Lecture 10

Hetero organic mass of solid fuels. Classification. Research methods and characteristics of the group of resinous substances. Their content in the oil and petroleum products. Mineral oil components. Mineral salts and salts of organic acids, phenolates, metal complex compounds of oil, minerals found in oils. Water in oil. Methods for the qualitative determination of mineral oil components. Intermolecular interactions. Supramolecular structures. Associates. Complexes. Role of intermolecular interactions resin-asphaltene compounds and hydrocarbons in petroleum refining.

Plan of the lecture

1. Types and characteristics of resinous substances

2. Types of mineral oil components

3. The intermolecular interaction. Types of supramolecular structures.

1.Resinous-asphaltene substances do not belong to a specific class of organic compounds. They are a complex mixture of macromolecular compounds hybrid structure comprising a part of the molecules of oxygen, sulfur, nitrogen, metals and some variables in amounts which do not effect may be attributed to the hydrocarbons. Since these heterogeneous elements are present in the oils in connection with very heavy hydrocarbon radicals for sufficiently high content of tar substances can not be considered only hydrocarbon oil mixture.

Hydrocarbon resins are macromolecular substances dark-brown oil dispersed in colloidal and practically it does not pass into the distillative distillates.

Molecular weight resin oil ranges 460-1600 and asphaltene - from 1600 to 5500. The molecular weight of the secondary asphaltenes decreases to 600-900. A similar decrease in the molecular weight is typical for secondary pitches.

Resins are present in all crude oils and their content ranges are rather broad range from tenths of a percent to tens of percent. In addition, there are heavy tar oil, in which the content of resin-asphaltene substances reaches 10-50% (wt), such as some oil in Kazakhstan, Central Asia, the Komi Republic (Russian Federation), Bashkortostan, mined in limited quantities. Most are rich in resin-asphaltene substances young aromatic base oil.

Asphaltenes and resins, allocated from the oil under conditions excluding changes in their composition and structure, termed native, but has been modified or formed during the refining process called secondary.

The high molecular weight tarry substances leads to the fact that almost all the distillative resin residue remains in neperegonyayuschemsya - tar. Heterogeneous elements contained in the tar substances in the form of compounds of unknown structure. The distillation of resin collapse and form compounds, which are modified fragments of the original complex molecules. Actually they are known as sulfur and nitrogen compounds oil. The process of spontaneous disaggregation of resinous substances in general could occur even in the depths.

High molecular weight resinous substances leads to the fact that almost all of the distillation of resin does not remain in the residue is distilled - tar. Heterogeneous elements contained in the tar substances in the form of compounds of unknown structure. The distillation of resin collapse and form compounds, which are modified fragments of the original complex molecules. Actually they are known as sulfur and nitrogen compounds oil. The process of spontaneous disaggregation of resinous substances in general could occur even in the depths.

The resin is a mixture of several substances the similarity is determined by the overall plan of the structure and high molecular weight. Additional resinous substances are substances having a molecular weight greater than 1000, along with a low molecular weight. Because of this, the solubility of resin components is different, what is the use for the conditional separation resin into several groups. Chemically inactive resinous substance that does not allow them to separate by the functional reagent. At the same time, relatively high polar properties enable the resin adsorb silica and other surfactants.

2. The components of the mineral oil is meant inorganic substances defined therein, after drying, filtration and settling. Mineral oil contained in components in the form of salts formed with acids and metals, metal complexes and colloidally dispersed minerals. The elements that make up these substances, often referred to as micronutrients.

The total content of mineral components in the oil is determined by burning and calcining the resinous distillation residue oil. Since this process involves high temperatures, it is understood that the resulting ash composition and has nothing to do with those compounds in the form of minerals that were in the oil. Many carbonate sulfates, halides and other compounds with calcination or decompose or volatilize. As a result, information about the presence of halides, selenium and sulfur compounds are not complete and, in any case, are not accurate.

Responding to their active compounds, oil borrows from the surrounding rocks calcium, sodium, iron, aluminum and some other widely distributed elements. These elements are always present in the oil ash.

The total content of mineral elements are usually very low. It does not exceed hundredths, tenths of a percent less oil. Resinous oil, generally speaking, richer in mineral elements, but there are exceptions. For example, oil with a specific gravity of 0.939 Binaqadi contains about 20% of resinous substances and 0.0138% ash, whereas less resinous oil from Ramani relative density 0.8640 resinous substance with a content of about 12% when burning ash leaves 0.15% ie ten times more.

In the composition of oils found more than 40 different items that can be divided into three groups:

1. variable valence metals (V, Ni, Fe, Mo, Co, W, Cr, Cu, Mn, Pb, Ga, Ag, Ti);

2. alkali and alkaline earth metals (Na, K, Ba, Ca, Sr, Mg);

3. halogens and other elements (C1, Br, I, Si, Al, Zn, etc.).

3. Under the influence of intermolecular forces resinous substances form -asfaltenovye associates - packages of condensed aromatic hydrocarbons. The asphaltenes form a three-dimensional structure of the polycyclic aromatic monolayers. Stability of supramolecular structures of asphaltenes is determined by the presence of free radicals, as evidenced by the phenomenon of paramagnetism and high concentration of paramagnetic centers in asphaltenes.

Educated asphalt-resinous compounds supramolecular structures called complex structural units, which consist of a nucleus and the solvation shell surrounding the core. The kernel is an associate of the most high-molecular compounds and characterized by a certain thickness, coherence and strength. Solvate layer formed at the interface due to the adsorption and diffusion of the components of the dispersion of the local environment of the lower molecular weight hydrocarbons and heteroatom compounds.

These packages are distributed in a liquid hydrocarbon phase and form the nucleus of oil particles. Middle layer of the kernel are resin solvation shell surrounding the core. This is followed by a transition layer from hydrocarbons of medium molecular weight. In this layer, the forces attracting molecules to each other, almost no effect. This system is easily destroyed in the presence of party agents, which can be wall or pipe storage. Therefore, the need for oil in its composition administered stabilizing agents.

The control questions

1. Characteristics of groups of resinous substances

2. Mineral oil components and methods of their determination

3. Water in Oil

4. The supramolecular structure of oil