DK143163B - PROCEDURE FOR COMPLETE OR PARTIAL NEUTRALIZATION OF THE SUBSEQUENTLY FUEL CONSUMPTION PRODUCED ACID COMBUSTION PRODUCTS AND THE USE OF THE PROCEDURE - Google Patents

Description

(11) PUBLICATION 143163 (61) Appendix to Patent No. 140343 DENMARK (BD int.ci.3 c 10 l 10/00 • (21) Application No. 3637/78 (22) Filed on 17 · 3-Aug. 1978 (24) Race day 3 Mar. 1978 (44) The application submitted and

the petition for publication published on July 6. 1 98I

DIRECTORATE OF

PATENT AND TRADEMARKET SYSTEM (30) Priority * 0 · «from (41) Aim. avail. Sep 4 1979 (71) HANS CHRISTIAN MAACK ANDERSEN, Nylandsalle 13, 8700 Horsens, DK.

(72) Inventor: Same.

(74) Plenipotentiary in the proceedings:

International Patent Office.

(54) A method of completely or partially neutralizing the acidic combustion products formed by the combustion of sulfur-containing fuels, and means of use in the practice of the process.

Patent No. 14o.343 relates to a method for completely or partially neutralizing the acidic combustion products formed by combustion of sulfur-containing fuels by continuously injecting basic substances into the combustion zone, and the peculiar according to the main patent is the simultaneous injection of the following compounds: a) sodium or potassium nitrate b) ammonium nitrate c) magnesium carbonate d) carbon, and e) ammonium carbonate.

Said patent further relates to an agent for use in the process which is characterized in that it comprises a mixture of the compounds mentioned under a) -e).

It has now been found that it is possible to obtain even better results by altering the method and agent of said patent, which consists in replacing the magnesium carbonate in whole or in part by calcium hydroxide.

In the said change, calcium hydroxide is used as a substitute for an equal amount of weight of magnesium carbonate, so the sum of the weight percent of magnesium carbonate and calcium hydroxide falls within the limits set out in the main patent claims 2 and 5 for magnesium carbonate, i.e. between 15 and 40% by weight.

Preferably, the total amount of magnesium carbonate is replaced by calcium hydroxide.

The process of the process and the composition of the agent are otherwise unchanged from that of the main patent.

The reason that the use of calcium hydroxide with the other components considered seems to provide a more effective acid neutralization than the use of magnesium carbonate with said additional components cannot be stated with certainty, as it cannot be precisely stated which chemical reactions actually occur. takes place under the conditions prevailing in the combustion zone. However, it is believed that the greater ability of the calcium hydroxide to release ammonia from the ammonium carbonate is essential for the improved result.

The amount of altered agent to be used per day. kg of sulfur in the fuel is the same as for the agent according to the main patent.

The process according to the invention is further illustrated by the following examples

Example 1 In a heat plant the firing was carried out with oil containing 2.5% sulfur.

A probe was introduced into the chimney vent, and by means of a constant-speed vacuum pump, flue gas was sucked through two series of bottles containing 10% by weight aqueous sodium carbonate solution. At each experiment, the bubbling was done for 1/2 hour.

Experiments were carried out partly while the fire burned without blowing in the agent in question and partly while in an amount of approx. 5 kg per tonnes of oil were blown with an agent of the following composition: potassium nitrate 38% by weight ammonium nitrate 11% by weight calcium hydroxide 25% by weight carbon 3% by weight ammonium carbonate 23% by weight

The sulfite content was determined partly in a sodium carbonate solution through which the smoke was bubbled for 1/2 hour without using the agent in question (A), and in similar solutions where the flue gas was bubbled, also for 1/2 hour with the agent in question dosed in the flame (B), and finally the sulfite content was determined in a corresponding sodium carbonate solution through which no flue gas (C) was passed. The results were as follows: A. Sulfite content calculated as SC ^: 5.0 mg / liter B. "" "": 1.7 mg / liter C. (Blind sample): 0.3 mg / liter

It is noted that conditions at the time of the experiment indicated that the absorption of SO2 in the sodium carbonate solution was not complete under the conditions used. However, the fact that the amount of SC ^ absorbed by the experiment in which the agent in question was injected is less than 1/3 of the amount absorbed when no agent is injected must be taken as indicates that the use of the agent causes a drastic reduction in the amount of SO2 in the flue gas.

Example 2

Also, this example was done in a guy installed in a heating plant where the fuel was heavy fuel oil. The oil fired was a g rotary kiln and the boiler had a performance of 1.78 x 10 kcal / h and a heat surface of 60 m ^.

The agent used had the same composition as set forth in Example 1, and it was added to the boiler boiler through the secondary air system. By an ejector principle, the powder was aspirated and blown in at the suction side of the secondary air fan in an amount of 3.5 kg per unit. tons of oil.

The composition of the flue gas before and during the treatment was measured by the Jysk Technological Institute, Arhus, which among other things. a. Performed analysis for sulfur dioxide and sulfur trioxide content and controlled the flue gas temperature.

143163 4

The sulfur trioxide content was determined by extracting a partial gas stream and condensing the SO 2 content at 73 ° C and subsequently titrating the condensate with NaOH solution. Therefore, the result is given below in ml of NaOH solution consumed.

The sulfur dioxide content was determined in the gas after condensation of SO 2 by passing the gas through two successive wash bottles each containing 3% hydrogen peroxide in which the sulfur dioxide was absorbed and quantitatively determined.

The experiments were performed such that two sets of measurements were first performed without addition of the agent. Thereafter, the continuous addition of the agent was initiated and after 1/2 hour a further two sets of measurements were made. The results obtained are given in the table below:

Without Addition With Addition Change

Analysis Medium Analysis Medium% 1 I 2___3 4___

Sulfur dioxide (mg / dm3) 2.35 1.84 2.09 1.58 1.56 1.57 -25

Sulfur trioxide (ml / m3) 4 3.57 3.79 2 1.98 1.99 -47.5 Flue gas temperature (° C) 210 210 210 190 190 190 - 9.5

As can be seen from the above table, the contents of the flue gases of sulfur dioxide and sulfur trioxide were reduced by 25% and 47.5%, respectively, and a remarkable reduction in the flue gas temperature was achieved, which can be attributed to the fact that the agent was only capable of short-term use. to remove a significant amount of boiler coatings mainly consisting of soot.

It is reasonable to assume that a greater reduction of sulfur dioxide and sulfur trioxide content in the flue gas would have been found if the tests had been carried out in a boiler with smaller coatings than was the case, with some of the sulfur oxides detected by Assays 3 and 4 are believed to result from the combustion of sulfur-containing boiler coatings released by the use of the agent.