Burning natural gas

Batch (or beU) annealing is done within a sealed inner retort that contains a protective atmosphere. Burning natural gas is contained between the latter and an external retort. Continuous (strand or strip) annealing uses a furnace sealed at both ends to contain a protective atmosphere while permitting passage of the strip. Strand annealing is normally carried out at strip thicknesses from 0.25 mm (0.010 in.) to 3.18 mm (0.125 in.). 

To generate electricity for homes and businesses, research Stirling generators fueled by either solar energy or natural gas have been tested. They run on solar power when the sun is shining and automatically convert to clean burning natural gas at night or when the weather is cloudy. 

NOTE Economizers are, in fact, fitted to some gas-fired, packaged FT boilers. The economizer is designed to recover some of the enthalpy lost as a result of the increased water vapor content in the exit gases from burning natural gas. 

To ensure complete combustion, 20 per cent excess air is supplied to a furnace burning natural gas. The gas composition (by volume) is methane 95 per cent, ethane 5 per cent. Calculate the mols of air required per mol of fuel. 

A gas turbine with power output of 10.7 MW and an efficiency of 32.5% burns natural gas. In order to reduce the NOx emissions to the environmental limits, 0.6 kg steam is injected into the combustion per kg of fuel. The airflow through the gas turbine is 41.6 kg-s 1. The composition of the natural gas can be assumed to be effectively 100% methane with a molar mass of 16 kg-kmoU1. The kilogram molecular volume can be assumed to occupy 22.4 m3 at standard conditions. 

Mowery, D.L., Graboski, M.S., Ohno, T.R. et al. (1999) Deactivation of Pd0-Al203 oxidation catalyst in lean-burn natural gas engine exhaust aged catalyst characterization and studies of poisoning by H20 and S02, Appl. Catal. B 21, 157. 

A type of carbon black produced by burning natural gas or oil in a large furnace with a supply of air much lower than that required for complete combustion. The main types are super abrasion (SAF), intermediate super abrasion (TSAF), high abrasion (HAF), fast extrusion (FEF), general purpose (GPF), conductive (CF) and semireinforcing (SRF). 

If natural gas is used to produce electricity in a power plant, however, the efficiency is much lower—around 37%. Why The heat from the burning natural gas is used to boil water. The kinetic energy of the resulting steam is transformed to mechanical energy for turning a turbine. 

Water Dew Point For flue gas, the water dew point is that temperature at which the actual water vapor pressure equals the water saturation vapor pressure. Cooling the flue gas below this temperature will result in the formation of liquid water [or ice, below 273 K (0°C)]. For example, burning natural gas with 3 percent excess oxygen (15 percent excess air), the flue gas water dew point would be (Fig. 24-57) 330K(56.7°C). 

Steam-cracking reactors typically consist of several steel tubes, perhaps 100 m long and 4 in. in diameter in a tube furnace with reactants and steam fed through the several tubes in parallel. The ceramic fined furnace is heated by burning natural gas at the walls to heat the tubes to 900°C by radiation. The reactor is fed by ethane and steam in a ratio of 1 1 to 1 3 at just above atmospheric pressure. The residence time in a typical reactor is approximately 1 sec, and each tube produces approximately 100 tons/day of ethylene. We will return to olefins and steam cracking in Chapter 4. 

Fig. 14.12 Stack concentrations of UHC as function of NO in the exhaust of a lean-burn natural gas fired engine [234], The following conditions can be assumed for the exhaust system inlet composition CH4 = 4410 ppm, C2H6 = 490 ppm, O2 = 8.5%, H2O =13%, CO2 = 6.5%, NO = 10-1813 ppm, NO2 = 3-544 ppm, balance nitrogen temperature = 680°C, reactor residence time = 210 ms, pressure = 1.7 bar.

Why does burning natural gas produce less carbon dioxide than burning either petroleum or coal Hint Consider the chemical formulas of the compounds making up these materials.)... 

Another special situation arises when one resource has its origin in two different processes. For instance, when a process uses the electricity provided by an energy company, it is possible that this electricity is generated partly by burning coal and partly by burning natural gas. In this case, the process should be considered to use two different types of electricity electricity from coal and electricity from natural gas. Both types of electricity then have their own derived depletion time and, based on how much they contribute to the total amount of electricity supplied, their own exergy flow. 

Incomplete combustion caused by insufficient oxygen yields water and carbon monoxide or carbon in place of carbon dioxide. Small amounts of carbon monoxide in air are probably harmless, but carbon particles form soot, which often contains dangerous polycyclic hydrocarbons and may carry dangerous gases into the alveoli of lungs. Carbon monoxide is a colorless, odorless, poisonous gas. Furnaces are designed to burn natural gas with a blue... 

In November 1978, Secretary Schlesinger of the Department of Energy stated that all industry would be forced to switch to coal from natural gas and oil. However, shortly after, the DOE Secretary Schlesinger announced in December 1978 that the government now wanted electric utilities and industrial plants to switch back to burning natural gas rather than burning oil. 

Just how much methane is going to be in the market in the future Just what is going to be the impact of the Coal Conversion Act which, simply stated, requires that industries and electric utilities shall not build new facilities to burn natural gas or to burn petroleum What is the future market for methane ... 

As illustrated in Table 5.9, the H2 to CO molar ratio in the synthesis gas product stream depends on the raw materials and the operating conditions. By burning natural gas with a limited quantity of oxygen (that is less than the stoichiometric requirement), a synthesis gas that has a H2 to CO molar ratio of approximately 2 to 1 can be produced ... 

The heat used to cook is produced by burning natural gas in the stove burner. 

Is it possible to take hydrocarbons straight out of the ground and use them as they are Since the earliest recorded history, people have done just that. In the past, people used crude oil that seeped up to Earth s surface to waterproof boats and buildings. They also used it to grease wheels and even dress the wounds of animals and humans. As well, people burned natural gas, mainly to supply lighting for temples and palaces. 

Fuel for electric power generation accounts for about 20 percent of marketed natural gas production. This market segment is extremely price-sensitive and competes directly with fuel oil and coal. Given the current environmental emphasis on reduction of air pollutants, the use of cleaner-burning natural gas is expected to increase significantly in the foreseeable future. 

It is certain that world use of natural gas will increase dramatically in the near future as industrialized countries replace coal-fired facilities with cleaner-burning natural gas. In addition, a number of countries remote from major markets are in the process of installing world-scale plants for utilization of natural gas and gas liquids for production of fertilizers, methanol, premium gasoline blending stocks, and other basic petrochemical derivatives that will result in higher-value products from natural gas and gas liquids for which there are no local markets. 

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