Showing papers on "Co-processing published in 2012"
TL;DR: The new process and the related LCA are framed within a meaningful case of industrial symbiosis, where multiple waste streams are utilised in a multi-output industrial process to maximise resources and energy recovery from post-consumer waste glass.
124 citations
TL;DR: In this article, the authors compared specific energy consumption among countries in fossil power generation, steel, and cement sectors using common system boundaries, allocation, and calculation methods, and found that characteristics vary by sub-sectors.
81 citations
TL;DR: In this article, the authors tried to answer the question: Is cement production still a sustainable industry in the 21st century? Approach: It starts off by considering the current status quo and potential alternatives for the production process, right from the raw meal composition stage through to the final application of cement in concrete.
Abstract: Problem statement: This paper tries to answer the question: Is cement production still a sustainable industry in the 21 st century? Approach: It starts off by considering the current status quo and potential alternatives for the production process, right from the raw meal composition stage through to the final application of cement in concrete. Results: In the process alternative raw meal components and energy sources are reviewed in detail. The changes that could and should be made to cement plants and equipment to produce cement more sustainably, as well as different types of other binders that can be used for construction, are discussed. The suitability of the cement production process to destroy wastes and utilize byproducts from other industrial processes, are highlighted and analysed. Alternative methods and equipment to manufacture cement, are summarized and ways to get rid off or convert the released carbon dioxide from the cement manufacturing, are discussed. Conclusions: In the final instance the conclusion is reached that the cement industry, despite proven new technology, equipment and concepts, can do more to respond fast enough and to a sufficient extent to improve the sustainability of their operations substantially and to an acceptable level for the 21 st century.
44 citations
TL;DR: In this paper, the authors studied the possibility of recovering two forms of waste from the paper industry, sludge from the purification of waste water and residue from cleaning the pulp, and showed that increasing the content of waste increases linear expansion and water absorption and in turn reduces resistance to compression.
38 citations
TL;DR: The possibilities of the energetic utilized SRF and the characterization of SRF before and during the energetic utilization will be discussed and methods are being developed or adapted to current analytical methods for the characterization.
34 citations
TL;DR: The huge number of research studies carried out during recent decades focused on finding an effective solution for the waste treatment, have allowed some of these residues to become new raw materia as mentioned in this paper.
34 citations
TL;DR: In this paper, the dioxins formation and suppression mechanisms in RDF (Refuse derived fuel)cement kiln co-processing were investigated by analyzing dioxin concentrations of solid and gas samples.
Abstract: This paper tentatively studies dioxins formation and suppression mechanisms in RDF (Refuse derived fuel)cement kiln co-processing by analyzing the dioxin concentrations of solid and gas samples of the critical points where dioxins are more likely to form in kiln system based on cement kiln co-processing technical characteristics and a few of recognized dioxins formation mechanisms and factors. Testing results show that trace amount of dioxins could be detected in all of the solid and gas samples from main points of preheater. The raw mill and bag filter play a key role on dioxins absorption and capture from gas, absorption rate of both reaches up to 91.6%.Dionxins concentration of emission is below the international standard limit of 0.1ng TEQ/Nm 3 . Materials with high heat value such as plastics, paper, wood, textile, etc. derived from raw MSW
20 citations
23 Jan 2012
TL;DR: In this article, the authors summarized carbon-recycling routes available and investigated how in the long-term they could be applied to enhance waste management in both industrial countries as well as developing and emerging economies, concluding with a case study looking at the system-wide global warming potential and cumulative energy demand of producing high-density polyethylene (HDPE) from organic waste feedstock via gasification followed by Fischer-Tropsch synthesis (FTS).
Abstract: Managing solid waste is one of the biggest challenges in urban areas around the world. Technologically advanced economies generate vast amounts of organic waste materials, many of which are disposed to landfills. In the future, efficient use of carbon containing waste and all other waste materials has to be increased to reduce the need for virgin raw materials acquisition, including biomass, and reduce carbon being emitted to the atmosphere therefore mitigating climate change. At end-of-life, carbon-containing waste should not only be treated for energy recovery (e.g. via incineration) but technologies should be applied to recycle the carbon for use as material feedstocks. Thermochemical and biochemical conversion technologies offer the option to utilize organic waste for the production of chemical feedstock and subsequent polymers. The routes towards synthetic materials allow a more closed cycle of materials and can help to reduce dependence on either fossil or biobased raw materials. This chapter summarizes carbon-recycling routes available and investigates how in the long-term they could be applied to enhance waste management in both industrial countries as well as developing and emerging economies. We conclude with a case study looking at the system-wide global warming potential (GWP) and cumulative energy demand (CED) of producing high-density polyethylene (HDPE) from organic waste feedstock via gasification followed by Fischer–Tropsch synthesis (FTS). Results of the analysis indicate that the use of organic waste feedstock is beneficial if greenhouse gas (GHG) emissions associated with landfill diversion are considered.
19 citations
TL;DR: In this paper, the effect of waste utilization in the cement industry on the resource productivity of Japan based on information for fiscal year 2008 was investigated and shown that waste utilization for cement production contributed to an increase in resource productivity.
Abstract: According to Japanese government policy, the input of natural resources should be minimized and input resources should be utilized to the greatest extent possible so that, eventually, minimum waste is generated. The cement industry of Japan has worked hard to maximize waste utilization. Focusing on the cumulative amounts of the elements needed for clinker and gross calorific values, this study estimated the extent to which waste utilization has directly or indirectly reduced natural resource consumption and greenhouse gas emissions associated with cement production at 32 factories in Japan and clarified the effect of waste utilization in the cement industry on the resource productivity of Japan based on information for fiscal year 2008. Had no wastes been utilized, the cement industry consumption of limestone would have been 18% higher; of clay, 2,899% higher; and of energy, 22% higher. The utilization of wastes in the mixing and burning process of cement production directly reduced greenhouse gas emissions (12% emitted gas reduction) by a larger amount than the indirect reduction achieved by their utilization during the admixing process (10% reduction). Waste utilization for cement production contributed to an increase in resource productivity of about 8,000 Japanese Yen/ton.
18 citations
TL;DR: In this paper, a co-pyrolysis of high density polyethylene with low-cost additives, such as bituminous coal, bagasse fly ash, coal-based thermal power plant fly ash and deoiled cake of jatropha, has been carried out in a batch reactor in the presence of nitrogen at 450°C under atmospheric pressure.
Abstract: Co-pyrolysis of high density polyethylene with low cost additives, such as bituminous coal, bagasse fly ash, coal-based thermal power plant fly ash, and deoiled cake of jatropha, has been carried out in a batch reactor in the presence of nitrogen at 450°C under atmospheric pressure. Liquid products obtained by co-pyrolysis were characterized by ASTM D86 and gas chromatography/mass spectrometry. The yield of liquid product was found to be 54% upon pyrolysis of only high density polyethylene. It increased to between 63 and 80% when high density polyethylene was co-processed with bagasse fly ash, coal-based thermal power plant fly ash, bituminous coal, and deoiled cake of jatropha. ASTM D86 (boiling point distribution) analyses of liquid product from only high density polyethylene pyrolysis indicated that 62% diesel-like, 35% gasoline-like, and 3% heavier had formed. Co-processing high density polyethylene with bagasse fly ash, coal-based thermal power plant fly ash, bituminous coal, and deoiled cak...
14 citations
TL;DR: In this paper, a process to capture CO2 by integrating the recovery and utilization of waste heat has been designed, where the Aspen Plus software was used to calculate the amount of heat and the efficiency of energy utilization.
Abstract: Large amounts of energy are consumed during the manufacturing of cement especially during the calcination process which also emits large amounts of CO2. A large part of the energy used in the making of cement is released as waste heat. A process to capture CO2 by integrating the recovery and utilization of waste heat has been designed. Aspen Plus software was used to calculate the amount of waste heat and the efficiency of energy utilization. The data used in this study was based on a dry process cement plant with a 5-stage preheater and a precalciner with a cement output of 1 Mt/y. According to the calculations: 1) the generating capacity of the waste heat recovery system is 4.9 MW. 2) The overall CO2 removal rate was as high as 78.5%. 3) The efficiency of energy utilization increased after the cement producing process was retrofitted with this integrated design.
TL;DR: The preparation of sustainable building materials is demonstrated through the adequate reuse of the granite waste through incorporation, as a filler-functional admixture, into cement-based mortar formulations.
Abstract: Presently, appropriate waste management is one of the main requisites for sustainable development; this task is tackled by the material construction industry. The work described herein is focused on the valorization of granite waste through incorporation, as a filler-functional admixture, into cement-based mortar formulations. The main components of the waste are SiO2 (62.1 %), Al2O3 (13.2 %), Fe2O3 (10.1 %), and CaO (4.6 %). The presence of iron oxides is used to develop the photocatalytic properties of the waste. Following heating at 700 °C, α-Fe2O3 forms in the waste. The inclusion of the heated sample as a filler admixture in a cement-based mortar is possible. Moreover, this sample exhibits a moderate ability in the photodegradation of organic dye solutions. Also, the plastering mortars, in which the heated samples have been used, show self-cleaning properties. The preparation of sustainable building materials is demonstrated through the adequate reuse of the granite waste.
01 Jan 2012
TL;DR: In this paper, the Fourier Transform Infrared 3 2 3 4 -1 Spectroscopy analysis identified the wavenumber was at roughly 990-970 cm, and mainly due to Si-O bonds of calcium silicate hydrates.
Abstract: INTRODUCTION The goal of this study is to identify the optimal component ratios for making cement that maximize the amount of cement clay that can be replaced by recycled waste foundry sand, limestone and ferrate as raw materials. A computational model was utilized to determine the composition of raw clinkers. In this study, the amount of free CaO was < 1% and the loss on ignition parameter met eco-cement criteria of CNS 61. Results demonstrate that the major components of ordinary Portland cement, such as C S, C S, C A, and C AF, were in all eco-clinkers. The Fourier Transform Infrared 3 2 3 4 -1 Spectroscopy analysis identified the wavenumber was at roughly 990-970 cm , and mainly due to Si-O bonds of calcium silicate hydrates. The heavy metal leaching concentrations for different clinkers complied with regulatory thresholds developed by Taiwan's Environmental Protection Agency. Thus, this study demonstrates the feasibility and safety in utilizing waste foundry sand in cement additives. .
01 Jan 2012
TL;DR: In this article, the authors discuss the key aspects in hazardous waste management by cement kilns, which could be described as a great example of a win-win situation, where using the hazardous waste as the substitution of raw materials, fuel or gypsum during the cement manufacturing process provides an energy and material recovery.
Abstract: Most developing countries seldom have possessed hazardous waste incinerators or decomposition technologies for treatment of hazardous waste such as PCB stockpiles, obsolete pesticides and other hazardous waste. For solving this issue, using cement kilns as a hazardous waste management option is gaining increasing favour around the world. The cement industry is an intensive energy consuming industry. Reusing the hazardous waste as the substitution of raw materials, fuel or gypsum during the cement manufacturing process provides an energy and material recovery which could be described as a great example of win–win situation. This chapter discusses the key aspects in hazardous waste management by cement kilns.
30 Jun 2012
TL;DR: In this paper, the authors evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement, and the results show that the clinkering is temperature independent, at least within a controllable temperature range.
Abstract: The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent,more » at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted at a full-scale cement plant with alternative fuels to examine their compatibility with the cement production process. Construction and demolition waste, woodchips, and soybean seeds were used as alternative fuels at a full-scale cement production facility. These fuels were co-fired with coal and waste plastics. The alternative fuels used in this trial accounted for 5 to 16 % of the total energy consumed during these burns. The overall performance of the portland cement produced during the various trial burns performed for practical purposes very similar to the cement produced during the control burn. The cement plant was successful in implementing alternative fuels to produce a consistent, high-quality product that increased cement performance while reducing the environmental footprint of the plant. The utilization of construction and demolition waste, woodchips and soybean seeds proved to be viable replacements for traditional fuels. The future use of these fuels depends on local availability, associated costs, and compatibility with a facilityâs production process.« less
Journal Article•
TL;DR: The origins of co-incineration of alternative fuels in kilns for the production of cement clinker go back to the beginning of the 70s of the twentieth century, but orig-inally the cement industry was used for the thermal utilization of only small amounts of liquid hazardous waste (including solvent derived fuels and waste petroleum de-rivatives), municipal waste, including refuse derived fuels, used tires (including tire derived fuels), sewage sludge and other solid waste as mentioned in this paper.
Abstract: The origins of co-incineration of alternative fuels in kilns for the production of cement clinker go back to the beginning of the 70’s of the twentieth century, but orig-inally the cement industry was used for the thermal utilization of only small amounts of liquid hazardous waste (including solvent derived fuels and waste petroleum de-rivatives), municipal waste (including refuse derived fuels), used tires (including tire derived fuels), sewage sludge and other solid waste [1–6]. At the same, as substitute fuels, coal sludge, oil shale, petroleum coke and biomass were used [7–9].The use of alternative fuels brings economic and environmental bene ts. They result from the reduction in consumption of non-renewable energy sources (fossil fuels), the possibility to safely dispose of problem waste and the recovery of energy from waste (or waste-derived fuels), as well as the reduction of global emission of air pollutants and greenhouse gases (including CO
TL;DR: In this paper, a milling system designed solely to contaminated soil was introduced with hot air (250-350°C) to dry water and simultaneously vaporize POPs, and the gaseous POPs was directly destroyed in the precalciner, while the milled soil with partly removal of organic pollutants was homogenized in a sealed silo and then took part in clinker sintering.
Abstract: This paper aims to study the co-processing of POPs (DDTs and HCHs) contaminated soil as an alternative raw material for sustainable clinker production. The milling system designed solely to contaminated soil was introduced with hot air (250-350 °C) to dry water and simultaneously vaporize POPs. The gaseous POPs was directly destroyed in the precalciner, while the milled soil with partly removal of organic pollutants was homogenized in a sealed silo and then took part in clinker sintering. According to the experiment results the moisture content reached an average of 0.4%, and the average 200 μm and 80 μm sieve residues were 1.9% and 19.0% respectively after grinding. Furthermore, clinkers and emission which were produced with contaminated soil as SiO2 substitute were monitored. There was no DDTs and HCHs residue both in clinkers and in exhaust, which demonstrated the success of eliminating organic pollutants and utilizing the soil as alternative SiO 2 materials in our cement plant.
01 Jan 2012
TL;DR: Li et al. as discussed by the authors evaluated the environmental impact caused by materials mining, transportation, raw material preparation, clinker calcination and finish grinding and mixing, which are general processes that are involved in cement materials production and transportation.
Abstract: Cement production has received increasing attention due to its high consumption of energy and resource.Life cycle assessment(LCA) is an effective tool for cleaner production audits.We constructed LCA model to quantify emissions and resource consumption in each phase of the cement production process for a cement plant in Dalian.We evaluated the environmental impact caused by materials mining,transportation,raw material preparation,clinker calcination and finish grinding and mixing,which are general processes that are involved in cement materials production and transportation.Cradle-to-grave analysis was performed using the GaBi4 software with CML 2001 Dec 07 by which global warming,human toxicity and acidification potential influence was analyzed and compared.Result shows that during the whole lifetime of cement production,clinker calcination could cause the most important impact to the environment in terms of carbon dioxide discharging and smog generation,etc.Furthermore,clinker calcination is also ranked the first place in energy consumption.According to the result of LCA analysis,the focus of cleaner production audit and the cleaner production plan were put forward.In addition,we selected the plan with the most significant waste heat generation,and compared the environmental assessment before and after the implementation of this plan,to quantitatively analyze the cleaner production plan.
Patent•
11 Jul 2012
TL;DR: In this paper, a co-processing process for hazardous solid wastes is proposed, which consists of drying, crushing and grinding preprocessing on the hazardous solid waste, and then conveying the preprocessed waste to a powder bin and feeding it to a smoke chamber of a cement kiln for processing.
Abstract: The invention provides a cement kiln co-processing process for hazardous solid wastes. The process comprises the following steps of: a) performing drying, crushing and grinding preprocessing on the hazardous solid wastes; b) conveying the preprocessed hazardous solid wastes to a powder bin; and c) feeding the hazardous solid wastes from the powder bin, pneumatically conveying to a smoke chamber of a cement kiln, and processing. The hazardous solid wastes are directly conveyed to the smoke chamber of the cement kiln, and by utilizing the characteristics of high combustion temperature, high material processing capacity and the like of the cement kiln, the hazardous solid wastes replace partial cement raw material to be fired into cement; meanwhile, effects of reducing volume and quantity and comprehensively utilizing are achieved, and the hazardous solid wastes are subjected to reduction, harmlessness and resource processing.
TL;DR: In this article, three industrial wastes for blending with Portland cement viz. fly ash, blast furnace slag, and waste of glass industry were used for the purpose of improving the properties of Portland Cement.
Abstract: Utilization of industrial waste in construction industry. This experimental work is an effort to try to develop the awareness & importance of industrial waste management & its utilization in productive manner among the people. In today’s more environmentally-Conscious world, a more responsible approach to the environment is to increase the use of by-products of one industry which is disposed off as waste as raw material for some other industry. Developed countries have made rapid strides in the utilization of supplementary Cementitious material in cement & concrete. Lack of awareness Consumer preferences, negatives marketing strategies & Lot of miss-understanding among the people have impeded their utilization in our country. In this work I have chosen three industrial wastes for blending with Portland cement Viz. Fly ash, Blast furnace slag & waste of glass industry. All these three waste after grinding properly were blended with ordinary Portland cement in different proportions. Then that of blended cement was tested for various properties of cements such as Fineness, Standard Consistency; Soundness, Setting time & Compressive Strength. As all these three wastes in powder form are of cementitious materials, they are proved to be best when blended with Cement. I have got improved results related to most of the properties of cement as compared to that of ordinary Portland cement. All these wastes prove the slogans true that are “ash to cash” or “refuse to resource” & “wastes to wealth”. In our country annually huge quantities of wastes are produced by the industries. Instead of disposing off these wastes if they are utilized in such a manner then it will provide an eco-friendly Solution, simultaneously solving the problem of pollution. So such waste can be blended with Cement, is the step towards economy & obviously towards progress of the nation.
Patent•
10 Oct 2012
TL;DR: In this article, a method of co-processing for calcium-added and passivated town sludge is proposed, which is an economical, fuel-saving and low-pollution method for resource utilization of the sludge.
Abstract: The invention discloses a method of cement kiln co-processing for calcium-added and passivated town sludge and solves the technical problems that the content of organic matters in the town sludge is lower while the content of heavy metals in the town sludge is higher, the nature of the sludge is not stable, the moisture content of the sludge is high and the sludge is difficult to transport. The implementation steps of the method are as follows: firstly, the constituents and the moisture content of the town sludge are tested, the pH value of the town sludge is usually between 6 and 8, and when the sludge meets leachate within the pH value range or in the landfilling state, the heavy metals are dissolved out easily, and the increasing of the pH value of the sludge is beneficial for passivation of the heavy metals and reduction of dissolution of the heavy metals; the town sludge is mixed with waste lime to ensure that the pH value of the mixture is between 9 and 10, and the mixture is kept stable at room temperature for 2-7 days; and the mixture enters a novel dry-process cement kiln from below a predecomposition furnace, silicon and calcium in the sludge and calcium in the lime can be used to produce silicate cement, and the organic matters in the sludge can be burnt so as to replace partial cement kiln fuel. The method of the cement kiln co-processing for the calcium-added and passivated town sludge is an economical, fuel-saving and low-pollution method for resource utilization of the town sludge.
Patent•
27 Jun 2012
TL;DR: In this paper, a co-processing technology of organic hazardous wastes in a cement kiln is presented, which consists of: (a) liquefying the organic waste with a solvent for reducing the viscosity of the waste; (b) filtering the organic wastes after precipitation; (c) adding a stabilizer into the organic hazardous waste after filtering; and (d) spraying the waste after pretreatment into the concrete kiln via a kiln entry system for replacing part of fuel.
Abstract: The invention provides a co-processing technology of organic hazardous wastes in a cement kiln. The co-processing technology comprises the following steps of: (a) liquefying the organic hazardous wastes with a solvent for reducing the viscosity of the organic hazardous wastes; (b) filtering the organic hazardous wastes after precipitation; (c) adding a stabilizer into the organic hazardous wastes after filtering for stabilization; and (d) spraying the organic hazardous wastes after pretreatment into the cement kiln via a kiln entry system for replacing part of fuel. Waste gas produced in the step (d) can achieve the emission standard after treatment. The co-processing technology disclosed by the invention is low in energy consumption, the organic hazardous wastes can be effectively disposed, the production of clinker during the incineration process is avoided, the coal consumption during the cement production process is saved, and the organic hazardous wastes can truly realize reduction, harmlessness and resource disposal.
01 Jan 2012
TL;DR: In this article, waste glass can be used as either aggregate replacement or admixture in concrete, as is shown in many studies conducted by the developed countries for several decades, and the results show that recycling of waste glass in concrete is well promising considering the fact that significant environmental,economical and technical benefits can be achieved.
Abstract: Accounting for a large proportion in municipal solid waste stream,piles of waste glass has contributed to a series of resources and environmental problems.There are two major ways of recovering and recycling waste glass in now days.One way is recycling in its own industry,another is reusing in other areas.Undoubtedly,the reuse of waste glass in concrete areas is among the most attractive options.Waste glass can be used as either aggregate replacement or admixture in concrete,as is shown in many studies conducted by the developed countries for several decades.Many attempts have been made to produce new kinds of concrete materials with waste glass.Some achievements have been obtained while some problems are still to be solved.The results show that recycling of waste glass in concrete is well promising considering the fact that significant environmental,economical and technical benefits can be achieved.
01 Jan 2012
TL;DR: In this article, the authors evaluated the environmental impacts of three different technologies, including municipal solid waste (MSW) gasification followed by Fischer-Tropsch synthesis (FTS), plasma gasification of construction and demolition (C&D) wood for syngas production with energy recovery, and forest residuals use in a biorefinery for polyitaconic acid (PIA) production, were assessed using life-cycle assessment.
Abstract: Shifting the resource base for chemical and energy production from fossil feedstocks to renewable raw materials is seen by many as one of the key strategies towards sustainable development. The utilization of biomass for the production of fuels and materials has been proposed as an alternative to the petroleum-based industry. Current research and policy initiatives focus mainly on the utilization of lignocellulose biomass, originating from agriculture and forestry, as second generation feedstocks for the production of biofuels and electricity. These activities act on the assumption that significant amounts of biomass for non-food purposes are available. However, given a certain productivity per area, the current massive growth in global biofuels demand may in the long term only be met through an expansion of global arable land at the expense of natural ecosystems and in direct competition with the food-sector. Although many studies have shown the potential of biofuels production to reduce both, greenhouse gas emissions and non-renewable energy consumption, these production routes are still linear processes which depend on significant amounts of agricultural or forestry production area. Cascading use, i.e. when biomass is used for material products first and the energy content is recovered at end-of-life, may provide a greater environmental benefit than primary use as fuel. Considering waste and production residues as alternative feedstocks could help to further reduce pressures on global arable land. This research focused on thermochemical and biochemical technologies capable of utilizing organic waste or forestry residuals for energy, chemical feedstock, and synthetic materials (polymers) generation. Routes towards synthetic materials allow a closer cycle of materials and can help to reduce dependence on either fossil or biobased raw materials. The system-wide environmental burdens of three different technologies, including (1) municipal solid waste (MSW) gasification followed by Fischer-Tropsch synthesis (FTS), (2) plasma gasification of construction and demolition (C&D) wood for syngas production with energy recovery, and (3) forest residuals use in a biorefinery for polyitaconic acid (PIA) production, were assessed using life-cycle assessment. The first two studies indicated that MSW gasification and subsequent ethylene and polyethylene production via FTS has lower environmental impacts than conventional landfilling. In the future, as societies may shift towards the use of renewable energy, power offset by conventional waste-to-energy systems would not be as significant and chemicals production routes may then become increasingly competitive (in terms of environmental burdens) also to waste incineration. While production cost of Fischer-Tropsch derived chemicals seems not yet competitive to fossil-based chemicals provision, future price increases in global oil prices as well as changes in waste tipping fees, and efficiency gains on site of the waste conversion systems, may alter the economics and allow carbon recycling routes to reach a price competitive to fossil-based production routes. The third study found that plasma gasification of C&D wood for energy recovery has roughly similar environmental impacts than conventional fossil-based power systems. However, process optimization with respect to coal co-gasified, coke used as gasifier bed material, and fuel oil co-combusted in the steam boiler, would allow to significantly lower the system-wide environmental burdens. The fourth study looked at PIA production from softwood hemicellulose in a stream integrated approach (with the partially macerated wood and lignin being used in other existing processes such as pulp & paper plants for conventional pulp and bioenergy production). The assessment indicated lower global warming potential, energy demand, and acidification, for the wood-based PIA polymer, when compared to corn-based PIA and fossil-based polyacrylic acid (PAA). However, water use associated with wood-derived PIA was found to be higher than for fossil-based PAA production and land occupation is highest for the wood-derived polymer. It is hoped that results of this dissertation will add to the current debate on sustainable waste and biomass utilization and to establish future supply chains for green and sustainable chemical products.
TL;DR: In the present article various solid recovered fuels and their applications in the metallurgical industry are detailed.
TL;DR: In this paper, alternative fuels were added into a cement kiln as alternative fuels using screw conveyor, and the results showed that, except for NOx, emission rate and concentrations of TSPs, HCl, HF, SO2, CO from the kiln flue gas were increased and volatized significantly after adding alternative fuels.
Abstract: Re-processing of aged refuse with particle size of 100mm, heating value above 3000kcal/kg above, chlorine content of about 0.13% was added into cement kiln as alternative fuels using screw conveyor. The results show that: except for NOx, emission rate and concentrations of TSPs, HCl, HF, SO2, CO from cement kiln flue gas were increased and volatized significantly after adding alternative fuels. Dosage of 2t/h of alternative fuels affected little on kiln system, so, main process parameters were normal and no more substantial fluctuations, but, the amount of feeding coal at calciner were adjusted more frequently. Element of S in hot raw material into the kiln seemed no significant changes while K and Cl content was significantly increased within the manageable range. Compressive strength, flexural strength, water demand for normal consistency, surface area of clinker all reduced when using alternative fuels, initial setting time and final setting time were increased compared with clinker saturation. Adding alternative fuels saving of coal, but the actual effect of alternative fuel was less than theoretical results, indicating that intermittent feeding mode was not desirable.
Journal Article•
TL;DR: Wang et al. as mentioned in this paper analyzed the data of thermal testing in Xinyi glass factory and found that the temperature of stack gas from the kiln in each glass production line is 100 ℃ higher than which is from cement kiln.
Abstract: Pure low temperature and waste heat power generation system began to be used in the industries of steel and glass,which brought huge benefits on environment and economy to enterprisesBased on the analysis of the data of thermal testing in Xinyi glass factory,the temperature of stack gas from the kiln in each glass production line is 100 ℃ higher than which is from cement kilnThe electric energy output can reach 14000 kWFrom the benefit assessment of waste heat power generation system,we get the conclusion that costs can be earned back in 2-3 yearsMoreover,the system could make full use of energy,and reduce the emissions of toxic dust and gas,such as SO2 and CO2,etc
TL;DR: In this paper, the authors present a review of some of the challenges that involve the use of organic waste materials as fuels in boilers, and how these can be resolved, and some real cases are presented.
Abstract: There are attractive opportunities to use organic waste materials as a source of energy for several industries. This allows for the elimination of waste and residues, and at the same time saving money and minimising the use of fossil fuels. This entails important challenges due to the special nature of wastes and the need to focus on appropriate equipment design that minimise the risks involved, really obtain the economic advantages, keep environmental emissions within limits and ensure process safety and equipment stability. This study presents a review of some of the challenges that involve the use of organic waste materials as fuels in boilers, and how these can be resolved. Some real cases are presented.
Journal Article•
TL;DR: In order to use waste in the concrete,maintaining its strength, reducing waste and influence on the properties of cement, the experiment has adjusted the proportion of fly ash,slag adjustment,waste incineration ash,construction waste,electroplating sludge,city sewage river sediment percentage as discussed by the authors.
Abstract: A large number of waste to add have greater damage to the strength of concrete.In order to use waste in the concrete,maintaining its strength,reducing waste and influence on the properties of cement,the experiment has adjusted the proportion of fly ash,slag adjustment,waste incineration ash,construction waste,electroplating sludge,city sewage river sediment percentage.After the test of the composite cement sample measurement of mechanical properties,the conclusion is,the individual waste should not be used,and the appropriate selection of waste type and proportion,mixing with the composite,on the cement mechanical properties affected is not too large.Using composite waste in cement has certain feasibility and necessity,using the waste,reducing costs,protecting the environment.The economic significance and social significance is very prominent.