Method of processing of water flow downstream of fischer-tropsch reactor

FIELD: process engineering.

SUBSTANCE: invention relates to water treatment. Treatment of water flow fed from Fischer-Tropsch reactor comprises the fed of water flow portion to aerator, to distiller and /or evaporator and therefrom to said aerator again. Note here that process gas is fed to said aerator to produce gaseous flow to be fed to the plant for production of synthesis gas.

EFFECT: possibility to use at least a portion of water flow fed from Fischer-Tropsch reactor as a process water for production of synthesis gas.

14 cl, 1 dwg

 

The present invention relates to a method of purification of an aqueous stream coming from the reaction of Fischer-Tropsch.

More specifically, the present invention relates to a method of purification of an aqueous stream coming from the reaction of the Fischer-Tropsch process comprising feeding part of the aqueous stream to a saturator, feeding a part of the specified water flow in the distillation and/or Stripping column, feeding the aqueous stream leaving the head of the distillation and/or Stripping columns, in the saturator.

The technology of the Fischer-Tropsch process for producing hydrocarbons from mixtures of hydrogen and carbon monoxide known as synthesis gas described in the scientific literature. The full list, which shows the main works by the reaction of the Fischer-Tropsch process, is contained in Bureau of Mines Bulletin, 544 (1955) under the heading "Bibliography of the Fischer-Tropsch Synthesis and Related Processes", the authors of H. C. Anderson, J. L. Wiley and A. Newell.

The technology of the Fischer-Tropsch process in General is based on the use of slurry reactors used for chemical reactions performed in multiphase systems where gaseous phase was bubbled into a suspension of solids (solid phase) and liquid (liquid phase). In the case of the reaction of the Fischer-Tropsch process, the gaseous phase consists of synthesis gas or "syngas", which is a combination of hydrogen (H2) and carbon monoxide (CO) p�and molar ratio of H 2/CO of 1 to 3, preferably about 2; the liquid phase at the reaction temperature mainly includes the reaction product, i.e. mainly linear hydrocarbons with many carbon atoms, and the solid phase mainly includes the catalyst. The synthesis gas may contain carbon dioxide (CO2and the water in smaller amounts. The presence in the specified synthesis gas sulfur, nitrogen, halogen, selenium, phosphorus and arsenic or their derivatives is undesirable. For this reason, and depending on the quality of the synthesis gas, it is preferable to remove sulfur and other impurities before applying the specified synthesis gas in a Fischer-Tropsch reactor. Ways of removal of these impurities is known in the art. Using barrage layers, known as "protective layers" on the basis of zinc oxide is preferred for the removal of sulfur or its derivatives. Moreover, it is usually preferable to remove carbon dioxide (CO2), which can be formed from synthesis gas when the sulfur or its derivatives are not yet deleted. To this end, for example, this can be done by bringing the synthesis gas into contact with a moderately alkaline solution (e.g., solution of potassium carbonate) in a Packed column.

The synthesis gas preferably comes from steam reforming and/or partial oxidation of natural gas,usually methane or other heavier hydrocarbons, usually present in natural gas (e.g., ethane, propane, butane), according to methods known in the art.

In the process of steam reforming of desulfuromonas natural gas is usually mixed with steam and passed at elevated temperature and pressure through the catalyst layer comprises a catalyst containing a transition metal, preferably Nickel. Couples usually provide through the saturator, in which water is brought into contact with the above-mentioned pre-heated with natural gas.

Alternatively, synthesis gas can be obtained from other industrial processes, such as, for example, the process is autothermal reforming process or a process known as S. R. O. (catalytic partial oxidation (CONFERENCE)), which use streams of high purity oxygen or enriched air, together with desulfuromonas natural gas and the catalyst, or from the gasification of coal or other carbonaceous products with steam at high temperatures as described, for example, in "Catalysis Science and Technology", Vol.1, Springer-Verlag, New York, 1981.

When the reaction of the Fischer-Tropsch carbon monoxide and hydrogen into liquid water and organic molecules mainly composed of carbon and hydrogen (i.e., hydrocarbons). Moreover, during the reaction of the Fischer-Tropsch may form other organic molecules that �will gain oxygen, in addition to carbon and hydrogen, called oxygen-containing compounds.

The Fischer-Tropsch reaction is usually performed at a temperature equal to or higher than 150°C, e.g., from 180°C to 350°C, maintaining the internal reactor pressure of from 0.5 MPa to 10 MPa, preferably from 1 MPa to 5 MPa.

As noted above, the reaction of the Fischer-Tropsch catalyst promotes. The catalysts preferably have the property to increase the rate of reaction, while not draining the meter during the reaction. The type of the catalyst affects the relative amount of hydrocarbons produced from the reaction of Fischer-Tropsch. The catalyst commonly used in reactions of Fischer-Tropsch, as a rule, contain at least one metal belonging to group 8, 9 or 10 of the Periodic table of elements (according to IUPAC classification of 22 June 2007).

Catalysts containing cobalt, iron, ruthenium and/or Nickel, can preferably be used for the conversion of synthesis gas to hydrocarbons suitable for the production of gasoline and/or diesel fuel. For example, a particularly suitable cobalt catalysts for Fischer-Tropsch to get from synthesis gas to heavy hydrocarbons. Iron has the advantages of easy availability and relative efficiency, but its disadvantage is the increase in the proportion of reaction, known as the "water gas shift", in which a portion of carbon monoxide�a and the formed water is converted to carbon dioxide and hydrogen. Nickel favors the reaction of chain termination, and it is preferably used for selectively producing methane from synthesis gas. Ruthenium has the advantage of high acidity, but it is quite expensive.

In the reaction of the Fischer-Tropsch usually receive a mixture of gaseous hydrocarbons, liquid hydrocarbons and solid hydrocarbons having the number of carbon atoms from 1 to 100 or more different molecular weight. Depending on the molecular weight distribution, the compounds are suitable for various applications. For example, a mixture comprising liquid hydrocarbons, can be subjected to additional processing to obtain gasoline and middle distillates. Solid hydrocarbons can be subjected to additional processing to convert them into liquid and/or gaseous hydrocarbons. Therefore, to use the Fischer-Tropsch reaction for the subsequent production of fuel required to increase the production of liquid and/or solid hydrocarbons, such as hydrocarbons containing at least 5 carbon atoms per molecule (C5+hydrocarbons).

In addition to hydrocarbon mixtures in the reaction of the Fischer-Tropsch process also produces water according to the following reaction equation:

n CO+2n H2→CnH2n+n H2O.

The amount of water formed is in�the significant SMA, since a mole of water is formed per mole of carbon monoxide to convert to hydrocarbons. Usually, when using the catalyst, preventing the water-shift reaction, for example, cobalt and/or ruthenium, water-shift reaction is minimized, so that the total amount of water formed close to the number obtained from the stoichiometric reaction. For catalysts, enabling the water-shift reaction, for example, iron, water-shift reaction is more significant, so that the amount of water formed is always significant, but lower than in the case of a stoichiometric reaction.

Before cleaning the water from the reaction of Fischer-Tropsch, is usually subjected to a preliminary separation process. It is usually passed through a three-phase separator from which the organic condensate and vapor phase and the aqueous phase, which still contains organic compounds, dissolved or suspended, and it is preferably treated on the coalescence filter.

Separated so the water is still contaminated with hydrocarbon compounds, usually in an amount of less than 1 ppm (parts per million), and oxygen-containing compounds, soluble in water. The amount of impurities depends on the catalyst and the reaction conditions, particularly temperature and giving�message. With increasing reaction temperature, the total amount of oxygen-containing compounds increases, and the group of organic acids is increased more significantly.

The main oxygen-containing impurities are alcohols such as methanol and ethanol, is typically present in an amount of from 0.5 wt.% to 5 mass%. Heavier alcohols (e.g., propanol, butanol, pentanol, etc.) and other oxygenated compounds such as aldehydes (e.g., acetaldehyde, Propionaldehyde, Butyraldehyde, etc.), ketones (acetone, methylpropylamine, etc.) and acids (e.g., formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, Caproic acid, enanthic acid, Caprylic acid, etc.) are also present in smaller quantities, the latter are usually present in concentrations less than 1.5 wt.%. The present number of connections within each group decreases with increasing molecular weight and are compounds with the number of carbon atoms to 25. Water can also contain small amounts of nitrogen-containing and sulfonated compounds derived from the raw materials used, in addition to traces of metal that come from the reactor. Metals may also be present in the form of suspended solids.

, Investigators s�flax, the water coming from the reaction of the Fischer-Tropsch process, has no commercial value and cannot be disposed into drains as such, because of the presence of organic compounds, which can impart various shortcomings. For example, an organic oxygen-containing compounds (particularly acid) impart corrosion properties, hydrocarbons - the tendency to foam (foaming).

Moreover, rainwater or other technical water present in the production area, may be added to water produced by the reaction of Fischer-Tropsch.

Therefore, the apparatus for treatment of water supplied from the reaction of the Fischer-Tropsch process, as necessary for reuse of this water within the Fischer-Tropsch process (for example, as process water or as cooling water in the reaction section) and for discharging to the outside, or for other applications (for example, as water for irrigation or drinking water).

Treatment or combination of treatment types water supplied from the reaction of Fischer-Tropsch, is determined by the limitations imposed by its end use and organic substances present in it.

For example, an installation for the treatment of water supplied from the reaction of the Fischer-Tropsch process, can be a unit of biological type, which treatment is usually preceded by distillation and/or Stripping, to remove most volatile organic compounds. Water obtained after biological treatment, then usually subjected to a further final processing to remove solids, and, optionally, salts remaining after biological treatment. An approach of this type is described for example in US 7166219, US 7150831 or in WO 2005/113426.

Alternatively, water from the reaction of the Fischer-Tropsch process, can be treated physico-chemical type. For example, in US 6462097 described method for processing a Stripping there is the step of adsorption on activated charcoal. Water flow from said phase adsorption on activated charcoal enriched with organic compounds, can then be directed into the reaction reactor. Similar proposals are also described, for example, in US 6225358, US 5053581, US 5004862 in which organic compounds, such as C1-C6alcohols present in the water coming from the reaction of Fischer-Tropsch, it is possible to return and then convert to simple molecules such as COx/H2(synthesis gas).

Other types of processing physico-chemical type provide the possibility to separate one or more streams enriched in organic compounds.

For example, in US 2004/0262199 described the possibility of separation by distillation mainly alcohol�new stream with the contents are not acidic compounds (NCC) from 55 wt.% to 85 wt.% maximum. This thread can be used as fuel or, alternatively, it can be further processed to extract valuable products.

Education by processing physico-chemical type of one or more streams enriched in various groups of organic compounds, simultaneously with the water purified to the required degree, described for example in US 7153432, where a method is proposed, containing at least two stages, the first of which represents a stage of distillation, and the second is a stage of separation by membranes, and perhaps, if necessary, other auxiliary stage to bring purified water to the desired degree of purity.

In particular, in US 7153432 described method of purification of water formed as a by-product in the reaction of the Fischer-Tropsch process, comprising: (a) implementation distillation or liquid-liquid extraction of the water formed as a by-product in the reaction of the Fischer-Tropsch process to remove at least a portion of the alcohols present in said water, and to obtain a first stream enriched in water, and (b) processing the specified first stream enriched in water by a process of separation by membrane, which ensures the removal of at least part of the solids, present in the suspension, along with some organically�and acids to produce purified water. The process of separation by means of membranes may be selected from the group including microfiltration, ultrafiltration, reverse osmosis, and diffusion evaporation.

Other uses of the water flowing from the reaction of the Fischer-Tropsch known in the art.

For example, in WO 2005/113426 described method of use of the water flowing from the reaction of the Fischer-Tropsch process carried out at low temperature (TFT), which includes the step of supplying water from this reaction, in the saturator, which is part of a production apparatus for producing synthesis gas in order to saturate the stream of gaseous hydrocarbons supplied in a specified setting.

In US 7323497 described method of synthesis of hydrocarbons comprising: (a) implementation of catalytic steam reforming of a mixture of hydrocarbons and steam to obtain a gas subjected to a partial reforming process; (b) implementation of the partial oxidation gas is subjected to partial reforming process using oxygen-containing gas and bringing the gas to equilibrium by means of a steam reforming catalyst to provide a mixture of synthesis gas subjected to the reforming process; (C) cooling the mixture of synthesis gas subjected to reforming, below the dew point of the vapor to condense water and separating condensed water to produce synthesis gas, containing water; (d) synthesis of hydrocarbon�in the specified synthesis gas contains no water, by the reaction of the Fischer-Tropsch and (e) separation of hydrocarbons from water formed as a by-product, characterized in that at least the specified portion formed as a by-product of water is fed to the saturator, where it is in contact with the source of the hydrocarbons, thus providing a mixture of hydrocarbons and steam intended for the catalytic steam reforming process.

In US 5004862 described cleaning method of the condensed stream obtained from the synthesis of hydrocarbons or synthesis of alcohols comprising: (a) alignment of the condensed stream into contact with a hot gaseous mixture comprising methane and steam to remove (by otparku) impurities from the condensate, and these pollutants include hydrocarbons and oxygen-containing compounds of low molecular weight; (b) removing a gaseous stream containing impurities and a gaseous mixture; (C) separate extraction of purified water. The above stage (a) is preferably performed in a column with perforated plates, but it can equivalently be performed in a Packed column or any device that provides a countercurrent separation of vapor and liquid.

In US 6225358 a method for producing a heavy using hydrocarbon�, comprising the following stages: carrying out the reaction of oxygen-containing gas and a light hydrocarbon to produce synthesis gas; feeding the synthesis gas to a Fischer-Tropsch reactor; converting the synthesis gas to an output stream containing heavy hydrocarbons; removal of impurities from a stream of waste water, which is the stage of removal of impurities from a stream of waste water comprises the steps of: increasing the concentration of impurities in the column of the hub to receive the effluent with high concentration of impurities; condensing the effluent with high concentration of impurities, to obtain a condensed concentrated flow; collecting the condensed concentrated stream in the collection for irrigating fraction; the use of a Stripping gas in a Stripping column to remove contaminants from at least part of the condensed concentrated stream to obtain a treated aqueous stream and a stream containing the impurities and boil-off gas.

In US 2008/0119574 described a method of extracting organic compounds from waste water comprising: feeding gaseous stream in the saturator; mixing additional water flow, comprising the extractable organic compounds, with the recycled water stream; heating the mixed�wow incremental water flow; supply additional water flow in the saturator; saturated gaseous stream comprising the feed gas, steam and organic compounds extracted from incremental water flow; the formation of the recycled water flow; bypass on bypass line part of the feed gaseous flow from the saturator to increase the operating temperature of the saturator and to increase the degree of extraction of organic compounds derived from incremental water flow, and mixing part of the feed stream was passed through the bypass line, with rich gaseous stream.

However, it was discovered that the water supply is coming from the reaction of the Fischer-Tropsch directly to the saturator can cause various problems. For example, organic compounds present in said water, in particular acid, in addition to the problems noted above (i.e. corrosion problems installing and/or foaming), can cause poisoning of the catalysts used in the steam reforming process.

The problem of detection of the method that provides the possibility of using at least part of the aqueous stream coming from the reaction of the Fischer-Tropsch process water in the plant for producing synthesis gas, subsequently sent to the installation of the Fischer-Tropsch process to obtain �of glendorado.

Now found that by treating an aqueous stream obtained from the reaction of the Fischer-Tropsch process, using the purification method comprising feeding part of the aqueous stream to a saturator, feeding a part of the specified stream in the distillation and/or Stripping column, feeding the aqueous stream leaving the head of the distillation and/or Stripping columns, specified in the saturator, it is possible to overcome the disadvantages described above and to use at least part of the specified water flow in the plant for producing synthesis gas, subsequently sent to the installation of the Fischer-Tropsch process for producing hydrocarbons. In particular, the specified water flow can be used in the production of synthesis gas as a source of steam and due to the presence of oxygen-containing organic compounds, in particular alcohols, as a source of hydrogen and carbon, thus increasing the production of the specified synthesis gas.

Therefore, this method reduces the amount of fats sent to the saturator, and thus prevents corrosion problems installing due to the presence of these organic acids, and the problems with poisoning of the catalysts that are typically used to produce synthesis gas.

Hence, according to the first aspect, the present invention relates to SPO�higashiura purification of an aqueous stream (i), coming from the reaction of the Fischer-Tropsch process, including:

- the supply of part of the specified water flow (i) in an amount less than or equal to 50 wt.%, preferably from 25 wt.% to 45 mass%, the total weight of the specified water flow (i) in the saturator [aqueous stream (ia)];

- the supply of part of the specified water flow (i) in an amount greater or equal to 50 wt.%, preferably from 55 wt.% to 75 mass%, the total weight of the specified water flow (i), a distillation column [aqueous stream (ib)] by obtaining two outgoing streams:

- an aqueous stream (ii) leaving the head of the column, including alcohols containing from 1 to 20 carbon atoms, preferably from 1 to 8 carbon atoms; organic acid containing from 1 to 8 carbon atoms, preferably from 2 to 4 carbon atoms, wherein these acids are present in a concentration of less than or equal to 2 mass%, preferably, from 0.01 wt.% to 1.5 mass%, relative to the total mass of the specified aqueous stream (ii), and other possible volatile compounds;

- an aqueous stream (iii) leaving the lower part of the distillation column comprising an organic acid containing from 1 to 8 carbon atoms, preferably from 2 to 4 carbon atoms;

- the supply of the specified stream (ii) specified in the saturator;

- supply process gas to a specified saturate� with obtaining a gaseous stream (iv), emerging from the head of the saturator;

- submission of specified gaseous stream (iv) in an apparatus for producing synthesis gas.

According to a preferred embodiment of the present invention, the specified gaseous stream (iv) is fed to a catalytic steam reforming process.

In the present description and the appended claims define the intervals of the numerical values always include the boundary values, unless otherwise indicated.

The Fischer-Tropsch reaction can be preferably carried out as described in US 6 348 510, and the content of that patent is incorporated herein by reference.

Aqueous stream (ii) has a concentration of alcohols preferably higher or equal to 20 mass%, more preferably, from 30 wt.% to 60 mass%, relative to the total mass of the specified aqueous stream (ii).

Water flow (iii) contains an organic acid in an amount of preferably greater or equal to 50 wt.%, more preferably from 65 wt.% to 90 mass%, the total weight of the organic acids present in the specified aqueous stream (ib).

In the present description and attached claims, the term "volatile compounds", possibly present in the specified aqueous stream (ii) relates to such compounds, as for example, hydrocarbons, aldehydes, ketones, or mixtures thereof.

Alternatively, distil�alonna column may be a Stripping column.

Alternative specified distillation column may represent a distillation and Stripping column.

Distillation and/or Stripping column consists of a condenser in the head part, reboiler in the lower part of the strengthening of steps placed above the feeder, and exhaustive stages below the feed. These restorative and comprehensive steps can be obtained by using the plates for distillation and/or Stripping columns, or with the help of nozzles structured or unstructured type.

For the purposes of the present invention can preferably use a distillation and/or Stripping column, with the configuration of the asymmetric type, for example, having a plate forming a reinforcing theoretical stage, in an amount approximately equal to half of the number of plates forming theoretical satisfactory degree. Alternatively, you can use the distillation and/or Stripping column without plates forming the reinforcing theoretical level.

In the present description and attached claims, the term "aqueous stream (ii) leaving the head of the column" refers to the flow exiting the condenser in the head part forming part of the specified column. The specified capacitor preferably is a capacitor full�th condensation.

In the present description and attached claims, the term "aqueous stream (iii) leaving the bottom of the column" refers to the flow emerging from reboiler in the lower part, forming part of the specified column.

Distillation and/or Stripping column preferably operates at atmospheric pressure, although the specified column can operate well at pressures above or below atmospheric pressure, such as, for example, from 0.05 MPa abs.(0.5 ATM. abs.) to 0.4 MPa abs.(4 ATM. ABA).

Temperature is usually determined by the pressure and composition of the aqueous stream (i) coming from the reaction of Fischer-Tropsch. In General, for working pressures of 0.05 MPa abs.(0.5 ATM. abs.) to 0.4 MPa abs.(4 ATM. abs), the temperature in the head part of the column is maintained in the range from 70°C to 125°C, and in the lower part of the column in the range from 90°C to 160°C.

In the specified aqueous stream (i) may be present non-condensable compounds.

In the present description and attached claims, the term "non-condensable compounds" refers to the synthesis gas in trace amounts (for example, hydrogen and/or carbon monoxide), possibly present in the aqueous stream (i) coming from the reaction of Fischer-Tropsch.

In said distillation and/or Stripping column, in addition to forming the above-mentioned water flows (ii) and (iii), can proiskhozhdenie these non-condensable compounds. The specified removal is usually effected by means of the purge gas stream in the condenser in the head part forming part of the specified column.

As mentioned above, the saturator usually serves to provide the steam required for the saturation process gas, preferably natural gas, usually methane, before it is fed to a plant for producing synthesis gas. In the saturator water is usually brought into contact with the above pre-heated process gas. For the purposes of the present invention, the saturator can be operated either in counterflow or in parallel flow with external recirculation or without it.

For the purposes of the present invention can preferably be used any type of saturator known in the art. Specific examples of the carbonator, which can preferably be used include: dispensing units in the form of vertical tubes, dispensing units in the form of irrigation towers, dispensing units in the form of a pneumatic scrubber baffles, the carbonator in the form of a column with perforated plates, the carbonator in the form of a Packed column, a carbonator in the form of a column with irrigated walls, etc.

In the method according to the present invention, the specified gaseous stream (iv) out of the head of the saturator, while the purge flow (v), including organic acids, Pris�corresponding fittings in the specified aqueous stream (ii), out of the lower part of the saturator. Specified blowdown stream (v) may include other oxygen-containing compounds (e.g., alcohols, hydrocarbons, aldehydes, ketones) that are present in the specified aqueous stream (i).

The purge flow (v) has a concentration of organic acids, preferably less than or equal to 10 mass%, more preferably, from 2 wt.% to 8 mass%, relative to the total mass of the specified blowdown stream (v).

Specified blowdown stream (v) can be produced, or it can be fed into the distillation column.

Alternative specified blowdown stream (v) can be directed to the burner installation for steam reforming.

According to the method of the present invention, the specified blowdown stream (v) is preferably served in a distillation column, after combining it with the aqueous stream (ib) coming from the reaction of Fischer-Tropsch.

The saturator preferably operates at a temperature from 160°C to 200°C and a pressure of 3 MPa abs.(30 bar abs.) up to 6 MPa abs.(60 bar abs).

Before feeding to the distillation and/or Stripping column, the aqueous stream (i) coming from the reaction of Fischer-Tropsch, can preferably be subjected to filtration, for example, with the use of coalescing filters or separators are able to separate hydrophilic compounds from lipophilic compounds to maximizeyour� the removal of undesirable organic compounds, in particular hydrocarbon present in said aqueous phase, which could cause the formation of foam in equipment downstream.

Foam also can be avoided by adding a suitable defoamer selected from, for example, known in the industry defoamers (e.g., anionic surfactants, organosilicon surfactants, polyethylene glycols, or mixtures thereof).

Water flow (iii) has a high water content, preferably greater than or equal to 90 mass%, more preferably greater than or equal to 95 mass%, the total weight of the specified water flow (iii).

Depending on the end use, and therefore obtained the degree of purity specified aqueous stream (iii) can be subjected to additional treatments to clean, such as, for example, treatment of ion-exchange resins, reverse osmosis, crystallization, electrodialysis, various types of biological treatment.

In particular, the specified aqueous stream (iii) having a value of chemical oxygen demand (COD) of 500 mg/l to 12,000 mg/l, can advantageously be subjected to biological treatment both aerobic and anaerobic type.

Further, the present invention is illustrated in more detail by means of one embodiment with reference to Fig.1, is shown below./p>

A method according to the present invention can be realized, for example, as shown in Fig.1.

As shown in Fig.1, a water stream (1) coming from the reaction of Fischer-Tropsch, to which is added a defoamer, serves:

partially implemented (for example, in quantities less than or equal to 50 wt.% the total weight of the specified water flow (1)) [aqueous stream (3)] in the saturator (7);

partially implemented (for example, in quantities less than or equal to 50 wt.% the total weight of the specified water flow 1) [aqueous stream (2)] a distillation column (4).

Specified distillation column (4) preferably consists of plates, forming a reinforcing steps positioned above the feed in an amount of more than 2, usually 3 to 15, and plates forming a satisfactory level, located below the feed, in quantities greater than 5, usually from 6 to 30, more specifically from 8 to 14. Specified distillation column (4) consists of 6 plates, forming a reinforcing theoretical (or add) the degrees, and 12 plates, forming a comprehensive theoretical stage. Distillation column (4) also includes a condenser in the head part (not shown in Fig.1) and the reboiler at the bottom (not shown in Fig.1).

As noted above, comprehensive restorative and feet can be obtained by using plates for distillation columns or by using nozzles �strukturirovannogo or unstructured type.

The aqueous stream (6) comprising alcohols and organic acids, and other volatile components out of the head portion of the distillation column, and these organic acids are present in a quantity less than or equal to 2 mass%, preferably, from 0.01 to 1.2 mass%, the total weight of the specified water flow (6).

The removal of non-condensable compounds that are present in the specified aqueous stream (1), can also be specified in the distillation column (4) through the purge gas stream in the condenser in the head part forming part of the said distillation column (4) (not shown in Fig.4).

Specified aqueous stream (6) is fed to the saturator (7), which also serves the process gas [gaseous stream (9)] (e.g., natural gas).

Organic acids present in the aqueous stream (6) primarily serves the recycling in the method according to the present invention by means of a purge stream (8) exiting the bottom of the saturator (7).

Thus, the gaseous stream (10), which serves in an apparatus for producing synthesis gas, in particular, in the steam reforming section (not shown in Fig.1), comes out of the head of the saturator (7).

As shown in Fig.1, specified blowdown stream (8) is combined with the aqueous stream (2) flowing from the reaction of the Fi�EPA-Tropsch and served in a distillation column (4).

Water flow (5), depending on the desired end use, can be submitted:

- anaerobic biological treatment (11);

- aerobic biological treatment (12);

- processing (13) using reverse osmosis, to obtain purified water (14).

Below is illustrative and not limiting examples for a better understanding of the present invention and its embodiments.

Example 1

After the reaction of the Fischer-Tropsch process, as described in US 6348510 (IFP-ENI) and with reference to Fig.1, the water which was separated by decantation from the reaction exit stream [aqueous stream (1)], to which was added 2 ppm (parts per million) of antifoam polypropylene glycol with an average molecular weight 2000, filed:

partially, 36 wt.% the total weight of the specified water flow (1) [aqueous stream (3)], at a nominal flow rate of 41 t/h, in the saturator (7);

partially 64 wt.% the total weight of the specified water flow (1) [aqueous stream (2)], at a nominal flow rate of 73 t/h, a distillation column (4).

Distillation column (4) has 6 reinforcing steps and 12 comprehensive steps, the capacitor is full of condensation in the head part and the reboiler at the bottom and operates at a nominal flow rate of 73 t/h the Office of the distillation column (4), operating at atmospheric� pressure and temperature from 90°C (temperature in the head part) to 105°C (temperature in the lower part), carried out so that the water flow coming out of the head portion of the distillation column [aqueous stream (6)], was 2 t/h, and, after a suitable pump, sent to the saturator (7).

According to gas chromatographic analysis, water flow (6) had the following composition:

- alcohols: 43 wt.% the total weight of the specified water flow (6);

organic acid: 1 wt.% the total weight of the specified water flow (6).

According to gas chromatographic analysis, a water stream (5) exiting reboiler in the lower part of the distillation column (4) containing organic acids present in the aqueous stream (2), had the following composition:

- organic acids: 76 wt.% the total weight of the organic acids present in the specified aqueous stream (2).

The specified water flow (5), after suitable cooling, can be sent to subsequent processing for cleaning.

The saturator (7) is a vertical tubular saturator, equipped with a system of steam heating and the external recirculation cycle, equipped with a gas-liquid separator operating at a pressure of 4 MPa (40 bar) and 180°C, in a co-current with the flow of saturated natural gas. Natural gas [gaseous stream (9)] is then sent, in countercurrent, to the saturator (7) at nominal costs�e 150000 m 3(n.)/p.m.

The purge stream (8) obtained at the outlet from the bottom of the saturator (7) at a nominal flow rate of 1 t/h.

According to gas chromatographic analysis indicated the purge stream (8) had the following composition:

- organic acids: 7 wt.% relative to the total mass of the specified blowdown stream (8).

Specified blowdown stream (8) were combined with the specified water flow (2) and sent to distillation column (4).

Rich gaseous stream (10) with a nominal flow rate of 200,000 m3(n.)/h was obtained at the exit of the head of the saturator (7), and he was sent to the plant for producing synthesis gas.

1. The method of purification of an aqueous stream (i) coming from the reaction of the Fischer-Tropsch process, including:
- the supply of part of the specified water flow (i) in an amount less than or equal to 50 wt.% the total weight of the specified water flow (i) in the saturator (water flow (ia));
- the supply of part of the specified water flow (i) in an amount greater or equal to 50 wt.% the total weight of the specified water flow (i), a distillation column (aqueous stream (ib)) to produce two output streams:
- an aqueous stream (ii) leaving the head of the column, including alcohols containing from 1 to 20 carbon atoms, organic acids containing from 1 to 8 carbon atoms, and the acid �rootstown in a concentration of less than or equal to 2 wt.% relative to the total mass of the specified aqueous stream (ii), and possible hydrocarbons, aldehydes, ketones, or mixtures thereof;
- an aqueous stream (iii) leaving the lower part of the distillation column comprising an organic acid containing from 1 to 8 carbon atoms, preferably from 2 to 4 carbon atoms;
- the supply of the specified stream (ii) specified in the saturator;
- the supply of process gas into the specified saturator obtaining a gaseous stream (iv) leaving the head of the saturator;
- submission of specified gaseous stream (iv) in an apparatus for producing synthesis gas.

2. A method according to claim 1, wherein said aqueous stream (i) served in the specified saturator in an amount from 25 wt.% to 45 wt.% the total weight of the specified water flow (i).

3. A method according to claim 2, wherein said aqueous stream (i) served in the specified distillation column in an amount of from 55 wt.% to 75 wt.% the total weight of the specified water flow (i).

4. A method according to claim 1, wherein said aqueous stream (ii) has a concentration of organic acids from 0.01 wt.% to 1.5 wt.% relative to the total mass of the specified aqueous stream (ii).

5. A method according to claim 1, wherein said aqueous stream (iv) is fed to a catalytic steam reforming process.

6. A method according to claim 1, wherein said aqueous stream (ii) has a concentration of alcohols greater than or equal to 20 wt.% the total weight of the specified water sweat�CA (ii).

7. A method according to claim 6, wherein said aqueous stream (ii) has a concentration of alcohols of 30 wt.% to 60 wt.% relative to the total mass of the specified aqueous stream (ii).

8. A method according to claim 1, wherein said aqueous stream (iii) contains an organic acid in an amount greater than or equal to 50 wt.% the total weight of the organic acids present in the specified aqueous stream (ib).

9. A method according to claim 8, wherein said aqueous stream (iii) contains an organic acid in an amount of from 65 wt.% to 90 wt.% the total weight of the organic acids present in the specified aqueous stream (ib).

10. A method according to claim 1, wherein the purge stream (v) comes from the lower part of the saturator.

11. A method according to claim 10, wherein said blowdown stream (v) has a concentration of organic acids is less than or equal to 10 wt.% relative to the total mass of the specified blowdown stream (v).

12. A method according to claim 11, wherein said blowdown stream (v) has a concentration of organic acid of from 2 wt.% 8 wt.% relative to the total mass of the specified blowdown stream (v).

13. A method according to any one of claims. 10-12, wherein said blowdown stream (v) served in the distillation column after combining it with the aqueous stream (ib) coming from the reaction of Fischer-Tropsch.

14. A method according to claim 1, wherein said saturator operates at the temperature�round from 160°C to 200°C and a pressure of 3 MPa abs.(30 bar abs.) up to 6 MPa abs.(60 bar abs.).



 

Same patents:

FIELD: chemistry.

SUBSTANCE: artesian water is fed into a condenser, heated to temperature of 21°C to 31°C and then fed into a system for preliminary purification from undissolved impurities. Further, the water is fed into a reverse osmosis apparatus, from which permeate water and a concentrate are output. The permeate water is fed into a mixer and the concentrate is fed through a heat exchanger at temperature of 42°C to 68°C into a vacuum evaporation crystallisation apparatus, wherein a vacuum of 0.8 to 0.4 atm is generated by a vacuum pump. Further, the suspension with crystals is fed for dehydration. The distillate from the vacuum evaporation crystallisation apparatus is fed into the heat exchanger where it is condensed, and then into the condenser where it is completely condensed, thereby imparting excess heat to the artesian water from the water-bearing layer, and then from the condenser into the mixer for mixing with the permeate water. In the mixer, the permeate water is diluted with the distillate in a ratio ranging from 8:2 to 10:8. The volume of the distillate fed into the mixer is controlled by varying the number of cycles of returning the concentrate to the reverse osmosis apparatus and controlling the value of the vacuum, temperature and time of evaporating the concentrate. Water in the mixer is ozonised. Mineral and organic trace elements are added. The obtained water is collected in a storage tank, bottled and then shipped to the consumer.

EFFECT: invention enables to obtain water with a given composition of mineral and organic substances.

1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to versions of a method of breaking down a colloidal system by electrochemical decomposition of emulsions and to apparatus for carrying out said method. One version of the method includes: separating solid contaminants from the emulsion; preheating the emulsion in a heat regenerator; achieving minimum emulsion stability by regulating pH; decomposing the emulsion in an electrochemical decomposition reactor by passing the emulsion between an anode made of electrochemically active material and a cathode made of electrochemically inactive material, as a result which colloidal particles of the emulsion are attached to flakes which form foam, when using as the flocculant a compound obtained in situ from the material of the electrochemically active anode; discharging the foam obtained from the step described above and discharging the purified water through a filter for final purification and/or into a reservoir for final settling and into a heat regenerator.

EFFECT: use of the present invention reduces power consumption when purifying water.

21 cl, 2 ex, 2 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to methods aiming at purifying melamine production effluents. Proposed method comprises preliminary heat treatment of triazine contained in effluents. During said pretreatment, vapors are condensed from gas phase, while liquid phase is subjected, after said pretreatment, to thermal hydrolysis whereat NH3 is removed from obtained liquid phase containing H2O, CO3 and NH3. Invention covers also the device that comprises required process elements including thermal pretreatment plant with heat exchanger, vapor condenser, device for thermal hydrolysis, device to remove ammonia from liquid phase product at the stage of thermal hydrolysis.

EFFECT: continuous, safe and efficient treatment of effluents of melamine production.

21 cl, 2 ex, 1 tbl

FIELD: technology for refining heavy oil.

SUBSTANCE: method for refining catcher oil product of slow carbonization plant includes thermo-exposure of water in sedimentation tank and refining of dehydrated catcher oil product on distillation plant. Catcher oil product of slow carbonization plant forming at stage of heating of coke chambers is sent to first sedimentation tank, where water is separated from it, and then sent for mixing with carbonization raw stock. Catcher oil product formed at coke steaming stage in coke chambers, is sent into second sedimentation tank, where it is mixed with light hydrocarbon fraction, water is separated from it and it is sent for mixing with carbonization raw stock, or for mixing with heavy oil leftovers for production of reduced fuel oil. Invention allows reduced amount of catcher oil product formed at slow carbonization device, increased output of light products (gasoline, diesel fraction) from slow carbonization device, decreased costs of transportation and refining of catcher oil product, decreased corrosion-erosion wear of equipment during transportation and refining of catcher oil product.

EFFECT: decreased volume of catcher oil product of slow carbonization device by 70-80%, increased output of clear oil products from slow carbonization device by 1,5%.

4 cl, 1 ex, 1 tbl

FIELD: treatment of mineralized water containing admixtures in form of sodium sulfate and chloride.

SUBSTANCE: proposed method consists in preliminary softening of water, concentration of salts for obtaining pure water and brine, partial alkalizing and additional saturation of brine, cooling of brine at separation of sodium sulfate crystals, boiling-down of mother solution and cooling at extraction of remaining sodium chloride; brine is additionally saturated with sodium chloride to the following ratio: Na2SO4:1: (1.6-2.0); then, mirabilite is subjected to crystallization at temperature of from (-8) to (-10)°C; extracted mirabilite crystals are washed with saturated sodium sulfate solution at temperature of 40°C at ratio of washing solution to mirabilite of 1:1 returning it to mirabilite crystallization process; after mirabilite has been freed from mother solution, part of sodium chloride is extracted, washed with sodium chloride solution saturated at temperature of 20°C at ratio of flushing solution to sodium chloride of (0.5-1.0): 1 and boiled-down solution with remaining part of sodium chloride and flushing solution is divided into three flows. At stage of extraction of sodium chloride, no more than 60% of sodium chloride is subjected to crystallization.

EFFECT: improved grade of sodium sulfate and chloride due to increased concentration of main agent; reduced content of admixtures in commercial products.

2 cl, 1 dwg, 1 tbl, 16 ex

FIELD: swimming pools water treatment.

SUBSTANCE: the invention is pertaining to the field of water treatment, in particular, to purification and disinfection means of the recirculating water in the closed contours of swimming pools, which use the principle of operation based on a joint application of the ozone-sorption and vacuum-ejection equipment at utilization of chemical compounds of the metals possessing of oligodynamic properties. The water purification installation in a swimming pool contains located on a pipeline a circulation pump, a bypass trunk line, a sand filter, an ozonizer and an adjusting gate. Besides the installation is supplied with a unit of reception of solutions of disinfectants, the first ejection mixer, a unit of the sand filter disinfection, consisting of the second ejection mixer and the first function switch of the operation modes, a multi-nozzle ejection mixer; a sorption unit; a heat exchanger; a controller of ozone concentration in the recirculating water; a sensor of a reduction-oxidation potential; a transducer of the reduction-oxidation potential; a unit of primary water preparation, the second function switch of operation modes; a filter screen and the perforated pipeline. The technical result: increased sanitary-and-epidemiologic reliability of the waters purification processes and disinfection and also prevention of secondary bacterial pollution of a swimming pool.

EFFECT: the invention ensures increased sanitary-and-epidemiologic reliability of the waters purification processes and disinfection prevention of a swimming pool secondary bacterial pollution.

6 cl, 1 dwg

The invention relates to a method of chemical treatment of water and can be used in various industries, including petrochemical, requiring the use of chemically treated water

FIELD: machine building.

SUBSTANCE: electrohydraulic water activation installation comprises a chamber filled with water and equipped by electrodes, a cover with a channel for water supply. The chamber is limited by a recess in the piston bottom, cylinder walls and the cover with a channel for water supply, a plug with an insulated positive electrode is screwed into the cover, a cylindrical electrically insulated spring-damper is installed between the bottom part of the cylinder additionally serving as a negative electrode and the piston, the lateral part of the cylinder is fitted by a hole to discharge water after electrohydraulic impact in the water-filled chamber from a corona discharge between the electrodes at switching on of a high-frequency generator of primary pulses.

EFFECT: improvement of electrohydraulic water activation efficiency.

1 dwg

FIELD: chemistry.

SUBSTANCE: surface of a film of oil or oil products is treated with a reagent which contains a natural polymer and the reaction product is collected. The reagent used is polysaccharide microgel with mass of 20000-200000 Da and particle size of 50-600 nm in an aqueous solution with concentration of not less than 0.2 g/l. According to the first version of the method, before and after spraying the reagent, the periphery of the film of oil or oil products is treated with a biodegradable surfactant in the form of an aqueous solution with concentration of not less than 0.1 g/l. According to the second version of the method, the reagent is first mixed with a biodegradable surfactant in the form of an aqueous solution with concentration of not less than 0.1 g/l. Mixing is carried out until the ratio of the polysaccharide microgel to the biodegradable surfactant is 12:1-2:1.

EFFECT: high efficiency of the process of collecting oil or oil products from a water surface, low specific consumption of reagents and low residual content of said reagents in water.

2 cl, 6 ex

FIELD: oil and gas industry.

SUBSTANCE: invention can be used in gas and oil production industry for associated crude iodine production from iodine-lean confined groundwater. The method is implemented by a sequence of electrochemical iodide ion oxidation, molecular iodine sorption on carbon, electrochemical reduction of iodine to iodides, and desorption. All stages are performed in the same chemical reactor represented by a sorption column. Activated carbon with minimum iodine adsorption capacity of 1,000 mg/g is used as a sorbent. Graphite electrode at the column bottom is used as an anode, copper cathode in the form of plate at the column top is used as cathode. After the carbon is saturated with iodine, electrode polarity is reversed to desorb iodine from carbon in the form of iodide ions. Confined groundwater, including one with low iodine content, is used as iodine source.

EFFECT: enhanced iodine production efficiency.

2 cl, 1 dwg, 1 tbl, 1 ex

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to means for protection against contaminants introduced by gravity draining at steam pumping and/or those peculiar thereto. This system is used at the plant based on gravity draining at steam pumping for production of heavy oil. This control system allows the simultaneous control over silicon dioxide, hardness and oil contamination existing in evaporator feed water.

EFFECT: ruled out heat exchange surface fouling, higher reliability.

9 cl, 16 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in industry at the stage of fine or additional purification of water from traces of heavy metal ions, in the purification of vapour condensate in boiler houses and TPP plants in the creation of closed technological water circulation. To realise the method of ion-exchange water purification sewage waters and technological solutions are passed through a sorbent, containing hydrazide groups. as the sorbent used is activated carbon, preliminarily processed with a gas mixture of ammonia and hydrazine, taken in volume ratios of 1:2-2.5, at a temperature of 350-450°C. The method provides the removal of ions of metals with a variable valence: Cu2+, Zn2+, Ni2+, Cr3+, Fe3+, as well as ions of metals: Bi3+, Zr4+, Sr2+, Co2+ from water, with the preservation by the sorbent of the sorption activity in a wide range of the water solution pH values.

EFFECT: purification of water from traces of heavy metal ions.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to water purification by crystallisation and can be used in everyday life, food industry and medicine. The water purification apparatus includes a temperature-controlled heat-exchange vessel 1, means of feeding source water for purification and means 2 of draining ice water and liquid concentrate of contaminants, means 3 of cooling and freezing water and means 5 of melting ice with cooling 4 and heating elements 6, a control unit 7 connected to the means of feeding source water for purification and draining ice water and liquid concentrate of contaminants 2 from the heat-exchange vessel 1 and means of cooling and freezing water 3 and melting ice 5. The heat-exchange vessel 1 has a flat slit-type internal cavity or an annular slit-type cavity 15, and one of the walls of the heat-exchange vessel 1, which is free from the cooling 4 and heating elements 6, is made of transparent material and has one or more internal air cavities 17.

EFFECT: invention improves the quality of water purification and enables to monitor the purification process.

3 dwg

FIELD: chemistry.

SUBSTANCE: method consists in mixing cyano-containing solutions and pulps with hydrogen peroxide and a gas ozone-oxygen mixture with the ozone concentration of more than 160 g/m3, in the ozone/hydrogen peroxide ratio of 1.5:1, pH 11-12, temperature of 45-50°C in the presence of copper ions. The cyano-containing solutions and pulps are deactivated in the copper ion concentration of not less than 1:8 to the cyanide and rhodanide concentration.

EFFECT: higher rate and effectiveness of deactivating the cyano-containing solutions and pulps, lower consumption of agents and power costs, improved economical efficiency of the process.

2 cl, 2 ex

FIELD: biotechnology.

SUBSTANCE: biohybrid composite material for sorption and degradation of crude oil and petroleum products is proposed. The material is a thermoplastic polymer with fibre-forming properties - acrylonitrile copolymer with methyl acrylate. It comprises incorporated phosphorus-containing cationites and/or nitrogen-containing anionites, the cell walls of aquatic plants of the family Lemnaceae (Lemnaceae) and immobilized cells of bacteria-oil destructors.

EFFECT: composite material has high adsorption capacity and a higher degree of biodegradation of petroleum hydrocarbons.

2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the field of natural water purification for economic-drinking and industrial water supply, including slightly muddy coloured low-temperature water. The method includes the reagent processing of water with a coagulant and a flocculant, carrying out volume coagulation under the conditions of mechanical mixing, clarification in horizontal settling tanks, equipped with floatation chambers at the output, filtration, decontamination of the purified water, collection of washing water into a balancing reservoir with its further mixing with initial water.

EFFECT: provision of the drinking water quality independent on seasonal fluctuations of the initial water quality and temperature conditions, increased degree of clarification of water to be coagulated before filtration, reduction of the washing water consumption.

1 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: inventions can be used for processing sewage waters and conditioning sludge before its dehydration. A lime-based composition for processing waters and sludge contains, at least, one mineral agent, which contains at least lime and at least one linear, branched and/or transversely cross-linked hydrophilic organic polymer of a non-ionic, anionic, cationic or amphoteric origin. The mineral agent contains slaked lime in the solid phase, with the organic polymer being includes on the surface and inside the said solid phase of slaked lime, where the said lime-based composition represents a solid composition. The method of preparing the composition for processing waters and sludge includes the introduction of the mineral agent and a water solution, dispersion or an inverse emulsion, which contains the organic polymer and water, in contact. The method includes the realisation of a partial reaction of quicklime with all or a part of water, which contains the organic polymer, obtaining slaked lime in the solid phase, including the organic polymer.

EFFECT: inventions provide the effective conditioning of sludge to be dehydrated due to the distribution of the polymer in a smaller amount relative to the mineral agent.

15 cl, 7 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: apparatus includes an ejector housing, having a water nozzle and a mixing chamber, a water inlet unit in the form of a main pipeline with a mixing chamber and controlled valves, an inlet unit in the form of a mouth piece into a gas ejector. The mixing chamber of the main pipeline is fitted with a graduated washer. The ejector is installed after the graduated washer at an angle to the main pipeline. The ratio of the diameters of the water nozzle of the ejector D1, the opening of the graduated washer D2 and the main pipeline D3, specifically D1:D2:D3 is equal to 1:3:10. The water nozzle and the mixing chamber are installed in the ejector housing relative to each other while enabling adjustment of the position thereof. The internal lower part of the mixing chamber of the ejector is in the form of a helical surface, and the angle of inclination of the ejector to the main pipeline is equal to 50°.

EFFECT: high quality of the disinfectant aqueous solution.

2 dwg, 1 tbl

FIELD: transport, distribution.

SUBSTANCE: invention relates to distribution of fluid. Distribution tray comprises flat part to make fist side adapted for fluid intake and second side with several holes, and overflow device extending through said flat part. Note here that said first part is located on first side while second part is arranged on second side. Said second part allows fluid to flow there through. Besides, it includes insert is arranged inside overflow device to make the contraction and expansion of fluid passage channel. Note here that said insert makes the contraction whereat one or several cut-out are made. Several holes are arranged downstream of the overflow device and several holes upstream of said contraction.

EFFECT: uniform fluid flow.

14 cl, 9 dwg

Mixer // 2542258

FIELD: process engineering.

SUBSTANCE: invention relates to mixing assembly with spinning mixing member. Said to mixing assembly with spinning fluid mixing member comprises mixing blades arranged at mixing member hub and bubbling device feeds gas, for example air, for dispersion purposes. Bubbling device comprises distribution gas filled sleeve spinning along with said mixing element hub and communicated with discharge pipes and stationary feed pipe tightly communicated with spinning sleeve inner space. Discharge pipe outlets are located nearby mixing blades and inside volume covered by mixing member to discharge gas at appropriate points in appropriate flow direction.

EFFECT: optimised gas dispersion.

6 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: method involves passing of one or more fluid media from a tray set above to a chamber, the chamber includes one or more side walls fitted by a hole and the above set tray is fitted by a drain, the method also implies creation of a channel leading out of the chamber and connecting the respective drain with the respective hole to increase time and area of contact inside the channel and the chamber.

EFFECT: efficient mixing of different phases.

10 cl, 7 dwg

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