REDUCTION OF POLLUTANT EMISSIONS OF INTERNAL COMBUSTION ENGINES

Abstract

Method for reducing the pollutant emissions of internal combustion engines, wherein an aqueous solution containing glyoxal and a polymer product of citric acid and glycerol is added as an additive, additive for reducing the pollutant emissions of internal combustion engines, said additive consisting of an aqueous solution containing glyoxal and a polymer product of citric acid and glycerol, and the use thereof for reducing pollutant emissions.

Claims

1. Method for reducing the pollutant emissions from combustion engines, comprising providing an aqueous solution containing a polymer product of citric acid and glycerine as an additive and supplying the additive to a combustion chamber of the combustion engine.

2. Method according to claim 1, wherein the additive further contains glyoxal.

3. Method according to claim 2, wherein the additive is injected directly into the combustion chamber by a high-pressure pump system.

4. Method according to claim 3, wherein a volume ratio of glyoxal to polymer product of citric acid and glycerine ranges from 10:1 to 1:1.

5. Method according to one of claim 2, wherein the cooling requirement of the combustion engine is regulated by varying an amount of water of the additive.

6. Method according to claim 2, wherein the additive is introduced into a suction tract of the combustion engine.

7. Method according to claim 6, wherein a volume ratio of glyoxal to polymer product of citric acid and glycerine ranges from 1:10 to 1:1.

8. Method according to claim 1, characterised in that an aqueous glyoxal solution is supplied directly into the combustion chamber and the additive is supplied into a suction tract of the combustion engine.

9. Method according to claim 8, wherein the aqueous glyoxal solution is injected into the combustion chamber by a high-pressure pump system and the additive is evaporated in the suction tract via an air filter being soaked with it.

10. Additive for reducing the pollutant emissions of combustion engines consisting of an aqueous solution containing a polymer product of citric acid and glycerine.

11. Additive for reducing the pollutant emissions of a combustion engine consisting of an aqueous solution containing glyoxal and a polymer product of citric acid and glycerine.

12. Additive according to claim 11, characterised in that a volume ratio of glyoxal to polymer product of citric acid and glycerine for a direct injection into a combustion chamber of the combustion engine ranges from 10:1 to 1:1.

13. Additive according to claim 11, characterised in that a volume ratio of glyoxal to polymer product of citric acid and glycerine for an introduction into a suction tract of the combustion engine ranges from 1:10 to 1:1.

14. (canceled)

15. (canceled)

16. (canceled)

17. Method according to claim 1, wherein the additive is injected directly into the combustion chamber by a high-pressure pump system.

18. Method according to claim 17, wherein a cooling requirement of the combustion engine is regulated by varying an amount of water of the additive.

19. Method according to claim 1, wherein the additive is introduced into a suction tract of the combustion engine.

20. Method according to claim 19, wherein the additive is evaporated in the suction tract via an air filter being soaked with it.

21. Method according to claim 8, wherein the aqueous glyoxal solution is supplied directly into the combustion chamber and the additive is supplied into a suction tract of the combustion engine.

22. Method according to claim 2, wherein an aqueous glyoxal solution is injected into the combustion chamber by a high-pressure pump system and the additive is evaporated in a suction tract of the combustion engine via an air filter being soaked with it.

Description

EXAMPLE 1

[0026] To produce the citric acid polymerisate, 30 g citric acid monohydrate was stirred with 15 g glycerine in a glass with the aid of a motorically operated whisk and placed in a conventional domestic microwave (here Koenic KMW 4441 DB model) with a nominal power of 1450 Watt and frequency of 2450 MHz. The mixture was heated for 2 minutes. Here, the formation of steam on the upper glass edge could be observed. After cooling, a clear viscous mass was obtained which could be easily dissolved in water.

EXAMPLE 2

[0027] With a first experiment on a Mini Cooper D, the air filter was soaked with 40 ml of a 50% solution made of citric acid polymerisate and water (PCS), namely before kilometre 106,411 and before kilometre 106,930. In addition, before kilometre 106,943, 20 ml of 40% glyoxal solution (GR) was added in the air filter instead of water. With a 35 l tank capacity, this corresponds to an additive amount of 0.5 per mille of active substance per 1 l fuel before kilometre 106,411 and 0.5 per mille before kilometre 106,930 plus 8 ml glyoxal corresponding to 0.2 per mille per 1 l diesel before kilometre 106,943.

[0028] In FIGS. 1a and 1b, the results of the measuring of turbidity are depicted in 1/m and of absorption in %. It was measured according to the official German measuring process for the emissions test. Both the turbidity and the absorption are a measure for the number of carbon black particles in the exhaust gas. Based on a starting turbidity of 14.1 1/m, a reduction to 1 1/m could be achieved by the soaking of the air filter with citric acid polymerisate corresponding to the method according to the invention. The additional addition of glyoxal solution led to a further reduction to 0.3 1/m. As the results show, reductions of the pollutant emissions being unknown up until now can thus be achieved with the method according to the invention, in particular with using of the combination of citric acid polymerisate with glyoxal. Reductions of the particulates of approximately 100% were obtained. As FIG. 1b shows, the improvement persisted for more than one year even without further addition.

EXAMPLE 3

[0029] In a second experiment on a VW Touareg R50, at first 100 ml of a 40% glyoxal solution was placed in the two air filters (before km 148,706). Moreover, according to the invention, 100 ml of a 50% citric acid polymerisate solution was placed in the two air filters. With a tankful of 80 l diesel, the addition of 100 ml glyoxal solution and 100 ml citric acid polymerisate solution corresponds to an additive amount of 0.5 per mille in one litre of diesel. Before the 4th test, there was 0.65 per mille active substance per 1 l diesel (tankful 76 l diesel), wherein it is assumed that only a fraction reaches the combustion chamber via the suction tract, probably in the microgram range.

[0030] The measured values for turbidity and absorption are depicted in FIGS. 2a and 2b. It is recognised that, once again, very significant pollutant reductions were achieved. With the addition of glyoxal solution alone that took place as a comparison, a reduction of turbidity from 10 1/m to 9 1/m resulted. The additional addition of citric acid polymerisate solution obtained a decrease to 4.8 1/m. However, it is assumed that, when adding the citric acid polymerisate, the glyoxal was already used up (increase of the turbidity to 9.5 1/m at kilometre 148,782). The addition of the combination of glyoxal and citric acid polymerisate solution before kilometre 149,135 led to a drastic reduction of the turbidity to 2.2 1/m. FIG. 2b shows that the values even improved over more than one year without any further addition.

[0031] The particulates with diesel engines consist of a considerable amount of carbon black, an energy carrier, which is therefore not used. The extreme decrease of the unburnt material in purely mathematical terms leads to the conclusion of a consumption reduction. Evidence regarding this could be found in empirical values of 7 different motor vehicles (BMW 530 Diesel, BMW 750 12-Cylinder, 3 Audi A6 Diesel of various classes, Mini Cooper D, VW Touareg R50). Consumption reductions of 12.5 to 20% were found, depending on the driving mode and motor vehicle, from which, in turn, a reduction of the CO.sub.2 emissions and, as a result of the added supply of energy carrier, here coal dust, a power increase can be deduced.

[0032] It is proven that glyoxal as fuel additive reduces the emission of CO.sub.2, hydrocarbons, and NO.sub.x, and decreases consumption, too. This also happens when supplying it as component of the additive according to the invention. In the preferred embodiment, where the additive consists of an aqueous solution of glyoxal and citric acid polymerisate, also a synergistic reduction of particulates emission, consumption, and emission of CO, hydrocarbons, and nitrous oxides is achieved by one single additive. Problems of phase separation and demixing, which occurred for the known addition to fuel are not to be expected in the case of aqueous solutions.