A comparative analysis of woody biomass and coal for electricity generation under various CO2 emission reductions and taxes

Mitigating global climate change via CO₂ emission control and taxation is likely to enhance the economic potential of bioenergy production and utilization. This study investigated the cost competitiveness of woody biomass for electricity production in the US under alternative CO₂ emission reductions and taxes. We first simulated changes in the price of coal for electricity production due to CO₂ emission reductions and taxation using a computable general equilibrium model. Then, the costs of electricity generation fueled by energy crops (hybrid poplar), logging residues, and coal were estimated using the capital budgeting method. Our results indicate that logging residues would be competitive with coal if emissions were taxed at about US$25 Mg⁻¹ CO₂, while an emission tax US$100 Mg⁻¹ CO₂ or higher would be needed for hybrid poplar plantations at a yield of 11.21 dry Mg ha⁻¹ yr⁻¹ (5 dry tons ac⁻¹ yr⁻¹) to compete with coal in electricity production. Reaching the CO₂ emission targets committed under the Kyoto Protocol would only slightly increase the price of fossil fuels, generating little impact on the competitiveness of woody biomass. However, the price of coal used for electricity production would significantly increase if global CO₂ emissions were curtailed by 20% or more. Logging residues would become a competitive fuel source for electricity production if current global CO₂ emissions were cut by 20–30%. Hybrid poplar plantations would not be able to compete with coal until emissions were reduced by 40% or more.     

Climate policy scenarios in Brazil: A multi-model comparison for energy

This paper assesses the effects of market-based mechanisms and carbon emission restrictions on the Brazilian energy system by comparing the results of six different energy-economic or integrated assessment models under different scenarios for carbon taxes and abatement targets up to 2050. Results show an increase over time in emissions in the baseline scenarios due, largely, to higher penetration of natural gas and coal. Climate policy scenarios, however, indicate that such a pathway can be avoided. While taxes up to 32 US$/tCO₂e do not significantly reduce emissions, higher taxes (from 50 US$/tCO₂e in 2020 to 16 2US$/tCO₂e in 2050) induce average emission reductions around 60% when compared to the baseline. Emission constraint scenarios yield even lower reductions in most models. Emission reductions are mostly due to lower energy consumption, increased penetration of renewable energy (especially biomass and wind) and of carbon capture and storage technologies for fossil and/or biomass fuels. This paper also provides a discussion of specific issues related to mitigation alternatives in Brazil. The range of mitigation options resulting from the model runs generally falls within the limits found for specific energy sources in the country, although infrastructure investments and technology improvements are needed for the projected mitigation scenarios to achieve actual feasibility.     

The economical and environmental performance of miscanthus and switchgrass production and supply chains in a European setting

The purpose of this study is to analyse the economical and environmental performance of switchgrass and miscanthus production and supply chains in the European Union (EU25), for the years 2004 and 2030. The environmental performance refers to the greenhouse gas (GHG) emissions, the primary fossil energy use and to the impact on fresh water reserves, soil erosion and biodiversity. Analyses are carried out for regions in five countries. The lowest costs of producing (including storing and transporting across 100 km) in the year 2004 are calculated for Poland, Hungary and Lithuania at 43–64 € per oven dry tonne (odt) or 2.4–3.6 € GJ^?1 higher heating value. This cost level is roughly equivalent to the price of natural gas (3.1 € GJ^?1) and lower than the price of crude oil (4.6 € GJ^?1) in 2004, but higher than the price of coal (1.7 € GJ^?1) in 2004. The costs of biomass in Italy and the United Kingdom are somewhat higher (65–105 € odt^?1 or 3.6–5.8 € GJ^?1). The doubling of the price of crude oil and natural gas that is projected for the period 2004–2030, combined with nearly stable biomass production costs, makes the production of perennial grasses competitive with natural gas and fossil oil. The results also show that the substitution of fossil fuels by biomass from perennial grasses is a robust strategy to reduce fossil energy use and curb GHG emissions, provided that perennial grasses are grown on agricultural land (cropland or pastures). However, in such case deep percolation and runoff of water are reduced, which can lead to overexploitation of fresh water reservoirs. This can be avoided by selecting suitable locations (away from direct accessible fresh water reservoirs) and by limiting the size of the plantations. The impacts on biodiversity are generally favourable compared to conventional crops, but the location of the plantation compared to other vegetation types and the size and harvesting regime of the plantation are important variables.     

The costs of mitigating carbon emissions in China: findings from China MARKAL-MACRO modeling

In this paper MARKAL-MACRO, an integrated energy-environment-economy model, is used to generate China’s reference scenario for future energy development and carbon emission through the year 2050. The results show that with great efforts on structure adjustment, energy efficiency improvement and energy substitution, China’s primary energy consumption is expected to be 4818 Mtce and carbon emission 2394 MtC by 2050 with annual decrease rate of 3% for the carbon intensity per GDP during the period 2000–2050. On the basis of this reference scenario, China’s marginal abatement cost curves of carbon for the year 2010, 2020 and 2030 are derived from the model, and the impacts of carbon emission abatement on GDP are also simulated. The results are compared with those from other sources. The research shows that the marginal abatement costs vary from 12US$/tC to 216US$/tC and the rates of GDP losses relative to reference range from 0.1% to 2.54% for the reduction rates between 5% and 45%. Both the marginal abatement costs and the rates of GDP losses further enlarge on condition that the maximum capacity of nuclear power is constrained to 240 GW or 160 GW by 2050. The paper concludes that China's costs of carbon abatement is rather high in case of carbon emissions are further cut beyond the reference scenario, and China's carbon abatement room is limited due to her coal-dominant energy resource characteristic. As economic development still remains the priority and per capita income as well as per capita carbon emission are far below the world average, it will be more realistic for China to make continuous contributions to combating global climate change by implementing sustainable development strategy domestically and playing an active role in the international carbon mitigation cooperation mechanisms rather than accepting a carbon emission ceiling.     

Global warming and environmental benefits of hydroelectric for sustainable energy in Turkey

Over the last two decades; technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries. Turkey has a total gross hydropower potential of 433 GWh/yr, but only 125 GWh/yr of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country would be tapped. Turkey's total economically usable small hydropower potential is 3.75 GWh/yr. It is expected that the demand for electric energy in Turkey will be about 580 billion kWh by the year 2020. Turkey is heavily dependent on expensive imported energy sources that place a big burden on the economy and air pollution is becoming a great environmental concern in the country. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Environmentally friendly energy development has enormous implications for developing countries as major emitters due to their rapid economic and population growth. With some possible options, the paper concludes that the reduction of emissions can only be achieved when policies are supportive and well targeted, standards and incentives are realistic and flexible, and the public is actively responsive to environmental degradation. Turkey's high rate of energy-related carbon emissions growth is expected to accelerate, with emissions climbing from 57 million tons in 2000 to almost 210 million tons in 2020. Carbon intensity in Turkey is higher than the western developed nation average. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. This paper deals with Turkey's renewables energy sources for sustainable environment.     

Economic and greenhouse gas emission analysis of bioenergy production using multi-product crops—case studies for the Netherlands and Poland

In the face of climate change that may result from greenhouse gas (GHG) emissions, the scarcity of agricultural land and limited competitiveness of biomass energy on the market, it is desirable to increase the performance of bioenergy systems. Multi-product crops, i.e. using a crop partially for energy and partially for material purposes can possibly create additional incomes as well as additional GHG emission reductions. In this study, the performance of several multi-product crop systems is compared to energy crop systems, focused on the costs of primary biomass fuel costs and GHG emission reductions per hectare of biomass production. The sensitivity of the results is studied by means of a Monte-Carlo analysis. The multi-product crops studied are wheat, hemp and poplar in the Netherlands and Poland. GHG emission reductions of these multi-product crop systems are found to be between 0.2 and 2.4 Mg CO_2eq/(ha yr) in Poland and 0.9 and 7.8 Mg CO_2eq/(ha yr) in the Netherlands, while primary biomass fuel costs range from −4.1 to −1.7 €/GJ in the Netherlands and from 0.1 to 9.8 €/GJ in Poland. Results show that the economic attractiveness of multi-product crops depends strongly on material market prices, crop production costs and crop yields. Net annual GHG emission reductions per hectare are influenced strongly by the specific GHG emission reduction of material use, reference energy systems and GHG emissions of crop production. Multi-product use of crops can significantly decrease primary biomass fuel costs. However, this does not apply in general, but depends on the kind of crops and material uses. For the examples analysed here, net annual GHG emission reductions per hectare are not lowered by multi-product use of crops. Consequently, multi-product crops are not for granted an option to increase the performance of bioenergy systems. Further research on the feasibility of large-scale multi-product crop systems and their impact on land and material markets is desirable.     

Greenhouse gas emissions and energy balance of palm oil biofuel

The search for alternatives to fossil fuels is boosting interest in biodiesel production. Among the crops used to produce biodiesel, palm trees stand out due to their high productivity and positive energy balance. This work assesses life cycle emissions and the energy balance of biodiesel production from palm oil in Brazil. The results are compared through a meta-analysis to previous published studies: Wood and Corley (1991) [Wood BJ, Corley RH. The energy balance of oil palm cultivation. In: PORIM intl. palm oil conference – agriculture; 1991.], Malaysia; Yusoff and Hansen (2005) [Yusoff S, Hansen SB. Feasibility study of performing an life cycle assessment on crude palm oil production in Malaysia. International Journal of Life Cycle Assessment 2007;12:50–8], Malaysia; Angarita et al. (2009) [Angarita EE, Lora EE, Costa RE, Torres EA. The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia. Renewable Energy 2009;34:2905–13], Colombia; Pleanjai and Gheewala (2009) [Pleanjai S, Gheewala SH. Full chain energy analysis of biodiesel production from palm oil in Thailand. Applied Energy 2009;86:S209–14], Thailand; and Yee et al. (2009) [Yee KF, Tan KT, Abdullah AZ, Lee KT. Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability. Applied Energy 2009;86:S189–96], Malaysia. In our study, data for the agricultural phase, transport, and energy content of the products and co-products were obtained from previous assessments done in Brazil. The energy intensities and greenhouse gas emission factors were obtained from the Simapro 7.1.8. software and other authors. These factors were applied to the inputs and outputs listed in the selected studies to render them comparable. The energy balance for our study was 1:5.37. In comparison the range for the other studies is between 1:3.40 and 1:7.78. Life cycle emissions determined in our assessment resulted in 1437 kg CO₂e/ha, while our analysis based on the information provided by other authors resulted in 2406 kg CO₂e/ha, on average. The Angarita et al. (2009) [Angarita EE, Lora EE, Costa RE, Torres EA. The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia. Renewable Energy 2009;34:2905–13] study does not report emissions. When compared to diesel on a energy basis, avoided emissions due to the use of biodiesel account for 80 g CO₂e/MJ. Thus, avoided life cycle emissions associated with the use of biodiesel yield a net reduction of greenhouse gas emissions. We also assessed the carbon balance between a palm tree plantation, including displaced emissions from diesel, and a natural ecosystem. Considering the carbon balance outcome plus life cycle emissions the payback time for a tropical forest is 39 years. The result published by Gibbs et al. (2008) [Gibbs HK, Johnston M, Foley JA, Holloway T, Monfreda C, Ramankutty N, et al., Carbon payback times for crop-based biofuel expansion in the tropics: the effects of changing yield and technology. Environmental Research Letters 2008;3:10], which ignores life cycle emissions, determined a payback range for biodiesel production between 30 and 120 years.     

Modeling climate change mitigation from alternative methods of charcoal production in Kenya

Current carbon accounting methodologies do not accommodate activities that involve emissions reductions from both land-use change and energy production. This paper analyzes the climate change mitigation potential of charcoal production in East Africa by examining the impact of changing both land management and technology. Current production in a major charcoal producing region of Kenya where charcoal is made as a by-product of land clearance for commercial grain production is modeled as the “business-as-usual” scenario. Alternative production systems are proposed based on coppice management of native or exotic trees. Improved kilns are also considered. Changes in aboveground, belowground, and soil carbon are modeled and two distinct baseline assessments are analyzed: one is based on a fixed area of land and one is based on the quantity of non-renewable fuel that is displaced by project activities. The magnitude of carbon emissions reductions varies depending on land management as well as the choice of carbonization technology. However, these variations are smaller than the variations arising from the choice of baseline methodology. The fixed-land baseline yields annualized carbon emission reductions equivalent to 0.5–2.8 tons per year (t y^?1) with no change in production technology and 0.7–3.5 t y^?1 with improved kilns. In contrast, the baseline defined by the quantity of displaced non-renewable fuel is 2–6 times larger, yielding carbon emissions reductions of 1.4–12.9 t y^?1 with no change in production technology and 3.2–20.4 t y^?1 with improved kilns. The results demonstrate the choice of baseline, often a political rather than scientific decision, is critical in assessing carbon emissions reductions.     

Energy and environmental evaluation of municipal facilities: Case study in the province of Barcelona

The service sector is extraordinarily important for the European economy, as it accounts for 75% of the GDP. Yet it is also a huge consumer of energy, especially in urban environments. Municipalities have the authority to develop and manage municipal services, and as a result the European Commission drew up the Covenant of Mayors in which the signatory municipalities pledge to reduce their CO₂ emissions by 20% of their 1990 rates. Sustainable Energy Action Plans (SEAPs) emerged from this covenant with the goal of analysing the current consumption patterns and compiling the actions that the municipalities should undertake in order to fulfil their pledges.This article focuses on analysing the energy consumption and greenhouse gas emissions of 978 municipal service facilities in the province of Barcelona in the year 2005. The average consumption per facility by surface area is 118.8 kWh/m². Regarding greenhouse gas emissions, the average annual emissions in the facilities studied in the province of Barcelona were 40.0 kg CO₂ eq/m².     

Carbon footprint evaluation at industrial park level: A hybrid life cycle assessment approach

Industrial parks have become the effective strategies for government to promote sustainable economic development due to the following advantages: shared infrastructure and concentrated industrial activities within planned areas. However, due to intensive energy consumption and dependence on fossil fuels, industrial parks have become the main areas for greenhouse gas emissions. Therefore, it is critical to quantify their carbon footprints so that appropriate emission reduction policies can be raised. The objective of this paper is to seek an appropriate method on evaluating the carbon footprint of one industrial park. The tiered hybrid LCA method was selected due to its advantages over other methods. Shenyang Economic and Technological Development Zone (SETDZ), a typical comprehensive industrial park in China, was chosen as a case study park. The results show that the total life cycle carbon footprint of SETDZ was 15.29 Mt, including 6.81 Mt onsite (direct) carbon footprint, 8.47 Mt upstream carbon footprint, and only 3201 t downstream carbon footprint. Analysis from industrial sector perspectives shows that chemical industry and manufacture of general purpose machinery and special purposes machinery sector were the two largest sectors for life cycle carbon footprint. Such a sector analysis may be useful for investigation of appropriate emission reduction policies.     

Temporal CO2 emissions associated with electricity generation: Case study of Singapore

Studying temporal patterns in emissions associated with electricity generation is increasingly important. On the supply side, there is interest in integrating renewable energy sources (solar, wind), which are known to vary daily and hourly. On the demand side, the concept of demand response is driving a need to better understand the impact of peak versus off-peak loading, with the objective of maximizing efficiency. In this study, we examine the case of electric power generation in Singapore, and aim to assess the half-hourly variation in associated average carbon dioxide emissions. Given the country’s serious push for clean energy solutions and a possibility of adopting carbon trading in the future, we feel the need to address the currently existing gap in research on daily CO₂ emissions patterns. By associating representative electricity generation data with the characterized fleet of power plants, half-hourly emissions are found to range between 415 and 455 kg CO₂ per MW h. Marginal emission factors show a fluctuating daily pattern between 390 and 800 kg CO₂/MW h. Policy makers able to work with real generation data can use this approach to understand the carbon footprint of short-term supply and demand interventions.     

Life cycle analysis of vehicles powered by a fuel cell and by internal combustion engine for Canada

The transportation sector is responsible for a great percentage of the greenhouse gas emissions as well as the energy consumption in the world. Canada is the second major emitter of carbon dioxide in the world. The need for alternative fuels, other than petroleum, and the need to reduce energy consumption and greenhouse gases emissions are the main reasons behind this study. In this study, a full life cycle analysis of an internal combustion engine vehicle (ICEV) and a fuel cell vehicle (FCV) has been carried out. The impact of the material and fuel used in the vehicle on energy consumption and carbon dioxide emissions is analyzed for Canada. The data collected from the literature shows that the energy consumption for the production of 1 kg of aluminum is five times higher than that of 1 kg of steel, although higher aluminum content makes vehicles lightweight and more energy efficient during the vehicle use stage. Greenhouse gas regulated emissions and energy use in transportation (GREET) software has been used to analyze the fuel life cycle. The life cycle of the fuel consists of obtaining the raw material, extracting the fuel from the raw material, transporting, and storing the fuel as well as using the fuel in the vehicle. Four different methods of obtaining hydrogen were analyzed; using coal and nuclear power to produce electricity and extraction of hydrogen through electrolysis and via steam reforming of natural gas in a natural gas plant and in a hydrogen refueling station. It is found that the use of coal to obtain hydrogen generates the highest emissions and consumes the highest energy. Comparing the overall life cycle of an ICEV and a FCV, the total emissions of an FCV are 49% lower than an ICEV and the energy consumption of FCV is 87% lower than that of ICEV. Further, CO₂ emissions during the hydrogen fuel production in a central plant can be easily captured and sequestrated. The comparison carried out in this study between FCV and ICEV is extended to the use of recycled material. It is found that using 100% recycled material can reduce energy consumption by 45% and carbon dioxide emissions by 42%, mainly due to the reduced use of electricity during the manufacturing of the material.     

Full-scale co-firing trial tests of sawdust and bio-waste in pulverized coal-fired 230 t/h steam boiler

Co-firing trial tests of sawdust and bio-waste coming from cereal production with hard coal were carried out at Skawina Power Plant in Poland (1532 MW in fuel, currently belonging to CEZ Group). Skawina Power Plant is a tangentially-fired pulverized coal unit with nine boilers (4 boilers of 210 t/h and five boilers of 230 t/h live steam respectively) that produces 590 MW electricity and 618 MW of heat (district heating and process steam).The paper presents an analysis of energy and ecological effects of sawdust and bio-waste co-firing in the existing pulverized hard coal boiler. The mixture of coal and biomass was blended in the coal yard, and fed into the boiler through the coal mills. During the tests, combustion of mixtures composed of hard coal and sawdust (with mass share of 9.5%) and hard coal – bio-waste (6.6% mass basis) were examined. The co-firing tests were successful. Based on the analysis of the test results, the influence of biomass co-firing on specific components of energy balance (e.g. stack losses and boiler thermal efficiency) was discussed, in comparison to combustion of coal alone. The emission indices during coal combustion were calculated and compared to the emission indices for biomass co-firing. It was proved that co-firing of both biomass sorts leads to a decrease of CO and SO₂ emissions. Due to the possibility of considering the part of the energy generated during biomass co-firing as renewable energy, the procedure for biomass based renewable energy share determination is presented and illustrated with an example.     

Techno-economic analysis of using corn stover to supply heat and power to a corn ethanol plant – Part 2: Cost of heat and power generation systems

This paper presents a techno-economic analysis of corn stover fired process heating (PH) and the combined heat and power (CHP) generation systems for a typical corn ethanol plant (ethanol production capacity of 170 dam³). Discounted cash flow method was used to estimate both the capital and operating costs of each system and compared with the existing natural gas fired heating system. Environmental impact assessment of using corn stover, coal and natural gas in the heat and/or power generation systems was also evaluated. Coal fired process heating (PH) system had the lowest annual operating cost due to the low fuel cost, but had the highest environmental and human toxicity impacts. The proposed combined heat and power (CHP) generation system required about 137 Gg of corn stover to generate 9.5 MW of electricity and 52.3 MW of process heat with an overall CHP efficiency of 83.3%. Stover fired CHP system would generate an annual savings of 3.6 M$ with an payback period of 6 y. Economics of the coal fired CHP system was very attractive compared to the stover fired CHP system due to lower fuel cost. But the greenhouse gas emissions per Mg of fuel for the coal fired CHP system was 32 times higher than that of stover fired CHP system. Corn stover fired heat and power generation system for a corn ethanol plant can improve the net energy balance and add environmental benefits to the corn to ethanol biorefinery.     

Decentralised carbon footprint analysis for opting climate change mitigation strategies in India

Carbon footprint (CF) refers to the total amount of carbon dioxide and its equivalents emitted due to various anthropogenic activities. Carbon emission and sequestration inventories have been reviewed sector-wise for all federal states in India to identify the sectors and regions responsible for carbon imbalances. This would help in implementing appropriate climate change mitigation and management strategies at disaggregated levels. Major sectors of carbon emissions in India are through electricity generation, transport, domestic energy consumption, industries and agriculture. A majority of carbon storage occurs in forest biomass and soil. This paper focuses on the statewise carbon emissions (CO₂, CO and CH₄), using region specific emission factors and statewise carbon sequestration capacity. The estimate shows that CO₂, CO and CH₄ emissions from India are 965.9, 22.5 and 16.9 Tg per year, respectively. Electricity generation contributes 35.5% of total CO₂ emission, which is followed by the contribution from transport. Vehicular transport exclusively contributes 25.5% of total emission. The analysis shows that Maharashtra emits higher CO₂, followed by Andhra Pradesh, Uttar Pradesh, Gujarat, Tamil Nadu and West Bengal. The carbon status, which is the ratio of annual carbon storage against carbon emission, for each federal state is computed. This shows that small states and union territories (UT) like Arunachal Pradesh, Mizoram and Andaman and Nicobar Islands, where carbon sequestration is higher due to good vegetation cover, have carbon status >1. Annually, 7.35% of total carbon emissions get stored either in forest biomass or soil, out of which 34% is in Arunachal Pradesh, Madhya Pradesh, Chhattisgarh and Orissa.     

Environmental aspects of ethanol derived from no-tilled corn grain: nonrenewable energy consumption and greenhouse gas emissions

Nonrenewable energy consumption and greenhouse gas (GHG) emissions associated with ethanol (a liquid fuel) derived from corn grain produced in selected counties in Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin are presented. Corn is cultivated under no-tillage practice (without plowing). The system boundaries include corn production, ethanol production, and the end use of ethanol as a fuel in a midsize passenger car. The environmental burdens in multi-output biorefinery processes (e.g., corn dry milling and wet milling) are allocated to the ethanol product and its various coproducts by the system expansion allocation approach.The nonrenewable energy requirement for producing 1 kg of ethanol is approximately 13.4–21.5 MJ (based on lower heating value), depending on corn milling technologies employed. Thus, the net energy value of ethanol is positive; the energy consumed in ethanol production is less than the energy content of the ethanol (26.8 MJ kg⁻¹).In the GHG emissions analysis, nitrous oxide (N₂O) emissions from soil and soil organic carbon levels under corn cultivation in each county are estimated by the DAYCENT model. Carbon sequestration rates range from 377 to 681 kg C ha⁻¹ year⁻¹ and N₂O emissions from soil are 0.5–2.8 kg N ha⁻¹ year⁻¹ under no-till conditions. The GHG emissions assigned to 1 kg of ethanol are 260–922 g CO₂ eq. under no-tillage. Using ethanol (E85) fuel in a midsize passenger vehicle can reduce GHG emissions by 41–61% km⁻¹ driven, compared to gasoline-fueled vehicles. Using ethanol as a vehicle fuel, therefore, has the potential to reduce nonrenewable energy consumption and GHG emissions.     

The effects of operating conditions on emissions from masonry heaters and sauna stoves

Emissions from masonry heaters and sauna stoves were studied. In the sauna stove the production of organic gaseous carbon (OGC) at 10 gC kg^?1 (per kilogram of fuel), carbon monoxide (CO) at 55 g kg^?1, fine particle mass (PM₁) at 5 g kg^?1 and number emissions (N) at 1.8 × 10¹⁵ kg^?1 was higher than in other measured appliances. In a modern technology masonry heater with a unique grate, the emissions were very low: 0.4 gC kg^?1 OGC, 14 g kg^?1 CO and 0.7 g kg^?1 PM₁. Conventional masonry heaters, using small logs, clearly produced higher emissions when compared to using large logs. Doubling the fuel load caused emission factors to increase by up to 4- times (OGC), except for the number emission, which decreased from 4.0 × 10¹⁴ to 2.0 × 10¹⁴ kg^?1. From the conventional masonry heater 90% of the PM was emitted during the firing phase. Its combustion process is different to that in stoves or conventional open fireplaces. The insufficient supply of air, due to too fast pyrolysis, and increased ash release, due to the high combustion temperature, are the main parameters which cause high particle and gas emissions in masonry heaters and sauna stoves.     

Kuroshio power plant development plan

As a country lacking energy reserves, Taiwan imports 99.2% of its energy, with only a small portion of indigenous energy, such as hydro, wind, and solar. In 2008, each Taiwanese spent 85,000 NTD dollars (1 USD ～ 32 NTD) to purchase oil, coal, gas, and nuclear fuel from foreign countries, accounting for a total payment of 1.8 trillion NTD, more than the annual budget of the Taiwan government of 1.7 trillion NTD. In the same year, Taiwan emitted about 1% of the world's greenhouse gas (GHG), or 12 tons per person-year, ranking 18th globally. These situations in terms of energy security and carbon emission are very severe.To resolve these severe situations, harnessing the power of the Kuroshio in eastern Taiwan offers a great opportunity. The Kuroshio is a branch of the North Pacific Ocean current. Due to the westward-enhanced effect, this ocean current is strong and stable as it passes through eastern Taiwan. The flow rate is about 30 sverdrup (Sv) or 1000 times that of the Yangtze River, the average speed is 1 m/s, the flow direction is fixed to the north, and the flow path is close to the east coast of Taiwan. By precisely locating high-quality sites and implementing sequential works with careful planning, one can possibly generate exploitable power more than 30 GW. With 30 GW of clean energy, Taiwan could effectively enhance energy security, reduce GHG emission, and lower energy-purchasing cost.This paper proposes a feasibility study to explore the power of the Kuroshio. The content consists of four parts: (1) assessment of Kuroshio power reserves, (2) development of turbine generators, (3) development of turbine-anchor system, and (4) deep-sea marine engineering of turbine clusters. By integrating these technologies above, we propose a project to construct a 30 MW pilot plant. In this project, we also discuss the financial analysis and propose new regulations, environmental impact analysis, risk assessment, and other relevant issues.     

The role of biofuels for transportation in CO2 emission reduction scenarios with global versus regional carbon caps

This study analyzes how international climate regimes affect cost-efficiency of fuel choices in the transportation sector. The analysis is carried out with a regionalized version of the Global Energy Transition model, GET-R 6.0. Two different carbon dioxide (CO₂) reduction scenarios are applied, both meeting an atmospheric CO₂ concentration target of 450 ppm by the year 2100. The first scenario, “global cap” (GC), uses a global cap on CO₂ emissions, and global emissions trading is allowed. In the second scenario, “regional caps” (RC), industrialized regions start to reduce their CO₂ emissions by 2010 while developing regions may wait several decades and emission reductions are not tradable across regions. In this second scenario, CO₂ emissions are assumed to meet an equal per capita distribution of 1.0 tC/capita, in all six regions, by 2040; emissions then follow a common reduction path, toward approximately 0.2 tC/capita by 2100. Three main results emerge from our analysis: (i) the use of biofuels in the industrialized regions is significantly higher in RC than in GC; (ii) the use of biofuels in RC actually increases the weaker (i.e., higher) the CO₂ concentration target (up to 550 ppm); and (iii) biofuels never play a dominant role in the transportation sector. We find that biofuels may play a more important role in industrialized countries if these take on their responsibilities and reduce their emissions before developing countries start reducing their emissions, compared to the case in which all countries take action under a global cap and trade emission reduction regime.     

Energy policy tools for agricultural residues utilization for heat and power generation: A case study of sugarcane trash in Thailand

Cane trash could viably substitute fossil fuels in heat and power generation projects to avoid air pollution from open burning and reduce greenhouse gas (GHG) emission. It is competitive with bituminous and other agro-industrial biomass. Using cane trash for heat generation project could provide a higher reliability and return on investment than power generation project. The heat generation project could be viable (Financial Internal Rate of Return, FIRR = 36–81%) without feedstock subsidy. With current investment and support conditions, the capacity of 5 MW option of power generation project is the most viable (FIRR = 13.6–15.3%); but 30 MW, 1 MW and 10 MW options require feedstock subsidy 450–1100 Baht/t-cane trash to strengthen financial viability. Furthermore, the revenue from carbon credit sales could compensate the revenue from current energy price adder and increases 0.5–1.0% FIRR of power generation project. Using cane trash for 1 MW power generation could reduce GHG emission 637–861 t CO₂eq and avoid air pollutant emissions of 3.35 kg nitrogen oxides (NO_x), 0.41 kg sulfur oxides (SO_x) and 2.05 kg volatile organic compounds (VOC). Also, 1 t steam generation from cane trash could avoid pollutant emissions of 0.6 kg NO_x, 0.07 kg SO_x, and 0.37 kg VOC. The potential of cane trash to cause fouling/slagging as well as erosion are not significantly different from other biomass, but chlorinated organic compounds and NO_x could be higher than bituminous and current biomass feedstock at sugar mill (bagasse and rice husk).