Savitri Garivait

Air pollutant emissions from rice straw open field burning in India, Thailand and the Philippines

Rice is a widely grown crop in Asia. China (30%) and India (21%) contribute to about half of the worlds total rice production. In this study, three major rice-producing countries in Asia are considered, India, Thailand and the Philippines (the later two contributing 4% and 2% of the worlds rice production). Rice straw is one of the main field based residues produced along with this commodity and its applications vary widely in the region. Although rice production practises vary from one country to another, open burning of straw is a common practice in these countries. In this study, an approach was followed aiming at (a) determining the quantity of rice straw being subject to open field burning in those countries, (b) congregating pollutant specific emissions factors for rice straw burning, and (c) quantifying the resulting air pollutant emissions. Uncertainties in the results obtained as compared to a global approach are also discussed.

Greenhouse gas emissions from the production and use of palm methyl ester in Thailand

This study compares the life cycle Greenhouse Gas (GHG) emissions from Palm Methyl Ester (PME) and conventional diesel (diesel hereinafter) used for transportation in Thailand. The life cycle GHG emissions from the production and use of PME were found to be 79.5% less than that from diesel production and use. Hence, a fuel switch from diesel to PME, according to the Thai governments plan of using a 10% blend of biodiesel countrywide by 2012, will contribute to reducing global warming potential by 7.8 million tonne CO2-eq per year as well as reducing crude oil imports.

Alternative Rice Straw Management Practices to Reduce Field Open Burning in Thailand

Open burning of rice straw causes release of air pollutants, which contributes to enhance climate change related issues. Moreover, the burning practice was a reason of losing carbon content from crop land to the atmosphere. This study focuses on estimation of carbon content loss to the atmosphere through open burning of rice straw and suggests alternative rice straw management practices to reduce field open burning in Thailand. Field experiments were conducted to collect samples of rice straw to quantify residue to product ratio (RPR) and analyze their carbon content by elemental analysis. Ash samples were also collected to analyze their carbon content. Carbon losses to the atmosphere through field burning were then estimated. To better understand traditional practices of open burning in Thailand, statistics related to seasonal rice production/harvesting were also investigated. Finally, economic and environmental benefits associated to alternative rice straw management options were considered and discussed against traditional open burning practices.

Interannual variability of nitrogen oxides emissions from boreal fires in Siberia and Alaska during 1996–2011 as observed from space

Past studies suggest that forest fires contribute significantly to the formation of ozone in the troposphere. However, the emissions of ozone precursors from wildfires, and the mechanisms involved in ozone production from boreal fires, are very complicated. Moreover, an evaluation of the role of forest fires is prevented by the lack of direct observations of the ozone precursor, nitrogen oxides (NOx), and large uncertainties exist in the emissions inventories currently used for modelling. A comprehensive understanding of the important processes and factors involving wildfires has thus been unobtainable. We made 16 year consistent analyses of NOx emissions from boreal wildfires by using satellite observations of tropospheric nitrogen dioxides (NO2) from 1996 to 2011. We report substantial interannual variability of tropospheric NO2 originating from large boreal fires over Siberia in 1998, 2002, 2003, 2006, and 2008; and over Alaska in 2004, 2005, and 2009. Monthly comparisons of NO2 enhancements with fire radiative power (FRP) show reasonably strong correlation, suggesting that FRP is a better proxy than burned area for boreal fire NOx emissions. We provide space-based constraints on NOx emission factors (EFs) for Siberian and Alaskan fires. Although the associated uncertainty is relatively large, the derived EFs fall into a in reasonably agreeable range with those previously determined by in situ ground-based and airborne observations over these regions.

Bottom up approach to estimate air pollution of rice residue open burning in Thailand

Rice residue open burning is a farmer activity potentially contributes to global warming. This study was conducted with the objective of examining the spatial and temporal distribution of emissions from rice residue open burning in Thailand by using questionnaire survey and field experimentation. A sample of 1000 Thai farmers was interviewed in order to study the fire behaviours of farmers. One hundred and twenty rice sampling plots were selected for measuring rice residue characteristics. Of the farmer’s fire behaviour, 45% of farmer regularly uses prescribed burning technique for land preparation activities. The amount of rice residue was approximately 117.7 Mt. Although nearly 60% of total residue was subjected to burning in the fields, only 15% of rice residue is actually burned in the fields because the residue and soil have high moisture content. The burning emissions are computed at 1.67 Mt of CO, 0.04 Mt of NOx, 0.35 Mt of PM2.5, 0.12 Mt of PM10, and 0.01 Mt of BC. Approximately 30%, 26%, and 17% of all emissions are contributed by the lower-northern, central, and western regions of Thailand, respectively. Moreover, 31% and 30% of all emissions are annually emitted from December to January and April to May over one month periods following each harvesting season. The comparisons of rice residue burning emissions provided by this study and previous studies have found the emissions discovered in this study to range from one to five times higher than the finding of previous studies. This finding demonstrates the importance of the assessment of activity data specific to farming fire characteristics.

Estimating emissions from forest fires in Thailand using MODIS active fire product and country specific data

Studies on air pollution and climate change have shown that forest fires constitute one of the major sources of atmospheric trace gases and particulate matter, especially during the dry season. However, these emissions remain difficult to quantify due to uncertainty on the extent of burned areas and deficient knowledge on the forest fire behaviours in each country. This study aims to estimate emissions from forest fires in Thailand by using the combination of the Moderate Resolution Imaging Spectroradiometer (MODIS) for active fire products and country-specific data based on prescribed burning experiments. The results indicate that 27817 fire hotspots (FHS) associated with forest fires were detected by the MODIS during 2005–2009. These FHS mainly occurred in the northern, western, and upper north-eastern parts of Thailand. Each year, the most significant fires were observed during January–May, with a peak in March. The majority of forest FHS were detected in the afternoon. According to the prescribed burning experiments, the average area of forest burned per fire event was found to fall within the range 1.09 to 12.47 ha, depending upon the terrain slope and weather conditions. The total burned area was computed at 159309 ha corresponding to the surface biomass fuel of 541515 tons dry matter. The forest fire emissions were computed at 855593 tons of CO2, 56318 tons of CO, 3682 tons of CH4, 108 tons of N2O, 4928 tons of PM2.5, 4603 tons of PM10, 357 tons of BC and 2816 tons of OC.

Energy and greenhouse gas emissions reduction potential of sugarcane field residues power generation in Thailand.

This paper presents an approach to evaluate the net energy potential of sugarcane field residues in Thailand. It was estimated that around 13,595 ktons of sugarcane field residues was burned in the field annually in the country. Assuming 100% collection efficiency, this amount could be converted to 210.46 PJ through power generation. The quantity of greenhouse gases (GHGs) including CO2, CH4, and N2O emitted from open burning of sugarcane residues was compared to that released from power production using life cycle analysis methodology for the estimation. It was found that the avoided GHG emissions obtained for power generation represent 11,836 ktons CO2equivalent, based on the country specific emission factor of electricity production using coal as fuel of 1.09 kg CO2/kWh. Although this enormous potential for energy production in Thailand, sugarcane field residues availability is subject to seasonal variability, which limits its capacity to serve as fuel for power generation. The total avoided GHG emissions were therefore 11,836 ktons CO2eq and 8,285 ktons CO2eq annually for collection efficiency of 100% and 70%, respectively. Comparatively to the national CO2 emissions from coal power generation of 34,532 ktons CO2eq in 2011, the avoided GHG emissions would be about 34% and 24% for collection efficiency of 100% and 70%, respectively. Index Terms—Greenhouse gas (GHG), sugarcane field residues, power generation, open burning, emission reduction.

Fuel Characteristics of Agricultural Residues in Thailand

In Thailand, well recognized as one of the first-rank exporters of agricultural and food products, agricultural residue has been used as an energy source, especially in rural areas. In order to characterize the chemical properties of major agricultural residues to be used as fuel, an analytical protocol was developed. In this article, details of the analytical protocol are first described and preliminary results are then presented and discussed. Results of this study could serve to establish a database of Thai biomass fuels or feedstock that would support decision making in terms of energy conversion technology selection and operating conditions setting.

Spatial and Temporal Distribution of Forest Fire PM10 Emission Estimation by Using Remote Sensing Information

Abstract— This study aims to assess the PM10 emission emitted and the spatial and temporal distribution of PM10 emissions from forest fire during the 2005-2009 periods. The active fire product is known as fire hot spots (FHS) from MODerate-resolution Imaging Spectro-radiometer (MODIS) sensor were used to assess the forest fire areas in Thailand. During this period, Active fires was detected nearly 87,000 FHS with a highest significant in the deciduous forest, corresponding with a damaged forest area of about 78,200 km and about 92% of it was burned habitually. The effecting of forest fire had resulted in a combusted surface fuel of approximately 22,388,000 tonns dry matter and PM10 emission was emitted at 187,331 tonns. The obtained results have been used occasionally as reference to develop risk area map of PM10. Risk area map is often use as a reference for many decision-making policies.