RU2540670C1 - Sorbent for oil gas treatment from hydrogen sulphide and method of its manufacturing - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: sorbent for oil gas treatment from hydrogen sulphide contains ferrous and manganese oxides received from wastes of the water treatment plant during water treatment from iron, polyvinyl alcohol and glycerine. The suggested method of sorbent manufacturing includes the following stages: to solution of polyvinyl alcohol disperse residue received during treatment of water from iron is added at stirring and mixed with glycerine, then treated by ultrasound, upon the period of 24 hours the residue is filtered and passed through die holes with diameter of 5 mm, granules are dried at temperature of 25-50°C.

EFFECT: simplified method of sorbent manufacturing.

2 cl, 2 ex, 1 tbl

Description

The invention is intended for the oil and gas industry, relates to sorbents for the purification of gases, including associated petroleum gases (APG) from hydrogen sulfide, and can be used in the preparation of associated petroleum gas for consumption.

Hydrogen sulfide (H ₂ S), present in gases, including petroleum, is an aggressive substance that provokes acid corrosion, which in this case is called hydrogen sulfide corrosion. When dissolved in water, it forms a weak acid, which can cause pitting in the presence of oxygen or carbon dioxide. At the same time, the service life of equipment and apparatus is significantly reduced in the production, transportation, processing and use of gas. In industrial conditions, pipes, valves, gas meters, compressors and refrigerators are exposed to particularly severe corrosive effects. It is extremely difficult to deal with hydrogen sulfide corrosion: despite the addition of acid corrosion inhibitors, pipes made from special grades of stainless steel quickly fail. Hydrogen sulfide, joining unsaturated compounds, forms mercaptans, which are an aggressive and toxic part of sulfur compounds - chemical poisons. Thorough cleaning of gases from hydrogen sulfide is necessary in the production of synthetic ammonia, synthetic alcohols, in the hydrogenation of fats, in the production of household gases used in the metallurgical industry, etc.

The urgency of the problem of gas purification from hydrogen sulfide is enhanced by the requirements of ensuring environmental safety in the development of sulfur deposits, by reducing harmful emissions into the atmosphere. At the same time, special attention is paid to improving existing and developing new desulfurization technologies that exclude emissions of toxic hydrogen sulfide and its combustion products into the environment. Despite all the disadvantages listed above, hydrogen sulfide is a valuable chemical raw material, because from it you can get a huge amount of inorganic and organic compounds.

Thus, the purification of gas from hydrogen sulfide is caused not only by the requirements of the sanitary-hygienic order, but also dictated by the production need:

- protect the apparatus and equipment from corrosion during transport, processing and use of gas;

- have gas suitable for domestic, energy and industrial use;

- to obtain by processing refined gases products of proper quality without impurities of sulfur compounds;

- in some cases, benefit from the extraction of elemental sulfur.

The invention relates to a method for removing sulfur and sulfur-containing compounds from various gases using an adsorbent. Adsorption processes are mainly used in cases where it is necessary to achieve very low concentrations of sulfur compounds in the gas. Various adsorbents for cleaning gases from hydrogen sulfide are known.

Known zinc-copper absorber, catalyst GIAP-10 (Zn oxides) or GIAP-10-2 (Zn and Cu oxides). TU 6-03-2002-86 [http: him-kazan.ru | giap-10]. The sorbent is designed for fine cleaning of generator, water, coke and natural gases from sulfur compounds. The high sulfur intensity of the absorber is determined by the preliminary carbonization of the zinc component, after calcination of which it is possible to significantly increase the surface of the active component by reducing the size of crystallites. The disadvantages of this sorbent are the need for regular regeneration and periodic full replacement; the possibility of its operation only at a temperature of 350-390 ° C. The concentration of hydrogen sulfide is not more than 80 mg / nm ³ (before purification) and 0.5 mg / nm ³ (after purification). Sulfur-containing at 400 ° C, at least 24%.

Known solid synthetic sorbent for the purification of gases from hydrogen sulfide with a content of 35-95% manganese oxides [Patent US 4225417, 1980]. The disadvantage of this sorbent is the relatively low (140 mg / g) absorption capacity of hydrogen sulfide. In addition, its practical use is economically disadvantageous because of the need to organize special production for it.

Known solid sorbent for cleaning gases from hydrogen sulfide, including oxide compounds of manganese [Patent SU 625753]. The advantage of this sorbent is a fairly high level of absorption capacity. However, the practical use of this sorbent is also economically unprofitable due to the fact that it is obtained from waste from the manganese industry in a complex technological way, requiring the organization of special production.

Known solid sorbent for the purification of industrial gases from hydrogen sulfide [RF patent 2381832], which is an enriched or unenriched ore containing 18-70 wt.% Manganese oxides, selected from the series: oceanic ferromanganese nodules or ferromanganese ore containing manganese compounds in the form pyrolusite, and manganese ore containing manganese compounds in the form of brownite or cryptomelan. The invention expands the range of cheap sorbents with high sorption properties. However, production and additional costs for the extraction of ore are necessary.

Closest to the proposed invention is a sorbent of hydrogen sulfide and the method of its production according to the application No. 95102800 from 1995, publ. 01/10/1997, the Sorbent is obtained by co-grinding solid iron oxides with an activator-blowing agent, such as ammonium chloride, in the amount of 5-15% by weight of the main component and sodium binder-lingosulfate in the amount of 15-30% by weight of the main component. Tablets or granules are made from the mixture, which are subjected to heat treatment in a hydrogen atmosphere, first under polythermal conditions up to 500-650 ° C for 1 h, and then under isothermal conditions at 500-650 ° C for 60-90 min. Due to porosity, this sorbent has an increased activity, but insufficient for the manufacture of compact filters for the purification of gases from hydrogen sulfide. Its practical use is economically disadvantageous due to the need to organize special production for it.

The objective of the invention is to obtain a sorbent for removing hydrogen sulfide from petroleum gases and to develop a method for its production from wastes from deferrization stations of underground waters.

The technical result consists in simplifying the method of producing the sorbent, the possibility of its use at a temperature of 18-25 ° C and atmospheric pressure.

The sorbent for the purification of gases from hydrogen sulfide contains in a dispersed state a mixture of iron and manganese oxides (ОЖМ), isolated from waste from deferrization stations of underground waters, a water-soluble polymer (polyvinyl alcohol) and glycerin in the following ratio of components,%:

Polymer - 1.0%

Glycerin - 1-3%

ОЖМ (dispersed) - the rest

As the raw material for the sorbent use waste obtained at the deferrization stations of groundwater of the Tomsk region, which have the composition shown in table 1, and after drying are a light brown dispersed powder with a particle size of 0.2-0.3 microns . The method of producing the sorbent includes the following operations: a precipitate isolated from waste water treatment plants when cleaning water from iron is added to a solution of polyvinyl alcohol with stirring, and glycerin is mixed, treated with ultrasound, the precipitate is filtered off after 24 hours, it is forced through 5 mm diameter nozzles and drying the granules at a temperature of 25-50 ° C.

Examples of specific performance.

Example 1

Prepare a 1.0% solution of polyvinyl alcohol (PVA - 1.0%) by dissolving 1 g of PVA in 100 ml of water, add 96 g of a precipitate (OM) and 3 g of glycerol with stirring. Everything is thoroughly mixed, treated with ultrasound and leave the resulting mass for 24 hours at room temperature. In this case, delamination occurs, the upper transparent aqueous layer is drained, and the sediment is pressed through dies with a diameter (d = 5 mm) and granules are obtained. The granules are dried at a temperature of 25-50 ° C and examined as a sorbent for the extraction of hydrogen sulfide from gases.

Example 2

Prepare a 1.0% solution of polyvinyl alcohol (PVA), dissolving in 100 ml of water 1 g of PVA, add 98 g of precipitate (OMC) and 1 g of glycerol with stirring. Everything is thoroughly mixed, treated with ultrasound and leave the resulting mass for 24 hours at room temperature. In this case, delamination occurs, the upper transparent aqueous layer is drained, and the sediment is pressed through dies with a diameter (d = 5 mm) and granules are obtained. The granules are dried at a temperature of 25-50 ° C and examined as a sorbent for the extraction of hydrogen sulfide from gases.

Method for measuring sorbent sulfur intensity

Testing the sorbent for sulfur intensity is carried out at room temperature in the temperature range from 18 to 24 ° C. A sample of the sorbent in an amount of 30.0 cm ^{2 is} loaded into the adsorber, the layer is compacted by tapping the adsorber with a wooden stick. Set the flow rate of the gas mixture by the rheometer, note the readings of the gas meter. The start time of the test is noted.

The gas meter and stopwatch adjust the exact flow. At the same time, they check for leaks by touching the joints of the installation parts with a strip of indicator paper dipped in a solution of acetic acid. Achieve complete tightness. These operations begin immediately after the start of the supply of the gas mixture.

If a breakdown of hydrogen sulfide is detected (darkening of the indicator paper in the tube at the outlet of the adsorber), the gas mixture is stopped. The gas meter readings, the end time of the tests, the ambient temperature and atmospheric pressure are noted.

The test is completed, the spent adsorbent is discharged. Its weighing is not required.

Results Processing

The volume of the gas mixture spent on testing V _t lead to normal conditions by the formula

where V _o is the volume of gas reduced to normal conditions (temperature 0 ° C and pressure 760 mm Hg), dm ³ ;

V _t is the volume of gas measured at temperature t and barometric pressure V, dm ³ ;

B - barometric pressure, mmHg;

t is the temperature of the measured gas volume, ° C.

The consumption of S,% wt., Determined by the formula

where 1,54 is the density of hydrogen sulfide, reduced to normal conditions, g / DM ³ ;

a - volume fraction of hydrogen sulfide in the gas mixture,%;

V _o is the volume of gas reduced to normal conditions (temperature 0 ° C and pressure 760 mm Hg), dm ³ ;

m - sample of the tested adsorbent, g;

0.94 is the ratio of the atomic mass of sulfur to the molecular weight of hydrogen sulfide.

Samples are tested for sulfur intensity at various feed rates of the gas mixture.

Sample 1 (example 1) - the feed rate of the gas mixture is 1000 rpm. Absorption of H ₂ S - 16.0%

Sample 2 (example 1) - the feed rate of the gas mixture is 500 rpm. Absorption of H ₂ S - 21.0%

Sample 3 (example 2) - the feed rate of the gas mixture is 1000 rpm. Absorption of H ₂ S - 17.0%

Sample 4 (example 2) - the feed rate of the gas mixture is 500 rpm. Absorption of H ₂ S - 22.5.0%

Thus, the proposed sorbent based on waste water treatment plants when cleaning water from iron, modified with polyvinyl alcohol and glycerin, can be used in the purification of petroleum gas from hydrogen sulfide, having a sulfur capacity comparable to the best domestic counterparts.

Table 1 The chemical composition of precipitation obtained as a result of groundwater aeration at the intake of Tomsk Components concentration,% of the mass. SiO ₂ 5.56 Al ₂ O ₃ 7.99 Fe ₂ O ₃ 31.8 MnO 39.1 Cao 6.47 MgO 9.99

Claims (2)

1. Sorbent for the purification of petroleum gases from hydrogen sulfide based on iron oxides, characterized in that it contains a dispersed precipitate, including iron and manganese oxides obtained from waste water treatment plants for water purification from iron, polyvinyl alcohol and glycerin in the following ratios of components, wt .%:
Polyvinyl alcohol 1,0 Glycerol 1-3 Iron and Manganese Oxides Rest 2. A method of producing a sorbent for cleaning petroleum gases from hydrogen sulfide in the form of granules according to claim 1, containing iron oxide, characterized in that dispersed precipitate isolated from waste water treatment plants when cleaning water from iron and glycerol are added to a solution of polyvinyl alcohol , stirred, sonicated, after 24 hours the precipitate is filtered off, pressed through 5 mm diameter nozzles and the granules are dried at a temperature of 25-50 ° C.