Anaerobic digestion (AD) has gained popularity as an effective way to treat organic materials, produce clean energy, and reduce greenhouse gas emissions. There is a significant number of large-scale AD facilities operating world-wide, largely treating livestock wastes, and used primarily for electricity production in industrialized countries. At the same time, there are millions of small, household-scale ADs deployed in developing countries, mostly to provide biogas resources for heating and cooking. Decentralized low-volume AD systems could provide a local, renewable energy source (for electricity, heating, or both), reduce or eliminate waste disposal costs, and limit discharges of high strength wastes. The purpose of this study was to evaluate the feasibility of deploying low-volume anaerobic digestion (LVAD) systems at institutions generating significant food waste, using Rochester Institute of Technology (RIT) as a case study. Mass flows and energy balance, net present value (NPV), and discounted payback period (DPP) were used to assess the feasibility of implementing an anaerobic digestion system utilizing the campus organic waste resources. Our study showed that a positive NPV can be achieved if subsidies and incentives were applied to offset the initial capital investment. However, the economics can be improved by driving down equipment cost and accepting food waste from other establishments to generate revenue from tipping fees.

This review paper describes techniques proposed for applying microwave-induced plasma gasification (MIPG) for cleaning rivers, lakes and oceans of synthetic and organic waste pollutants by converting the waste materials into energy and useful raw materials. Rivers close to urban centers tend to get filled with man-made waste materials, such as plastics and paper, gradually forming floating masses that further trap biological materials and animals. In addition, sewage from residences and industries, as well as rainwater runoff pour into rivers and lakes carrying solid wastes into the water bodies. As a result, the water surfaces get covered with a stagnant, thick layer of synthetic and biological refuse which kill the fish, harm animals and birds, and breed disease-carrying vectors. Such destruction of water bodies is especially common in developing countries which lack the technology or the means to clean up the rivers. A terrible consequence of plastic and synthetic waste being dumped irresponsibly into the oceans is the presence of several large floating masses of garbage in the worlds’ oceans, formed by the action of gyres, or circulating ocean currents. In the Pacific Ocean, there are numerous debris fields that have been labeled the Great Pacific Garbage Patch. These patches contain whole plastic litters as well as smaller pieces of plastic, called microplastics, which are tiny fragments that were broken down by the action of waves. These waste products are ingested by animals, birds and fishes, causing death or harm. Some of the waste get washed ashore on beaches along with dead marine life. The best solution for eliminating all of the above waste management problems is by the application of MIPG systems to convert solid waste materials and contaminated water into syngas, organic fuels and raw materials. MIPG is the most efficient form of plasma gasification, which is able to process the most widest range of waste materials, while consuming only about a quarter of the energy released from the feedstock. MIPG systems can be scaled in size, power rating and waste-treatment capacity to match financial needs and waste processing requirements. MIPG systems can be set up in urban locations and on the shores of the waterbody, to filter and remove debris and contaminants and clean the water, while generating electric power to feed into the grid, and fuel or raw materials for industrial use. For eliminating the pelagic debris fields, the proposed design is to have ships fitted with waste collector and filtration systems that feeds the collected waste materials into a MIPG reactor, which converts the carbonaceous materials into syngas (H 2 + CO). Some of the syngas made will be used to produce the electric power needed for running the plasma generator and onboard systems, while the remainder can be converted into methanol and other useful products through the Fischer-Tropsch process. This paper qualitatively describes the implementation schemes for the above processes, wherein MIPG technology will be used to clean up major waste problems affecting the earth’s water bodies and to convert the waste into energy and raw materials in a sustainable and environmentally friendly manner, while reducing the dependence on fossil fuels and the release of carbon dioxide and methane into the atmosphere.

Anaerobic digestion (AD) involves the conversion of organic matter in the absence of oxygen to produce methane (CH 4 )-rich bio-gas that can be used for heating, vehicle fuel, or for generating electricity. The evolution of AD systems has historically followed two distinct paths: small residential-scale systems in the developing world to provide modest bio-gas resources for heating and cooking, and multi-million dollar facilities in the developed world for grid electricity production. However, there is a strong need to explore the possibility of applying AD technology in the medium-scale range (on the order of 100s of kW to 1 MW), which would be relevant to many farm installations and food processing plants that have significant organic waste resources. In this paper, technical and economic feasibility assessments have been conducted of two specific applications important to New York State: treatment of dairy farm resources in the Upstate region, and treatment of brewery and distillery waste in the New York City region where significant waste disposal barriers exist. In each case, a comprehensive analysis was first conducted of the available waste resources. Then, using data available in the open literature, an estimate of the total amount of renewable bio-gas that can be produced (bio-methane potential, BMP) was developed and used to compute the achievable size of a centralized AD system. For both the farm and brewery applications, it was determined that energy systems based on anaerobic digestion can be economically and environmentally viable, provided that ample organic resources are available, as well as incentives to offset the initial capital investment.

Anaerobic codigestion of dairy manure and food-based feedstocks reflects a cradle-to-cradle approach to organic waste management. Given both of their abundance throughout New York State, waste-to-energy processes represent promising waste management strategies. The existing waste-to-energy literature has not yet fully realized the environmental impacts associated with displaced grid electricity generation and feedstock-hauling emissions on the net environmental impact of centralized codigestion facilities. The key objective of this study is to provide a comprehensive environmental impact assessment with the purpose of understanding the existing environmental status of centralized codigestion facilities. Real-time data from an operational codigestion facility located in Western New York State was used to conduct this environmental impact statement. A comprehensive inventory of greenhouse gas emissions associated with renewable electricity production at the codigestion facility was developed using the Emissions & Generation Resource Integrated Database (eGRID) (U.S. EPA), while emissions associated with feedstock hauling were quantified using the fuel life-cycle approach developed by the Greenhouse gases, Regulated Emissions, and Energy use in Transportation model (GREET) (U.S. DOE). With each of the emissions models used for this analysis, it was determined that the net environmental impact associated with hauling food-related feedstocks from the many locations throughout the Northeast U.S. region would be acceptably low, and thus could be part of future sustainable development of centralized codigestion facilities.

Prior research conducted by our Institute has revealed the large quantities of food waste available in New York State, particularly in the Upstate corridor extending from Buffalo to Syracuse. The Finger Lakes region is heavily populated with agricultural operations, dairy farms and food processing plants, including those producing milk, yogurt, wine, and canned fruits and vegetables. The diverse supply of organic waste generated by these facilities offers the opportunity for sustainable energy production through one of three primary pathways: • Anaerobic digestion to produce methane • Fermentation to produce alcohols • Transesterification to produce biodiesel. Generally speaking, food wastes are better suited for biochemical conversion instead of thermo-chemical conversion (combustion, gasification, pyrolysis) due to their relatively high moisture content. The current paper provides an initial assessment of food wastes within the 9-County Finger Lakes region around Rochester, New York. Available databases were utilized to first identify all the relevant companies operating in one of four broad industry sectors: agriculture, food processing, food distribution and food services (including restaurants). Our analysis has demonstrated that anaerobic digestion can be a viable method for sustainable energy production from food waste in the Finger Lakes region, due to the dual economic benefits of effective disposal cost reduction and production of methane-rich biogas.

Anaerobic digestion is a waste-to-energy conversion process that offers potential economic and environmental benefits of organic waste diversion and renewable energy generation. However, these systems are often not feasible for small-to-medium size food processors, due to the significant capital investment involved. The key objective of this study is to identify the volume and composition of dairy manure and liquid-phase food manufacturing waste streams available in New York State (NYS) to make co-digestion of multiple feedstocks in centralized anaerobic digester facilities an economically attractive alternative. Organic waste volume and property data were obtained via Freedom of Information Law (FOIL) requests at the county and municipal levels for each of the 62 counties in NYS. Spatial analyses of dairy confined animal feeding operations (CAFO) locations relative to food manufacturing facility locations were analyzed using Microsoft MapPoint imaging software, which identified concentrations of high strength liquid-phase waste in the upstate corridor extending between Buffalo and Albany. The results show that if anaerobically digested, dairy CAFO manure and food manufacturing waste can contribute significantly to the State’s renewable energy portfolio. A laboratory scale two-phase anaerobic digester (bioDrillTS-AD200 © ) can help establish the correlation between waste properties (e.g. total solids, etc.) and quantity and quality of biogas produced.

A device was developed for laboratory testing of a heat generating process that can use commercial organic by-products as fuel. This process, Activated Carbon Facilitated Oxidation (AC FOX), enables less refined organic compounds to be used as fuel sources, including glycerin, animal fats, and forms of brown grease. AC FOX oxidizes these compounds on the carbon surface in an exothermic reaction that does not involve combustion via flame. Although AC FOX has been demonstrated and patented, further development is required for industrial application. The device developed in this project forms a packed column vessel measuring three inches in diameter by five inches in height. Multiple ports have been drilled for temperature sensors and fluid flow. A thermosyphon design is being tested for heat transfer, and consists of a steel tube that will be partially filled with a working fluid. The bottom of the tube, evaporator, sits centrally in the packed column of activated carbon while the top section, condenser, is submerged in water. This device will enable the establishment of optimal conditions for AC FOX heat generation.