

Fidas24

Table 2 Firewood properties and measurement methods Parameter

Unit

Value

Standard

Water a

[wt.-%]

11.6

DIN CEN/TS 14774-2:2004

Ash a

[wt.-%]

0.4

DIN EN 14775:2010

Net caloric value b

[MJ/kg] 15.6

DIN CEN/TS 14918:2005

Elements C / H / N / S b

[wt.-%]

49.1 / 6 / 0.1 / 0.02

DIN CEN/TS 15104:2005

Length of wood pieces

[cm]

30

a

as received (wet base) / b dry base

Table 3 Results of CFE and DYI combustion tests

CO Phase

OGC

PM O2

Batches

λ

TFG

η

[mg/m³13vol.-%O2]

[vol.%]

[-]

[°C]

[%]

HO [kW]

Ceramic foam element all batches

21

2142 175

55

15.7

4.2

233

70.5

Starting phase

6

3790 346

86

17.0

4.7

196

67.8

7.0 6.8

ACS Paragon Plus Environment

21

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 29

Nominal load

10

1310 102

41

15.3

3.7

253

71.5

7.7

Partial load

5

1515 73

40

14.5

3.2

246

72.2

5.4

all batches

21

2009 141

57

15.5

4.0

247

70.0

7.3

Starting phase

6

3109 237

89

16.4

4.6

211

69.3

Nominal load

10

1420 105

42

15.4

3.8

265

69.6

7.5

Partial load

5

1881 85

48

14.5

3.2

257

71.8

5.7

Dummy DYI

7.8

List of abbreviations: λ… Lambda, TFG…flue gas temperature, η… efficiency, HO…heat output

Table 4 Results of CCFE and DYII combustion tests

CO Phase

OGC

PM O2

λ

TFG

η

HO

[°C]

[%]

[kW]

7.3

Batches [mg/m³13vol.-%O2]

[vol.- %]

Catalytic ceramic foam all batches

16

1417 71

41

13.6

3.6

244

70.7

Starting phase

4

1588 72

74

15.2

3.6

221

73.3

Nominal load

8

1283 78

30

13.5

3.6

253

69.5

6.9

Partial load

4

1629 50

37

15.2

3.6

240

71.5

5.0

all batches

16

1762 102

57

13.2

3.6

242

70.7

7.4

Starting phase

4

1757 73

76

15.4

3.7

214

73.5

Nominal load

8

1501 103

51

13.3

3.4

260

69.5

7.5

Partial load

4

2399 128

55

15.6

3.9

225

71.7

4.6

10.7

Dummy DYII

10.5

List of abbreviations: λ… Lambda, TFG…flue gas temperature, η… efficiency, HO…heat output

ACS Paragon Plus Environment

22

Page 23 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Table 5 Results of honeycomb catalyst

CO Phase

OGC

PM O2

λ

TFG

η

HO

[°C]

[%]

[kW]

7.4

Batches [mg/m³13vol.-%O2]

[vol.- %]

Honeycomb catalyst all batches

21

601

63

42

14.5

3.3

271

71.7

Starting phase

6

921

101

60

15.4

3.7

243

70.8

Nominal load

10

385

50

32

14.2

3.1

285

71.9

7.8

Partial load

5

671

41

40

13.7

2.9

280

72.4

5.3

7.9

List of abbreviations: λ… Lambda, TFG…flue gas temperature, η… efficiency, HO…heat output

Table 6 p-values for different combustion phase p-value Set up

CFE

CCFE

HC

Phase CO

OGC

PM

Starting phase

n.a.

n.a.

0.84

Nominal load

0.47

0.89

0.78

Partial load

0.27

0.56

0.37

Starting phase

0.33

0.73

0.94

Nominal load

0.05

0.36

0.00

Partial load

0.11

0.21

0.15

Starting phase

0.00

0.07

0.08

Nominal load

0.00

0.00

0.01

Partial load

0.00

0.08

0.42

ACS Paragon Plus Environment

23

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 29

Author information Corresponding Author E-mail: [email protected], Phone: +49 7472 951 142 Notes: The authors declare no competing financial interest.

ACS Paragon Plus Environment

24

Page 25 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

References (1) AEBIOM. AEBIOM Statistical Report - European Bioenergy Outlook, 2015. (2) Fuller, G. W.; Tremper, A. H.; Baker, T. D.; Yttri, K. E.; Butterfield, D. Contribution of wood burning to PM10 in London. Atmospheric Environment 2014, 87, 87–94, DOI: 10.1016/j.atmosenv.2013.12.037. (3) Sarigiannis, D. Α.; Karakitsios, S. P.; Kermenidou, M.; Nikolaki, S.; Zikopoulos, D.; Semelidis, S.; Papagiannakis, A.; Tzimou, R. Total exposure to airborne particulate matter in cities: the effect of biomass combustion. The Science of the total environment 2014, 493, 795– 805, DOI: 10.1016/j.scitotenv.2014.06.055. (4) Fountoukis, C.; Butler, T.; Lawrence, M. G.; Denier van der Gon, H.A.C.; Visschedijk, A.; Charalampidis, P.; Pilinis, C.; Pandis, S. N. Impacts of controlling biomass burning emissions on wintertime carbonaceous aerosol in Europe. Atmospheric Environment 2014, 87, 175–182, DOI: 10.1016/j.atmosenv.2014.01.016. (5) Bari, M. A.; Baumbach, G.; Brodbeck, J.; Struschka, M.; Kuch, B.; Dreher, W.; Scheffknecht, G. Characterisation of particulates and carcinogenic polycyclic aromatic hydrocarbons in wintertime wood-fired heating in residential areas. Atmospheric Environment 2011, 45, 7627–7634, DOI: 10.1016/j.atmosenv.2010.11.053. (6) Bari, M. A.; Baumbach, G.; Kuch, B.; Scheffknecht, G. Particle-phase concentrations of polycyclic aromatic hydrocarbons in ambient air of rural residential areas in southern Germany. Air Qual Atmos Health 2010, 3, 103–116, DOI: 10.1007/s11869-009-0057-8. (7) Caseiro, A.; Bauer, H.; Schmidl, C.; Pio, C. A.; Puxbaum, H. Wood burning impact on PM10 in three Austrian regions. Atmospheric Environment 2009, 43, 2186–2195, DOI: 10.1016/j.atmosenv.2009.01.012. (8) Yttri, K. E.; Dye, C.; Braathen, O.-A.; Simpson, D.; Steinnes, E. Carbonaceous aerosols in Norwegian urban areas. Atmos. Chem. Phys. 2009, 9, 2007–2020, DOI: 10.5194/acp-9-20072009. (9) Puxbaum, H.; Caseiro, A.; Sánchez-Ochoa, A.; Kasper-Giebl, A.; Claeys, M.; Gelencsér, A.; Legrand, M.; Preunkert, S.; Pio, C. Levoglucosan levels at background sites in Europe for assessing the impact of biomass combustion on the European aerosol background. J. Geophys. Res. 2007, 112, DOI: 10.1029/2006JD008114. (10) Glasius, M.; Ketzel, M.; Wahlin, P.; Jensen, B.; Monster, J.; Berkowicz, R.; Palmgren, F. Impact of wood combustion on particle levels in a residential area in Denmark. Atmospheric Environment 2006, 40, 7115–7124, DOI: 10.1016/j.atmosenv.2006.06.047. (11) Schaap, M.; Denier van der Gon, H.; Dentener, F.; Visschedijk, A.; Van Loon, M.; Putaud, J. P.; Guillaume, B.; Liousse, C.; Builtjes, P. Anthropogenic black carbon and fine aerosol distribution over Europe. J. Geophys. Res. 2004, 109, DOI: 10.1029/2003JD004330. (12) Sarigiannis, D. Α.; Karakitsios, S. P.; Zikopoulos, D.; Nikolaki, S.; Kermenidou, M. Lung cancer risk from PAHs emitted from biomass combustion. Environmental research 2014, 137C, 147–156, DOI: 10.1016/j.envres.2014.12.009. (13) Jalava, P. I.; Happo, M. S.; Kelz, J.; Brunner, T.; Hakulinen, P.; Mäki-Paakkanen, J.; Hukkanen, A.; Jokiniemi, J.; Obernberger, I.; Hirvonen, M.-R. In vitro toxicological characterization of particulate emissions from residential biomass heating systems based on old and new technologies. Atmospheric Environment 2012, 50, 24–35, DOI: 10.1016/j.atmosenv.2012.01.009. (14) Chapman, R. S.; Watkinson, W. P.; Dreher, K. L.; Costa, D. L. Ambient particulate matter and respiratory and cardiovascular illness in adults: particle-borne transition metals and the

ACS Paragon Plus Environment

25

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 26 of 29

heart–lung axis. Environmental Toxicology and Pharmacology 1997, 4, 331–338, DOI: 10.1016/S1382-6689(97)10031-X. (15) Carvalho, R. L.; Jensen, O. M.; Tarelho, L. A. Mapping the performance of wood-burning stoves by installations worldwide. Energy and Buildings 2016, 127, 658–679, DOI: 10.1016/j.enbuild.2016.06.010. (16) Orasche, J.; Seidel, T.; Hartmann, H.; Schnelle-Kreis, J.; Chow, J. C.; Ruppert, H.; Zimmermann, R. Comparison of Emissions from Wood Combustion. Part 1: Emission Factors and Characteristics from Different Small-Scale Residential Heating Appliances Considering Particulate Matter and Polycyclic Aromatic Hydrocarbon (PAH)-Related Toxicological Potential of Particle-Bound Organic Species. Energy Fuels 2012, 121017163608008, DOI: 10.1021/ef301295k. (17) Orasche, J.; Schnelle-Kreis, J.; Schön, C.; Hartmann, H.; Ruppert, H.; Arteaga-Salas, J. M.; Zimmermann, R. Comparison of Emissions from Wood Combustion. Part 2: Impact of Combustion Conditions on Emission Factors and Characteristics of Particle-Bound Organic Species and Polycyclic Aromatic Hydrocarbon (PAH)-Related Toxicological Potential. Energy Fuels 2013, 27, 1482–1491, DOI: 10.1021/ef301506h. (18) Mudgal, S.; Turbe, A.; Roy, N. Lot 15 Solid fuel small combustion installations. Task 2: Economic and Market Analysis. Preparatory Studies for Eco-design Requirements of EuPs (II) in contract for the European Commission DG TREN. Working document, version 3 (04/2009) 2009, 2009. (19) Schmidl, C.; Luisser, M.; Padouvas, E.; Lasselsberger, L.; Rzaca, M.; Ramirez-Santa Cruz, C.; Handler, M.; Peng, G.; Bauer, H.; Puxbaum, H. Particulate and gaseous emissions from manually and automatically fired small scale combustion systems. Atmospheric Environment 2011, 45, 7443–7454, DOI: 10.1016/j.atmosenv.2011.05.006. (20) Kjällstrand, J.; Olsson, M. Chimney emissions from small-scale burning of pellets and fuelwood—examples referring to different combustion appliances. Biomass and Bioenergy 2004, 27, 557–561, DOI: 10.1016/j.biombioe.2003.08.014. (21) Happo, M. S.; Uski, O.; Jalava, P. I.; Kelz, J.; Brunner, T.; Hakulinen, P.; Mäki-Paakkanen, J.; Kosma, V.-M.; Jokiniemi, J.; Obernberger, I. et al. Pulmonary inflammation and tissue damage in the mouse lung after exposure to PM samples from biomass heating appliances of old and modern technologies. The Science of the total environment 2013, 443, 256–266, DOI: 10.1016/j.scitotenv.2012.11.004. (22) Monteleone, B.; Chiesa, M.; Marzuoli, R.; Verma, V. K.; Schwarz, M.; Carlon, E.; Schmidl, C.; Ballarin Denti, A. Life cycle analysis of small scale pellet boilers characterized by high efficiency and low emissions. Applied Energy 2015, 155, 160–170, DOI: 10.1016/j.apenergy.2015.05.089. (23) Ozgen, S.; Caserini, S.; Galante, S.; Giugliano, M.; Angelino, E.; Marongiu, A.; Hugony, F.; Migliavacca, G.; Morreale, C. Emission factors from small scale appliances burning wood and pellets. Atmospheric Environment 2014, 94, 144–153, DOI: 10.1016/j.atmosenv.2014.05.032. (24) Verma, V. K.; Bram, S.; Vandendael, I.; Laha, P.; Hubin, A.; Ruyck, J. de. Residential pellet boilers in Belgium: Standard laboratory and real life performance with respect to European standard and quality labels. Applied Energy 2011, 88, 2628–2634, DOI: 10.1016/j.apenergy.2011.02.004.

ACS Paragon Plus Environment

26

Page 27 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

(25) Meyer, N. K. Particulate, black carbon and organic emissions from small-scale residential wood combustion appliances in Switzerland. Biomass and Bioenergy 2012, 36, 31–42, DOI: 10.1016/j.biombioe.2011.09.023. (26) Wöhler, M.; Jaeger, D.; Reichert, G.; Schmidl, C.; Pelz, S. K. Influence of pellet length on performance of pellet room heaters under real life operation conditions. Renewable Energy 2017, 105, 66–75, DOI: 10.1016/j.renene.2016.12.047. (27) Kelz, J.; Brunner, T.; Obernberger, I.; Jalava, P.; Hirvonen, M. R. PM emissions from old and Modern Biomass Combustion Systems and their Health effects. Proceedings of 18th European Biomass Conference and Exhibition 2010, 2010, 1231–1243, DOI: 10.5071/18thEUBCE2010-OA11.5. (28) Evtyugina, M.; Alves, C.; Calvo, A.; Nunes, T.; Tarelho, L.; Duarte, M.; Prozil, S. O.; Evtuguin, D. V.; Pio, C. VOC emissions from residential combustion of Southern and midEuropean woods. Atmospheric Environment 2014, 83, 90–98, DOI: 10.1016/j.atmosenv.2013.10.050. (29) Sutar, K. B.; Kohli, S.; Ravi, M. R.; Ray, A. Biomass cookstoves: A review of technical aspects. Renewable and Sustainable Energy Reviews 2015, 41, 1128–1166, DOI: 10.1016/j.rser.2014.09.003. (30) Prapas, J.; Baumgardner, M. E.; Marchese, A. J.; Willson, B.; DeFoort, M. Influence of chimneys on combustion characteristics of buoyantly driven biomass stoves. Energy for Sustainable Development 2014, 23, 286–293, DOI: 10.1016/j.esd.2014.08.007. (31) Reichert, G.; Schmidl, C.; Haslinger, W.; Moser, W.; Aigenbauer, S.; Figl, F.; Wöhler, M. Investigation of user behavior and operating conditions of residential wood combustion (RWC) appliances and their impact on emissions and efficiency. Proceedings of 4th Central European Biomass Conference [Online], 2014. http://www.biomasseverband.at/veranstaltungen-undbildung/tagungen-und-vortraege/4-mitteleuropaeische-biomassekonferenz/biowaermesimulation-und-effizienzoptimierung/ (accessed September 19, 2015). (32) Ellner-Schuberth, F.; Hartmann, H.; Turowski, P.; Roßmann, P. Berichte aus dem TFZ: Partikelemissionen aus Kleinfeuerungsanlagen für Holz und Ansätze für Minderungsmaßnahmen, 2010. (33) Reichert, G.; Hartmann, H.; Haslinger, W.; Oehler, H.; Mack, R.; Schmidl, C.; Schön, C.; Schwabl, M.; Stressler, H.; Sturmlechner, R. et al. Effect of draught conditions and ignition technique on combustion performance of firewood roomheaters. Renewable Energy 2017, 2017, DOI: 10.1016/j.renene.2016.12.017. (34) Kistler, M.; Schmidl, C.; Padouvas, E.; Giebl, H.; Lohninger, J.; Ellinger, R.; Bauer, H.; Puxbaum, H. Odor, gaseous and PM10 emissions from small scale combustion of wood types indigenous to Central Europe. Atmospheric Environment 2012, 51, 86–93, DOI: 10.1016/j.atmosenv.2012.01.044. (35) Schön, C.; Hartmann, H.; Turowski, P. User and fuel impacts on flue gas emissions of a chimney stove. Proceedings of 19th European Biomass Conference and Exhibition 2011, 960– 966, DOI: 10.5071/19thEUBCE2011-OA7.4. (36) Tissari, J.; Hytönen, K.; Sippula, O.; Jokiniemi, J. The effects of operating conditions on emissions from masonry heaters and sauna stoves. Biomass and Bioenergy 2009, 33, 513–520, DOI: 10.1016/j.biombioe.2008.08.009. (37) Wöhler, M.; Andersen, J. S.; Becker, G.; Persson, H.; Reichert, G.; Schön, C.; Schmidl, C.; Jaeger, D.; Pelz, S. K. Investigation of real life operation of biomass room heating appliances –

ACS Paragon Plus Environment

27

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 28 of 29

Results of a European survey. Applied Energy 2016, 169, 240–249, DOI: 10.1016/j.apenergy.2016.01.119. (38) Reichert, G.; Schmidl, C.; Haslinger, W.; Schwabl, M.; Moser, W.; Aigenbauer, S.; Wöhler, M.; Hochenauer, C. Investigation of user behavior and assessment of typical operation mode for different types of firewood room heating appliances in Austria. Renewable Energy 2016, 93, 245–254, DOI: 10.1016/j.renene.2016.01.092. (39) Eriksson, A. C.; Nordin, E. Z.; Nyström, R.; Pettersson, E.; Swietlicki, E.; Bergvall, C.; Westerholm, R.; Boman, C.; Pagels, J. H. Particulate PAH emissions from residential biomass combustion: time-resolved analysis with aerosol mass spectrometry. Environmental science & technology 2014, 48, 7143–7150, DOI: 10.1021/es500486j. (40) Schmidl, C.; Haslinger, W.; Aigenbauer, S.; Figl, F.; Kirchhof, J.; Moser, W.; Reichert, G.; Schwabl, M.; Verma, V.; Wöhler, M. Improvement of Real Life Operation Performance of Residential Wood Combustion Appliances. Proceedings of 21th European Biomass Conference and Exhibition, 2013. (41) Reichert, G.; Haslinger, W.; Kirchhof, J.-M.; Schmidl, C.; Sedlmayer, I.; Schwabl, M.; Stressler, H.; Sturmlechner, R.; Wöhler, M.; Hochenauer, C. Honeycomb Catalysts Integrated in Firewood Stoves - Potentials and Limitations. In Proceedings of 5th Central European Biomass Conference [Online], 2017. http://www.cebc.at/service/publikationen/5-mitteleuropaeischebiomassekonferenz/ (accessed January 28, 2017). (42) Aleysa, M.; Weclas, M.; Leistner, P. Korrelation der Filter-Reaktor-Architektur mit thermophysikalischen Funktionsbedingungen zur Erforschung und Entwicklung eines nichtkatalytischen 3D-porösen Filter-Reaktor-Systems für biomassebetriebene Kleinfeuerungsanlagen: Research report, 2015. (43) Gabathuler, J. P.; Mizrah, T.; Eckert, L.; Fischer, A.; Käser, P.; Maurer, A. New Developments of Ceramic Foam as a Diesel Particulate Filter. SAE Technical Paper Series. (44) Kaivosoja, T.; Viren, A.; Tissari, J.; Ruuskanen, J.; Tarhanen, J.; Sippula, O.; Jokiniemi, J. Effects of a catalytic converter on PCDD/F, chlorophenol and PAH emissions in residential wood combustion. Chemosphere 2012, 88, 278–285, DOI: 10.1016/j.chemosphere.2012.02.027. (45) Hukkanen, A.; Kaivosoja, T.; Sippula, O.; Nuutinen, K.; Jokiniemi, J.; Tissari, J. Reduction of gaseous and particulate emissions from small-scale wood combustion with a catalytic combustor. Atmospheric Environment 2012, 50, 16–23, DOI: 10.1016/j.atmosenv.2012.01.016. (46) DIN Deutsches Institut für Normung e.V. Roomheaters fired by solid fuel - Requirements and test methods; German version EN 13240:2001 + A2:2004; Beuth Verlag GmbH: Berlin, 2005, 97.100.30 (13240:2001 + A2:2004). (47) Reichert, G.; Hartmann, H.; Haslinger, W.; Oehler, H.; Pelz, S.; Schmidl, C.; Schwabl, M.; Stressler, H.; Sturmlechner, R.; Wöhler, M. et al. beReal - Development of a New Test Method for Firewood Roomheaters Reflecting Real Life Operation. Proceedings of 24th European Biomass Conference and Exhibition, 2016. (48) DIN Deutsches Institut für Normung e.V. Solid biofuels - Fuel specifications and classes Part 4: Graded wood chips (ISO 17225-4:2014)German Version EN ISO 17225-2:2014; Beuth Verlag GmbH, 2014, 27.190;75.160.10 (17225-4:2014). (49) DIN Deutsches Institut für Normung e.V. Residential space heating appliances fired by wood pellets –Requirements and test methods; Beuth Verlag GmbH: Berlin, 2006, 97.100.30 (14785:2006). (50) DIN Deutsches Institut für Normung e.V. Residential solid fuel burning appliances – Emission test methods; Beuth Verlag GmbH: Berlin, 2010, 97.100.30 (15883).

ACS Paragon Plus Environment

28

Page 29 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

(51) Aleysa, M.; Weclas, M.; Leistner, P. Korrelation der Filter-Reaktor-Architektur mit thermophysikalischen Funktionsbedingungen zur Erforschung und Entwicklung eines nichtkatalytischen 3D-porösen Filter-Reaktor-Systems für biomassebetriebene Kleinfeuerungsanlagen: Abschlussbericht über Forschungsprojekt gefördert von der Deutschen Bundesstiftung Umwelt mit dem AZ: 30550, 2014. (52) Adler, J.; Kalisch, A. Keramikfilter in der Abgasanlage zur Staubemissionsminderung von Biomassefeuerungen: Research report, 2009. (53) Hartmann, H.; Mack, R. Performance of foam ceramic elements in log wood stoves. Presentation at IEA Task 32 Workshop [Online]. http://www.ieabcc.nl/ (accessed November 22, 2016). (54) Ozil, F.; Tschamber, V.; Haas, F.; Trouvé, G. Efficiency of catalytic processes for the reduction of CO and VOC emissions from wood combustion in domestic fireplaces. Fuel Processing Technology 2009, 90, 1053–1061, DOI: 10.1016/j.fuproc.2009.03.019. (55) Reichert, G.; Schmidl, C.; Schwabl, M.; Sedlmayer, I.; Stressler, H.; Sturmlechner, R.; Wöhler, M.; Haslinger, W. Emission Reduction of Firewood Stoves by Integrated Honeycomb Catalysts. Proceedings of World Sustainable Energy Days 2015. (56) Elsasser, M.; Busch, C.; Orasche, J.; Schön, C.; Hartmann, H.; Schnelle-Kreis, J.; Zimmermann, R. Dynamic Changes of the Aerosol Composition and Concentration during Different Burning Phases of Wood Combustion. Energy Fuels 2013, 27, 4959–4968, DOI: 10.1021/ef400684f. (57) Pettersson, E.; Boman, C.; Westerholm, R.; Boström, D.; Nordin, A. Stove Performance and Emission Characteristics in Residential Wood Log and Pellet Combustion, Part 2: Wood Stove. Energy Fuels 2011, 25, 315–323, DOI: 10.1021/ef1007787. (58) Ozgen, S.; Becagli, S.; Bernardoni, V.; Caserini, S.; Caruso, D.; Corbella, L.; Dell'Acqua, M.; Fermo, P.; Gonzalez, R.; Lonati, G. et al. Analysis of the chemical composition of ultrafine particles from two domestic solid biomass fired room heaters under simulated real-world use. Atmospheric Environment 2016, DOI: 10.1016/j.atmosenv.2016.11.048. (59) Ferrandon, M.; Berg, M.; Björnbom, E. Thermal stability of metal-supported catalysts for reduction of cold-start emissions in a wood-fired domestic boiler. Catalysis Today 1999, 53, 647–659. (60) Wöhler, M.; Reichert, G.; Kirchhof, J.; Schwabl, M.; Schmidl, C.; Haslinger, W. Performance of a catalyst in a test stand under conditions similar to a stove. Proceedings of World Sustainable Energy Days 2013, 2013. (61) Bindig, R.; Butt, S.; Hartmann, I.; Matthes, M.; Thiel, C. Application of Heterogeneous Catalysis in Small-Scale Biomass Combustion Systems. Catalysts 2012, 2, 223–243, DOI: 10.3390/catal2020223.

ACS Paragon Plus Environment

29