Butane heating value

TOSCO tar oils have high viscosity and may not be transported by conventional pipelines. Heating values of product gas on a dry, acid gas-free basis are in the natural gas range if butanes and heavier components are included. 

There are direct substitutions of possible interest that would not be feasible without drastic changes in the feed system or pressure. Thus if the available substitute for natural gas is, eg, a manufactured gas containing much CO, there would almost always be a mismatch of the WIs unless the fuel could be further modified by mixing with some other gaseous fuel of high volumetric heating value (propane, butane, vaporized fuel oil, etc). Moreover, if there are substantial differences in eg, as a result of the presence of considerable H2 as well as CO in the substitute gas, the variation in dame height and dashback tendency can also make the substitution unsatisfactory for some purposes, even if the WI is reproduced. Refinements and additional criteria are occasionally appHed to measure these and other effects in more complex substitution problems (10,85). 

Propane is a more reactive paraffin than ethane and methane. This is due to the presence of two secondary hydrogens that could be easily substituted (Chapter 6). Propane is obtained from natural gas liquids or from refinery gas streams. Liquefied petroleum gas (LPG) is a mixture of propane and butane and is mainly used as a fuel. The heating value of propane is 2,300 Btu/ft. LPG is currently an important feedstock for the production of olefins for petrochemical use. 

Use specific heat values of 250 J/K mole for butane and 36 J/K mole for oxygen and nitrogen. 

An alternative approach for the utilization of biomass resources for energy applications is the production of dean-buming liquid fuels. In this respect, current technologies to produce liquid fuels from biomass are typically multi-step and energy-intensive processes. Aqueous phase reforming of sorbitol can be tailored to produce selectively a clean stream of heavier alkanes consisting primarily of butane, pentane and hexane. The conversion of sorbitol to alkanes plus CO2 and water is an exothermic process that retains approximately 95% of the heating value and only 30% of the mass of the biomass-derived reactant [278]. 

Liquefied propane is marketed as a fuel for outlying areas where other fuels may not be readily available and for portable cook stoves. In this form, the propane may be marketed as LPG (liquefied petroleum gas) or mixed with butane and pentane, the latter also constituents of natural gas (1.7% and 0.6%, respectively), LPG also is transported via pipelines in certain areas. The heating value ofpure propane is 2520 Btu/ft3 (283 Calones/m3) butane 3260 Biu/fL3 (366 Calories/m3) and pentane 4025 Btu/ft3 (452 Calories/m3). Propane and the other liquefied gases are clean and appropriate for most heating purposes, making them very attractive where they are competitively priced. 

Calculate the gross heating value in Btu/lbmol for a combustible gas mixture of 75 mol % methane, 10 mol % propane, and 15 mol % n-butane. The following gross heating value data are available ... 

Btu. (British thermal unit). The quantity of heat required to raise the temperature of 1 pound of water 1 degree F (usually from 39 to 40F). This is the accepted unit for the comparison of heating values of fuels. For example, fuel gases range from 100 (low producer gas) to 3200 (pure butane) Btu/cu ft. The usual standard for a city gas is approximately 500 Btu/cu ft. 

The fuel used for experiments was a typical LPG used by industry, composed of more fhan 98% propane, 0.9% ethane, and 0.8% butane with lower heating value equal to 93.2 MJ/Nm3. 

Surrogates of LPG can be made by blending mixtures of propane, butane, and natural gas. The surrogate LPG fuel should closely match the heating value and molecular weight of the actual fuel. 

A method of maintaining a constant-pressure fuel gas of uniform calorific value is indicated in Fig. l4-5. Liquid propane or butane may be fed into the system (sometimes actuated by an automatic calorimeter) to maintain the heating value, and natural gas is a< tted to carry the main heating load if process gases are insufficient. When sufficient process gas is produced to maintain well over 30 lb pressure in the balance tank, all... 

Values of the uptake at saturation, of butane, carbon dioxide and nitrogen, by a sample of carbon, expressed as a volume of liquid v,. The carbon had been "burnt off" to different extents by heating in oxygen at 500°C on a sorption... 

Values of yields for various fuels are listed in Table 2.3. We see that even burning a pure gaseous fuel as butane in air, the combustion is not complete with some carbon monoxide, soot and other hydrocarbons found in the products of combustion. Due to the incompleteness of combustion the actual heat of combustion (42.6 kJ/g) is less than the ideal value (45.4 kJ/g) for complete combustion to carbon dioxide and water. Note that although the heats of combustion can range from about 10 to 50 kJ/g, the values expressed in terms of oxygen consumed in the reaction (Aho2) are fairly constant at 13.0 0.3 kJ/g O2. For charring materials such as wood, the difference between the actual and ideal heats of combustion are due to distinctions in the combustion of the volatiles and subsequent oxidation of the char, as well as due to incomplete combustion. For example,... 

Since the complete oxidation of two isomeric hydrocarbons will give the same number of moles of C02 and H20, using the same moles of oxygen, we can find their heats of combustain. For butane and isobutane, the values determined experimentally are ... 

June et al. investigated the sorption and spatial distribution of butane and three hexane isomers within the pores of silicalite, using a Metropolis MC method (87) and MD simulations (85). Perturbations of conformation as a result of confinement within the pore were also reported. Heats of adsorption and Henry s law coefficients were found to be in good agreement with experimental values for butane (48-51 kJ/mol) (142,148,150,163-165) and n-hexane (70-71 kJ/mol) (163, 166, 167). The heats of sorption of the other two hexane isomers, 2- and 3-methylpentane, were predicted to be 5 kJ/mol lower than that of n-hexane. 

The configuration-bias Monte Carlo (CB-MC) technique (112) has also been extensively applied to characterize the sorption of alkanes, principally in silicalite (111, 156, 168-171) but also in other zeolites (172-174). Smit and Siepmann (111, 168) presented a thorough study of the energetics, location, and conformations of alkanes from n-butane to n-dodecane in silicalite at room temperature. A loading of infinite dilution was simulated, based on a united-atom model of the alkanes and a zeolite simulation box of 16 unit cells. Potential parameters were very similar to those used in the MD study of June et al. (85). As expected, the static properties (heat of adsorption, Henry s law coefficient) determined from the CB-MC simulations are therefore in close agreement with the values of June et al. The... 

Tamman (29) observed in 1920 that for electrically heated catalytic wire multiple steady states occur for a certain value of electrical current. Similar experimental observations were done by Buben (31) and Davies (30) and recently by Rader (35), Barelko (36), and Cardoso and Luss (33). The Luss results involving oxidation of butane and carbon monoxide on a platinum wire will be discussed in detail. 

Remove the chromatogram, dry it at 100 °C for 10 minutes and spray with ninhydrin reagent [0.2% solution in butan-l-ol, (1)] heat at 110°C for 5-10 minutes in order to develop the colour. Mark the centre of each spot with the metal scriber and evaluate and record the RF values. 

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