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EP-3870356-B1 - A PROCESS FOR REDUCING AMMONIA LOSS FROM ORGANIC MATERIAL TO THE ATMOSPHERE

EP3870356B1EP 3870356 B1EP3870356 B1EP 3870356B1EP-3870356-B1

Inventors

  • INGELS, RUNE

Dates

Publication Date
20260506
Application Date
20191023

Claims (12)

  1. A process for reducing ammonia loss from organic material to the atmosphere, comprising feeding air to a plasma generator and producing a concentration of 0.1-12% by volume of NOx in the air by direct nitrogen fixation; feeding the air containing NOx from the plasma generator to an absorption system comprising at least two absorption loops, wherein a first absorption liquid comprising liquid organic material is circulating in the first absorption loop and a second absorption liquid is circulating in the second absorption loop; absorbing the air containing NOx into the first absorption liquid and forming an acidic solution comprising nitrates and nitrites which brings the pH down to below 6 which is stopping the ammonia loss from organic material to the atmosphere; feeding off gases containing NO from the first absorption loop to the second absorption loop, and absorbing the off gases containing NO into the second absorption liquid having a lower pH than the first absorption liquid; oxidizing remaining NO in off gases from the second absorption loop to NO 2 .
  2. The process of claim 1, wherein the first absorption liquid has a pH of 4-6, particularly pH 5-6, and more particularly 5.5-5.8.
  3. The process of claim 1 or 2, wherein the second absorption liquid has a pH of 2-4, particularly pH 2-3, and more particularly 2-2.75.
  4. The process according to any of the preceding claims, wherein the first absorption loop comprises a first gas mixer or ejector, an optional separator, a first circulation pump and a first circulation tank.
  5. The process according to claim 4, wherein the first absorption loop further comprises a separator between the first ejector and the first circulation tank.
  6. The process according to any of the preceding claims, wherein the second absorption loop comprises a second ejector, a first absorber, an oxidation device, a second circulation pump and a second circulation tank.
  7. The process of any of the preceding claims, wherein acid is added to the second absorption loop, the acid is preferably selected from nitric acid, sulfuric acid or phosphoric acid.
  8. The process of any of the preceding claims, wherein off gases containing NO 2 from the second absorption loop are fed to a third absorption loop and absorbed into a third absorption liquid circulating in the third absorption loop.
  9. The process of claim 8, wherein the third absorption loop comprises a third ejector, a second absorber, a third circulation pump and a third circulation tank.
  10. The process of claim 8 or 9, wherein the third absorption liquid comprises liquid organic raw material.
  11. The process of any of claims 8-10, wherein the third absorption loop has a pH 7-7.5, particularly pH 7-7.3, and more particularly pH 7-7.2.
  12. The process of any of the preceding claims, wherein off gas comprising NO 2 from the second absorption loop is fed to a third absorption loop operating at pH 7-7.5, and remaining NOx is absorbed and diluted into a raw material tank.

Description

Technical field The invention relates to a cost effective process suitable for treating organic material, such as manure, organic waste or biogas-residue, to obtain nitrogen and nitrate enrichment, ammonia loss reduction, inhibition of biological nitrification and de-nitrification, elimination of multi-resistant bacteria and odor elimination. Background of the invention Prior art has not been able to successfully and in a practical way solve the agronomic nitrogen limitation originating from ammonia losses, to meet crop demand as well as the environmental challenges observed when manure and organic waste is used as fertilizer. The ammonia loss from manure and organic waste is in general addressed by applying various chemicals of acidic character, driving pH down to pH 4-5 and or binding ammonia as a salt. Odor has been treated with many standard odors suppressing agents. Ammonia emissions and effluents have been reduced through thermal stripping and subsequent absorption by means of a suitable mineral or organic acid. Air and oxygen treatment and use of oxidizing mineral acids like sulfuric and phosphoric acids have reduced the ammonia loss, but not helped the nutrient balance, not eliminated the odors nor helped stopping primary and secondary N2O emissions. EP2788037A1/WO2013085395A1 "Processes and plants for reducing ammonia loss and odor from organic material or waste to the atmosphere", is describing a process where air plasma or enriched air plasma is used to acidify and produce a concentration of 0.1-12% by volume of NOx in the air by direct nitrogen fixation, absorbing the NOx into an absorption liquid to form an acidic nitrogen solution, and feeding the solution to the organic material or waste. The technique is sensitive to electric power price, energy efficiency and is not giving the optimum acidification reactions. US5192355 "Manufacturing and using nitrogen fertilizer solutions on a farm" refers to a process where nitrous oxides are produced from an arc system. The oxides are introduced to water to produce an acidic nitrogen solution comprising nitrates and nitrites. To this solution, other reactants are added to produce a liquid fertilizer. The invention is conceptual and producing concentrated nitric acid and mineral fertilizer solutions according to standard industrial principles. US 2110431 "Process for the absorption of nitrogen oxides from gases" describes a process for the absorption of nitrogen oxides from gases leaving an acid absorption system of a nitric acid plant. US 4276276 "Process for nitrite production" describes a process which by controlling the oxidation of nitric oxide permits reduced emission of nitrogen oxides and increased yield in the production of ammonium nitrite and alkali metal nitrites. The ammonia loss of 30-40% from the livestock farming, must be compensated from industrially produced ammonia, based on fossil fuels and the Haber Bosch process. The production and logistic cost of this ammonia is creating additional greenhouse gas emissions in the form of CO2 and N2O. The global industrial production of nitrogen fertilizer corresponds to the loss from livestock farms, food waste and low nitrogen use efficiency of mineral fertilizers. The overall science and chemistry involved can be described in: 1) All organic materials contain chemically bound nitrogen and other nutrients. The nitrogen is in the form of ammonia typically from urea, uric acid and proteins. Organic waste is nutrients and energy on the way to be lost. The best way to recover the nutrients has been to recycle the organic waste and manure back to the fields as fertilizer. This practice has reduced the demand for phosphate fertilizer by 30-40% inside the EU over the last 20 years. However, nitrogen is still being lost. The loss is coming from the microbial enzymatic activity releasing free ammonia, where according to global figures, 30% is lost to air and 10% is lost to water through leaching due to a low Nitrogen Use Efficiency, NUE. The loss reaction from urine starts with hydrolysation of urea which is described in equation la, and the general mineralization of organic material results in ammonium carbonates, aqueous ammonia and carbonic acid which is lost as volatile ammonia and carbon dioxide as in equation Ib.         (NH2)2CO + 3H2O = (NH4)2CO3 + H2O = NH4HCO3 + NH4OH     la         2NH4OH + H2CO3 = 2NH3(g) + CO2(g) + 2H2O     IbThe carbon dioxide is very volatile and is directly lost to the air, resulting in an increased pH to 9-10 of the organic material and the subsequent loss of the ammonia, proportional to the initial loss of CO2.2) The N to P2O5 ratio in organic material is too low for a balanced fertilization. The content of nitrogen should typically be double of the P2O5 to meet the nutrient demand of most crops.3) The ammonia emissions and secondary N2O emissions from manure processing, storage and field application are significant contributions to global warming. The ammonia emitted f