Production of light

Heavy residue conversion is linked to the demand for high quality diesel motor fuel (aromatics content 10%, cetane number 55) as well as to the demand for production of light fuel-oil having very low sulfur, nitrogen and metal contents. 

Energy in the form of injected water or CO2 may be suppHed to increase the rate of production of light cmde oils. AppHcation of heat to the reservoirs, eg, using hot water, steam, heated CO2, fireflood, or in situ combustion, however, is generally associated with the production of heavier, viscid cmdes. 

These processes are aH characterized by low isobutane conversion to achieve high isobutylene selectivity. The catalytic processes operate at conversions of 45—55% for isobutane. The Coastal process also operates at 45—55% isobutane conversion to minimize the production of light ends. This results in significant raw material recycle rates and imposing product separation sections. 

A major use of propane recovered from natural gas is the production of light olefins by steam cracking processes. However, more chemicals can be obtained directly from propane by reaction with other reagents than from ethane. This may be attributed to the relatively higher reactivity of propane than ethane due to presence of two secondary hydrogens, which are easily substituted. 

Adding ZSM-5 catalyst additive is another process available to tlie refiner to boost production of light olefins. ZSM-5 at a typical concentration of 0.5 to 3.0 wt% is used in a number of FCC units to increase the gasoline octane and light olefins. As part of the cracking of low octane components in the gasoline, ZSM-5 also makes C. C4, and Cj olefins (see Figure 6-2). Paraffinic feedstocks respond the most to ZSM 5 catalyst additive.. 

Increasing use of feed segregation to maximize production of light olefins. 

Ammonia has always been the starting material for the synthesis of aliphatic amines. Thus, processes have been developed for the condensation of NH3 with alkyl halides (Hoffman reaction) or with alcohols in the presence of various catalysts. The latter reachon, first discovered by Sabatier in 1909 [8, 9] is nowadays the main method of industrial production of light amines (e.g. methylamines 600 000 t/yr) [5]. 

The rate of photolytic transformations in aquatic systems also depends on the intensity and spectral distribution of light in the medium (24). Light intensity decreases exponentially with depth. This fact, known as the Beer-Lambert law, can be stated mathematically as d(Eo)/dZ = -K(Eo), where Eo = photon scalar irradiance (photons/cm2/sec), Z = depth (m), and K = diffuse attenuation coefficient for irradiance (/m). The product of light intensity, chemical absorptivity, and reaction quantum yield, when integrated across the solar spectrum, yields a pseudo-first-order photochemical transformation rate constant. 

Table I compares the conditions and results of this operation to those for conventional SRC for Illinois 6 coal. At the short residence time, the coal conversion determined by pyridine solubility is 89% compared to 95% at conventional SRC conditions. The hydrogen consumption and production of light gases are reduced significantly at short residence time, while the SRC yield is increased.

The production of light coloured products with a requirement for low build-up of static electricity requires the addition of an ingredient which is capable of providing the rubber with a low electrical resistance. Quartemary ammonium salts and ethylene oxide condensates provide one route. Of the common plasticisers, phosphate types have the lowest electrical resistance conferring properties in rubbers. Special antistatic plasticisers, such as polyethylene glycol fatty alcohol ethers, are designed to give rubbers with low surface resistivity. 

Eigen, N., C. Keller, M. Dornheim, T. Klassen, and R. Bormann, Industrial production of light metal hydrides for hydrogen storage, Scr. Mater., 56, 847-851, 2007. 

Chemiluminescence is defined as the production of light by chemical reactions. This light is cold , which means that it is not caused by vibrations of atoms and/or molecules involved in the reaction but by direct transformation of chemical into electronic energy. For earlier discussions of this problem, see 7 9h Recent approaches towards a general theory of chemiluminescence are based on the relatively simple electron-transfer reactions occurring in aromatic radical-ion chemiluminescence reactions 10> and on considerations of molecular orbital symmetry as applied to 1.2-dioxetane derivatives, which very probably play a key role in a large number of organic chemiluminescence reactions 11>. 

D. M. Hercules 4,166) gives the following main criteria for the production of light. To be chemiluminescent, a reaction must provide... 

In this chapter a two a selectivity model is proposed that is based on the premise that the total product distribution from an Fe-low-temperature Fischer-Tropsch (LIFT) process is a combination of two separate product spectrums that are produced on two different surfaces of the catalyst. A carbide surface is proposed for the production of hydrocarbons (including n- and iso-paraffins and internal olefins), and an oxide surface is proposed for the production of light hydrocarbons (including n-paraffins, 1-olefins, and oxygenates) and the water-gas shift (WGS) reaction. This model was tested against a number of Fe-catalyzed FT runs with full selectivity data available and with catalyst age up to 1,000 h. In all cases the experimental observations could be justified in terms of the model proposed. 

A unique CL reagent, /n.v(2,2 -bipyridyl)rut.hcnium(II) [Ru(bpy)32+] for the postcolumn CL reaction, was applied to HPLC detection. The oxidative-reduction reaction scheme of CL from Ru(bpy)32+ is shown in Figure 17. When the production of light following an oxidation of Ru(bpy)32+ to Ru(bpy)33+ at an electrode surface is measured, this CL reaction is termed electrogenerated chemiluminescence (ECL). The CL intensity is directly proportional to the amount of the reduc-tant, that is, the analyte. 

Based on the reaction of luminol and hydrogen peroxide, detection by electrogenerated CL (ECL) was also applied in CE [85], In this detection technique, which has been used until now in LC and in FIA, the production of light is followed by an oxidation or reduction reaction at an electrode that serves the... 

Fig. 9.4. Reaction cross-sections, as a function of energy per nucleon, for the production of light elements for some typical cases. Adapted from Read and Viola (1984). Courtesy Vic Viola.

A spectrophotometer is a combination of spectrometer and photometer. A photometer is an instrument which is used for the production of light of selected colour or wavelength. The spectrometry involves the determination of the light absorptive capacity of a chemical. So spectrophotometric analysis provides a significant method of determining minute quantities of a substance. 

Bioluminescence provides the basis for sensitive enzymic assay methods both for substrate assays and coupled enzyme assays. Firefly luciferase (EC 1.13.12.5) catalyses the production of light (540-600 nm) by the oxidation of luciferin (d-LH2) (Figure 8.18). 

Uses. The main uses of gallium is in the manufacture of semiconductors which are generally obtained by the combination of Ga with P and As. Gallium arsenide is capable of converting electricity directly into coherent light (production of light-emitting diodes). 

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