Costs fuel conversion

The biggest problems of the CEC Pinto fleet were that vehicle conversions were expensive and alcohol fuels were more expensive than gasoline. Changes to the fuel tank, fuel lines, and the carburetor were too labor-intensive to be done cheaply. However, these changes if designed, could be made during the vehicle manufacturing at Httle additional cost (30). Brazil priced ethanol at 65% the cost of gasoline (10) so that conversions could be cost-effective because of the savings on the fuel costs.  [c.425]

Many formulated foods and certain animal products tolerate freezing and thawing weU because their stmctures can accommodate ice crystallization, movement of water, and related changes in solute concentrations. Starches can be modified for freeze—thaw stabiHty against gel breakdown through several cycles. By contrast, most fmits and vegetables lose significant stmctural quaHty on freezing and during storage because their rigid ceU stmctures fail to accommodate to ice crystal formation. Frozen food storage equipment must be designed to minimize temperature fluctuations. It is not possible to store foods at temperatures low enough to ensure complete conversion of all water to ice. Commercial frozen food storage temperatures (—18 to —24°C) represent an economic balance between storage costs measured in time, energy, and capital investment, and desired shelf Hfe and product quaHty.  [c.459]

The single-step manufacture of MIBK offers lower investment and operating costs, and avoids the low conversion of acetone in the first stage and the reversion of mesityl oxide to acetone in the second stage, which are experienced in the three-step process. Direct synthesis is achieved using a multifunctional catalyst which effects acid aldolization, dehydration, and hydrogenation. Veba-Chemie s patents (84—86) describe a catalyst composed of a cation-exchange resin loaded with 0.05% palladium, and over which is passed a 2 1 mole feed ratio of H2 acetone at approximately 135°C and 6.2 MPa. At these conditions a 96% selectivity to MIBK is achieved at 35% acetone conversion. Refined MIBK is then recovered from a four-column refining train in which the first column removes light hydrocarbons, and the second recycles unconverted acetone. A decanter is then located upstream of the final two columns and is used to separate an aqueous phase. The third column removes 2-propanol—water mixture, and the final column produces refined MIBK overhead and a heavies (diisobutyl ketone) tails stream. A similar process is operated by Deutsche Texaco (87—90) at operating conditions of 130—140°C and 3 MPa. An acetone conversion of 40% and a consumption of 1.4 kg of acetone per kg of MIBK is reported (91). A flow sheet of the Deutsche Texaco process is shown in Figure 3 (92).  [c.491]

The function of the MHD combustor is to process fuel, ie, coal oxidizer, ie, preheated air, possibly enriched with oxygen and seed to generate the high temperature electrically conducting working fluid requited for the MHD channel. There are several design requirements (/) highly efficient combustion, ie, high carbon conversion and low heat losses, in order to achieve the temperature (2800—3000 K) required for adequate electrical conductivity (2) innovative wall designs capable of extended life, to contain 500—1000 kPa (5—10 atm) of pressure in the presence of molten slag, seed, and heat fluxes up to 50 W/cm (J) spatially and temporally homogeneous output flow, requiring sophisticated aerothermodynamic design (4) low pressure drop through the combustor, because this directly affects the net power output of the MHD topping cycle (5) effective seed utilization, which means minimizing slag—seed interactions which remove seed from the gas, and attaining uniform seed dispersion (6) electrical isolation of the combustor and its ancillary systems at voltages of 20—40 kV below ground potential, because of the electrical contact of the combustor with the MHD channel (this is particularly challenging for the slag-rejection system) and (7) efficient slag rejection, up to 50 70% of the ash content of the coal burned, as low slag rejection (high ash carry-over) increases seed recovery costs. These design requirements differ sufficiently from those of conventional coal combustors so as to require essentially new technology for the development of MHD coal combustors.  [c.427]

The majority of pump manufacturers offer their products with standard or optional mechanical seals. The mechanical seal manufacturers make seal models designed to substitute packings. The majority of pumps can be converted to mechanical seals without machining or design change. And still other pumps can be converted to mechanical seals with a slight design adjustment that doesn t affect flow or head. The conversion to a seal improves the pump s efficiency. The cost of the seal and die labor to convert the pump will be returned in reduced operating costs in just a few months.  [c.181]

Most large boilers use a separate fuel for auxiliary or standby purposes. One actual example was a boiler fired with wood residue as the primary fuel and residual oil as the standby. A change was made to natural gas as the primary fuel, with residual oil kept for standby. This change was made to lower particulate emissions and to achieve a predicted slightly lower cost. Because of gas shortages, the plant now operates on residual oil during most of the cold season, and the resulting particulate emission greatly exceeds that of the previously burned wood fuel. In addition, an SO2 emission problem exists with the oil fuel that never occurred with the wood residue. Overall costs have not been lowered because natural gas rates have increased since the conversion.  [c.450]

Natural gas is frequently found in association with crude oil, in the search for cmde oil, or fortuitously at gi eat distances from developed gas markets or from existing gas-transmission infrastructure-providing access to such markets. In the first half of the twentieth century, carbon black—high-quality soot used as colorant in printing inks and as an additive to rubber in tires—was a leading scavenger industry for stranded gas in North America. Later in the century, manufacture of fertili zer, particularly ammonia and urea, created a major part of the early demand for gas along the U.S, Gulf Coast, in Alaska s Cook Inlet basin and in China. The oil industry has recently devoted great effort to promoting gas-to-liquids (GTM) conversion systems to make stranded gas into motor gasoline or diesel fuel. Several GTM technologies are firmly proved, but thus far appropriate market conditions for their commercial application have been hard to find. All of these initiatives are seeking opportunities to convert abundant, low-cost gas into a higher-valued commodity that is liquid or solid at ambient temperatures, and thus can be moved in normal tankers, barges or railcars, rather than requiring costly transcontinental pipelines or cryogenic (super-cooled) transport systems, Other notable applications for stranded gas are the local generation of electricity for local consumption and, particularly in the Middle East and North Africa, desalinization of seawater.  [c.826]

Two-thirds of Earth s surface is covered by oceans. These bodies of water are vast reservoirs of renewable energy. In a four-day period, the planet s oceans absorb an amount of thermal energy from the sun and kinetic energy from the wind equivalent to the world s known oil reserves. Several technologies exist for harnessing these vast reserves of energy for useful purposes. The most promising are ocean thermal energy conversion (OTEC), wave power plants, and tidal power plants. All of these produce electricity from the oceans reserves of renewable energy. Because the ultimate source of energy from the oceans is solar radiation (or the gravitational force of the sun and the moon in the case of tidal energy), ocean energy systems are renewable, have no fuel costs, and are relatively nonpolluting when compared  [c.888]

Two-thirds of Earth s surface is covered by oceans. These bodies of water are vast reservoirs of renewable energy. In a four-day period, the planet s oceans absorb an amount of thermal energy from the sun and kinetic energy from the wind equivalent to the world s known oil reserves. Several technologies exist for harnessing these vast reserves of energy for useful purposes. The most promising are ocean thermal energy conversion (OTEC), wave power plants, and tidal power plants. All of these produce electricity from the oceans reserves of renewable energy. Because the ultimate source of energy from the oceans is solar radiation (or the gravitational force of the sun and the moon in the case of tidal energy), ocean energy systems are renewable, have no fuel costs, and are relatively nonpolluting when compared  [c.889]

External costs for fossil fuels are generally largest at the point of end use (combustion), though exploration (oil and gas drilling, mining), processing (refineries), and transportation (pipeline ruptures, tanker spills) can each contribute significant external costs in particular cases. For nuclear power, the accident risks associated with the conversion stage and the long-term issues surrounding disposal of spent fuel are the external costs that typically garner the most attention. There are also external costs from other stages of the nuclear fuel cycle, including the various effects of exploration, hai vesting, and processing, as well as the risk of nuclear weapons proliferation from the spread of fissionable materials and related knowledge.  [c.1169]

Distillation. As for nitrogen, all high purity oxygen is derived from air through the air separation (qv) process using cryogenic distillation (qv). Generally, air separation units that manufacture commercial purity oxygen also remove nitrogen and other light impurities to levels low enough for high purity appHcations. Argon is stiU present at concentrations above 1 part in 10, but is not considered an impurity for most appHcations of high purity oxygen. Heavy impurities, typically hydrocarbons and noble gases, are usually not removed from commercial purity oxygen. To make high purity grades, an additional distillation column is added to the process. Some on-site nitrogen generators are also able to generate a small stream of high purity oxygen. Chemical Conversion andJidsorption. Where additional distillation is not practical, hydrocarbons and heavy noble gases can also be removed by combining chemical conversion with adsorption. Commercial purity oxygen is passed through a high temperature bed of oxidation catalyst usually combinations of platinum and rhodium on a high surface area alumina support. Hydrocarbon impurities are oxidized to CO2 and H2O. Temperatures in excess of 700°C are needed in the catalyst bed to ensure complete oxidization of methane. Because the process flow rates are typically small, these temperatures can be maintained without excessive energy costs. The CO2 and H2O products from catalytic oxidation of hydrocarbon impurities are removed using a temperature swing adsorption (TSA) process. The adsorbent is typically one of the molecular sieves (qv), such as 13x. If designed appropriately, the adsorption process can also be used to remove the heavy noble gases. Usually, however, only radon removal is necessary. Because radon has a 3.8-d half-life, it is only necessary to slow its transit through the adsorber bed for sufficient time for natural decay to reduce the concentration to an acceptable level.  [c.88]

The July data are generally typical of ethylene costs ia the summer season. Natural gas prices are weaker ia the summer, hence the cost of gas Hquids is seasonally lower. Conversely, gasoline demand and prices are seasonally higher due to the peak driving season, and the cost of naphtha reflects this strength. In July the cash costs of producing ethylene from naphtha are about five and one half to six cents per kg of ethylene higher than the cash costs from ethane or propane hence gas Hquids are the most economical source of feedstock. Table 4 also presents the cash costs of ethylene from the same feedstocks in November 1991 ethane remained the preferred feedstock ia November, but now naphtha appears favorable to propane by more than four cents per kg. Seasonally higher fuel prices ia the winter increased the costs of gas Hquids while weaker gasoline markets lowered the relative price of naphtha. Thus an operator with feedstock flexibiHty would vary the feedslate over time in order to achieve the lowest possible costs. The historical feedslate for olefins production in the United States is presented in Table 5.  [c.174]

In the context of biomass energy costs, dry, woody, and fibrous biomass species have an energy content of approximately 20 MJ /kg (8600 Btu/lb) or 20 GJ/t (17.2 MBtu/short ton). If such types of biomass were available at deflvered costs of 1.00/GJ ( 1.054/MBtu), or 20.00/dry t ( 18.14/dry short ton), biomass on a strict energy content basis without conversion to biofuels would cost less than most of the deflvered fossil fuels Hsted in Table 28. The U.S. Department of Energy has set cost goals of deflvered biomass energy crops at 1.90—2.13/GJ ( 2.00—2.25/MBtu) (91) and 0.18/L ( 0.67/gal) for fuel ethanol from biomass without subsidies in 2000, 0.22 to 0.26/L ( 0.85 to 1.00/gal) by the year 2007 for biocmde-derived gasoline, 3.32/GJ ( 3.50/MBtu) for methane from the anaerobic digestion of biomass by the year 2000, and 4.5 cents/kWh for electricity from biomass by the late 1990s (92).  [c.36]

Biomass Production. In 1992, there was no biomass species grown and harvested ia the United States specifically for conversion to biofuels, with the possible exceptions of feedstocks for fuel ethanol and a few tree plantations. This is understandable from an economic standpoint. Eor example, the average natural gas price in the United States in 1991 at the point of production, not end use cost, was estimated to be 1.51/GJ ( 1.59/MBtu) (U.S. Energy Information Agency Washington, D.C.). Eor biomass to compete on an equivalent basis, it must be grown, harvested, and gasified to produce methane at an average cost of 1.51/GJ ( 1.59 /MBtu). Assuming an unreaHstic gasification cost of zero, the maximum biomass cost that is acceptable under this condition is 29.73/dry ton. At an optimistic yield of 4.45 dry t/hm -yr (10 dry short ton /acreyr) a biomass energy crop producer for a gasification plant will realize not more than 667.60/hm -yr ( 270.30/acreyr), a marginal amount to permit a net return on an energy crop without other incentives. This simplistic calculation emphasizes the effect of depressed fossil fuel prices on biomass energy crops. Negative feedstock costs, ie, wastes, substantial by-product credits, captive uses, and/or tax incentives, are needed to justify energy crop production on strict economic grounds.  [c.42]

The cost of capital is taken to be 30% of the total investment. Results are illustrated in Eigure 13 where it is seen that the cost of capital falls steeply with increasing current density, but tends to level out at the higher current densities. Electrical power costs increase continuously with current density because of the linear nature of cell voltage and current at well above reversible current densities. The membranes, maintenance, and labor factor fall with increasing current density, but are flatish for much of the range. The sum total conversion cost, excluding raw materials, is seen to go through a minimum at about 0.5 A/cm. This is the optimum operating current density for this cost model.  [c.95]

The most important aspect of this is that profits can be increased by either an increase in revenues or a decrease in expenses. With end-of-pipe treatment technologies, the investments required increase expenditures and decrease profit. However, if we can capitalize on an air pollution problem by recovering a valuable product, or identifying a secondary market for the waste, then a revenue stream is created which can offset the overhead and investment requirements for the equipment. There are different categories of revenues and expenses, and it is important to distinguish between them. Obviously, revenue is money coming into the company from the sale of goods or services, from rental fees, from interest income, etc. The profit equation shows that an increase in revenue leads to a direct increase in profit, and vice versa if all other revenues and expenses are held constant. Let s assume that other expenses/revenues are held constant in the discussions below. Revenue impacts must be closely examined. For example, if we take the two cases for an electric utility considered back in Chapter 6, one being a coal-fired plant and the other based on natural gas, air pollution control costs theoretically should be considerably lower for the case of the plant whose technology is based on a clean fuel. However, that is not necessarily the situation. In this situation, older coal burning electricity generating facilities have less stringent NO emission standards to meet than do newer plants based upon Combined Cycle Natural Gas (CCNG) turbine technologies in many states. The cost for converison to CCNG technologies is high, and operational costs for equipment are significantly greater in meeting the more stringent NO, emissions standards. In addition, those plants that are in the process of conversion from the older technology to the newer face the temptation of dispatching more electricity from the coal-fired portion of the operation since their operating and depreciation costs are lower. Hence, the financial analysis for an air pollution control project  [c.508]

Revenue impacts must be closely examined. For example, companies often can cut wastewater treatment costs if water use (and, in turn, the resulting wastewater flow) is limited to nonpeak times at the wastewater treatment facility. However, this limitation on water use could hamper production. Consequently, even though the company s actions to regulate water use could reduce wastewater charges, revenue could also be decreased, unless alternative methods could be found to maintain total production. Conversely, a change in a production procedure as a result of a technology change could increase revenue. For example, moving from liquid to dry paint stripping can not only reduce water consumption, but also affect production output. Because clean-up time from dry paint-stripping operations (such as bead blasting) is generally much shorter than from using a hazardous, liquid based stripper, it could mean not only the elimination of the liquid waste stream (this is a pollution prevention example), but also less employee time spent in the cleanup operation. In this case, production is enhanced and revenues are increased by the practice. Another potential revenue effect is the generation of marketable byproducts such as biosolids. Such opportunities bring new, incremental revenues to the overall operation of the plant. The point to remember is that the project has the potential to either increase or decrease revenues and profits - and that s the reason for doing a financial analysis.  [c.589]

By contrast, U.S. coal resources are not restricted by supply however, the environmental consequences of coal use have had a nijyor impact on coal development. The Power Plant and Industrial Fuel Use Act of 1978 was developed in response to perceived natural gas shortages it prohibited not only the switching from oil to gas in power generation plants, but also the use of oil and gas as primai y fuel in newly built large plants. However, coal remains the least expensive source of energy consequently, coal has soared from 1980 to 2000. The most significant change in the use ol coal reflects compliance with the Clean Air Act Amendments of 1990 (CAAA 90), which have stringent sulfur dioxide emission restrictions. Production of coal that complies with this Act has caused a shift from production east of the Mississippi to west of the Mississippi. Many western states have substantial coal resources, particularly low-sulfur coal resources, such as those in the Powder River Basin of Wyoming. In fact, Wyoming has been the largest coal-producing state since 1988. CAAA 90 allows utilities to bring coal-fired generating units into compliance, for example, by replacing coal-fired units with natural gas, or by using renewable or low-sulfur coals. Conversion to natural gas from coal in power plants, made feasible by the relatively low costs of natural gas generation in the late 1980s and early 1990s has eroded coal s 1990 share of 53 percent of domestic electricity generation. Clearly policy and regulations such as CAAA  [c.506]

Compression or conversion for greater use in the transportation market is promising for two reasons First, natural gas is usually cheaper than liquid fuel and, second, there exist large quantities of stranded gas—remotely located natural gas sources that are not economical to use because tanker or pipeline transportation costs can be over four times as much as for crude oil. Often this gas is recompressed and injected back into the oil-producing zones to help maintain reseixoir pressure and optimal crude oil flow to the wellhead. In some cases this gas is wasted by being flared, but this practice is increasingly frowned upon. The demand for cleaner-burning transportation fuels, and the advances in gas turbines that have dramatically improved the efficiency of natural gas powered electricity generation have renewed interest in developing ways to compress or liquefy this gas to lower Its shipping cost. Liquefaction can mean cooling the natural gas until it condenses at -187°C (at atmospheric pressure) or converting it chemically to a suitable liquid fuel. Both of these schemes entail considerable energy costs.  [c.828]

After World War II, the variable-pitch popeller was combined with a gas turbine to create the turbine propeller, or turboprop. The use of a gas turbine to drive the propeller increased propulsive efficiency, fuel economy, and generated less noise than conventional piston engine propeller aircraft. Turboprop airliners, first developed in Great Britain, began commercial operations in the early 1950s and were considered an economical alternative to turbojet airliners. Propellers are the most efficient form of aerial propulsion because they move a larger mass of air at a lower velocity (i.e., less waste) than turbojets and rockets. That efficiency is only present at speeds tip to 500 mph (800 km/h). Beyond that, the tips of the rotating propeller suffer from near-sonic shockwaves that degrade its aerodynamic efficiency to the point where it loses power and cannot go any faster. Given that limitation and the higher efficiencies of turbojets at speeds above 500 mph for long distance flights, the propeller appeared to be obsolete as a viable energy conversion device for air transport. Wliat occurred was that each propulsion technology proved the most efficient in different applications. The high efficiency of the aerial propeller, between 85 to 90 percent, and its lower operating costs created a strong economic impetus for air carriers to encourage the improvement of propeller-driven aircraft for the rapidly  [c.958]

See pages that mention the term Costs fuel conversion : [c.201]    [c.419]    [c.1117]   
Fundamentals of air pollution (1994) -- [ c.450 , c.451 ]