Estimation of Carbon Footprints of Bituminous Road Construction Process

Built Environment: New Default for Asphalt?

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

The environment awareness of toxic gases emissions during the production, transportation, and construction of hot mix asphalt concrete (HMAC) have led to the development of Warm, half warm, and cold mix asphalt concrete. Such development of alternative mixtures is considered as sustainable materials in asphalt concrete paving process. The temperature reduction in the mixing of binder during production, handling, and compaction of the mix results in saving energy, reduction of emissions and significant reduction in production costs. Warm and Cold mixtures technology is considered as more environmentally friendly option to prepare asphalt by adding the binder in the form of an emulsion. Very limited laboratory and practical experience are available in Iraq for these mixtures. However, no trial section was constructed yet which considers such sustainable techniques. Until recent time there were even no technical specifications giving rules for design and use of these warm and cold mixtures. In this investigation, asphalt concrete mixtures usually used for wearing course have been prepared in the laboratory using the traditional hot mix and the sustainable alternatives of warm and cold mix techniques. Emulsified asphalt was implemented as a binder in case of warm and cold mixtures. Specimens were subjected to indirect tensile strength and double punching shear strength determination at 25°C. It was concluded that lower bulk density for cold mix was obtained as compared to hot and warm mixtures. The tensile strength of warm mix and Cold mix are lower by (82.8 and 93.1) % than that of hot mix. The punching shear strength of cold mix is lower by 50 % than that of warm or hot mix.

Increasing concerns on environment and greenhouse effect, coupled with increased construction prices led to the development of new technologies by the Asphalt industry to produce Asphalt Concrete (AC) pavements. Extensive research is being done to evaluate the impact and performance of these new technologies. Warm Mix Asphalt (WMA) is one of these technologies that allow mixing, production, placing and compaction of asphalt mixes at significantly lower temperatures as compared to the traditional Hot Mix Asphalt (HMA) practice. Lower temperatures result in reduced fuel usage, fume exhausts, greenhouse gas emissions, wear and tear at plants; while enhancing worker health and safety conditions. The performance characteristics of asphalt mixtures containing WMA technologies may be affected and should be quantified. A detailed laboratory study has been conducted to evaluate and quantify the performance of different WMA technologies. Eleven mixes from three overlay field projects across Louisiana were taken into consideration. Evotherm, Rediset, Foaming and Latex were different warm mix technologies used. Each project included a companion HMA mixture section to allow comparison of WMA to conventional HMA. Mechanistic tests were conducted on plant produced–lab compacted (PL) specimens to evaluate Rutting (permanent deformation), Fatigue/Fracture and Low temperature cracking performance of the mixtures at high, intermediate and low temperatures respectively. The testing factorial included Dynamic Modulus, Indirect Tensile Strength (ITS), Flow Number (FN), Loaded Wheel Tester (LWT), Beam Fatigue, Semi-Circular Bend (SCB), Dissipated Creep Strain Energy (DCSE), Thermal Stress Restrained Specimen Test (TSRST) and Modified Lottman Test. A Life Cycle Assessment (LCA) has been performed to evaluate the economic and environmental benefits of WMA. Overall, the WMA mixtures showed similar performance compared to that of control HMA mixtures. Asphalt mixtures with Rediset and Latex showed better performance than conventional mixtures with respect to fatigue and permanent deformation. The use of WMA technologies resulted in lesser aging of the binder. Energy assessment has shown a 12-15 % energy savings. On average, $1.61 of cost savings per ton of produced asphalt was observed along with a considerable reduction in air pollutants without any reduction in the mechanistic performance of these mixtures.

A comparative study of the induction healing behaviors of hot and warm mix asphalt

Warm-mix asphalt (WMA) is a group of technologies that allow for the placement of asphalt at production temperatures 35°F–100°F lower than traditional hot-mix asphalt (HMA). Some of the benefits for using WMA are that it lowers fuel consumption, lessens the aging of the asphalt binder, decreases the production of greenhouse gases, allows for the placement of asphalt plants in more restrictive areas, and improves worker conditions. First used in Europe, WMA was introduced to the U.S. with a European scanning tour in 2002. In 2004 the first field tests in the U.S. were constructed, with the first production paving jobs in 2006. Warm Mix Technology is divided into three distinct classifications based on the mechanism used to produce the end product. In one class, foaming, small amounts of water are mixed with the hot asphalt oil. A second process uses organic additives or waxes to decrease the viscosity of the oil. The last class use chemicals or surfactants to aide in the coating of the aggregate at lower temperatures. All three processes have been used in cold weather climates. A surfactant was chosen for Crow Wing County Road 108. Most surfactants require little if any plant modifications when compared to a foaming process in which the modifications could be as simple as adding another bin to a rap feeder or as complicated as adding manifolds and injectors to the plant. The use of a wax was rejected, as one of the ways to get a cost comparable product for this project was to substitute a warm mix product using PG 58-28 oil for a hot mix product using PG 58-34 oil. Research indicated that one of the benefits of warm mix using the foaming or surfactant process is that they generally perform better than the waxes for thermal cracking. On August 19th of 2008 2913 tons of WMA and 272 tons of HMA were placed on Crow Wing County Road 108 by Anderson Brothers Construction Company of Brainerd. A level 2 gyratory mix design was used incorporating Evotherm 3G in the asphalt binder. The additive was added at the Flint Hills refinery in Minneapolis at a rate of 0.5% by the weight of the binder. The product arrived at the paving plant ready to use, requiring no modifications to the plant or the paving equipment. During production the only change made to the normal testing procedure of the mix was the temperature at which the gyratory samples were made. The oil met all the requirements of a PG 58-28 oil and the mix met all of the requirements of a Level 2 gyratory design. The binder was cut 0.1% from the HMA design to bring the production air voids in the WMA up to the desired levels. The densities of the road cores of the WMA (ave. 92.7%) were found to be slightly below that of the HMA (94.1%) but still at a respectable level for a 2 inch lift on a 5 ton road over gravel. Answers that will come over time are whether or not WMA will perform better than HMA for thermal cracking, will it will have a longer life span and will prices become comparable to HMA. Some other countries currently believe the answers are “yes” and are willing to pay a higher price today to realize cost savings in the future.

PDF HTML阅读 XML下载 导出引用 引用提醒 基于生命周期评价的上海市水稻生产的碳足迹 DOI: 10.5846/stxb201304240794 作者: 作者单位: 上海市农业科学院,上海市农业科学院,上海市农业科学院,上海市农业科学院,江西农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家科技部支撑计划后世博专项资助项目（2010BAK69B18）；上海市科委崇明科技攻关专项资助项目（10DZ1960101） Life cycle assessment of carbon footprint for rice production in Shanghai Author: Affiliation: Shanghai Academy of Agricultural Sciences,Seed management station of Shanghai,,,Jiangxi Agricultural University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:碳足迹是指由企业、组织或个人引起的碳排放的集合。参照PAS2050规范并结合生命周期评价方法对上海市水稻生产进行了碳足迹评估。结果表明：（1）目前上海市水稻生产的碳排放为11.8114 t CO2e/hm2，折合每吨水稻生产周期的碳足迹为1.2321 t CO2e；（2）稻田温室气体排放是水稻生产最主要的碳排放源，每吨水稻生产的总排放量为0.9507 t CO2e，占水稻生产全部碳排放的77.1%，其中甲烷（CH4）又是最主要的温室气体，对稻田温室气体碳排放的贡献率高达96.6%；（3）化学肥料的施用是第二大碳排放源，每吨水稻生产的总排放量为0.2044 t CO2e，占水稻生产总碳排放的16.5%，其中N最高，排放量为0.1159 t CO2e。因此，上海低碳水稻生产的关键在降低稻田甲烷的排放，另外可通过提高氮肥利用效率，减少氮肥施用等方法减少种植过程中碳排放。 Abstract:Global climate change has become an urgent issue of concern. Climate change will increasingly threaten our food production, security and even the survival of the human race. It also has a serious impact on natural ecosystems and the socioeconomic system. With the increasing scale and improvement in mechanization levels, the economic linkage between agricultural production and reduction of Greenhouse Gas (GHG) emissions is even closer in the agricultural production system. Therefore, the development of a low-carbon agricultural model is one of the long-term strategies for low-carbon economic growth throughout the country.This research of carbon footprint is introduced to measure the GHG emission over the rice production cycle. The carbon footprint can be defined as the total carbon emissions caused by an organization, event, product or person. At present, carbon footprints are used to measure GHG emissions in products, services, organizations, cities and countries and offer the decision basis for the formulation of GHG emission reduction schemes.Agricultural ecological systems, every year, also produce a lot of GHG emissions. The whole process of prenatal, intrapartum and postpartum agricultural production are closely related to energy consumption and GHG emission. In the process, all the agricultural inputs, such as chemical fertilizers, pesticides, seeds, cultivation, plant protection, agricultural machinery, irrigation and harvest also produce greenhouse gas emissions.The whole cultivation of rice involves methane (CH4) emission. This study shows that rice cultivation is one of the biggest sources of GHG emissions in crop cultivation. Rice paddies emit a large amount of methane in their water logged mode. Different irrigation modes have a great influence on the emission of GHG. Straw return is another factor that promotes GHG emissions. Soil organic content increases with the return of straw, with an increase in the soil methanogen activity, leading to increased methane emissions.The current carbon footprint research is the first time it has been used to measure the carbon emissions involved in rice production. The carbon footprint for rice production in Shanghai was assessed by the PAS2050 paradigm and life cycle assessment. The study area, located in Changjiang Farm, which belongs to the Guangming Group in Chongming County Shanghai City atlatitude 121°32'22' E, longitude31°40'23' N. Chongming County, in the Yangtze River Estuary, is a typical sub tropical monsoon climate with mild climate, abundant rainfall, annual average temperatures of 15.3 ℃, and annual precipitation of 1245 mm. It is the major grain production base for Shanghai city with winter wheat and summer rice forming their main planting patterns, which are typical for the middle and lower reaches of the Yangtze River rice-wheat rotation cropping pattern.The entire carbon emission of rice production in Shanghai was 11.8114 t CO2e (CO2-equivalents)/hm2, corresponding to a 1.2321 t CO2e/t rice grain yield. GHG emissions from paddy fields were the major source, which emitted 0.9507 t CO2e/t rice and accounted for 77.1% of total carbon emissions during rice production. Moreover, CH4 was the largest source for GHG emissions with a contribution rate of 96.6%.Chemical fertilizers were the second largest emission source in rice production. Chemical fertilizers emitted 0.2044 t CO2e for each ton of rice production, contributing 16.5% of total carbon emissions in rice production. N fertilizer was the biggest emission source, which released 0.1159 t CO2e/t rice.This research investigates the GHG emissions over the whole process of the Shanghai rice production cycle and reveals the energy consumption and GHG emissions in rice production. Thus, a rice carbon footprint is calculated by assessing the GHG emissions in Shanghai rice production. The results are beneficial for producing reduction plans of reducing GHG emissions in Shanghai rice production. Furthermore, the results will supply both practicable and theoretical foundations for drafting carbon footprint formulations in other industrial areas. 参考文献 相似文献 引证文献

High temperature for producing reclaimed asphalt mixture becomes the main concern in recycling as this will further age the reclaimed asphalt binder. Highly stiff binder causes workability and compatibility problems, hence affects the desirable performance of pavement. Warm mix asphalt additive is able to decrease the production temperature by reducing the binder viscosity. The synergy of warm mix asphalt and reclaimed asphalt mixtures resulted in a more environmental and energy savings benefits. The effects of a warm mix additive on the rheological properties of conventional asphalt binder containing a high proportion of recovered reclaimed asphalt binder were evaluated. Reclaimed asphalt were obtained from two sources and modified with a warm mix additive named RH. The recovered binders were blended with conventional binder at proportion of 0, 30 and 40 % and then tested for viscosity, stiffness and frequency dependency. Fuel usage and greenhouse gas emission were estimated based on the required fuel to heat up the aggregate and binder from ambient temperature up to the mixing temperature. The addition of RH improves the flow of binders by reducing the viscosity, thus decreases the construction temperature. The initial stiffness of reclaimed asphalt binders influences the effects of RH on the complex modulus and phase angle. The complex modulus increases while the phase angle decreases as the frequency increases, which indicates the binders have become stiffer. The differences in the magnitude of complex modulus are more noticeable at lower frequency and it gets close to each other at the higher frequency. This indicates that in the long run, the performance of modified reclaimed asphalt binders will be slightly better than the conventional hot mix asphalt. The warm mix additive and reclaimed asphalt composite in this study has the potential to reduce the fuel usage and green house gas (GHG) emission by 21 %.

Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use.The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011).

Advantages of nitrogen fertilizer deep placement in greenhouse gas emissions and net ecosystem economic benefits from no-tillage paddy fields

Food processing is a major thriving industry globally and provides livelihood to millions of workers. Food processing is an energy intensive process and often has an impact on the environment which remains undiagnosed and hence not quantified. Food processing industry comprises the organized as well as unorganized sector with varying levels of energy requirement and therefore the carbon foot prints also significantly vary. Higher energy use is often related to higher greenhouse gas (GHG) emission which is responsible for global warming and climate change. Carbon footprint (CFP) of food industry is an estimate of the energy use and GHG emissions caused due to the processing and delivery of food items to the consumer and also disposal of packaging. Recently there is a growing interest in estimating the carbon footprint of food industries to know how improved technologies can be used to make food processing less energy and carbon intensive. In this book chapter we would like to provide an overview of energy use and carbon footprint of different types of food industries. Quantification of CFP is generally done using Life Cycle Assessment (LCA) in which GHG emissions are measured from the very beginning of the production process to its final use and disposal. GHG emission from a food industry will include both direct emissions as well as indirect emissions. The CFP of different sectors like fruit and beverage industry, sugar production, dairy sector, fisheries, meat and poultry supply chains are presented. Apart from this, research gaps and possible steps to minimize the carbon footprint will be mentioned. Assessing the CFP of food industries can help in identifying the GHG sources and can be useful in developing alternative technologies which are more energy efficient and reduces GHG emission. Further, change in dietary pattern also contributes immensely to reduce the environmental impact of food consumption.

Kuwait Oil Company (KOC) has commissioned a study to determine the potential contribution that Carbon Capture and Storage alone (CCS), Carbon Capture and Storage with Enhanced Oil Recovery (CCS-EOR) or other identified measures could make to reducing Kuwait's / KOC's Greenhouse Gas (GHG) emissions, by implementation of recommendations. This study was examined various methods to reduce GHG emissions, including CCS, and will provide a strategy for the implementation of various GHG emission reduction technologies for KOC of international and national requirements to address the global challenge of climate change, with particular focus on the Middle East and the Oil and Gas industry. A cost effective GHG emission reduction target for KOC is proposed to limit GHG emissions as Business as Usual in 2030. Achieving this target requires implementing the Prioritized GHG Emissions Reduction Plan with specific Key Performance Measures (KPMs) for KOC. This Plan is based on a package of GHG emission reduction measures that would be cost neutral to KOC. Adopting a similar approach across the whole of Kuwait is expected to reduce emissions by 2030 projections. CCS and CCS-EOR would accrue costs but have the potential to make the greatest contribution to reducing GHG emissions. This Study recommends CCS and CCS-EOR are suitable for longer-term consideration. Furthermore, the top management KPMs has been identified that will help the management to monitor and control the GHGs emissions to address the global challenge of climate change.

Aktualnie ważnym wyzwaniem dla sektora rolniczego jest redukcja emisji gazów cieplarnianych (GHG) w celu złagodzenia skutków zmian klimatycznych. Istnieje potrzeba dokładnej identyfikacji źródeł emisji oraz upowszechnienia praktyk rolniczych, które przyczyniałyby się do zmniejszenia emisji we wszystkich ogniwach produkcji roślinnej. Do przeprowadzenia obiektywnych porównań i wyboru najlepszych rozwiązań technologicznych według kryterium emisyjności potrzebna jest szczegółowa ocena ilościowa emisji GHG. W opracowaniu przedstawiono ocenę emisji GHG w produkcji roślinnej za pomocą śladu węglowego (CF). Udział operacji technologicznych w powstawaniu CF scharakteryzowano na przykładzie rzepaku ozimego. Wyniki badań wskazują, że największe znaczenie w kształtowaniu CF ma proces nawożenia mineralnego. Wpływ pozostałych procesów na CF jest wielokrotnie mniejszy. Miejscem głównych emisji GHG w nawożeniu mineralnym rzepaku są emisje bezpośrednie i pośrednie GHG z pól. Po emisjach GHG z pól, produkcja nawozów stanowi drugie źródło emisji z nawożenia. Zmiany praktyk rolniczych polegających na zwiększeniu efektywności nawożenia azotowego oraz stosowaniu nawozów o niskich współczynnikach emisji stwarzają obecnie możliwość redukcji emisji GHG i przez to, tym samym mogą przyczynić się do zmniejszenia CF produktów roślinnych.

Asphalt mixtures emission and energy consumption: A review

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third