Combustion Of Peat Research Articles

Direct carbonation of peat-wood fly ash for carbon capture and utilization in construction application

Carbon dioxide (CO2) emissions from industrial processes contribute largely to the greenhouse effect and climate change. One of these industries is the cement industry, which contributes around 8% of CO2 emissions caused by mankind. Two promising and interesting ways to reduce CO2 emission are the utilization of alternative cementitious materials and carbon capture and utilization through CO2 mineralization. In this study, peat-wood fly ashes from fluidized bed combustion were used as a construction material for mineral carbonation. A self-hardening characteristic of this type of fly ash was utilized, and simultaneous carbonation and hydration reactions were studied. The study showed that fly ashes from the fluidized bed combustion of peat and wood could be used to capture and mineralize CO2 during hydration reactions. At the same time, CO2 could improve the strength of self-hardened fly ashes. One interesting future possibility is fly ash tile production at energy plants: fly ashes can be used to capture CO2 from flue gases, thus improving the strength of produced tiles.

Characterization of carbonaceous compounds emitted from Indonesian surface and sub surface peat burning

Indonesia has been experiencing an annually reoccurring forest fire events over the peatlands in eastern Sumatera and western Kalimantan and the impacts on the air pollution episodes in the surrounding countries gained international concerns. The most notable events were in 1997 and 2015 which caused significant losses both on human health and economy in the region. Fires in peat layers could spread radially due to peat structure and emitted substantial amount of aerosols containing carbonaceous compounds, including BC/EC and OC. In this study, peat samples from different levels of depth were collected from western part of Kalimantan and were burned in a combustion chamber received from Kyoto University. Particulate (PM2.5) samples from burning experiments were collected and the carbonaceous components (i.e. BC/EC and OC) were also analyzed, respectively. The results showed that average concentration of PM2.5 emitted from the combustion of the surface peat (SF) samples was 7,467 ± 3,976 μg/m³. while the corresponding value for the subsurface (SSF) was 5,693 ± 2,137 μg/m³. In average, EC and OC compositions were 1.9% and 70% to the total of PM2.5 concentrations, respectively. Emission factors (EFs, in g/kg) were estimated for PM2.5, EC, and OC for SF samples of 4.51 ± 0.42, 0.21 ± 0.17, and 3.77 ± 0.82, respectively. The associated EFs for SSF samples were 4.53 ± 1.67, 0.1 ± 0.09, and 1.82 ± 0.43 g/kg, respectively. The results may substantially contribute to fill in the gaps of the availability of EFs for both SF and SFF peat fires in the country to improve the existing PM emission database.

Deposition of brown carbon onto snow: changes in snow optical and radiative properties

Abstract. Light-absorbing organic carbon aerosol – colloquially known as brown carbon (BrC) – is emitted from combustion processes and has a brownish or yellowish visual appearance, caused by enhanced light absorption at shorter visible and ultraviolet wavelengths (0.3 µm≲λ≲0.5 µm). Recently, optical properties of atmospheric BrC aerosols have become the topic of intense research, but little is known about how BrC deposition onto snow surfaces affects the spectral snow albedo, which can alter the resulting radiative forcing and in-snow photochemistry. Wildland fires in close proximity to the cryosphere, such as peatland fires that emit large quantities of BrC, are becoming more common at high latitudes, potentially affecting nearby snow and ice surfaces. In this study, we describe the artificial deposition of BrC aerosol with known optical, chemical, and physical properties onto the snow surface, and we monitor its spectral radiative impact and compare it directly to modeled values. First, using small-scale combustion of Alaskan peat, BrC aerosols were artificially deposited onto the snow surface. UV–Vis absorbance and total organic carbon (TOC) concentration of snow samples were measured for samples with and without artificial BrC deposition. These measurements were used to first derive a BrC (mass) specific absorption (m2 g−1) across the UV–Vis spectral range. We then estimate the imaginary part of the refractive index of deposited BrC aerosol using a volume mixing rule. Single-particle optical properties were calculated using Mie theory, and these values were used to show that the measured spectral snow albedo of snow with deposited BrC was in general agreement with modeled spectral snow albedo using calculated BrC optical properties. The instantaneous radiative forcing per unit mass of total organic carbon deposited to the ambient snowpack was found to be 1.23 (+0.14/-0.11) W m−2 per part per million (ppm). We estimate the same deposition onto a pure snowpack without light-absorbing impurities would have resulted in an instantaneous radiative forcing per unit mass of 2.68 (+0.27/-0.22) W m−2 per ppm of BrC deposited.

Composition and properties of soils developed within the ash disposal areas originated from peat combustion (Tyumen, Russia)

Composition and properties of soils developed within the ash disposal areas originated from peat combustion (Tyumen, Russia)

A proposal of community-based firefighting in peat hydrological unit of Kahayan – Sebangau River: methods and approaches

In 2019, Indonesia has experienced a very recent El Nino event, which generates an impact on the severity of forest and peatland fires both in Kalimantan and Sumatra. Some provinces such as Central Kalimantan, South Kalimantan, Riau, South Sumatra, and Jambi have been covered in a thick and poisonous haze for months. The total number of fire in Central Kalimantan processed from NASA hotspot data from January to October is reaches 10 000, which approximately 86% occur during two months of the dry season (September – October 2019). The areas that experienced very severe fires in 2019 were Peat Hydrological Unit (PHU) Kahayan – Sebangau River in the administrative boundaries of Pulang Pisau and Palangka Raya. The interesting is the fire in 2019 becomes the four of top fire in Central Kalimantan after 2015, 2006 and 2009. About 10,000 hectares of land including peatlands have been burned only in Central Kalimantan during the forest and land fires season. The smoldering type of peat combustion underground with low-temperature combustion is the most common occurrence in dry peatland areas. This unique fire behavior answers some of the questions why smoldering fires occur over long durations, and why peat fires are difficult to extinguish and produce more smoke. This paper will review the update of 2019’s fire in Central Kalimantan and introduce the methods and approaches of firefighting by the local community. The method that will be presented is a combination of scientific data with the experience of the firefighting team, which is called Tim Serbu Api Kelurahan (TSAK). The collaboration project between the University of Palangka Raya, Kyoto University and CIFOR that supported by the Ministry of Agriculture, Forestry and Fishery Japan has proposed to draft a manual for fire prevention and protection for the local fire fighting. This manual covers the method of fire investigation, firefighting preparedness such as making wellbore, fire break, the installation on machine and horse as well as the effective peat rewetting and watering. This method has been tested successfully to slow the movement and spread of fire under thick peat. On the other hand, there is still a need for sophisticated equipment for underground fire detection such as thermal cameras or drones.

Numerical modeling of peat burning processes in a vortex furnace with countercurrent swirl flows

The paper presents the process of peat burning in a swirl furnace with counter-current swirl flows and the results of a numerical study. The cyclone-vortex technology of solid fuel combustion allows the furnace volume of a boiler unit, its dimensions and weight to be reduced. The aim of the work is a numerical study of the combustion of pulverized peat in a cylindrical vortex furnace with counter-current swirl flows. The results of computer simulation of the combustion of pulverized peat with a moisture content of 40%, an ash content of 6%, and a higher heat of combustion QpH = 12.3 MJ/kg are presented. The results of the influence of the design parameters of the furnace and heat load (from 100-15%) are given as well. When the heat load is reduced to 15%, the entrainment of unburnt particles increases. The cooled and adiabatic furnace is studied. A significant entrainment of unburned particles is observed in a cooled furnace. The fields of temperature distribution, gas velocity, and particle trajectory in the volume and at the outlet of the furnace are determined. The 3-D temperature distribution in the furnace volume indicates the combustion of peat particles at temperatures (1300-1450?C). Values of the tangential velocity of a swirl flow near the furnace outlet reach 150-370 m/s, which ensures the efficiency of separation of fuel particles and a reduction in heat loss due to mechanical underburning (up to 0.06%). The results of a numerical study show that the diameter of peat particles affects the combustion process, namely coke of particles with an initial diameter from 25-250 ?m burns out by 96%, and particles with a diameter of about 1000 ?m are carried away from the furnace and do not burn. The furnace provides a complete combustion of dust particles of peat by 99.8% and volatiles by 100%.

REDUCING THE FIRE HAZARD OF PEATLANDS, METHODS AND FIRE-FIGHTING EQUIPMENT TO INCREASE THE EFFICIENCY OF THEIR EXTINGUISHING

The article describes that peat has been used for energy and agricultural needs for a long time in several countries of the world. According to statistics from the International Peat Society (IPS), world peat reserves are over 400 million ha, of which more than 305 million ha are under development. In Ukraine, more than 2,500 peat deposits with an average depth of 1.4 m have been identified. Of these, about 81% of producing peat is used as fuel, and 19% is for agricultural purposes. However, every year hundreds of thousands cubic meters of peat deposits suffered from fires. Statistics of peat fires remains disappointing in the world in recent years. A similar situation is observed in Ukraine. Peat fires most often occur in places of peat extraction, as a rule, due to improper handling, from lightning discharges or spontaneous combustion. Peat fires often cover large areas and are difficult to extinguish, especially when a peat layer of considerable thickness burns. Peat can burn in all directions, regardless of the direction and strength of the wind, and under the soil it burns even with moderate rain and snowfall.
 The existing methods for preventing fires in peat-forest ecosystems are analyzed and, on this basis, methods for improving and developing new ones are proposed.
 One of the most effective means of preventing peat fires is to limit the spread of fire due to dug ditches and wide ditches along forests. Another way of protection is the flooding of drained peatlands. The most effective method of extinguishing is to ditch the territory with enclosing ditches. It is necessary to dig up to mineral soil or groundwater. The fire is extinguished by digging the burning peat and pouring it with plenty of water. Modeling the enclosing ditches, taking into account the moisture content of the litter and peat bogs, wind, and ambient temperature, makes it possible to determine their optimal sizes and location to increase the efficiency of the quenching process.
 Increasing the efficiency of extinguishing peat fires by improving the design of the fire barrel allows improving the supply of fire extinguishing substances to the combustible layer when extinguishing fires at a depth of 2 to 7 meters. Extinguishing is carried out throughout the deployment depth and ensures safe working conditions for firefighters during the elimination of deep fires.
 Improvement of existing fire extinguishing wetting solutions and the development of new ones allows achieving fire extinguishing and penetrating properties and increasing the extinguishing efficiency at depths of up to 7 meters

Haze emissions from smouldering peat: The roles of inorganic content and bulk density

Smouldering peat fires are reported across continents and their emissions result in regional haze crisis (large scale accumulation of smoke at low altitudes) and large carbon foot prints. Inorganic content (IC) and bulk density vary naturally in peatlands and are among the important parameters governing peat fires. However, their roles in fire emissions remain unknown. In this work, bench-scale burning of sphagnum peat conditioned to different values of IC and bulk densities were conducted in the laboratory environment. Mass loss rate, spread rate and transient emissions of 20 gas species and particles (PM10, PM2.5 and PM1) were simultaneously investigated. We found that peat with 50% moisture content can self-sustain smouldering propagation if IC is less than 40%, or its bulk density is lower than 287.5 kg m−3. Increasing IC or bulk density decreases peat mass loss rate and spread rate. High IC peat releases lower gas fluxes (especially for CH4 and NH3) throughout the experiment. In the ignition stage, increasing IC leads to an increase in particles with diameter between 1 and 2.5 μm; in the fire spread stage, IC has no influence on the particle fluxes. In contrast, increasing bulk density delays both gas and particle emission fluxes without altering the smoke composition significantly. The fundamental understanding of how soil properties affect peat wildfires facilitates the development of mitigation technologies against haze.

Novel use of peatlands as future locations for the sustainable intensification of freshwater aquaculture production – A case study from the Republic of Ireland

There has been an increasing interest in enhancing freshwater aquaculture processes without hindering the progress of the Water Framework Directive. This constitutes the first study to describe a new concept in integrated multitrophic aquaculture (IMTA) that uses cutaway peatlands (bogs) to farm rainbow trout and Eurasian perch with associated organic status that is powered by wind energy and utilizes algae and duckweed to treat rearing water. Approximately 5% of Ireland comprises bogs that support natural ecosystems where there is a pressing need to develop alternative innovation to that of burning peat in order to reduce Ireland's carbon emissions. Specifically, this study evaluates water quality from this new IMTA where intake and terminal holding tank samples were evaluated from May to August 2019. Physicochemical parameters (temperature, pH, nitrogen, phosphorus, oxygen, suspended solids, hardness and alkalinity), and ecotoxicological bioassays (Pseudokirchneriella subcapitata and Daphnia pulex), were used to investigate the potential effects that introducing aquaculture processes may have on peatlands. Nitrite (P < 0.001), nitrate (P = 0.016), and chemical oxygen demand (P = 0.011), were the only physicochemical parameters that differed significantly between the intake and holding tank water indicating that water quality for the most part remained unchanged. Low levels of toxicity were observed between the bioassays suggested the introduction of the processes into the bog were unlikely to cause adverse effects on the ecosystem and the organisms therein. Observations were similar to or lower than those reported previously by other researchers for intensive flow-through aquaculture processes that discharge to receiving water. Findings from this study support the use of peatlands as future locations for integrated aquaculture processes.

The effect of mixing peatland burning remains as fly ash and peat soil on its California Bearing Ratio value

Peat has been known for its high compressibility, low shear strength and high-water content. Moreover, when it comes to dry season, peat can easily be burnt leaving the large amount of carbon into the atmosphere also causes significant damage to peatland ecology. Based on these, peat burning remains are used as fly ash and it is expected to improve the strength of peat soils alongside to be environmentally safe. Laboratory tests were carried out according to that condition. A study on the influence of fly ash addition in peat soils was done by comparing the result from CBR (California Bearing Ratio). Different percentages of fly ash (i.e. 15, 20, and 25%) were added into peat soil at optimum moisture content amidst 5% of Portland cement for each sample with a variety of curing time of 2 hours, 1 day, 3 days, and 7 days. Changes were observed in specific gravity, acidity, and the microscopic structure. The CBR test results show that the peat gained strength due to the addition of fly ash, with the optimum result of 5.36% for unsoaked condition and 6.35% for soaked condition. Furthermore, according to the results, the peat soil can be used as a subgrade.

Lessons learnt from semi-arid wetland degradation. Las Tablas de Daimiel National Park

The Tablas de Daimiel National Park wetland developed in an area characterized by the cyclic nature of droughts, excessive aquifer exploitation and an evident aridification trend driven by climate change. The park and its surroundings have been exploited since prehistoric times and they are currently deeply anthropized to the point that both the physical survival of the wetland as well as its ecological function entirely depend on human action. A severe drought between 2006 and 2009 together with the drawdown of the water table caused the dry out of the system, reed overgrowth, disappearance of cut-sedge and sub-aquatic Chara spp. meadows and a smouldering peat fire. During this same period surface water, soil and groundwater were sampled for physical, hydrological and hydrochemical characterization. Upon drainage, the system functions as an artificial recharge system and becomes eutrophic showing large nutrient and salt content in soils and water. High water transmissivity capacities in the unsaturated zone and anthropic park management (soil compacted by heavy machinery, recirculation of low quality groundwater, reed reaping, water transfers, etc.) condition groundwater pollution. Increased knowledge of the physical-environment has allowed us to build a conceptual model of the surface water – groundwater interactions and to develop management tools to support the park management during a system dry out. Amongst these actions, we propose an unsaturated flow model for soil moisture simulation than can be used to predict critical soil water content for reed overgrowth or peat combustion risk.

Gaseous, PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt; mass, and speciated emission factors from laboratory chamber peat combustion

Abstract. Peat fuels representing four biomes of boreal (western Russia and Siberia), temperate (northern Alaska, USA), subtropical (northern and southern Florida, USA), and tropical (Borneo, Malaysia) regions were burned in a laboratory chamber to determine gas and particle emission factors (EFs). Tests with 25 % fuel moisture were conducted with predominant smoldering combustion conditions (average modified combustion efficiency (MCE) =0.82±0.08). Average fuel-based EFCO2 (carbon dioxide) are highest (1400 ± 38 g kg−1) and lowest (1073 ± 63 g kg−1) for the Alaskan and Russian peats, respectively. EFCO (carbon monoxide) and EFCH4 (methane) are ∼12 %–15 % and ∼0.3 %–0.9 % of EFCO2, in the range of 157–171 and 3–10 g kg−1, respectively. EFs for nitrogen species are at the same magnitude as EFCH4, with an average of 5.6 ± 4.8 and 4.7 ± 3.1 g kg−1 for EFNH3 (ammonia) and EFHCN (hydrogen cyanide); 1.9±1.1 g kg−1 for EFNOx (nitrogen oxides); and 2.4±1.4 and 2.0 ± 0.7 g kg−1 for EFNOy (total reactive nitrogen) and EFN2O (nitrous oxide). An oxidation flow reactor (OFR) was used to simulate atmospheric aging times of ∼2 and ∼7 d to compare fresh (upstream) and aged (downstream) emissions. Filter-based EFPM2.5 varied by &gt; 4-fold (14–61 g kg−1) without appreciable changes between fresh and aged emissions. The majority of EFPM2.5 consists of EFOC (organic carbon), with EFOC ∕ EFPM2.5 ratios in the range of 52 %–98 % for fresh emissions and ∼14 %–23 % degradation after aging. Reductions of EFOC (∼7–9 g kg−1) after aging are most apparent for boreal peats, with the largest degradation in low-temperature OC1 that evolves at &lt; 140 ∘C, indicating the loss of high-vapor-pressure semivolatile organic compounds upon aging. The highest EFLevoglucosan is found for Russian peat (∼16 g kg−1), with ∼35 %–50 % degradation after aging. EFs for water-soluble OC (EFWSOC) account for ∼20 %–62 % of fresh EFOC. The majority (&gt; 95 %) of the total emitted carbon is in the gas phase, with 54 %–75 % CO2, followed by 8 %–30 % CO. Nitrogen in the measured species explains 24 %–52 % of the consumed fuel nitrogen, with an average of 35 ± 11 %, consistent with past studies that report ∼1/3 to 2∕3 of the fuel nitrogen measured in biomass smoke. The majority (&gt; 99 %) of the total emitted nitrogen is in the gas phase, with an average of 16.7 % as NH3 and 9.5 % as HCN. N2O and NOy constituted 5.7 % and 2.9 % of consumed fuel nitrogen. EFs from this study can be used to refine current emission inventories.

Threshold peat burn severity breaks evaporation‐limiting feedback

AbstractA suite of autogenic ecohydrological feedbacks and moss traits are important for protecting vast peatland carbon stocks following wildfire disturbance. Here, we examine how peat burn severity and water table depth (WTD) affect the strength of one such feedback—the hydrophobicity–evaporation feedback (HEF). The HEF is an evaporation‐limiting feedback known to minimize water loss following wildfire. The peatland surface becomes hydrophobic creating an evaporative cap and thereby reducing post‐fire evaporation; however, recent studies hypothesize that this is dependent on peat burn severity. To test this hypothesis, we studied plots along a peat burn severity gradient in a partially drained black spruce peatland that burned during the 2016 Fort McMurray Horse River wildfire. Evaporation rates were significantly lower in plots where hydrophobicity was present. Hydrophobicity was lowest in the severely burned area, and the average instantaneous evaporation rate (2.75 mm day−1) was significantly higher than moderately and typical‐lightly burned areas (0.82 and 1.64 mm day−1, respectively). Based on lab results, increasing WTD affected hydrophobicity within lightly burned (singed) feather moss samples but not in heavily burned feather moss, showing the importance of post‐fire ground cover and in situ WTD. Our results provide evidence of a burn severity threshold where increased depth of burn removes the feather moss evaporative cap and causes the HEF to break down. We argue that this threshold has important implications for boreal peatlands, which are predicted to undergo climate‐mediated pre‐fire drying and increasing burn severities, potentially leading to further carbon losses due to enhanced post‐fire drying and concomitant decomposition.

Catalytic Co-Combustion of Peat and Anthracite in a Fluidized Bed

The catalytic combustion of peat, anthracite, and their mixture in a ratio of 40 : 60 wt % was studied. The addition of peat with a high yield of volatiles to anthracite increased the degree of burnout of the mixture. When the commercial aluminum-copper-chromium oxide catalyst IK-12-70 was used (bed height 1 m, process temperature 700–750°C, particle size of solid fuel less than 1.25 mm), the degree of burnout was 98.2% (peat), 50.9% (anthracite), and 74.2% (peat–anthracite mixture). For large particles of a shaped peat–anthracite mixture with an equivalent diameter of 11.6–18.6 mm, burnout in the upper part of the fluidized bed of the catalyst was 80.5%. The degree of burnout of large particles fed into the lower part of the fluidized bed was evaluated taking into account the degree of burnout of small particles that passed the bed. When large particles of the shaped peat–anthracite mixture were fed, burnout reached at least 95% at a temperature of 700–750°C and a catalyst bed height of 1 m. To avoid accumulation of ash particles in the fluidized bed, the particle size of peat and anthracite in the shaped fuel should not exceed 1–1.5 mm when using a catalyst with a particle size of 2 mm.

New estimate of particulate emissions from Indonesian peat fires in 2015

Abstract. Indonesia contains large areas of peatland that have been drained and cleared of natural vegetation, making them susceptible to burning. Peat fires emit considerable amounts of carbon dioxide, particulate matter (PM) and other trace gases, contributing to climate change and causing regional air pollution. However, emissions from peat fires are uncertain, due to uncertainties in emission factors and fuel consumption. We used the Weather Research and Forecasting model with chemistry and measurements of PM concentrations to constrain PM emissions from Indonesian fires during 2015, one of the largest fire seasons in recent decades. We estimate primary PM2.5 (particles with diameters less than 2.5 µm) emissions from fires across Sumatra and Borneo during September–October 2015 were 7.33 Tg, a factor 3.5 greater than those in the Fire Inventory from NCAR (FINNv1.5), which does not include peat burning. We estimate similar dry fuel consumption and CO2 emissions to those in the Global Fire Emissions Database (GFED4s, including small fires) but PM2.5 emissions that are a factor of 1.8 greater, due to updated PM2.5 emission factors for Indonesian peat. Fires were responsible for an additional 3.12 Tg of secondary organic aerosol formation. Through comparing simulated and measured PM concentrations, our work provides independent support of these updated emission factors. We estimate peat burning contributed 71 % of total primary PM2.5 emissions from fires in Indonesia during September–October 2015. We show that using satellite-retrieved soil moisture to modify the assumed depth of peat burn improves the simulation of PM, increasing the correlation between simulated and observed PM from 0.48 to 0.56. Overall, our work suggests that peat fires in Indonesia produce substantially greater PM emissions than estimated in current emission inventories, with implications for the predicted air quality impacts of peat burning.

Environmental Aspects and Energy Characteristics of the Combustion of Composite Fuels Based on Peat, Oil, and Water

The necessary conditions and integral characteristics of the ignition and subsequent combustion of mixed fuels prepared on the basis of peat, crude oil, and water were studied. Fuel mixtures were burned in the form of a layer (a weighed sample), slurry droplets, or pellets in a model combustion chamber at a temperature of 300–900°C. The results were compared with data obtained upon the combustion of lean coal under analogous conditions. The experimental results illustrate the energy and environmental feasibility of the combined burning of peat and oil-containing components in a fuel and energy cycle. As found experimentally, the composite fuels have a sufficiently high energy and environmental potential, and they can be used as a primary or secondary energy source.

Experimental study of moisture content effects on the transient gas and particle emissions from peat fires

Peat fires are a global-scale source of carbon emissions and a leading cause of regional air quality deterioration, especially in Southeast Asia. The ignition and spread of peat fires are strongly affected by moisture, which acts as an energy sink. However, moisture effects on peat fire emissions are poorly understood in the literature. Here we present the first experimental work to investigate transient gas and particle emissions for a wide range of peat moisture contents (MCs). We include drying, ignition, smouldering spread, and even flaming stages. Peat samples conditioned to different MCs were burnt in the laboratory where a suite of diagnostics simultaneously measured mass loss rate, temperature profiles, real-time concentration of 20 gas species, and size-fractioned particle mass. It was found that MC affects emissions, in addition to peat burning dynamics. An increase in MC below a smouldering threshold of 160% in dry basis leads to a decrease in NH3 and greenhouse gas emissions, including CO2 and CH4. The burning of wet peat emits more coarse particles (between 1 and 10 µm) than dry peat, especially during the ignition stage. In contrast, flaming stage emits mostly soot particles less than 1 µm, and releases 100% more fully oxidised gas species including CO2, NO2 and SO2 than smouldering. The examination of the resulting modified combustion efficiency (MCE) reveals that it fails to recongnise smouldering combustion with sufficient accuracy, especially for wet peat with MC > 120%. MCE confuses drying and flaming, and has significant variations during the ignition stage. As a result, MCE is not valid as a universal fire mode indicator used in the field. This work fills the knowledge gap between moisture and emissions, and provides a better understanding which can help mitigate peat fires.

BEBERAPA SIFAT FISIK DAN KIMIA TANAH GAMBUT TERBAKAR DAN TIDAK TERBAKAR DI DESA SUNGAI BESAR KABUPATEN KETAPANG

Peatlands is one of the ecosystem types in tropical rainforests. Peatland has very high conservation value and other functions such as the hydrological function carbon stocks, and biodiversity which is important for environmental comfort and animal life. The purpose of this study was to obtain information about the impact of fires on the physical and chemical properties of burning and non burning peat soils. This study carried out a field survey method with deliberate sampling (purposive sampling). The results showed that the physical and chemical properties of peat soil after a fire did not change, namely at soil temperature, air humidity was almost the same while the air temperature, soil moisture, pH, C-organic, depth, C/N (0-20 cm) has increased but not significantly. For the chemical properties of peat soil after fire there is an increase in the value of C-organic, CEC, phosphorus, sulfur,ash content, N-total depth (21-40 cm). this means that after fires the nutrients mostly affect peat soil. From the information on the nature of peat soil obtained in land restoration studies to use qualitative soil after burning.Keywords: Burn, chemical pea soil, Peatlands, Physicalpeat soil.

Smouldering combustion of peat with various permeability at natural convection of oxidizer

The regularities of smouldering combustion of peat with different permeability under conditions of natural oxidant convection were experimentally investigated. It is shown that as the permeability of peat samples increases, the peak temperature increases from 500 to 900 °C, and the spread rate increases from 8 to 80 mm/h, and oxygen is consumed more fully with increasing concentration of monoxide and carbon dioxide in gaseous products.

Wildfire overrides hydrological controls on boreal peatland methane emissions

Abstract. Boreal peatlands represent a globally important store of carbon, and disturbances such as wildfire can have a negative feedback to the climate. Understanding how carbon exchange and greenhouse gas (GHG) dynamics are impacted after a wildfire is important, especially as boreal peatlands may be vulnerable to changes in wildfire regime under a rapidly changing climate. However, given this vulnerability, there is very little in the literature on the impact such fires have on methane (CH4) emissions. This study investigated the effect of wildfire on CH4 emissions at a boreal fen near Fort McMurray, Alberta, Canada, that was partially burned by the Horse River Wildfire in 2016. We measured CH4 emissions and environmental variables (2017–2018) and CH4 production potential (2018) in two different microform types (hummocks and hollows) across a peat burn severity gradient (unburned (UB), moderately burned (MB), and severely burned (SB)). Results indicated a switch in the typical understanding of boreal peatland CH4 emissions. For example, emissions were significantly lower in the MB and SB hollows in both years compared to UB hollows. Interestingly, across the burned sites, hummocks had higher fluxes in 2017 than hollows at the MB and SB sites. We found typically higher emissions at the UB site where the water table was close to the surface. However, at the burned sites, no relationship was found between CH4 emissions and water table, even under similar hydrological conditions. There was also significantly higher CH4 production potential from the UB site than the burned sites. The reduction in CH4 emissions and production in the hollows at burned sites highlights the sensitivity of hollows to fire, removing labile organic material for potential methanogenesis. The previously demonstrated resistance of hummocks to fire also results in limited impact on CH4 emissions and likely faster recovery to pre-fire rates. Given the potential initial net cooling effect resulting from a reduction in CH4 emissions, it is important that the radiative effect of all GHGs following wildfire across peatlands is taken into account.