RU2302302C2 - Waste wooden sleepers neutralizing method - Google Patents

Abstract

FIELD: neutralizing of industrial waste materials, possibly neutralizing waste wooden sleepers.

SUBSTANCE: method is realized due to burying waste wooden sleepers under ground. Method comprises steps of disintegrating wooden sleepers and introducing them into oil deposit.

EFFECT: reduced contamination of environment at recovering waste wooden sleepers.

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Description

The invention relates to the field of neutralization of industrial waste and can be used for the neutralization of waste wood sleepers.

Wood railroad ties are widely used on railways. To increase the service life, these sleepers are impregnated with antiseptic agents, for example, compositions based on shale oils (1). Shale resin contains high-boiling phenols, aromatic hydrocarbons, sulfur-containing and other toxic compounds. Despite this, the service life of such sleepers is short. In reality, there is the problem of the destruction of toxic waste from wood sleepers, which accumulate in large volumes during repair work and / or are waste in the process of their production (marriage).

According to the federal classification catalog of waste, waste wood sleepers belong to finished products that have lost their consumer properties (Code 1712060013013). Waste wood sleepers contain many toxic and life-threatening substances. Approximate component composition of railway sleepers soaked in antiseptic agents (passport of hazardous waste):

Cellulose 80.0% Shale oil 8.2% Water 1.5% Benzene 0.1% Toluene 0.1% Phenol 0.1% Silica (SiO ₂ ) 6.0% Alumina (Al ₂ O ₃ ) 4.0%

A known method of destruction of hazardous hydrocarbon-containing wastes, including wood wastes, by the method of pyrolysis (high-temperature destruction) (2). Pyrolysis - processing of hydrocarbon-containing raw materials at high temperatures and lack of oxygen. Pyrolysis of wood is carried out by its decomposition when heated to 450 ° C without access of air with the formation of gaseous, liquid (wood resin) and solid products (charcoal).

The disadvantages of this method are the high cost and very high energy intensity. Contamination of the surrounding air environment is not excluded, especially during the pyrolysis of wood sleepers containing sulfur-containing and other compounds, the composition of which is not limited to carbon, hydrogen and oxygen.

The closest technical solution (prototype) is a method of waste disposal based on their disposal in land at industrial landfills (3). According to this method, waste of hazard class 2-3 is neutralized by burial in pits with waterproofing of the bottom and side walls or in pits with compacted soil with a permeability coefficient of not more than 10 ^-6 cm / s.

This method also does not exclude environmental pollution. Absolutely impermeable waterproofing materials and compacted soils do not exist. Possible contamination of the soil adjacent to the burial place, as well as the air due to the evaporation of volatile components. With increasing burial time, the probability of these events increases.

The aim of the invention is to reduce environmental pollution and disposal (beneficial use) of waste wood sleepers.

The real goal is achieved as follows. The waste of wood sleepers is mechanically crushed, and then introduced (pumped) into oil reservoirs.

The advantage of this method is that a large depth of oil reservoirs ensures the absence of environmental pollution (soil, air). In addition, during its implementation, waste wood sleepers are used to good use.

Wood sleepers contain approximately 10% of chemical compounds, similar in nature to chemical compounds that make up oil. These compounds are highly soluble in oil. When implementing the disposal of waste wood sleepers according to the proposed method, in fact, there is a replenishment of oil reserves with new components. And with subsequent oil production, these components return to the surface for reuse. The maximum effect can be obtained by introducing waste into oil fields containing predominantly volatile fractions with better solubility.

Another, equally important, advantage of the proposed method lies in the fact that when introducing waste wood sleepers into the oil field, it is possible to increase the oil recovery of oil reservoirs (oil recovery coefficient). In this case, a beneficial effect is achieved due to another component of the wooden sleepers - wood (up to 80% by weight), which is capable of swelling in water.

To displace oil from the field, water is pumped into it through injection wells under pressure. As oil reserves are depleted, water begins to break through relatively large channels in the rock. As a result, although there is still a lot of oil left in the rock (up to 50%), predominantly only water flows from production wells. To increase the oil recovery coefficient, substances that increase their volume in water (polyacrylamide, silicates, clays, sawdust, wood flour, lignin, peat, etc.) are introduced into oil fields through injection wells (4). After the introduction of these materials into the reservoir, they swell in water and block the channels through which water breaks through. This leads to the fact that the active displacement of oil begins from poorly drained and previously unreached areas of the oil reservoir. As a result, the oil recovery coefficient increases.

To implement the proposed method, waste wood sleepers are crushed by any known mechanical method. The maximum size of the crushed particles of waste wood sleepers is limited mainly by the diameter of the wells through which the waste is introduced. Minimum size - not limited. Optimum particle size - corresponds to the particle size of sawdust or wood flour.

Waste wood sleepers can be introduced into any zone of the oil field, but the maximum effect can be obtained by introducing waste into peripheral zones through injection wells. Waste can be introduced in various ways. Their injection together with liquids is preferred, in the particular case (when injected through injection wells) with water. The waste of wood sleepers can be pumped together with other components designed to increase oil recovery (silicates, clays, etc.) or separately from them.

Examples of the method.

Example 1

The waste of wood sleepers is mechanically crushed and mixed with a liquid. This mixture is pumped through existing or specially drilled wells anywhere in the field.

Example 2

The waste of wood sleepers is mechanically crushed to form sawdust. Prepare an aqueous suspension of waste wood sleepers. This suspension is pumped into the oil reservoir through injection wells.

Example 3

The waste of wood sleepers is mechanically crushed to form wood flour. Prepare aqueous suspensions from waste wood sleepers and clay. These suspensions are pumped into the oil reservoir through injection wells (jointly or sequentially one after another).

The effectiveness of the proposed method is evidenced by the following results:

1. The extraction of chemical compounds from waste wood sleepers in oil is confirmed experimentally.

2. The ability of waste wood sleepers to swell in the aquatic environment is confirmed experimentally.

3. The effectiveness of the use of waste wood sleepers for use as waterproofing (clogging) compounds is confirmed experimentally in model installations.

Literature.

1. Chemical encyclopedia: 5 tons: 1. Editorial: Knunyants I.L. et al. - M.: Sov. Encycl., 1988.

2. Chemical encyclopedia: 5 tons: 3. Editorial: Knunyants I.L. et al. - M.: Big Russian Encycl., 1992.

3. SanPiN 2.1.7.1322-03 Hygienic requirements for the placement and disposal of production and consumption waste.

4. Priority methods of increasing oil recovery and the role of supertechnologies. Proceedings of the scientific and practical conference dedicated to the 50th anniversary of the discovery of Devonian oil Romashkinskoye field. Bugulma, November 25-26, 1997 - Kazan: New Knowledge, 1988.

Claims (1)

A method of neutralizing waste wood sleepers, based on the disposal of waste underground, characterized in that the wood sleepers are crushed and injected into oil fields.