Despite many efforts and improvements over the last few decades, two of the major challenges facing Solid Oxide Fuel Cells (SOFCs) are slow heating rates to operating conditions (typically < 5 °C.min −1 ) and a limited ability to thermal cycle (< 200 cycles). Recently a novel hybridized setup that combines a fuel-rich combustion reformer with a SOFC was developed and utilized to investigate rapid heating, cooling and thermal cycling of a micro-Tubular SOFC. The setup places the SOFC directly in the flame and exhaust of the high temperature combustion of methane, which allows for extremely rapid temperature rise in the SOFC. A SOFC with a (La 0.8 Sr 0.2 ) 0.95 MnO 3-x cathode was tested in the setup, but limitations on air preheating for the cathode resulted in low SOFC cathode temperatures (∼500°C) and low power density. Thermal insulation improved pre-heating of the air delivered to the cathode, increased the SOFC cathode temperature and, when a (La 0.60 Sr 0.40 ) 0.95 Co 0.20 Fe 0.80 O 3-x cathode was applied to the SOFC, resulted in improved power density. After adjusting the thermal insulation, the air temperature near the cathode exceeded ∼750°C during testing. Over 3,000 thermal cycles were conducted at a heating rate exceeding 900°C.min −1 and a cooling rate that exceeded 300°C.min −1 . The open circuit voltage was analyzed over the 150 h test and a low degradation rate of ∼0.0008V per 100 cycles per fuel cell was observed. Unlike the previous test, which was conducted at lower temperatures, significant degradation of the current collector was observed during this test. Electrochemical impedance spectroscopy shows that degradation in the SOFC was due to increases in ohmic losses, activation losses at the cathode and increased concentration losses. The setup demonstrates that rapid thermal cycling of micro-Tubular SOFCs can be achieved, but there are limitations on the maximum temperature that can be sustained depending on the current collector.

Biomass offers the potential to economically produce hydrogen via gasification from an abundant and renewable feedstock. When hydrogen is produced from a biomass gasifier, it is necessary to purify it from syngas streams containing components such as CO, CO 2 , N 2 , CH 4 , and other products. Therefore, a challenge related to hydrogen purification is the development of hydrogen-selective membranes that can operate at elevated temperatures and pressures, provide high fluxes, long operational lifetime, and resistance to poisoning while still maintaining reasonable cost. Palladium based membranes have been shown to be well suited for these types of high-temperature applications and have been widely utilized for hydrogen separation. Palladium’s unique ability to absorb a large quantity of hydrogen can also be applied in various clean energy technologies, like hydrogen fuel cells. In this paper, a fully analytical interatomic Embedded Atom Potential (EAM) for the Pd-H system has been developed, that is easily extendable to ternary Palladium based hydride systems such as Pd-Cu-H and Pd-Ag-H. The new potential has fewer fitting parameters than previously developed EAM Pd-H potentials and is able to accurately predict the cohesive energy, lattice constant, bulk modulus, elastic constants, melting temperature, and the stable Pd-H structures in molecular dynamics (MD) simulations with various hydrogen concentrations. The EAM potential also well predicts the miscibility gap, the segregation of the palladium hydride system into dilute (α) and concentrated (β) phases.

A work on biogas potentials evaluation of household wastes in Johannesburg metropolitan area using the Automatic Methane Potential Test System (AMPTS) II is presented. The AMPTS II consists of three units — the sample incubation unit, CO 2 absorption unit and the gas volume measuring device. Organic fraction of wastes collected from households within Johannesburg metropolis were sorted, ground and prepared into slurry by mixing with water. Microcrystalline cellulose powder with 3.5% loss on drying and 0.28g/cc density was used as control substrate while anaerobic sludge collected from a functional biogas reactor was used as inoculum. Anaerobic sludge was classified as sample A, household waste containing mainly non-food waste was labelled sample B, sample C was microcrystalline cellulose used as positive control while household waste composing of mainly food waste was classified as sample D. Each sample was fed into a 50 mL bottle reactor in triplicates and stirred in a clockwise direction continuously for 5 minutes with a pulse interval of 1 minute at a set temperature of 37°C for 30 days retention time. NaOH solution was prepared into solution following standard procedure and mixed with a prepared 0.4 % Thymolpthalein solution. The resultant solution was poured into the 100 mL bottles of the CO 2 unit. Produced biogas was measured through water displacement in the volumetric bath and values read off through a data-logger connected to a laptop. Results indicated biochemical methane potential (BMP) of 69–800 NmL/g vs and biogas composition with more than 50% methane before CO 2 fixing and over 80% after CO 2 fixing. Given that the average amount of waste generated per person per day in South Africa is over 0.7 kg, there is huge potentials for biogas production from household wastes in Johannesburg.

One of the biggest issues associated to Carbon Capture and Utilisation (CCU) applications involves the exploitation of the captured CO 2 as a valuable consumable. An interesting application is the conversion of CO 2 into renewable fuels via electrochemical reduction at high temperature. Still unexplored in the literature is the possibility of employing a Molten Carbonate Electrolysis Cell (MCEC) to directly converting CO 2 and H 2 O into H 2 , CO and eventually CH 4 , if a methanation process is envisaged. The introduction of this concept into a reversible system — similarly to the process proposed with reversible solid-oxide cells — allows the creation of a cycle which oxidises natural gas to produce CO 2 and then employs the same CO 2 and excess renewable energy to produce renewable natural gas. The result is a system able to perform electrochemical storage of excess renewable energy (from wind or solar) and if/when required sell renewable natural gas to the grid. In this work, a simulation of a reversible Molten Carbonate Cell (rMCC) is proposed. The reference MCFC technology considered is that from FuelCell Energy (USA) whose smaller stack is rated at 375 kW (DC). A simplified 0D stack model is developed and calibrated against experimental data. The Balance of Plant (BoP) is in common between the two operation modes MCFC and MCEC. In the former case, natural gas is electrochemically oxidised in the fuel compartment which receives carbonate ions (CO 3 2− ) from the air compartment, fed with air enriched with CO 2 produced during electrolysis mode. The CO 2 in the anode off gas stream is then purified and stored. In electrolysis mode, the stored CO 2 is mixed with process H 2 O and sent to the fuel compartment of the MCEC; here, electrolysis and internal methanation occur. An external chemical reactor finalises the production of methane for either natural gas grid injection or storage and reuse in fuel cell mode. A thermodynamic analysis of the system is performed the yearly round-trip efficiency is assessed considering an assumed availability operating time of 7000 h/y. Finally, the overall green-house gas emission is assessed.

Anaerobic digestion (AD) is a viable method for conversion of food waste and other organic materials into methane-rich biogas. However, when used at high organic loading rates, using only food waste can lead to an unstable process. Process instability is indicated by frequent changes in pH, and increase in ammonia and hydrogen sulfide concentration. These uncontrolled changes combined with over-production of organic acids can inhibit biogas production and ultimately lead to digester failure. Therefore, certain co-substrates produced as wastes in the regional food sector were tested as stabilizing agents for food waste digestion with an objective of achieving stable non-manure based digestion. The substrates tested were acid whey, bread, manure, caffeinated drink, paper napkins and apple pomace. The biogas production was increased by 12% in reactors containing bread, by 10% with acid whey, and by 12% when the co-substrate was caffeinated drink. The reactors containing paper and manure showed decreased biogas production by 6% and 12% respectively, but these changes are relatively small and thus not considered inhibitory. Co-digestion with apple pomace was found to be inhibitory and resulted in digester failure. This initial study has demonstrated that the stability of AD systems may be improved by strategically combining available food waste feedstocks.

A molten carbonate electrolysis cell (MCEC) is capable of separating carbon dioxide from methane reformate while simultaneously electrolyzing water. Methane reformate, for this study, primarily consists of carbon dioxide, hydrogen, methane, and a high percentage of water. Carbon dioxide is required for the operation of a MCEC since a carbonate ion is formed and travels from the reformate channel to the sweep gas channel. In this study, a spatially resolved physical model was developed to simulate an MCEC in a novel hybrid reformer electrolyzer purifier (REP) configuration for high purity hydrogen production from methane and water. REP effectively acts as an electrochemical CO 2 purifier of hydrogen. In order to evaluate the performance of REP, a dynamic MCEC stack model was developed based upon previous high temperature molten carbonate fuel cell modeling studies carried out at the National Fuel Cell Research Center at the University of California, Irvine. The current model is capable of capturing both steady state performance and transient behavior of an MCEC stack using established physical models originating from first principals. The model was first verified with REP experimental data at steady state which included spatial temperature profiles. Preliminary results show good agreement with experimental data in terms of spatial distribution of temperature, current density, voltage, and power. The combined effect of steam methane reformation (SMR) and water electrolysis with electrochemical CO 2 removal results in 96% dry-basis hydrogen at the cathode outlet of the MCEC. Experimental measurements reported 98% dry-basis hydrogen at the cathode outlet.

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.

In order to achieve the international climate goals and to keep the global temperature increase below 2 °C, carbon capture and storage in large point sources of CO 2 emissions has received considerable attention. In recent years, mitigation of CO 2 emissions from the power sector has been studied extensively whereas other industrial point source emitters such as hydrogen industry have also great potential for CO 2 abatement. This study aims to draw an updated comparison between different hydrogen and power cogeneration systems using natural gas and coal as feedstock. The goal is to show the relative advantage of cogeneration systems with respect to CO 2 emission reduction costs. Accordingly, the Reference Case is selected as a large-scale H 2 production system with CO 2 venting using natural gas based on steam methane reforming. In this work, H 2 and electricity cogeneration with CO 2 capture based on auto-thermal reforming of natural gas has been simulated using ASPEN Plus™, while the cost and performance indicators for the plant based on steam methane reforming of natural gas and the coal-based plants have been adopted from the literature. Using a consistent approach, different plants are compared techno-economically. A sensitivity analysis has also been performed with variation in the most important input parameters including natural gas price (2–8 $/GJ), coal price (1–4 $/GJ), electricity price (30–90 $/MWh) and capacity factors (85–50%) and the results are presented here. The results demonstrate that the total efficiency of the system is slightly higher in natural gas-based systems than in coal-based systems. The results also indicate that although H 2 production cost increases with power cogeneration and CO 2 capture, cogeneration is a promising and attractive alternative for clean power generation. The highest sensitivity of the results has been observed for the fuel price.

Human activities like fossil fuel retrieval, biomass burning, waste disposal, and residential and commercial use of energy are continuing to effect the Earth’s energy budget by changing the emissions and resulting atmospheric concentrations of radioactively important gases, aerosols, and by changing land surface properties. These activities negatively contribute to Earth’s greenhouse gases including water vapor (H 2 O), carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), and ozone (O 3 ). Approximately 82% of greenhouse gases are developed from the United States, Asia, and Europe alone. Food and their extraction processes, including transportation of those extracts, account for about 35% of those greenhouse gases. This includes wasted, rotten, and uneaten food. About 40% of food in the United States today goes uneaten, resulting in more than 20 pounds of food per person every month. Not only does this mean that Americans are throwing out upwards of $165 billion each year, amounting to $1,350 to more than $2,275 annually in waste per family of four, but also 25 percent of all freshwater and huge amounts of unnecessary chemicals, energy, and land. Moreover, almost all of that uneaten food ends up rotting in landfills. This number has increased, in regards to organic matter, from approximately 16 percent of U.S. methane emissions in 2010 upwards to 25 percent in 2012. With the increase in supply and demand of food, in addition to the lower consumer cost, the statistics of wasted feedstocks are rapidly increasing. The purpose of this research is to utilize wasted food to extract natural hydrocarbon oils through thermal depolymerization in order to develop an alternative fuel. Thermal depolymerization is a hydrous pyrolysis process that breaks down long chained polymers into simpler compounds and light hydrocarbons, much of which can be separated and used for fuel. Polymers include essentially all organic matter i.e. matter made of living or once-living things, which include petroleum products like plastic, styro-foam, and nylon, as well as plant and animal material, and manure. Potatoes and corn starch were used as feedstocks for this research and thermal depolymerization was conducted on the feedstocks for analysis and fuel collection. With optimum use and a mature thermal depolymerization technology, the Earth might comfortably support 10 times its current population at a high standard of living. There is enough biomass existing now accessible on the surface of the earth to provide 100 years of human energy use.

This paper presents qualitative evidence to support the application of microwave induced plasma gasification (MIPG) technology for converting municipal solid wastes (MSW) to syngas and to use it for enhanced oil recovery (EOR). The target for the case study of this paper is the United Arab Emirates, which is a major producer and exporter of petroleum. The main EOR method employed by the UAE’s oil companies is the miscible gas flooding method, whereby natural gas or carbon dioxide is injected into the oil reservoirs to boost the oil pressure, reduce the viscosity of the oil and to increase the pumping rates. UAE purchases natural gas for power production and EOR from its neighbor, Qatar, which makes the UAE a net importer of natural gas and a major consumer of energy, while reducing the national income from the oil sales. The UAE is looking at ways to boost its oil production and to reduce the usage of natural gas, including the injection of carbon dioxide, nitrogen and steam generated by concentrated solar power. UAE and the other Arabian Gulf nations have some of the highest per capita rates of production of domestic waste. Landfilling is the prevalent form of waste disposal for industrial, commercial and residential waste. Incineration-type waste-to-energy power plants are being constructed, but they are not the most effective solution due to cost and environmental reasons. This paper proposes a solution that covers the two problems with one technology, namely MIPG of MSW. MIPG is shown to be the most efficient method of gasification available, as it uses much less energy for producing and sustaining the plasma than other techniques, and produces a much cleaner syngas than thermochemical gasification schemes. The syngas can be used for electricity generation or for making fuels and raw materials in the Fischer-Tropsch or similar processes. In this proposal, MIPG will be used to turn MSW, sewage sludge and biomass wastes into syngas. A part of the syngas will be used to produce electricity to power the petroleum extraction processes, while the carbon dioxide formed in this combustion of syngas can be captured and used for EOR in deep oil wells, which also functions as a form of sequestration of carbon. In addition, syngas can be turned into methane and synthetic natural gas using the Fischer-Tropsch or Sabatier process and then pumped into the oil wells. Some of the petroleum extracted can also be gasified using the MIPG method for the production of synthetic natural gas. Thus, the dependence on natural gas imports will be eliminated, while also achieving zero landfill targets.

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.

Academic institutions present a unique opportunity for anaerobic digestion (AD) projects in that they have a concentrated population that generates waste, utilizes heat and electrical power, and often are motivated to implement sustainability initiatives. However, implementation of AD on college campuses in the U.S. is only beginning to emerge and data required to size and operate digesters are limited. This paper provides formulae to estimate food waste generated at college and university campuses base upon data collected at the Rochester Institute of Technology. Bottom-up and top-down estimates are presented and results are compared to an extensive review of publicly available data from other colleges and universities. The bottom-up methodology resulted in a lower estimate (18 kg food waste/enrolled student) than the top-down estimate (29 kg/enrolled student). Both were significantly lower than the estimate previously reported in the literature (64 kg/enrolled student). Bench-scale co-digestion experiments of the food waste with dairy manure resulted in a methane yield of 437 ml CH 4 /g VS. Applying this methodology to only 4-year colleges in New York State has the potential to generate 27 million GJ of energy from food waste.

New energy plants coming online must be both economical and efficiently balanced to satisfy demanding requirements in the future. A balance of plant analysis was performed to determine the techno-economic feasibility of a 100 barrel oil equivalent (boe) per day, compact Gas to Liquid (GTL) methanol plant. Methanol itself is emerging as a possible alternative to gasoline; but it is also the precursor to dimethyl ether (DME), which has recently received a lot of attention as a low emitter of particulate matter and nitrous oxides, which can replace diesel in trucking applications and liquefied petroleum gas (LPG) in domestic applications. Production of synthesis gas (syngas) from methane gas was modeled via partial oxidation of fuel-rich mixtures in engine cylinders using GT-ISE. Two ignition modes were studied: spark ignition (SI) and homogeneous charge compression ignition (HCCI). The use of the engine as a compressor was also studied in order to reduce net compression requirements and therefore capital and operating costs. The low brake mean effective pressure (BMEP) allowed in HCCI operation substantially limits both the throughput and capability to produce high-pressure syngas. The use of mechanical power generated by the engine reformer to power other components such as compressors and the air separation unit (ASU) have been studied. The waste heat produced from the engine and methanol synthesis reactors was also considered in the analysis. Integration of all components in the system was performed in Aspen Plus. To inform plant design, a survey was performed of vendors with small-scale methanol synthesis technologies that could integrate an engine reformer. Aspen Process Economic Analyzer (APEA) was also used to generate estimates of plant component costs. A study of the profitability and payback period of the technology was performed to determine the cost to produce methanol based on the balance of plant analysis. The results of this analysis were used to gauge the technology’s feasibility and therefore provided constructive feedback to guide future plant design.

The nonstoichiometric cerium oxide (ceria) redox cycle is an attractive pathway for storing energy from concentrated sunlight in chemical bonds by splitting water and carbon dioxide. The endothermic reduction reaction (R1) CeO 2 - δ ox → CeO 2 - δ ed + Δ δ 2 O 2 is favored thermodynamically at high temperatures and low oxygen partial pressures, while the CO 2 and H 2 O splitting reactions (R2, R3) are exothermic and favored at lower temperatures and higher oxygen partial pressures. The produced hydrogen and carbon monoxide, referred to collectively as syngas, are important feedstocks used in the synthesis of ammonia and liquid fuels. (R2) CeO 2 - δ ed + Δ δ CO 2 → CeO 2 - δ ox + Δ δ CO (R3) CeO 2 - δ ed + Δ δ H 2 O → CeO 2 - δ ox + Δ δ H 2

Anaerobic Digestion is a biological process that takes place naturally when microorganisms break down organic matter in the absence of oxygen. In an enclosed chamber, controlled anaerobic digestion of organic matter produces biogas which is predominantly methane. The produced methane then can be directly used for rural cooking; or after certain conditioning, can be used in onsite power generation, heating homes or as vehicular fuel. Besides, food waste is increasingly becoming a major problem in every society imposing serious economic and environmental concerns. For this reason, many contemporary researches are emphasizing in finding sustainable solutions to recycle and produce energy from such waste. In this context, this paper aims to study and optimize the production of biogas from food waste (rice). For the experiment, an existing wet digestion biogas plant installed in Islamic University of Technology was used. The food waste (rice) for the research was collected from the cafeteria of Islamic University of Technology. Furthermore, a process simulation was performed by PROII software to estimate the methane production rate. Eventually, the simulated and experimental results were compared. The duration of the study period was 120 days. The experimental results showed that an average specific gas production of 14.4 kg-mol/hr can be obtained for 0.05 kg-mol/hr of starch loading rate. In case of the simulated results, the gas production was found to be 19.82 kg-mol/hr for the same loading rate of starch. The percentage of methane and CO 2 obtained in the biogas plant was 69% and 29% respectively.

In this paper, a thermodynamic model of a spark ignition internal combustion engine fueled with natural gas is developed in order to estimate the air-fuel-unburned gas temperature at before top dead center (BTDC). This temperature is used as controlled variable in a control loop in order to avoid the autoignition phenomena when the engine operates with a fuel with different methane number from the methane number requirement of the engine. The model formulation is based on a polytropic compression proccess whose coefficient was determined experimentally in a turbocharged internal combustion engine fueled with natural gas. To make feasible the use of differents gaseous fuels from natural gas, it was necessary to design two control strategies to avoid the knocking phenomenon and choose the best one. The ambient temperature is the disturbance considered, whose changes are significant in different places in the world. The first control strategy that was implemented is called “Robust”, which employs a conventional feedback control loop with a robust controller which is designed. The response of this control loop is compared to the response of the second control strategy called “Feedforward control”. The results obtained reveals that Feedforward control strategy has better performance than robust control strategy for this application. The control strategy and the model proposed will allow increase the range of application of gaseous fuels with low methane number (MN) leading to guarantee a safe running in internal combustion engines that currently are fueled with natural gas.

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.

With recent concerns on CO 2 emissions from coal fired electricity generation plants; there has been major emphasis on the development of safe and economical Carbon Dioxide Capture and Sequestration (CCS) technology worldwide. Saline reservoirs are attractive geological sites for CO 2 sequestration because of their huge capacity for sequestration. Over the last decade, numerical simulation codes have been developed in U.S, Europe and Japan to determine a priori the CO 2 storage capacity of a saline aquifer and provide risk assessment with reasonable confidence before the actual deployment of CO 2 sequestration can proceed with enormous investment. In U.S, TOUGH2 numerical simulator has been widely used for this purpose. However at present it does not have the capability to determine optimal parameters such as injection rate, injection pressure, injection depth for vertical and horizontal wells etc. for optimization of the CO 2 storage capacity and for minimizing the leakage potential by confining the plume migration. This paper describes the development of a “Genetic Algorithm (GA)” based optimizer for TOUGH2 that can be used by the industry with good confidence to optimize the CO 2 storage capacity in a saline aquifer of interest. This new code including the TOUGH2 and the GA optimizer is designated as “GATOUGH2”. It has been validated by conducting simulations of three widely used benchmark problems by the CCS researchers worldwide: (a) Study of CO 2 plume evolution and leakage through an abandoned well, (b) Study of enhanced CH4 recovery in combination with CO 2 storage in depleted gas reservoirs, and (c) Study of CO 2 injection into a heterogeneous geological formation. Our results of these simulations are in excellent agreement with those of other researchers obtained with different codes. The validated code has been employed to optimize the proposed water-alternating-gas (WAG) injection scheme for (a) a vertical CO 2 injection well and (b) a horizontal CO 2 injection well, for optimizing the CO 2 sequestration capacity of an aquifer. These optimized calculations are compared with the brute force nearly optimized results obtained by performing a large number of calculations. These comparisons demonstrate the significant efficiency and accuracy of GATOUGH2 as an optimizer for TOUGH2. This capability holds a great promise in studying a host of other problems in CO 2 sequestration such as how to optimally accelerate the capillary trapping, accelerate the dissolution of CO 2 in water or brine, and immobilize the CO 2 plume.

Many food processing plants in New York State generate large volume waste streams with a wide variety of physical and chemical properties. With greater environmental regulation and increasing fees for municipal sewer and solid waste disposal, additional innovative ‘disposal’ methods for these wastes need to be developed. One attractive alternative is to use the food processing waste as feedstock for a waste-to-energy conversion process comprising two distinct systems, namely waste-to-fuel and fuel-to-energy. The fuel can either be sold to generate revenue, or converted on-site to electrical or thermal energy to offset the plant power requirements. In this study, the technical viability and economic benefit of applying waste-to-energy solutions to a diverse selection of companies producing milk, cheese, beer, and tofu were assessed. Depending upon the volumes and composition of the available waste streams (including analysis of sugar content, biological oxygen demand, etc.) there may be a compelling business case to utilize the food waste as feedstock for ethanol, biodiesel or methane-rich biogas production.

The growth of urban population is increasing quickly worldwide, especially in developing countries. This fact substantially affects the generation of waste, whether liquid, gaseous or solid, which are deposited in places commonly known as landfills. The organic matter in solid residues promotes methane production, which is a high impact greenhouse gas. Researches on uses of biogas from anaerobic fermentation’s processes have been made; nevertheless most have focused on Biogas direct burning or on site generation of electricity, and a few on biofuel production for transportation purposes. Regardless of the development of technologies to use biogas as renewable energy source, there is not wide documentation of projects involving population growth and urban planning with sustainable power generation based on organic residues produced within cities. For the Latin American case the implementation of technologies for biogas utilization is poor and projects that allow the integration of methane production based on population growth with its energy needs would highly promote planning and implementation of policies for sustainable resources exploitation. Their impact in the short, medium and long term would be unprecedented at all levels. The model proposed here serves as analysis tool for developing sustainable energy policies based on urban growth prognostics leading to 100% utilization biogas emissions for both electrical and fuel power generation. In the methodology used is performed an identification and geographic location of the main emissions sources such as landfills and sewage plants. Main solid waste generation sources are identified and an estimation of organic residues amount is made. Based on organic residues and methane production models provided by EPA, it is possible to obtain a long-term estimate of landfill biogas generation according to demographic growth prognostics. The overall power generation provided by a purification and separation plant is obtained from past estimations. Electrical energy and pure methane are produced. Model is validated in Panama City, which authors analyze the implementation of a separation plant whose objective is the adaptation of biogas for automotive purposes covering all their energy demand with electrical energy generated from a percentage of collected biogas. It hopes to have a major impact on the public urban transport fleet of Panama and a future implementation of pipeline that will feed the energy requirements of the city.