PROCESS FOR PURIFYING FLUIDS

Abstract

A process removes substances from fluids, especially from exhaust gases of combustion plants, by contacting the fluid to be purified with Puzzolanes that contain at least 5% by weight of silicon and/or aluminum-compounds. These compounds can be dissolved away under the conditions prevailing during purification, such that they are excavated from the Puzzolanes.

Claims

1. A process for the purification of a fluid, the process comprising: contacting the fluid with Puzzolanes containing at least 5% by weight of silicon and/or aluminum compounds, under purification conditions that dissolve the compounds, such that the compounds are excavated from the Puzzolanes.

2. The process according to claim 1, wherein the purification conditions comprise a pH value of the fluid to be purified of 6.0 or less and/or elevated temperatures.

3. The process according to any of the claims 1, wherein the Puzzolanes exhibit a Blaine-value of at least about 2.500 cm.sup.2/g.

4. The process according to claim 1, wherein the Puzzolanes are used in admixture with silicon compounds selected from the group consisting of silica gel, silicates and/or zeolites, and aluminum compounds.

5. The process according to claim 1, wherein the Puzzolanes are used in admixture with elemental sulfur.

6. The process according to claim 5, wherein the sulfur is impregnated or sintered onto the Puzzolanes.

7. The process according to claim 1, wherein the Puzzolanes are mixed and/or impregnated with a component selected from the group consisting of, sulfides, polysulfides, thionates, polythionates, sodium tetrasulfides, metal salts, a catalytically active substance and any combination thereof, or wherein the Puzzolanes are charged with a component selected from the group consisting of elemental sulfur, water glass and any combination thereof or wherein the Puzzolanes are mixed with activated Trass.

8. The process according to claim 7, wherein the metal salts comprise vanadium, tungsten, titanium, palladium, rhodium, platinum, auer metal, Raney nickel, manganese oxide, Vanadium pentoxide, samarium(III)-oxide and/or Hopcalite or any combination thereof.

9. The process according to claim 1, wherein the Puzzolanes are mixed with coke, activated carbon and/or alkaline components or any combination thereof.

10. The process according to claim 1, wherein the fluid is purified from exhaust gases.

11. The process according to claim 1, wherein the purification comprises removal of contaminants from the fluid selected from the group consisting of mercury, heavy metals, nitric oxide, dioxines, chlorinated furanes, chlorinated hydrocarbons, aromatic hydrocarbons, carbon monoxide, hydrochloric acid, sulfur dioxide, sulfur hydride, bacteria, fungi, biological debris and any combination thereof.

12-13. (canceled)

Description

EXAMPLES

Example 1

Use of the Natural Puzzolan Vulkanit 500 for Purifying Exhaust Gases

[0061] 27 l of a gas exhibiting the following pre-determined composition

TABLE-US-00001 Nitrogen 90 Vol.-% Oxygen 10 Vol.-% HCl 18.1 mg/l Humidity 0.15 g/l Hg (als HgCl.sub.2) 4.428 g

[0062] has been guided at a rate of approx. 2.2 l/min at 170 C. through a tube containing 150 mg of a natural Puzzolane (Vulkanit 500, Hauri, Germany; active surface according to BET about 11; Blaine-value about 14.000). In the gas collected after the tube 0,931 g mercury could be found, which corresponds to an adsorption of mercury of about 78.9%.

Example 2

Comparative Assays

[0063] The experiment of Example 1 was repeated under the same conditions as above with the proviso of using the following materials: [0064] A) 150 mg Vulkanit 500 & 150 mg Chalk; [0065] B) 150 mg Chalk; [0066] C) 150 mg Bavarian Trass (Surface according to BET 22 m.sup.2/g); [0067] D)150 mg SiO.sub.2 [0068] E) 150 mg Na.sub.2SiO.sub.4 [0069] E) 150 mg Al.sub.2O.sub.3

[0070] The following results for mercury adsorption by the respective material could be determined: [0071] A) 83.2% [0072] B) 4.7% [0073] C) 12% [0074] D) 10.6% [0075] E) 8.4% [0076] F) 26.4%

[0077] From this it follows that mercury deposition of the Puzzolane used in Example 1 may be increased approximately additively by using in chalk in admixture. On the other hand, Bavarian Trass exhibiting an active surface nearly twice as large as Vulkanit 500 did only yield a mercury deposition of about 12%. In addition, the substances, which may be dissolved away from the Puzzolane (silicon-/aluminium-compounds) did not yield results, which could by means of addition equal to the results obtainable with Vulkanit 500 alone.

Example 3

Use of the Natural Puzzolane Vulkanit 500 in Admixture With Sulphur 27 1 of a gas exhibiting the following pre-determined composition:

[0078]

TABLE-US-00002 Nitrogen 90 Vol.-% Oxygen 10 Vol.-% HCl 18.1 mg/l Humidity 0.15 g/l Hg (als HgCl.sub.2) 4.428 g

[0079] were guided at 170 C. through a tube containing 150 mg of a mixture consisting of 125 mg Vulkanit 500 and 25 mg sublimed sulphur (corresponds to a ratio of 5:1). 0.079 g mercury could be found in the gas after having passed the tube, which correspond to a mercury deposition of about 98.21%.

Example 4

Use of the Natural Puzzolane Vulkanit 500 in Admixture With Sulphur and Chalk 27 1 of a gas exhibiting the following pre-determined composition:

[0080]

TABLE-US-00003 Nitrogen 90 Vol.-% Oxygen 10 Vol.-% HCl 18.1 mg/l Humidity 0.15 g/l Hg (als HgCl.sub.2) 4.428 g

[0081] were guided at 170 C. through a tube containing 150 mg of a mixture consisting of 125 mg Vulkanit 500 and 25 mg sublimed sulphur (corresponds to a ratio of 5:1) and 150 mg Chalk (Marker Zement, Harburg, Germany). In the gas having passed the tube merely 0.001 g mercury could be found, which correspond to a mercury deposition of about 99.98%.

Example 5

Use of the Natural Puzzolane SP 90

[0082] 27 l of a gas exhibiting the following pre-determined composition:

TABLE-US-00004 Nitrogen 90 Vol.-% Oxygen 10 Vol.-% HCl 18.1 mg/l Humidity 0.15 g/l Hg (als HgCl.sub.2) 4.428 g

[0083] were guided at 170 C. through a tube containing 150 mg of a mixture consisting of 150 mg SP 90 (Hauri, Germany, Blaine-value about 9000) (corresponds to a ratio of 5:1). In the gas having passed the tube mercury could be found in an amount of 1.204 g, which correspond to a mercury deposition of about 72.8%.

Example 6

Use of the Natural Puzzolane SP 90 in Admixture With Sulphur

[0084] 27 l of a gas exhibiting the following pre-determined composition:

TABLE-US-00005 Nitrogen 90 Vol.-% Oxygen 10 Vol.-% HCl 18.1 mg/l Humidity 0.15 g/l Hg (als HgCl.sub.2) 4.428 g

[0085] were guided at 170 C. through a tube containing 150 mg of a mixture consisting of 125 mg SP 90 (Hauri, Germany, Blaine-value about 9000) and 25 mg sublimed sulphur (corresponds to a ratio of 5:1). In the gas having passed the tube mercury could be found in an amount of 0.191 g, which correspond to a mercury deposition of about 95.69%.

Example 7

Use of the Natural Puzzolane Vulkanit 500 in the Prufication of Water

[0086] Different comparative assays were prepared by transferring Vulkanit V500 into graduated flasks up to a filling level of 200 ml and adjusting the volume to 1 liter with water, exhibiting a pH of 7.5 (assays : (A1, A2, A3, A4, A5, A6) and 6,0 (assays: B1, B2, B3, B4) and pH 3.0 (assays: C1, C2, C3, C4) (pH adjusted with 1N HCl). The volumes were transferred in stirring flasks and the volumes have been treated as follows:

TABLE-US-00006 (A1) stirring at 25 C. for 1 hours; (A2) stirring at 90 C. for 1 hour at reflux (A3) stirring at 25 C. for 6 hours (A4) stirring at 90 C. for 6 hours at reflux (A5) stirring at 25 C. for 24 hours (A6) stirring at 90 C. for 24 hours at reflux (B1) stirring at 25 C. for 1 hours (B2) stirring at 90 C. for 1 hour at reflux (B3) stirring at 25 C. for 6 hours (B4) stirring at 90 C. for 6 hours at reflux (C1) stirring at 25 C. for 1 hours (C2) stirring at 90 C. for 1 hour at reflux (C3) stirring at 25 C. for 6 hours (C4) stirring at 90 C. for 6 hours at reflux

[0087] In the assays A1-A6, B1-B4 and C1-C4 the amount of material dissolved away was determined. The following results had been achieved:

TABLE-US-00007 (A1) 0.4% (A2) 1.8% (A3) 1.3% (A4) 4.7% (A5) 3.4% (A6) 5.9% (B1) 6.7% (B2) 9.4% (B3) 13.6% (B4) 27.8% (C1) 17.4% (C2) 24.6% (C3) 31.2% (C4) 36.3%

[0088] It could be further determined (results not shown) that at a given temperature a prolongation of the treatment time period and/or a reduction of the pH-value did result in an increased excavation of material up to a certain upper level.

[0089] The above assays were repeated as described with the proviso that the solution contained 2 g HgCl.sub.2. The amount of mercury remaining in the water after the respective treatment has been determined and the following results have been obtained (indicated in g determined in solution and percentage bound to Puzzolanes).

TABLE-US-00008 (A1) 1.99 g (0.5%) (A2) 1.96 g (2.0%) (A3) 1.97 g (1.5%) (A4) 1.81 g (9.50%) (A5) 1.87 g (6.5%) (A6) 1.26 g (37.0%) (B1) 1.15 g (42.5%) (B2) 0.99 g (50.5%) (B3) 0.88 g (56.0%) (B4) 0.58 g (71.0%) (C1) 0.78 g (61.0%) (C2) 0.61 g (69.5%) (C3) 0.46 g (77.0%) (C4) 0.38 g (81.0%)

[0090] As may be seen from the above results the Puzzolanes show a surprisingly increased adsorptive capacity when about 5% by weight or more of silicon-/aluminium-compounds have been dissolved away from the material. In theory this may be in part be explained in that upon removing such an amount of releasable matter, internal surface area so far closed and hidden is now made accessible for adsorption.