Combining Anaerobic Digestion and Waste-to-Energy

Author(s):  
Karena M. Ostrem ◽  
Karsten Millrath ◽  
Nickolas J. Themelis

A large fraction of the municipal solid wastes (MSW) stream in the U.S. comprises of natural organic compounds (i.e., food and plant wastes) with high moisture content and low heating value. While these properties are undesirable during the combustion of MSW in waste-to-energy (WTE) plants, they are required for anaerobic digestion (AD). During AD, methane gas is produced that can be captured and used for energy generation. The required long residence times limit the throughput of an AD plant but further development may result in increasing the rates of bioreactions. This paper introduces current AD practices and identifies possible synergies between AD and WTE. It is suggested that co-siting of WTE and AD facilities may result in mutual benefits.

2012 ◽  
Vol 610-613 ◽  
pp. 2179-2182 ◽  
Author(s):  
Jun Zhao ◽  
Shu Zhong Wang ◽  
Zhi Qiang Wu ◽  
Lin Chen

Gasification and melting process is an environmentally friendly technology in municipal solid wastes (MSW) disposal. But it requires that the waste has lower moisture content. The author hopes to find a route can be used for the treatment of high moisture content MSW through gasification and melting by theoretical calculation and analysis. In this paper, firstly calculate the influence of moisture content on MSW calorific value and exhaust smoke temperature. Then calculate the influence of oxygen concentration on exhaust smoke temperature. Finally appropriate process parameters of gasification melting for high moisture content MSW are given.


2015 ◽  
Vol 799-800 ◽  
pp. 1244-1248
Author(s):  
Somrat Kerdsuwan ◽  
Krongkaew Laohalidanond

With the increasing amount of waste together with the high development of the country, the high amount of waste needed to be treated properly in order to lower the impact to the environment. Waste to Energy through incineration is considered as the appropriated technology to convert green and clean energy from discard matters, especially for the waste that has the mixing composition and has not segregate its composition in the developing country. Therefore, it is essential to simulate its combustion process to see how much of electrical power that can be generated and purpose the appropriated technic in order to improve its efficiency. This research deals with the process simulation of using incineration technology with high moisture content and low heating value in developing country. The simulation of 500 ton per day incineration technology was conducted by the unit operation in Aspen Plus® program in order to forecast the capacity of electricity production and the contaminants in flue gas emission. It was found that, even high moisture content and low heating value of waste, incineration can be one of the solutions to dispose waste properly and can recover green and clean energy in the form of electricity ranging from 3.78-6.29 MWe depending on waste’s quality. This green and clean energy recovery from waste could be used to reduce the using of fossil fuel in order to mitigate the emission of the greenhouse gas to atmosphere.


2020 ◽  
Vol 207 ◽  
pp. 02001
Author(s):  
Bogdan Gabriel Carp ◽  
Gabriel Mocanu ◽  
Ion V. Ion ◽  
Florin Popescu

The municipal solid wastes (MSW) can be turned into resources through recycling and energy recovery. To obtain the maximum amount of energy, the appropriate technology must be applied to waste treatment. The composition and characteristics of municipal solid wastes are determinant for technologies choice for MSW in a city/region. Municipal authorities from the Galati city proposed a recovery rate of recyclable materials of 60% from MSW and treatment of the post-recycling MSW as follow: biodegradable fraction by anaerobic digestion and the combustible fraction by incineration or gasification. In this study traditional and innovative waste to energy technologies have been analysed and the potential of electrical energy of waste has been estimated. Results show that plasma gasification system of raw MSW coupled with gas turbine engine has almost the same electrical energy production (32.92 GWh/year) as conventional gasification of combustible material from MSW (17.21GWh/year) coupled with anaerobic digestion of organic fraction of MSW (11.65 GWh/year). By recovering and using the landfill gas from the Tirighina landfill, 6.68 GWh of electricity can be produced annually.


Author(s):  
Nickolas J. Themelis

This report presents the results of a study that examined alternatives to landfilling the municipal solid wastes (MSW) of New York City. Detailed characterization of the wastes led to their classification, according to materials properties and inherent value, to “recyclable”, “compostable”, “combustible”, and “landfillable”. The results showed that the present rates of recycling (16.6%) and combustion (12.4%) in New York City can be increased by a) implementing an automated, modern Materials Recovery Facility (MRF) that separates the blue bag stream to “recyclables” and “combustibles”, and b) combusting the non-recyclable materials in a Waste-to-Energy (WTE) facility. Combustion of wastes to produce electricity is environmentally much preferable to landfilling. An advanced technology for combustion is that used in a modern Waste-to-Energy plant (SEMASS, Massachusetts) that processes 0.9 million metric tons of MSW per year, generates a net of 610 kWh per metric ton of MSW, recovers ferrous and non-ferrous metals, and has lower emissions than many coal-fired power plants.


Author(s):  
Nabil Kechaou ◽  
E Ammar

The Municipal Solid Waste of Agareb (Sfax –Tunisia), characterized by high organic fraction and moisture contents is the most worrying pollution source that must be managed by innovative treatment and recycling technologies. Bio-drying, as a waste to energy conversion technology, aims at reducing moisture content of this organic matter. This concept,  similar to composting, is accomplished by using the heat generated from the microbial degradation of the waste matrix, while forced aeration is used. The purpose of this work was to reduce the moisture content of the waste, by maximizing drying and minimizing organic matter biodegradation, in order to produce a solid recovered fuel with high calorific value.Keywords: Municipal solid wastes; organic matter; biodrying; composting; energy recovery.


2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Edwin N. Richard ◽  
Askwar Hilonga ◽  
Revocatus L. Machunda ◽  
Karoli N. Njau

AbstractRecently, there are increased efforts by municipals and researchers to investigate the potential of utilizing municipal solid wastes (MSW) for resources recovery. In many parts of developing countries, MSW is mostly collected for disposal with little emphasis on resources recovery. However, the MSW has high organic and moisture contents, and are suitable substrates for anaerobic digestion (AD) process to recover biogas for energy and digestate which can be used as fertilizers or for soil amendments. Resources recovery from the AD process consists of four metabolic stages; hydrolysis, acidogenesis, acetogenesis, and methanogenesis. These metabolic stages can be affected by several factors such as the nature of substrates, accumulation of volatile fatty acids, and ammonia inhibition. In this review, different optimization strategies towards resources recoveries such as pre-treatment, co-digestion, trace elements supplementation, optimization of key parameters and the use of granular activated carbon are discussed. The review reveals that the currently employed optimization strategies fall short in several ways and proposes the need for improvements.


Author(s):  
Shang-Hsiu Lee ◽  
Nickolas J. Themelis ◽  
Marco J. Castaldi

In boilers that use municipal solid wastes as fuel, metal wastage due to corrosion and erosion and tube fouling due to the buildup of deposits present serious problems to the system designer and operator. This study examines the corrosion mechanisms in Waste-To-Energy (WTE) boilers and summarizes the findings of a corrosion survey of several WTE facilities and of interviews with senior engineers in the WTE industry. In addition, this study examines the existing methods of reducing corrosion that are adopted in WTE plants. Finally, the study proposes experimental research on corrosion resistant materials to be carried in the near future.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Chaudhry Arslan ◽  
Asma Sattar ◽  
Ji Changying ◽  
Abdul Nasir ◽  
Irshad Ali Mari ◽  
...  

The biohydrogen productions from the organic fraction of municipal solid wastes (OFMSW) were studied under pH management intervals of 12 h (PM12) and 24 h (PM24) for temperature of37±0.1°C and55±0.1°C. The OFMSW or food waste (FW) along with its two components, noodle waste (NW) and rice waste (RW), was codigested with sludge to estimate the potential of biohydrogen production. The biohydrogen production was higher in all reactors under PM12 as compared to PM24. The drop in pH from 7 to 5.3 was observed to be appropriate for biohydrogen production via mesophilic codigestion of noodle waste with the highest biohydrogen yield of 145.93 mL/gCODremovedunder PM12. When the temperature was increased from 37°C to 55°C and pH management interval was reduced from 24 h to 12 h, the biohydrogen yields were also changed from 39.21 mL/gCODremovedto 89.67 mL/gCODremoved, 91.77 mL/gCODremovedto 145.93 mL/gCODremoved, and 15.36 mL/gCODremovedto 117.62 mL/gCODremovedfor FW, NW, and RW, respectively. The drop in pH and VFA production was better controlled under PM12 as compared to PM24. Overall, PM12 was found to be an effective mean for biohydrogen production through anaerobic digestion of food waste.


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