A Study on Marble-Based Geopolymer

Economic, environmental, and technical gains from the Kyoto Protocol: Evidence from cement manufacturing

Geopolymer is an aluminosilicate material, synthesized from source materials rich in silica and alumina and alkali solution. This product provides similar strength to Portland cement concrete. Geopolymer exhibits a wide variety of properties and characteristics, including high compressive strength, low shrinkage, acid resistance, fire resistance and low thermal conductivity. In term of acid resistance, acid rain is an important consideration due to global warming. Structures deteriorate as a result of persistence contact with acid rain with of pH less than 5. Thus, this research aims to improve acid resistance of fly ash-NaOH geopolymer mortars by incorporating rice husk ash (RHA). Artificial acid rain solution was prepared by mixing nitric acid and sulfuric acid at the ratio of 70:30 v/v. The geopolymer mortars were immersed in 5% nitric acid, 5% sulfuric acid, and 5% synthetic acid rain solutions for 36 weeks. The evaluations of its resistance to acid solution was investigated with surface corrosion, compressive strength, and microstructure. The results showed that the incorporation of RHA improved the acid rain resistance of geopolymer mortar through pore refinement and increase in strength. The mortar with fly ash to RHA ratio of 90:10 provided the highest compressive strength and good resistance to acid rain.

This report provides information on the energy savings, costs, and carbon dioxide emissions reductions associated with implementation of a number of technologies and measures applicable to the cement industry. The technologies and measures include both state-of-the-art measures that are currently in use in cement enterprises worldwide as well as advanced measures that are either only in limited use or are near commercialization. This report focuses mainly on retrofit measures using commercially available technologies, but many of these technologies are applicable for new plants as well. Where possible, for each technology or measure, costs and energy savings per tonne of cement produced are estimated and then carbon dioxide emissions reductions are calculated based on the fuels used at the process step to which the technology or measure is applied. The analysis of cement kiln energy-efficiency opportunities is divided into technologies and measures that are applicable to the different stages of production and various kiln types used in China: raw materials (and fuel) preparation; clinker making (applicable to all kilns, rotary kilns only, vertical shaft kilns only); and finish grinding; as well as plant wide measures and product and feedstock changes that will reduce energy consumption for clinker making. Table 1 lists all measures in this report by process to which they apply, including plant wide measures and product or feedstock changes. Tables 2 through 8 provide the following information for each technology: fuel and electricity savings per tonne of cement; annual operating and capital costs per tonne of cement or estimated payback period; and, carbon dioxide emissions reductions for each measure applied to the production of cement. This information was originally collected for a report on the U.S. cement industry (Worrell and Galitsky, 2004) and a report on opportunities for China's cement kilns (Price and Galitsky, in press). The information provided in this report is based on publicly-available reports, journal articles, and case studies from applications of technologies around the world.

Decarbonizing cement production

Potentials for energy efficiency improvement in the US cement industry

The consumption of Portland cement for the production of concrete is rapidly increasing because of the remarkable growth in the construction worldwide. Cement production is an energy intensive process. The energy consumption by the cement industry is estimated to be about 5% of the total global industrial energy consumption. Manufacturing process of cement consumes enormous quantities of raw materials from limited natural resources at a high rate and leads to their depletion. Due to the dominant use of carbon intensive fuels such as coal, the cement industry is a major emitter of carbon dioxide and other air pollutants. The cement industry contributes about 6 % of global carbon dioxide emissions which is the primary source of global warming. In addition to carbon dioxide emissions, significant amount of nitrogen oxides, sulphur dioxide, carbon monoxide, hydrocarbons and volatile organic compounds are emitted during cement manufacturing and causes severe environmental issues. In this regard, effective control techniques for reduction in carbon dioxide emissions from modern cement industry and an efficient procedure to achieve sustainable cement manufacturing process are discussed in this paper.

Assessment of the energy utilization and carbon dioxide emission reduction potential of the microbial fertilizers. A case study on “farm-to-fork” production chain of Turkish desserts and confections

Sustainable transformation of sewage sludge ash and waste industrial additive into green cement blend

Objectives: Water penetration and storage abilities make No-fine cement concrete unique as a pervious concrete, while using it in pavements to decrease flood risks. But still cement is the main part as a binder material, which contributes in global warming by having carbon dioxide emissions during cement production in plants. New researches have shown geo-polymer technology a good alternative material for concrete to omit cement and combat against the global warming which the world is concerned nowadays. No-fine geo-polymer concrete is the solution for both global warming and flood risks. Methods: This paper aims to find M20 grade eco-friendly no-fine geo-polymer concrete having ingredients of fly ash waste material, coarse aggregates, sodium hydroxide, sodium silicate and ground granulated blast furnace slag in different percentages to enhance its compressive strength by experimental various trials have ratio 1:4 to 1:8 of powder to aggregates. Findings: A ratio, 1:4 with 20% replacement of fly ash by ground granulated blasted furnace slag gave satisfactory compressive strength of 21.52 N/mm2 with 16632.85 mm/hour infiltration rate. Application/Improvements: Based on findings No-fines geo-polymer concrete can be used in low traffic pavements to combat against the flood risks and recharge ground water. Furthermore, research scholars are expected to use high morality of sodium hydroxide and lower size of aggregates which may increase the compressive strength of No-fines geo-polymer concrete. Keywords: Flood Risks, Global Warming, Infiltration, Pervious Concrete, Sodium hydroxide, Sodium Silicate

Cement, carbon dioxide, and the ‘necessity’ narrative: A case study of Mexico

Role of binary cement including Supplementary Cementitious Material (SCM), in production of environmentally sustainable concrete: A critical review

The cement industry accounts for roughly 8% of global carbon dioxide emission, and for every tonne of cement procured, a ton of carbon dioxide is released into the air. Cement industry is the backbone of global infrastructure development with no sign of slowing down, as such, it provides the most promising testbed for a carbon credit market to start up. Carbon credit functions as a conversion of money as payment to offset carbon dioxide emission, and can be acquired by reducing carbon emission or its greenhouse equivalents. This carbon credit can then be sold on the carbon market which provides financial incentive for companies to reduce their carbon emission. Acquiring carbon credit can be a viable capital gain strategy in developing nations due to their relatively low labor and overhead costs. This study aims to provide avenues to reduce carbon dioxide emission in cement fabrication as a way to acquire carbon credit for capital gain purposes to developing nations worldwide. This study uses literature review with a descriptive qualitative methodology, with data from relevant books and journals of renowned and reputable publishers online as validity. This study identified three promising avenues to reduce carbon dioxide emission in cement fabrication: alternative cement aggregate material fly ash and bottom ash, carbon capture and storage technology, and alternative fuel in cement fabrication. Three avenues provide pathways for players in the cement industry to adopt according to their capabilities in order to effectively reduce their carbon dioxide emission for acquiring carbon credit.

Cement is the most widely used man-made material. The global cement industry produces about 3.3 billion tons of cement annually. A lot of energy is needed to produce cement. About 200 kg of coal is used to produce each ton of cement. The cement industry also produces about five percent of the world's greenhouse gases. In order to reduce the use of fossil fuels and greenhouse gas emissions, some cement producers have the potential to recover waste heat. The method studied in this research is based on heat recovery from boilers installed at the outlet of clinker cooler and preheater of cement factory. Due to the low temperature of the gases available, three different fluids, water, R123 and R245fa are considered as the operating fluid. Also, energy and exergy analysis is performed in a Rankin cycle and the selection of optimal parameters is considered by using genetic algorithm. By selecting the decision parameters in the optimization of the genetic algorithm such as pinch temperature, evaporator pressure and operating mass flow rate, the optimal values of exergy efficiency were obtained.

Generation of industrial by-products has increased significantly with industrialization. One such by-product from iron smelting industry is iron slag, which is generated from blast-furnaces while extracting iron. This blast furnace slag is used to make a cementitious material by grinding it into fine powder, known as Ground Granulated Blast Furnace Slag (GGBS). This blast furnace slag is also used to make a glassy granular product, Granulated blast furnace Slag (GBFS) which can be used as fine aggregate. Present experimental work investigates feasibility of using GBFS as replacement of natural sand and GGBS as replacement of cement in concrete respectively. Concrete cubes have been prepared and their compressive strength is checked for M30 grade of concrete. Thus, it can be concluded that GGBS and GBFS can be used to partially replace cement up to 55% and sand up to 50% in concrete respectively without affecting their compressive strength. Thereby reducing carbon dioxide emission and curtailing cost of concrete by 20.25%.Generation of industrial by-products has increased significantly with industrialization. One such by-product from iron smelting industry is iron slag, which is generated from blast-furnaces while extracting iron. This blast furnace slag is used to make a cementitious material by grinding it into fine powder, known as Ground Granulated Blast Furnace Slag (GGBS). This blast furnace slag is also used to make a glassy granular product, Granulated blast furnace Slag (GBFS) which can be used as fine aggregate. Present experimental work investigates feasibility of using GBFS as replacement of natural sand and GGBS as replacement of cement in concrete respectively. Concrete cubes have been prepared and their compressive strength is checked for M30 grade of concrete. Thus, it can be concluded that GGBS and GBFS can be used to partially replace cement up to 55% and sand up to 50% in concrete respectively without affecting their compressive strength. Thereby reducing carbon dioxide emission and curtailing cost of co...

Radiological characterisation of alkali-activated construction materials containing red mud, fly ash and ground granulated blast-furnace slag