EIA study identifies nuclear's growing electricity share

Coal: Energy for the future

Solid waste (SW) outputs of industrial nations, mostly biomass, could fuel much more of their increasing energy needs than they currently do while creating good local jobs and industries. Using U.S. data as an example, 24 types of wasted or underutilized organic solids are identified. Now usually disposal problems, most of these SWs can be converted into useful gas, liquid, and solid (charcoal) fuels via pyrolysis. The non-condensable and condensable pyro-volatiles can be used by direct combustion as a clean source of heat energy or with advanced cleaning, in high-efficiency gas turbines or fuel cells. Pyrolysis processing has some important energy, environmental, economic, and security (EEES) advantages with respect to direct combustion or air or oxygen-blown partial combustion–gasification. An analytical semi-empirical model (ASEM) that points to some order in pyrolysis yields that could be helpful in optimizing the outputs of Solid Waste to Energy by Advanced Thermal Technologies (SWEATT) systems is described. We describe an analytical cost estimation (ACE) model that can be used to relate the cost of electricity for diverse electrical generating technologies including SWEATT systems to capital, operation, environmental control, cost of fuel (COF), and estimated costs of environmental and security externalities (ESE) such as climate change and terror threats. ACE can be useful particularly in estimating the impact of changes in COF and ESE, usually the most uncertain independent variables. The EEES issues related to soil applications of biomass pyrolysis products, i.e., biochar, are outlined. A growing International Biochar Initiative is underway to use biochar to sequester carbon in the soil, thereby mitigating climate change while enhancing soil fertility. High transportation costs due to the low energy densities of biomass/SW, compared to coal or petroleum, imply that siting SWEATT systems close to the SW source would have a number of cost and environmental advantages. The application of SWEATT systems in support of agricultural programs that grow high-yield vegetable oil crops intended for biodiesel production on non-food-producing lands is considered as a means of providing additional revenue streams. Additional SWEATT applications in conjunction with the other forms of the 24 types of SW are to be expected. energy type is very sensitive to its physical form as indicated in Table 2 which gives prices of various forms of energy in the United States at the beginning of 2010. The large carbon dioxide neutral (neither net producing nor consuming CO2) plant matter components in Table 1 can help in greenhouse heating mitigation. The great diversity of physical and chemical characteristics of fuel wastes (feedstock) in Table 1 implies that the world now needs “omnivorous feedstock converters” (OFCs) to change these solid fuels into much more usable liquid or gaseous fuels or better solid fuels. Fig. 1 is a conceptual illustration of an OFC adapted from a number of prior papers in which a SW pyrolyzer–gasifier–liquifier–carbonizer is coutilized with a natural gas-fired combined cycle (NGCC) system, as will be discussed below. Table 3 shows major ranks of coals as well as of peat, wood, and cellulose and their ultimate and proximate analyses as measured by industry for over a century. The SOLID WASTE, SOLID FUELS, AND THEIR PROPERTIES In 2011 the United States was heavily (~50%) reliant on foreign sources for its liquid fuels and somewhat (~10%) dependent upon imports for its gaseous fuels. Our country is now expending “blood and treasure” in its efforts to stabilize regions of the globe that supply these premium fuels. Yet the United States is well endowed with solid fuels in the form of coal, oil shale, and substantial quantities of renewable but wasted solids. As part of a continuing long search for alternatives to oil, this entry is focused on converting our solid waste to energy by advanced thermal technologies (SWEATTs) while mitigating environmental and economic problems. Table 1 is a list of United States’ abundant supply of solid waste (SW) whose organic matter can be converted into gaseous and liquid fuels as well as charcoal. The value society places on a specific fuel or D ow nl oa de d by [ T & F In te rn al U se rs ], [ M eg an H ila nd s] a t 0 6: 09 3 0 Ju ly 2 01 3 Energy: Solid Waste Advanced Thermal Technology 831 En er gy E ffi ci en cy –

Gas cooking appliances and indoor pollution.

ABSTRACTVarious liquid and gaseous alternative fuels have been proposed to replace the kerosene as aircraft fuel. Furthermore, new combustion technologies were developed to reduce the emissions of aero-engine. A staged fuel injection arrangement for a lean burn combustion system was applied to improve the operability of an aero-engine by achieving high flame stability at reduced combustion emissions. Originally, both circuits (pilot and main) are fuelled by kerosene; moreover, the pilot injector is operating at low power (engine idle and approach) and the pilot flame is anchored in an airflow recirculation zone. In the case of the performed research, the pilot injector was modified to allow the use of gaseous fuels. Thus, the burner model allows a flexible balancing of the mass flows for gaseous and liquid fuel. The present paper describes the investigation of ignitability for the proposed staged combustor model fuelled by gaseous and liquid fuels. A short overview on physical properties of used fuels is given. To investigate atomisation and ignition, different measurements systems were used. The effectiveness of two ignitor types (spark plug and laser ignitor) was analysed. The ignition performance of the combustor operating on various fuels was compared and discussed in detail.

Monolith and foam catalysts performances in ATR of liquid and gaseous fuels

Dual-fuel (DF) engines offer great fuel flexibility since they can either run on gaseous or liquid fuels. In the case of diesel pilot-ignited DF engines, the main source of energy is provided by gaseous fuel, whereas the diesel fuel acts only as an ignition source. Therefore, a proper auto-ignition of the pilot fuel is of utmost importance for combustion in DF engines. However, auto-ignition of the pilot fuel suffers from lower compression temperatures of Miller or Atkinson valve timings. These valve timings are applied to increase efficiency and lower nitrogen oxide (NOx) engine emissions. In order to improve the ignition, it is necessary to understand which parameters influence the ignition in DF engines. For this purpose, experiments were conducted and the influence of parameters, such as injection pressure, pilot fuel quantity, compression temperature, and air–fuel (A/F) equivalence ratio of the homogenous natural gas–air mixture were investigated. The experiments were performed on a periodically chargeable combustion cell using optical high-speed recordings and thermodynamic measurement techniques for pressure and temperature. The study reveals that the quality of the diesel pilot ignition in terms of short ignition delay and a high number of ignited sprays significantly depends on the injection parameters and operating conditions. In most cases, the pilot fuel suffers from too high dilution due to its small quantity and long ignition delays. This results in a small number of ignited sprays and consequently leads to longer combustion durations. Furthermore, the experiments confirm that the natural gas of the background mixture influences the auto-ignition of the diesel pilot oil.

Transition from fossil fuels to renewable energy is critical to achieve climate protection objectives. Fuel production using renewable energy and carbon dioxide is an essential part of reducing fossil dependence and reducing overall carbon footprint. One of the highest value applications in current markets is the production of liquid transportation fuels like sustainable aviation fuels (SAF) and low (fossil) carbon diesel fuel through carbon capture and utilization pathways. Liquid hydrocarbon fuels only achieve decarbonization goals if they replace fossil fuels and are produced from sustainable carbon resources.With the support of EERE BETO contract EE0008917, OxEon designed and fabricated a system to produce high value, energy dense, liquid transportation fuels from biogas. The technology has completed initial subsystem verification, and the fully integrated pre-pilot system demonstration is scheduled to start operation in Q1 2025. Anaerobic digester gas is first converted to synthesis gas (CO + H2, syngas), the bio-CO2 through CO2-steam co-electrolysis in a SOEC system and the bio-CH4 through a low energy, non-thermal plasma reformer.The combined syngas streams are compressed and supplied to a modular fixed bed FT reactor for production of liquid hydrocarbons, which serve as the feedstock for SAF, renewable diesel, and other qualified marine fuels. The combination of technologies offers several advantages: the yield of biofuel nearly doubles by using bio-CO2 compared to bio-CH4 alone. The FT reactor cooling system generates steam needed in the SOEC, which lowers the effective operating voltage (including phase change energy) from ~1.5 V/cell to < 1.3 V/cell, and oxygen by-product from the SOEC is used in the autothermal reformer, as is some of the FT produced water. The resulting product fuel is all bio-carbon. The system concept block diagram and the pre-pilot demonstration hardware are shown in Figure 1.The pre-pilot demonstration system was designed and fabricated by OxEon Energy and installed at Wasatch Resource Recovery (WRR). WRR is a public-private partnership producing renewable natural gas (RNG) from food waste. The OxEon pre-pilot system, converting anaerobic digester gas CO2 and CH4 to FT hydrocarbons with a production rate of 6-8 gallons/day is in the commissioning phase. Operation is scheduled to begin in Q1 2025. The system will demonstrate a cumulative time on stream of 500-1,000 hours, producing 100-250 gallons of FT synthetic crude. Subsystem verification of the SOEC, plasma reformer, and FT technologies were conducted to demonstrate key performance targets. In addition to the verification run specifically for this pre-pilot demonstration, OxEon has operated each subsystem technology in thousands of hours of validation testing. A current program sponsored by the Naval Research Laboratory (NRL), includes scope to upgrade FT produced hydrocarbons to MIL-SPEC compliant JP-5 fuel.There is an emerging market for FT technology aimed at a variety of small, distributed resources including biomass, biogas, and cement kiln CO2, augmented by renewable and nuclear-powered CO2 co-electrolysis to increase the sustainable fuel capacity. FT technology to convert these fuel sources to liquid fuels would require smaller systems that can be transported to the site versus site-built plants. Biomass/biogas has previously been an impractical feedstock for FT technology due to shipping logistics to meet required economies of scale. The challenge in developing these resources is producing a small-scale plant at the same cost per bbl/day capacity as large plants. To accomplish this task, OxEon Energy developed a system that uses larger diameter reactor tubes with a heat transfer insert to manage thermal control of the system. OxEon’s FT design requires fewer reactor tubes than the traditional fixed-bed industry design and uses standard pipe sizes for reduced reactor fabrication costs. These modular systems are designed for a 10-15 bbl/day production increment enabling 100 bbl/day modules.OxEon has demonstrated FT operation with a variety of syngas sources including syngas produced via natural gas reformation, reverse water gas shift (RWGS) of CO2, and co-electrolysis of steam and CO2. Extensive performance mapping with the modular FT reactor design has also informed catalyst characteristics such as pore size, support shape, and precious metal promoter loading to allow for targeted FT product production. OxEon’s FT systems have been built and operated for both government and private customers ranging in production from 100 mL/day to 2 bpd. Figure 1

There are many physical and financial factors that determine the optimum power generation solution on an Offshore installation - space requirements, weight, reliability, and maintenance requirements to name a few. On top of these factors, environmental impacts must be considered, such as emissions of Nitrous Oxides (NOx) and Carbon Dioxide (CO2), and visible pollution like flaring. Whereas in ‘conventional’ offshore oilfields, there is usually associated gas available to provide the fuel for power generation, Heavy Oilfields provide an additional challenge: they tend to be gas deficient, with insufficient associated gas over field life to fully fuel a power plant. This requires the import of fuel, such as diesel or Heavy Fuel Oil, as these are easily transportable and storable, but importing fuels, and especially premium refined liquid fuels, increases operational costs. Therefore it may be necessary to look at using the produced crude oil itself as the fuel for power generation, and this in itself requires careful consideration by the providers of the different potential power generation technologies. Liquid fuels also produce more NOx when burned, and are more carbon intensive than most gas fuels, increasing CO2 emissions. Heavy oil facilities usually need more heat for production and processing purposes than lighter crude oils, requiring combustion of more fuel to provide the process heat required and increasing CO2 emissions still further. This paper looks at the types of liquid fuels, especially crude oil, and alternative power generation technologies that can be considered, and the potential advantages and disadvantages of these technologies in an Offshore application. It also looks at ways of reducing combustion emissions such as NOx and using Cogeneration as a means of reducing CO2 emissions by maximising overall energy efficiency.

Novel integrated CCHP system for generation of liquid methanol, power, cooling and liquid fuels using Kalina power cycle through liquefied natural gas regasification

This article is the first in a series of articles aimed at introducing common methods for evaluating gaseous, liquid, and solid conventional and alternative fuels. The paper presents an overview of the monitored elements and their non-hydrocarbon compounds for individual liquid and gaseous fuels. Methods for determining these analytes are also presented. The significance of these determinations is also discussed. The emphasis is given mainly on standardized parameters and tests, but in some cases, we discuss also non-standardized tests or analyses not required by standards. The main goal of the article is to provide a comprehensive overview of elements and their non-hydrocarbon compounds monitored for individual fuels, the reason why these analytes are monitored, and what methods are used for this monitoring. Practically all liquid fuels discussed in this article are monitored for sulfur content. The limit value for sulfur content is 10 mg/kg, with the exception of paraffinic diesel fuel and some synthetic liquid fuels. Phosphorus content is monitored in all fuels containing a higher proportion of biocomponents. Examples such fuels are ethanol, FAME, E85, E95, and rapeseed oil. For fuels containing ethanol, the oxygen content (E5, E10) and alcohol content (E5, E10, E85 and E95), or ether content (E5, E10, E85) are also monitored. Among the minor elements, lead (E5, E10, E95), manganese (E5, E10, B7, and B10), copper (ethanol, E95), alkali metals (FAME) and alkaline earth metals (FAME and rape oil) are monitored. As with liquid fuels, the sulfur content of gaseous fuels is also monitored. Of the sulfur compounds, the sum of sulfur and carbonyl sulfide content is monitored for CNG, LNG, and their bioequivalents. For LPG for internal combustion engines, sulfane is determined qualitatively, whereas for LPG for heating purposes, the sulfur content is quantified. In the case of LPG for heating purposes, the ammonia content is determined qualitatively, and in the case of biogas according to ČSN 65 6514, the content of nitrogenous impurities except to nitrogen, and the sum of the content of carbon dioxide, nitrogen and oxygen are also evaluated.

This study is dedicated to investigations of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. As the object of the research, a low-emission gas turbine combustion chamber with partial premixing of fuel and air inside the outer and inner radial-axial swirls was chosen. The method of the research is based on the numerical solution of the system of differential equations which represent the physical process of mass and energy conservation and transformations and species transport for a multi-component chemically reactive turbulent system, considering nitrogen oxides formation and a discrete ordinates model of radiation. The chemistry kinetics is presented by the 6-step mechanism of combustion. Seven fuel supply operating modes, varying from 100% gaseous fuel to 100% liquid fuel, have been analysed. This analysis has revealed the possibility of the application of computational fluid dynamics for problems of dual-fuel combustion chambers for the design of a floating vessel’s gas turbine. Moreover, the study has shown the possibility of working in different transitional gaseous and liquid fuel supply modes, as they satisfy modern ecological requirements. The dependencies of the averaged temperature, NO, and CO concentrations along the length of the low-emission gas turbine combustion chamber for different cases of fuel supply are presented. Depending on the different operating modes, the calculated emission of nitrogen oxides NO and carbon monoxide CO at the outlet cross-section of a flame tube are different, but, they lie in the ranges of 31‒50 and 23‒24 mg/nm3 on the peak of 100% liquid fuel supply mode. At operating modes where a gaseous fuel supply prevails, nitrogen oxide NO and carbon monoxide CO emissions lie in the ranges of 1.2‒4.0 and 0.04‒18 mg/nm3 respectively.

The dual fuel concept of diesel engines is gaining popularity because of their ability to use alternative renewable gaseous fuels (natural gas, biogas, producer gas) and liquid fuels (biodiesel, alcohol, and others) simultaneously. The dual fuel mode (DFM) not only reduces the consumption of diesel or substitutes the diesel fuel, but there is an advantage of operating the engine in pure diesel mode (PDM) in case of shortage of gaseous primary fuel. The uses of renewable fuels in such engines have the positive impact on green ecosystem in terms of reduction in NOx and smoke emissions; however, there is the engine derating as performance penalty in comparison to engines operating under PDM. The most influential parameters in DFM engines are the type and flow rate of inducted gaseous fuel, fuel–air equivalence ratio (Φglobal), compression ratio (CR), and injection timing (IT). During the last few decades, the researchers have studied the effect of various parameters to improve the overall performance characteristics (performance, combustion, and emission) of DFM engines. This paper makes an in-depth analysis to unveil the physical characteristics of the crucial parameters of DFM engines with specific reference to the use of biogas with ternary blends (TB) of diesel, biodiesel, and ethanol. The paper addresses the issues on how the gaseous fuel flow rate, preheating of the intake charge, compression ratio, injection timing, and the type of oxygenated fuels dominate the overall performance characteristics.

Most commercial gaseous and liquid fuels are mixtures of multiple chemical compounds. In recent years, these mixtures became even more complicated when the suppliers started to admix biofuels into the petrochemical basic fuels. As the properties of such mixtures can vary with composition, there is a need for reliable analytical technologies in order to ensure stable operation of devices such as internal combustion engines and gas turbines. Vibrational spectroscopic methods have proved their suitability for fuel characterization. Moreover, they have the potential to overcome existing limitations of established technologies, because they are fast and accurate, and they do not require sampling; hence they can be deployed as inline sensors. This article reviews the recent advances of vibrational spectroscopy in terms of infrared absorption (IR) and Raman spectroscopy in the context of fuel characterization. The focus of the paper lies on gaseous and liquid fuels, which are dominant in the transportation sector and in the distributed generation of power. On top of an introduction to the physical principles and review of the literature, the techniques are critically discussed and compared with each other.

An NTC Zone Compliant Knock Onset Prediction Model for Spark Ignition Engines

Gas turbines are one of the most widely used technology for both power generation and mechanical drive applications. Their availability is a critical requirement for any plant uninterrupted operations. The subject case study details the root cause analysis done on repetitive clogging of liquid fuel nozzles due to liquid fuel coking on a dual fuel heavy duty gas turbine, that had an impact on the overall plant operation. The site is configured with two Frame 5/1PA single shaft Gas Turbine with standard combustion system, driving generator for power production. The two Gas Turbine Generators (GTGs) are completely identical and running on same liquid fuel and gas fuel. These gas turbines can only be started with liquid fuel and then change over to gas fuel as required. On one of the GTGs the issue of liquid fuel nozzles clogging due to liquid fuel coking happened twice in a span of six months. Few of the indications are Increase in exhaust temperature spreads and "failed to lite" during startup. Comparatively the other similar unit faced no such issue during its operations. Liquid fuel coking occurs if there is stagnant liquid fuel at high temperature over time at the Nozzles. For a duel fuel gas turbine, while it is running on gas fuel, constant air purge is provided in order to remove any residual liquid from the liquid fuel nozzles so it will not coke while running on gas fuel.