2nd law analysis of Portuguese municipal solid waste gasification using CO2/air mixtures

Mixed Solid Municipal Waste-Based Biochar for Soil Fertility and Greenhouse Gas Mitigation

The study of municipal solid waste management was carried out on the example of the city of Uman, the features of the municipal waste collection were considered. One of the promising utilization methods of the municipal waste organic component is proposed — anaerobic fermentation with subsequent composting of the resulting products. Urban population growth, industrialization, urbanization and economic prosperity lead to an increase in municipal solid waste (MSW). The aim of the work was to consider the characteristics of municipal solid waste management using the example of the city of Uman; inspect the features of collecting municipal waste; consider a separate collection system; identify problems and possible solutions. According to the statistics of Uman city council, 73-75 tons of municipal waste per day are delivered to the landfill. The control is carried out on the composition of the waste entering the landfill. Sorting takes place using a sorting line, which was put into operation in October 2016. Removal of municipal solid waste from the residential sector is carried out according to the schedule. The waste from the private sector of the city is removed during the day. Transportation (transport) of municipal waste is carried out by specially equipped vehicles. On the plots of the private residential sector, the collection of municipal waste is carried out by containerless and container methods. The containerless method is used in those areas of private building, where the possibility of the garbage truck's driving and its maneuvering are limited. Analysis of the current state of municipal solid waste management in the city of Uman showed that the main reasons for the increase in the volume of environmental pollution due to municipal solid waste is the lack of a high-quality management system in the field of MSW management, and especially the outdated waste collection and transportation scheme. The state of MSW management does not meet modern requirements. At the landfill, as a result of the introduction of the technology for the production of biogas from municipal solid waste, it is possible to obtain marketable products — biogas and compost. The city can receive income from the use of biogas as an alternative source of energy for heating buildings or from its consuming by the population. For the city of Uman, the volume of biogas formation at the MSW landfill in 2018 would have amounted to 5,441,280 m3, and in 2019 – 5,424,930 m3.Thus, it is possible to obtain significant volumes of biogas for the production of both heat and electricity. As a result of the study, recommendations were developed to improve the system for collecting municipal waste in the city of Uman. One of the promising utilization methods of the municipal waste organic component in the city of Uman is anaerobic fermentation followed by composting of the resulting products.

The municipal solid waste (msw) is a source of landfill gas (msw)—with methane gas content. Preoccupations for landfill gas (msw) management date back since 1976 when, at a landfill (msw) in California (USA), it turned out practically that the landfill gas (msw) with methane gas content contains a gas with high caloric value that can be collected and used for economic purposes. The landfill gas (msw) contains methane gas (30% - 60% volume), carbon dioxide (45% - 50% volume), hydrogen sulfide and other gases. Methane gas, carbon dioxide, nitrous oxide and other gases are listed in Kyoto Protocol as high greenhouse gases. Their ecological-rational management is both a national and global preoccupation. In terms of greenhouse gases, especially methane gas, the landfill (msw) is held responsible for 3.5% - 5% of the total global greenhouse gases. Practically, the quantitative estimation of the methane gas in a municipal solid waste landfill can be done by measuring the landfill gas (msw) flow in an extraction-collection well. In Romania, a quantitative estimation relationship of methane gas from deposits (msw) was made, approaching the problem in a different way. This paper presents the calculation formula, the working algorithm, the municipal waste landfill equation and the NOMOGRAMA of a municipal solid waste landfill (msw). The NOMOGRAMA allows us to define the values for parameter -m- (number of months needed for an amount of municipal solid waste (msw) to degrade, starting with the year from which the landfill gas (msw) emission with methane gas content is calculated). Taking into account the environmental conditions for each location of municipal solid waste landfill, the calculation uses various indexes and approximations, while the fundamental parameter remains -m- defined by the NOMOGRAMA of the municipal solid waste landfill (msw). A municipal solid waste landfill (msw) is a conglomerate of waste with various biodegradation periods between 2 - 3 years and 5 - 10 - 30 years. Degradation of waste (msw) in to dissolved organic carbon will take place in a number of months defined -m- starting with the year from which the methane gas emission with the NOMOGRAMA of the municipal solid waste landfill (msw) is calculated. The -m- values for the year of the quantitative emission of methane gas can be also done analytically, which requires good experience in the ecologic-rational management of the municipal solid waste (msw).

The necessity of economical and rational use of natural energy sources caused a rapid development of research on the possibilities of using non-conventional energy resources. Taking the above into account, a new technological process of thermochemical conversion of biomass and communal waste, commonly known as High Temperature Air/Steam Gasification (HTA/SG) and Multi-Staged Enthalpy Extraction Technology (HTAG-MEET), was developed. In relation to traditional techniques of gasification or combustion of hydrocarbon fuels, the presented concept is characterized by higher thermal efficiency of the process, low emission of harmful compounds of carbon, sulfur, nitrogen, dioxins, furans and heavy metals. The use of a high-temperature gasification factor causes an increased thermochemical decomposition of solid fuels, biomass and municipal waste into gaseous fuel (syngas), also with increased hydrogen content and Lower Calorific Value (LCV). In this study, the possibility of using a batch type reactor (countercurrent gasifier) was analyzed for gasification of biomass and municipal waste in terms of energy recovery and environmental protection. The proposed research topic was aimed at examining the possibility of using the thermal utilization of biomass and municipal waste through their high-temperature decomposition in the presence of air, a mixture of air and steam. The main goals of the research were achieved during the implementation of several parallel stages of the schedule, which included, primarily: (a) study of the possibility of using thermal utilization of biomass and municipal waste through their high-temperature gasification in the presence of air or a mixture of air and steam and, secondary (b) analytical and numerical modeling of high-temperature gasification of biomass and municipal waste with the use of ANSYS CFD Fluent 6.3 software. Selected results of the experimental and numerical studies are properly presented. The higher temperature gasification concept shows the capability of this technology for maximizing the gaseous product yield in an up-draft fixed bed gasifier. It was also observed that at a high temperature, steam addition contributed to the thermal conversion of biofuels to gas with higher production of hydrogen.

Utilization of glass shards from municipal solid waste in aluminium-based ultra-lightweight concrete

Technological process of compost production at Municipal Waste Recycling Plant, JSC (Togliatti) is examined. MWRP, JSC is operating according to aerobic biothermal composting technology, when municipal solid waste enters the natural biological cycle of matter and as a result undergoes the process of detoxification and turns into compost - valuable organic fertilizer. MWRP, JSC ensures full mechanization of technological processes, excluding any direct contact with toxic municipal solid waste. Compost produced at MWRP, JSC can be used as biofuel for greenhouses, as organic fertilizer in the spheres of agriculture, forestry, parks and gardens management and as a component of vegetative cover during landfill recultivation. The process of rapid biochamber composting of municipal solid waste does not pose any threat as far as the technology of environmental safety provision is concerned. In the process of municipal solid waste recycling non-compostable municipal waste is brought for disposal to the landfill and petroleum products derived from the waste are sent to be regenerated. Gaseous products of decomposition of organic matter found in municipal solid waste are taken out through vent headers into the gas outlet pipe and dissipate in the atmosphere.

Durability and Microstructure of Cement Composites Containing Qatar's Municipal Wastes

Municipal solid waste is a pool of various solid wastes by towns and cities from different types of household activities. All over the world, municipal solid wastes are dumped in permitted landfills. Landfill gas is a mixture of methane and carbon dioxide which is emitted from the dumping sites of municipal wastes. Methane is a flammable toxic greenhouse gas more damaging to the climate than carbon dioxide. Instead of discharging into the atmosphere and becoming a greenhouse gas which is harmful to the environment, methane can be collected in every landfill and used to produce useful energy. This paper outlines the basic procedure for estimation of methane from landfill site. The Landfill Gas Emissions Model (Landgem) is an automated estimation tool with a Microsoft Excel interface which is available from the EPA's Clean Air Technology Center. It can be used to estimate emissions rate of methane from municipal solid waste landfills. Based on the methane emission rate obtained from Landgem output and the heating value of methane, the net heat input available and hence the potential for generation of electric power can be computed. A typical case study on the evaluation of methane emission rate from a landfill site at Namibia and its potential for generation of electric power as well as the cost estimates are presented. It is found that the power plant would be able to provide 142 streetlights in the city with electrical energy every day.

Exergy analysis of Portuguese municipal solid waste treatment via steam gasification

In Uganda, the municipal solid wastes are generally a menace to the environment, ranging from indiscriminate dumping, open burning, and landfills, which would be utilized to augment agricultural fields through organic manure. The National Environment Management Authority (NEMA) of Uganda, however from 2009 to 2012 initiated and implemented a Clean Development Mechanism project. This project was established and conducted in nine urban centers with the key objective of reducing methane and other environmental nuisances while generating compost manure. The in-coming fresh municipal wastes at composting facilities were sorted into six categories; i) wood and wood products, ii) food and food wastes, iii) textiles, iv) garden, yard and park wastes, v) paper and pulp, and vi) glass, plastics, and metals. These were laboratory analyzed based on standard procedures, characterized and investigated for the pH, total organic carbon (TOC), total nitrogen (TN), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) (g kg−1). Statistical analyses were performed based on One-Way ANOVA, implemented in the SPSS program. The results indicate that the municipal fresh solid wastes were mainly dominated by biodegradable organic matter; garden, yard, and park wastes (49%), food and food wastes (43.2%), and the other wastes falling below 5.4%. Overall, the pH was 7.7 ± 0.02, TOC 318.2 ± 2.90, TN 12.1 ± 0.10, C/N 26.7 ± 0.20, P 4.4 ± 0.04, K 35.0 ± 0.49, Ca 38.9 ± 0.51, and Mg 5.8 ± 0.09. The concentration of the fresh wastes and macro-nutrients varied per municipality and were congruent with the economic activities and population lifestyles. We detected the effect of season/month on the concentration of wastes which corresponded with the various agronomical activities. The results from this study suggest that the notion of composting is potentially a viable organic waste management strategy in the country which can ultimately generate sufficient organic manure for agricultural input and thus enhanced carbon sequestration. Implications: In this study, we characterized the in-coming fresh municipal solid wastes and investigated the pH, total organic carbon (TOC), total nitrogen (TN), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) (g kg−1). We found that the municipal fresh solid wastes were mainly dominated by biodegradable organic matter (>90%). The results from this study suggest the notion of composting to be potentially a viable organic waste management strategy in Uganda which can ultimately generate sufficient organic manure for agricultural input. This is typically vital for enhancing carbon sequestration towards minimizing greenhouse gas emissions.

This paper presents a comprehensive economic analysis of recycling organic wastes through composting. A mathematical programming model is developed to examine the optimal level of compost production from sources of organic municipal solid waste, livestock manure and wastewater-treatment sludge. The model incorporates the spatial nature of the problem by referring to the locations of the sources for raw organic matter, of the composting plants and agricultural regions. Agricultural demand for compost is derived using estimated production functions for 42 crops, price elasticity of the vegetative agricultural outputs, and farmers' stated willingness to utilize compost. The model accounts for the costs of waste collection, compost production, transportation and landfilling; all include both direct costs and externalities. The optimal allocation of raw materials and outputs is achieved when the financial contribution of the composting system is maximized relative to the alternative of disposing of these organic wastes in landfills. We apply the model to the case of Israel. Today, despite the relatively high levels of organic material in municipal solid waste, the scarcity of landfill sites, and the low level of organic content in agricultural soils, only 37% of Israel's composting potential is realized. Subject to compliance with new environmental regulations, our analysis points to the possibility of an 89% composting rate, in which all livestock manure and sludge are composted, but only 75% of the organic municipal solid waste is utilized in this manner. This finding supports the strict enforcement of these environmental regulations, and indicates the need for a composting encouraging policy. However, regulations aimed at increasing the rate of municipal solid waste recycling should leave enough freedom for municipalities to select their waste disposal strategies. It is also concluded that, given the high costs of separating municipal waste at the 2 source, the government can increase composting rates by initializing and stimulating the formation of regional cooperation to ensure steady long run consumption of raw organic materials. Moreover, the government can increase agricultural demand for compost by both setting clear standards for high quality compost, and spreading the scientific information on the advantages of composting via the governmental agricultural instruction system. The presented methodology is applicable to other cases, as is the scientific-based data, which include the external costs and the compost production functions. This information is relevant for regions facing the same challenges, particularly where the soil's organic content is less than 2%; e.g., Portugal, Spain, Italy and Greece.

Determination of biomass content in combusted municipal waste and associated CO2 emissions in Estonia

This article discusses a promising direction focused on the use of recycled municipal solid waste in construction. In Russia, there are problems related to municipal solid waste management, which necessitates the modernization of this process and confirms the relevance of the issues raised. Analysis and use of the experience of foreign countries in the processing of municipal solid waste and its secondary use in Russia contributes to the search for a more environmentally responsible approach that entails both economic and social benefits. The use of solid municipal waste recycling products in construction is aimed at minimizing the negative impact on the environment and is a step towards the transition to a circular economy, where waste is turned into valuable resources. The article reflects on the various methods of recycling municipal waste and analyzes the priority areas for the processing of municipal solid waste. In addition, examples of successful building projects using recycled products are given, and the challenges and prospects of this approach, as well as its significance for sustainable development and environmental responsibility in the construction industry, are revealed.

US Department of Energy contractors continue to conduct research targeting the productive and responsible use of the more than 536,000 tons of municipal solid waste (MSW) that is generated each day in the United States. It is becoming more and more prudent to improve current methods of MSW management and to continue to search for additional cost-effective, energy-efficient means to manage our MSW resource. This bibliography is an updated version of Municipal Waste to Energy: An Annotated Bibliography of US Department of Energy Contractor Reports, by Caroline Brooks, published in 1987. Like its predecessor, this bibliography provides information about technical reports on energy from municipal waste that were prepared under grants or contracts from the US Department of Energy. The reports listed focus on energy from municipal waste technologies and energy conservation in wastewater treatment. The bibliography contains three indexes -- an author index, a subject index, and a title index. The reports are listed alphabetically in the subject areas and may appear under more than one subject. All of the reports cited in the original MSW bibliography are also included in this update. The number of copies of each report originally published varied according to anticipated public demand. However, all reports are available in either microfiche or hard copy form and may be ordered from the National Technical Information Service (NTIS), US Department of Commerce, Springfield, VA 22161. Explicit information on ordering reports is included in Appendix A.

Municipal Solid Waste Management (MSWM) plays an important role in sustainable development. The motivation for the present study includes the abysmal state and challenges in MSWM in urban India. The concept of zero waste is a latest one for confounding waste problems of our society. Urbanization contributes to enhanced municipal solid waste (MSW) generation along with unscientific handling degrades the urban environment and causes health hazards. The expansion of urban areas, industrialization and changing patterns of consumption results in increased municipal waste generation which deteriorate the quality of environment, posing risk to the sustainable development. The seriousness of the problem increases in a scenario where natural resources are decreasing, and the traditional system of landfills still being practiced extensively for solid waste disposal. This paper addresses the issue of MSW by taking the case of Jamshedpur. It discusses the present municipal waste management system, new technologies, projected population, and solid waste generation. In an evolutionary approach, it points out the challenges that the sector is facing and makes an attempt to suggest a way forward through new technologies and estimation of value-added products that can be produced from the solid waste...