The contemporary cement cycle of the United States

A country-level stock and flow model for cement, an important construction material, was developed based on a material flow analysis framework. Using this model, the contemporary cement cycle of the United States was constructed by analyzing production, import, and export data for different stages of the cement cycle. The United States currently supplies approximately 80% of its cement consumption through domestic production and the rest is imported. The average annual net addition of in-use new cement stock over the period 2000–2004 was approximately 83 million metric tons and amounts to 2.3 tons per capita of concrete. Nonfuel carbon dioxide emissions (42 million metric tons per year) from the calcination phase of cement manufacture account for 62% of the total 68 million tons per year of cement production residues. The end-of-life cement discards are estimated to be 33 million metric tons per year, of which between 30% and 80% is recycled. A significant portion of the infrastructure in the United States is reaching the end of its useful life and will need to be replaced or rehabilitated; this could require far more cement than might be expected from economic forecasts of demand for cement.     

Pulverization of fibrous mineral wool waste

Journal of Material Cycles and Waste Management - The total annual volume of mineral wool waste in the 27 European Union countries is expected to increase to 2.5 million tons per year by...     

Production of natural and recycled aggregates: the environmental impacts of energy consumption and CO<Subscript>2</Subscript> emissions

Natural aggregates (NA) are crushed and processed in crushing plants after the extraction stage in quarries. In the present study, the aggregates are divided into three scenarios, depending on the production methods. The first scenario considers the production of NA, the second scenario deals with the production of recycled aggregates (RA) with respect to construction and demolition waste, and the third scenario, which is a hybrid scenario, handles the combination of NA and RA by assuming a 50% mixing percentage. In this research, we assess the environmental impacts on the production of aggregates via each scenario, using life cycle assessment; in addition, energy consumption and CO₂ emissions are considered as the environmental variables. We conclude that Iran’s current policy with an annual energy consumption of 1.48 million tons of oil equivalent (toe) can have a footprint of 2.88 million tons of CO₂ eq emissions per year (the first scenario). Achieving 30 and 36% reduction in annual energy consumption and CO₂ emissions, respectively, by the third scenario compared to the first scenario indicates the destructive effect of the first scenario from the environmental outlook.     

Properties of concrete containing scrap-tire rubber--an overview

Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.     

中国2015年SO2排放总量宏观控制目标研究

1980年中国SO2排放量为1160万吨,2005年为2549万吨,伴随节能减排政策的实施和s02治理投资的增加,到2010年我国SO2排放量将降至2300万吨（削减10％）,仍位居世界第一位。在“十二五”期间,伴随人口、经济、能源的增长和发展模式的重大转变,我国2015年SO2排放总量面临微增长、不增长或减排的趋势。应用我国SO2减排宏观控制指标和模式预测了我国2015年SO2排放总量的4种图像或目标。提出了实现SO2排放总量削减10％目标的10条建议。     

中国2020年节能减排SO2排放量发展预测与对策研究

对中国2020年人口、国内生产总值、煤耗量和SO2排放量的发展情况进行了预测。预测结果表明,2020年中国人口总数可达到138858万人～139900万人,国内生产总值可达到78.29万亿元,能耗量达到42.83亿t,煤耗量达32.12亿t,SO2排放量达到1995万t。提出了中国2020年SO2排放量减排对策。     

中国2030年能源发展预测与对策研究

在回顾2000年-2010年中国能源消费的基础上,对中国2030年能源发展及耗煤量进行了预测,预测结果表明,2030年中国能耗总量将控制在55～60亿t标煤,耗煤量控制在40～45亿t标煤。建议中国2011年-2015年、2015年-2020年、2020年-2025年和2025年-2030年能源弹性系数分别为0.5、0.5、0.4和0.3。开展煤炭休养生息战略,多进口煤炭。     

Current status of waste to power generation in Japan and resulting reduction of carbon dioxide emissions

We discuss the current status of waste to power generation (WPG) in Japan and various scenarios involving indirect reduction of carbon dioxide emissions by WPG. The number of WPG facilities domestically as of 2005 was 286. Power generation capacity attained 1,515 MW and power generation 7,050 GWh/year. This amount substitutes energy otherwise acquired from natural resources such as fossil fuels in thermal power plants. If the basic unit of carbon dioxide is 0.555 kg-CO₂/kWh, then the corresponding carbon dioxide emission reduction is calculated to be 3.9 million tons, equivalent to 26.7% of the 14.6 million tons emitted by municipal solid waste incinerators (MSWI) in 2005. Using various existing technological options, the power generation efficiency could reach more than 20% in MSWI facilities with capacity of 300 tons/day, although present efficiency is only 12.0%. If about 85% of MSW were incinerated in MSWI with power generation efficiency of 20% as a feasible assumption, the total power generation and the corresponding carbon dioxide reduction would be 16,540 GWh/year and 9.18 million tons, respectively, equivalent to 62.7% of the carbon dioxide emitted by MSWI. Also, the ratio of the additional reduction of carbon dioxide emissions by WPG to the total additional reduction (20,000 ktons/year) in Japan during the first commitment period would be 26.3%, suggesting that promotion of WPG in MSWI is an effective option for prevention of global warming.     

流化床富氧焚烧含油污泥技术经济性分析

介绍了流化床富氧焚烧含油污泥技术的流程和优势,计算了富氧焚烧含油污泥系统主要设备的电耗和技术经济指标。流化床富氧焚烧含油污泥技术可实现烟气及其他污染物零排放,产生的蒸汽可直接供应油田生产和生活使用,产生的液态CO2可直接用于油井驱油,烟气中的SO2和NOx可转化为硫酸和硝酸。采用日处理200 t含油污泥的流化床锅炉年处理含油污泥量约73 kt,每年减少排污费7 300万元;锅炉年产蒸汽量约177 kt,每年节约蒸汽费用1 380.6万元,合计每年节约成本8 680.6万元。回收得到质量分数为40%的稀硫酸5.56 t/d,质量分数为37%的硝酸0.708 t/d,年回收CO2约99 kt。     

新疆某油田企业两轮清洁生产审核效益分析

新疆某油田企业于2007年进行了第一轮清洁生产审核工作,确定了清洁生产方案14项,其中无／低费方案9项,中／高费方案5项,产生的直接、间接经济效益总计为4057．27万元／a。该企业于2011年完成了第二轮清洁生产审核,确定了清洁生产方案14项,其中无／低费方案6项,中／高费方案8项,总计清洁生产方案产生经济效益1954．142万元／a。通过两轮清洁生产审核工作,企业产生了较好的经济效益与环境效益。     

The impact of municipal solid waste treatment methods on greenhouse gas emissions in Lahore, Pakistan

The contribution of existing municipal solid waste management to emission of greenhouse gases and the alternative scenarios to reduce emissions were analyzed for Data Ganj Bukhsh Town (DGBT) in Lahore, Pakistan using the life cycle assessment methodology. DGBT has a population of 1,624,169 people living in 232,024 dwellings. Total waste generated is 500,000 tons per year with an average per capita rate of 0.84kg per day. Alternative scenarios were developed and evaluated according to the environmental, economic, and social atmosphere of the study area. Solid waste management options considered include the collection and transportation of waste, collection of recyclables with single and mixed material bank container systems (SMBCS, MMBCS), material recovery facilities (MRF), composting, biogasification and landfilling. A life cycle inventory (LCI) of the six scenarios along with the baseline scenario was completed; this helped to quantify the CO2 equivalents, emitted and avoided, for energy consumption, production, fuel consumption, and methane (CH4) emissions. LCI results showed that the contribution of the baseline scenario to the global warming potential as CO2 equivalents was a maximum of 838,116 tons. The sixth scenario had a maximum reduction of GHG emissions in terms of CO2 equivalents of -33,773 tons, but the most workable scenario for the current situation in the study area is scenario 5. It saves 25% in CO2 equivalents compared to the baseline scenario.     

Improvement of Waste Recycling in PET Fiber Production

Production of polyethylene teraphtalate (PET) fiber in the world is increasing every year and reached to an amount of about 20 million tons a year in 2001. The wastes occur in the production of PET fiber in the amount of about 3–5% of total production. The PET does not degrade for a long time in nature. Since PET is a derivative of petroleum, the wastes of PET are valuable and must be recycled. One of the recycling method of PET wastes is re-melting. Thus, various properties of the PET wastes were improved using the re-melting method by employing an extruder manufactured for the work. Degradation during re-melting decreases the properties of the final product. The results indicate that the properties of recycled PET wastes can be monitored by designing the parameters of the extruder. Also, the further degradation of the material can be prevented and the recycling costs are minimized.     

Balancing the energy demand by a resource circulation project in Daejeon,Korea

Demand for sustainable renewable energy is on an increase worldwide, whereas the supply is limited. This paper analyses the feasibility of generating electricity and supplying the surplus steam to Daeduk Industrial Complex, by incinerating the combustible municipal waste generated in Daejeon Metropolitan City. The economic feasibility of surplus biogas generated from the anaerobic digestion of food waste and food waste leachate has been analysed. This study estimated resource circulation facility to supply 23,200 m³/day of biogas generated to Daejeon Combined Heat and Power plant. By 2023, it is expected to supply 25.7 tons of steam per hour all year round. The additional steam demand in Daeduk Industrial Complex is estimated as 101,537 tons/year. Surplus biogas will be supplied through an additional 960-m new installation. The cost of biogas is estimated at 30% of the unit biogas production cost. Daejeon Combined Heat and Power plant expects to make 60% additional profit, and Daeduk Industrial Complex and the communities nearby expect to achieve 10% cost savings. It also reduces the dependence of energy on fossil fuels, contributes to national environmental energy policy in reduction in greenhouse gases, creates competitiveness in local business and reduces corporate tax and generates revenue.     

Economic potential of recycling business in Lahore, Pakistan

The state of household waste recycling in Lahore city, Pakistan with a population of 7.2 million was analyzed. Data on solid waste recycling were gathered from residents of low-, middle- and high-income groups, as well as from scavengers and junkshops. The recycling activities in Lahore exert a significant impact on resource conservation, creation of jobs, provision of economic opportunity and reduction in the magnitude of waste disposal problems. A cost analysis is presented to show the income that can be generated through a well-planned recycling program. It is shown that 21.2% of all recyclable waste in Lahore is recycled, and it generates an amount of Rs. 271 million (US dollars 4.5 million) per year through the informal sector. However, if the recycling practice is owned by the formal sector, it can save an amount of Rs. 65 million by reducing the collection cost. If recycling is adopted as an industry, it can generate revenues of Rs. 530 million (US dollars 8.8 million) per year and can also save enormous amount of energy, as well as the natural resources.     

Management of MSW in Spain and recovery of packaging steel scrap

Packaging steel is more advantageously recovered and recycled than other packaging material due to its magnetic properties. The steel used for packaging is of high quality, and post-consumer waste therefore produces high-grade ferrous scrap. Recycling is thus an important issue for reducing raw material consumption, including iron ore, coal and energy. Household refuse management consists of collection/disposal, transport, and processing and treatment - incineration and composting being the most widely used methods in Spain. Total Spanish MSW production exceeds 21 million tons per year, of which 28.1% and 6.2% are treated in compost and incineration plants, respectively. This paper presents a comprehensive study of incineration and compost plants in Spain, including a review of the different processes and technologies employed and the characteristics and quality of the recovered ferrous scrap. Of the total amount of packaging steel scrap recovered from MSW, 38% comes from compost plants and 14% from incineration plants. Ferrous scrap from incineration plants presents a high degree of chemical alteration as a consequence of the thermal process to which the MSW is subjected, particularly the conditions in which the slag is cooled, and accordingly its quality diminishes. Fragmentation and magnetic separation processes produce an enhancement of the scrap quality. Ferrous scrap from compost plants has a high tin content, which negatively affects its recycling. Cleaning and detinning processes are required prior to recycling.     

Estimation of construction waste generation and management in Thailand

This study examines construction waste generation and management in Thailand. It is estimated that between 2002 and 2005, an average of 1.1 million tons of construction waste was generated per year in Thailand. This constitutes about 7.7% of the total amount of waste disposed in both landfills and open dumpsites annually during the same period. Although construction waste constitutes a major source of waste in terms of volume and weight, its management and recycling are yet to be effectively practiced in Thailand. Recently, the management of construction waste is being given attention due to its rapidly increasing unregulated dumping in undesignated areas, and recycling is being promoted as a method of managing this waste. If effectively implemented, its potential economic and social benefits are immense. It was estimated that between 70 and 4,000 jobs would have been created between 2002 and 2005, if all construction wastes in Thailand had been recycled. Additionally it would have contributed an average savings of about 3.0 x 10(5) GJ per year in the final energy consumed by the construction sector of the nation within the same period based on the recycling scenario analyzed. The current national integrated waste management plan could enhance the effective recycling of construction and demolition waste in Thailand when enforced. It is recommended that an inventory of all construction waste generated in the country be carried out in order to assess the feasibility of large scale recycling of construction and demolition waste.     

燃煤电厂电除尘器的节能和提效

介绍了华能北京热电厂液态排渣塔式直流炉4号电除尘器电源控制系统改造后所取得的成果.该电厂采用了ZH2005型控制器,烟尘排放质量浓度达到20mg/m3左右,可节省电费58万元/a,减排粉尘120t/a.     

Estimation of building-related construction and demolition waste in Shanghai

One methodology is proposed to estimate the quantification and composition of building-related construction and demolition (C&D) waste in a fast developing region like Shanghai, PR China. The varieties of structure types and building waste intensities due to the requirement of progressive building design and structure codes in different decades are considered in this regional C&D waste estimation study. It is concluded that approximately 13.71 million tons of C&D waste was generated in 2012 in Shanghai, of which more than 80% of this C&D waste was concrete, bricks and blocks. Analysis from this study can be applied to facilitate C&D waste governors and researchers the duty of formulating precise policies and specifications. As a matter of fact, at least a half of the enormous amount of C&D waste could be recycled if implementing proper recycling technologies and measures. The appropriate managements would be economically and environmentally beneficial to Shanghai where the per capita per year output of C&D waste has been as high as 842 kg in 2010.     

Can in situ vitrification seal arsenic/mercury sludges into a delisted glass monolith?

The U.S. Environmental Protection Agency helped select in situ vitrification (ISV) as an interim response action for the National Priority List (NPL) site at the Rocky Mountain Arsenal (RMA) in Commerce City, Colorado. That decision is being reviewed, pending redesign of the technology by its vendor for what would be the largest ISV project in the United States, involving 220 tons of arsenic, twenty-six tons of mercury, and low levels of organic compounds. That material was left in three arsenic precipitation basins that were used from 1942 to 1947 to manufacture chemical warfare agents and later backfilled. This article explores the eight principal environmental, technical, and financial factors that EPA's Region VII must address before committing $1,200 per cubic yard, or $14 million, to seal that material in glass.     

The current situation of solid waste management in China

With economic development, the quantity of solid waste is increasing rapidly in China; the total quantities of municipal solid waste (MSW), industrial solid waste (ISW), and hazardous waste (HW) in 2002 were 136.5 million tons, 945 million tons, and 10 million tons, respectively. In 2002, the quantity of MSW disposed of was 74.04 million tons, 89.30% of which was landfilled, 3.72% was incinerated, and 6.98% was composted. There are currently 651 disposal facilities for MSW in China. Mining gangue is the largest component of ISW, making up 27.5% of the total. In the Chinese industrial sector, the coal mining and processing industry contributed most to the total quantity of ISW, with 16.0% of the total quantity of ISW generated by this sector. In total, 44% of HW was recycled, 27% was stored, 13.5% was disposed of, and 15.4% was discharged. Of the total HW generated, 40% was produced by the chemical materials and chemical products industry. Five categories of HW, i.e., waste alkali, waste acid, inorganic fluoride waste, copper waste, and inorganic cyanide waste, made up 57.8% of the total HW generated. Solid waste pollution has become a huge challenge faced by those involved in Chinese environmental management, but this can be seen as an opportunity to improve environmental quality. This article introduces the strategies taken to improve solid waste management in China.