Analysis of greenhouse gas emission reductions by collaboratively updating equipment in sewage treatment and municipal solid waste incineration plants

Analysis of carbon reduction potential from typical municipal solid waste incineration plants under MSW classification.

Incineration is one of the most widely used treatments in the field of sewage sludge disposal. However, the choice of sewage sludge incineration process is still controversial. In this study, the comparative life cycle assessment of sewage sludge incineration processes, including the mono-incineration, co-incineration in coal-fired power plants and co-incineration in municipal solid waste (MSW) incineration plants, was carried out from the perspective of environment, carbon footprint and economy. The environmental assessment results show that terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity, human carcinogenic toxicity and human non-carcinogenic toxicity are the most significant environmental impacts. And the environmental performance of co-incineration in coal-fired power plants is the best. Moreover, the environmental impact is most sensitive to the dehydrant, electricity and fly ash chelating agent. Co-incineration in MSW incineration plants has the lowest carbon emissions, with only 70.50% and 82% of the carbon emissions from mono-incineration and co-incineration in coal-fired power plants, respectively. Furthermore, sewage sludge mono-incineration has the highest disposal costs because of the higher depreciation and solid waste disposal costs. The comprehensive evaluation results reveal that the optimization should focus on the selection of dehydrant and fly ash chelating agent, as well as the improvement of the equipment efficiency.

In order to give a MSW (municipal solid waste) incineration plant with a good combustion characteristic, a control system for MSW plant was designed. According to the detailed analysis of the composition data from the MSW incineration plant, the basic characteristics of MSW is revealed, and the combustion model of MSW incineration plant with its control strategy is discussed. The combustion control system includes grate system, primary air system and secondary air system. It is proved that the strategy is suitable for MSW incineration plant control. The significant economic and environmental benefits are achieved.

Comparative life cycle assessment of organic industrial solid waste co-disposal in a MSW incineration plant

Herein, a novel oxygen-enriched melting process for fly ash, which uses the biogas produced from the leachate of municipal solid waste incineration (MSWI) plants, is proposed to reduce the high cost of conventional fly ash – melting technology. The fly ash composition was estimated via X-ray fluorescence analysis; the six constituent elements detected in fly ash in the decreasing order of their content were calcium, chlorine, silicon, sulfur, sodium, and potassium. Based on literature and actual production data, the average yield of the leachate was 15% of the total waste entering the MSWI plants and the COD of leachate was 30,000–75,000 mg/L. The amount of biogas that can be used per ton of fly ash was calculated to be 62.0–157.0 m3. The analysis of melting thermal equilibrium revealed the amount of biogas required per ton of fly ash as 57.8 m3. The aforementioned research findings indicate that the biogas produced by MSWI plants can successfully meet the demands of the oxygen-enriched melting of fly ash produced in these plants. By establishing an oxygen-enriched-melting pilot platform, the pilot tests of melting were conducted on fly ash; the results revealed the good melting effects of fly ash. The X-ray diffraction analysis of the slag demonstrated that the content of the vitreous body met the technical requirements for glassy substances. Furthermore, the leaching toxicity test results revealed that heavy metals were well solidified in the slag. This study presents a novel fly ash – melting scheme for MSWI fly ash, namely, biogas oxygen-enriched melting strategy, which has the advantages of technical feasibility and cost-effectiveness. The proposed technique exhibits considerable prospects for widespread application in MSWI plants in China and can play an important role in the safe disposal of fly ash. Implications: In this paper, a low-cost melting method of municipal solid waste incineration(MSWI) fly ash is proposed. This method uses the biogas generated by MSWI plant itself as fuel for melting. Through research, it has been found that the production of biogas can meet the demand for fly ash melting. Adopting biogas as a molten fuel can significantly reduce the cost of melting, thereby significantly reducing the cost of fly ash melting. This study established a pilot scale platform for the melting of biogas and conducted pilot scale experiments on fly ash and additives. The experimental results showed that the melting system operated well and achieved the vitrification of fly ash. The leaching test results of the molten slag showed that heavy metals were well solidified in the slag. The research results can be extended to the MSWI plant for application, which can significantly reduce the cost of fly ash melting disposal, and has broad application prospects.

Monitoring methods of dioxin or dioxin surrogate compounds for management of the emission in MSW (Municipal Solid Waste) incineration plant have been widely developed. In this study, OHCs(Organic Halogenated Compounds) ,which have been studied a possibility of dioxin surrogate compounds, were selected for the index of the emission. Field study was conducted at a MSW incineration plant. OHC concentrations and behavior in gas treatment process at a MSW incineration plant were investigated. OHC concentrations were reduced during gas treatment process, and the behavior showed high removal efficiency in ACR (Activated Carbon Reactor). Moreover the OHC behavior was similar to that of aromatic compounds (DXN, CBz, and CPh) in ACR.

The characteristics and leaching behavior of heavy metals in fly ash, sampled from one MSWI (municipal solid waste incineration) plant in Shanghai China, were investigated. The results indicated that the main elements of fly ash were Fe, K, Na, Cl, Si, Ca, Al, and the total fraction of heavy metals was in the range of 0.8 % - 2.0%. Hence, MSWI fly ash was considered to be one kind of hazardous waste due to its potential environmental risk. Leaching toxicity was performed on fly ash samples from the MSWI plant in Shanghai China. Leaching toxicity of the heavy metals by the ALT (available leaching toxicity) procedure exceeded that by the HVEP (horizontal vibration extraction procedure) standard. Leaching concentrations of Ni, Zn, Cd and Pb exceeded the limit of hazardous waste identification standard. Hence, fly ash is a hazardous waste.

Greenhouse gas emission and exergy analyses of an integrated trigeneration system driven by a solid oxide fuel cell

An analysis of power generation from municipal solid waste (MSW) incineration plants in Taiwan

ABSTRACTIncreasing population in many countries consumed natural resources and generates secondary product. These secondary products may be in the form of pollutants and liberated in the atmosphere. In this paper, an analysis was performed for green house gas (GHG) emission from municipal solid waste disposal for Faridabad city, India. Land filling and waste-to-energy methods were considered for GHG emission and analysis was performed based on Intergovernmental Panel on Climate Change (IPCC) model. GHG emission and linear pinch analysis (LPA) were performed based on the 50% collection efficiency in Faridabad city over a period of 10 years (2015–2025). Two scenarios of emission forecasting, such as land filling and waste to energy (incineration), were incorporated in this study. Hybrid analysis was presented for emission forecasting and emission reduction to develop a sustainable municipal solid waste management system for Faridabad. A target of 20% and 30% reduction in GHG emission was formulated with the help of LPA. The result shows that GHG in Faridabad city has been continuously changed from 2015 to 2025.The result represented here could be a decision support matrix for municipalities to develop integrated municipal solid waste management system for upcoming smart cities in India. Moreover, another novelty of this study reflects that cities having approximate same population, waste characteristics, and waste management technology could adopt this model for saving of GHG inventory and target-based reduction.

With the global reduction actions of greenhouse gas (GHG) emissions, environmental facilities, including sewage treatment plants (STPs), need to reduce pollutants while minimizing GHG emissions. Therefore, more and more publications revealed the formation mechanism of GHGs in STPs and committed to finding better reduction schemes. From the perspective of bibliometrics, this study used CiteSpace to conduct quantitative and visual analysis based on 1,543 publications retrieved from Web of Science between 2000 and 2021 around the world. We have systematically evaluated the structure, development trend, hot spots, and research frontier in the field of GHG emissions from STPs and compared with the contents of top journals to verify the scientificity of the analysis. The results show that the number of publications has increased year by year, and the networks of authors and institutions show a strong correlation. Among them, the clusters of nitrous oxide, anaerobic digestion, and life cycle assessment (LCA) started earlier and received extensive attention, which derived other clusters in the research process. With the development of the field, researchers have gradually changed from single water treatment facilities to multi-carriers that can realize energy regeneration and utilization simultaneously. Accordingly, the GHG reduction of STPs through energy regeneration and resource recovery has become a hot point and frontier direction, which also challenges the breakthroughs in relevant technologies. Furthermore, it provides scientific support for the formulation of relevant incentive policies and economic subsidy systems, so as to alleviate the pressure of global warming and realize the sustainable development of STPs concurrently.

Diagnosis for monitoring system of municipal solid waste incineration plant

Characterization of PCDD/Fs and heavy metals from MSW incineration plant in Harbin

Uncertainty of greenhouse gas (GHG) emissions was analyzed using the parametric Monte Carlo simulation (MCS) method and the non-parametric bootstrap method. There was a certain number of observations required of a dataset before GHG emissions reached an asymptotic value. Treating a coefficient (i.e., GHG emission factor) as a random variable did not alter the mean; however, it yielded higher uncertainty of GHG emissions compared to the case when treating a coefficient constant. The non-parametric bootstrap method reduces the variance of GHG. A mathematical model for estimating GHG emissions should treat the GHG emission factor as a random variable. When the estimated probability density function (PDF) of the original dataset is incorrect, the nonparametric bootstrap method, not the parametric MCS method, should be the method of choice for the uncertainty analysis of GHG emissions.

Municipal solid waste (MSW) incineration is one of the most important atmospheric mercury emission sources. To investigate the mercury concentrations of MSW and mercury emission characteristics in incineration plants, this study analyzed the MSW sampled in 3 typical MSW incineration plants in Shanghai, Guangzhou and Wuhu respectively. The exhaust gas samples in incineration plants were sampled by using OH (Ontario Hydro) method. The mercury concentrations in fly ash, and bottom ash samples were also analyzed. The results indicated that mercury concentrations of MSW in Shanghai, Guangzhou, and Wuhu incineration plants were (0.39±0.04) mg·kg-1, (0.57±0.05) mg·kg-1, and (0.27±0.08) mg·kg-1 respectively. The mercury concentrations of exhaust gas in Guangzhou, Wuhu MSW incineration plants were (9.5±3.9) μg·m-3 and (24.1±6.0) μg·m-3 respectively; Particulate mercury (Hgp), gaseous oxidized mercury (Hg2+), and gaseous elemental mercury (Hg0) represented (0.9±0.8)%, (89.0±5.4)%, (10.1±4.6)% in Guangzhou MSW incineration plant, and (1.0±0.8)%, (65.4±27.6)%, (33.6±27.5)% in Wuhu MSW incineration plant, respectively. Gaseous oxidized mercury (Hg2+) of exhaust gas in different incineration process showed different distribution proportions. Besides, mercury removal efficiency of Guangzhou, Wuhu MWS incineration plants was 96.7% and 33.7%, respectively. The atmospheric mercury emission factors of Shanghai, Guangzhou, and Wuhu MSW incineration plants were (0.156±0.016) mg·kg-1, (0.019±0.002) mg·kg-1, (0.178±0.027) mg·kg-1 respectively. Compared with MSW incineration plants in Japan and Korea, the atmospheric mercury emission factor of Guangzhou incineration plant was slightly lower; Atmospheric mercury emission factors of Shanghai and Wuhu MSW incineration plants were close to those of domestic fractional MSW incineration plants.