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BR-102021022006-B1 - SYSTEM, INSTALLATION AND PROCESS FOR AMMONIA RECOVERY FOR AMMONIUM SULFATE PRODUCTION

BR102021022006B1BR 102021022006 B1BR102021022006 B1BR 102021022006B1BR-102021022006-B1

Abstract

SYSTEM, INSTALLATION AND PROCESS FOR AMMONIA RECOVERY FOR AMMONIUM SULFATE PRODUCTION. Hereinafter referred to as URA, consisting of a liquid waste pre-treatment unit (1); which, in turn, is connected to an alkalization unit (2) that receives the pre-treated liquid waste, which is stored in a hermetically sealed accumulation buffer tank to then be pumped to a hydraulic mixer, where it receives an injection of alkalizing solution, in line, by a dosing pump controlled by a process pH meter, continuing then until it reaches the reactor unit (3), which promotes the volatilization of ammonia by a high-pressure spray process (3A) and a mechanical agitation process by swirling (3B); whereby the ammonia gas and air mixture resulting from these processes is conveyed, by means of a centrifugal blower unit (C), to an ammonium sulfate production unit, comprising a reactor (4), where the pressurized gas and air mixture is diffused into a sulfuric acid solution using fine or ultrafine bubble diffusers, whereupon the chemical reaction of ammonia gas with sulfuric acid occurs, to produce ammonium sulfate in a concentrated solution, which is finally conveyed to a storage unit (...).

Inventors

  • LUIS FRANCISCO LOPES NOBRE

Assignees

  • LUIS FRANCISCO LOPES NOBRE

Dates

Publication Date
20260317
Application Date
20211103

Claims (7)

  1. 1- “AMMONIA RECOVERY SYSTEM FOR AMMONIUM SULFATE PRODUCTION” - URA system, characterized by the fact that it consists of a liquid waste pre-treatment unit (1); which, in turn, is connected to an alkalization unit (2) that receives the pre-treated liquid waste, which is stored in a hermetically sealed accumulation buffer tank to be pumped from there to a discharge line to the reactor unit (3); which promote the volatilization of ammonia by spraying processes (3A), with condensation of mist in a support medium of high specific area, increasing the liquid-atmosphere interface and by a swirling process (3B) in turbulent hydraulic regime; The mixture of volatilized ammonia gas and air from the reactor atmosphere resulting from these processes is conducted, by means of a centrifugal blower unit (C), to an ammonium sulfate production unit, comprising a reactor (4), where the pressurized gas and air mixture is diffused into a sulfuric acid solution using fine or ultrafine bubble diffusers, whereupon the chemical reaction of ammonia gas with sulfuric acid occurs, to produce ammonium sulfate in a concentrated solution; which is then conducted to a storage unit (5).
  2. 2- “AMMONIA RECOVERY INSTALLATION FOR AMMONIUM SULFATE PRODUCTION”, characterized by comprising a liquid pre-treatment unit (1) defined by a hermetic storage tank (1.1) equipped with a frequency-controlled pumping unit (1.2) that conveys the liquid residue through filter elements (sand and/or activated carbon) that remove particulate matter and soluble organic matter from the liquid residue; the alkalization unit (2) is defined by a hermetically sealed accumulation buffer tank (2.1) for storing the pre-treated liquid, from which it is pumped by a dosing pump (2.2), receiving in the discharge line an injection of alkalizing solution carried out by a dosing pump (2.3), which is automatically controlled according to the pre-established pH “setpoints” and then continues its path, being conducted to a pressurized hydraulic mixer (2.4), to sequentially reach the reactor unit (3); the latter being composed of at least two reactors (3A, 3B) with distinct characteristics; so that both reactors (3A, 3B) provide a device for discharging liquid effluent including a water seal to prevent air admission; whereby the ammonia gas (NH3 gas) volatilized mixes with the air contained in the atmospheres of the reactors (3A and/or 3B) and this mixture (NH3 gas) + air is drawn in by a centrifugal blower (C) and pumped into a reactor (4), where it is diffused into a sulfuric acid solution, by fine or ultrafine bubble diffusers, giving rise to the chemical reaction of ammonia gas with sulfuric acid and the production of a concentrated ammonium sulfate solution, which in batch form is sent to a storage and quality control reservoir (5).
  3. 3- “AMMONIA RECOVERY INSTALLATION FOR AMMONIUM SULFATE PRODUCTION”, according to claim 2, characterized in that the reactor unit (3) comprises a reactor (3A) of the type employing specialized spray nozzles for volatilization of solubilized ammonia (NH3aq) by high-pressure spraying of the pre-treated and alkalized liquid residue; having inside it a support medium of high specific area for condensation of mist and volatilization of residual ammonia still solubilized (NH3aq) in the liquid residue, by increasing the contact area of the liquid-atmosphere interface; employing air intake/release control valves as a function of the atmospheric pressure “setpoint” provided in the Reactor (3A); and comprising a reactor (3B) of the type employing a mechanical mixer designed to achieve high turbulence (Reynolds > 150,000), equipped with air intake/release control valves based on the atmospheric pressure “setpoint” predicted for the Reactor (3B).
  4. 4- “AMMONIA RECOVERY INSTALLATION FOR AMMONIUM SULFATE PRODUCTION”, according to claim 3, characterized by the fact that the URA installation also provides for the interconnection of the reactor atmosphere (4) with reactors (3A) and (3B) for closed-circuit recirculation of the mixture (AG) of ammonia gas (NH3 gas) and air contained in the atmospheres of these units of the installation.
  5. 5- “PROCESS FOR AMMONIA RECOVERY FOR THE PRODUCTION OF AMMONIUM SULFATE”, characterized by comprising the following steps: a) storing the liquid waste to be treated; b) filtering the liquid waste to remove particulate matter and soluble organic matter; c) storing the filtered waste in a hermetically sealed accumulation tank; d) alkalizing the pre-treated liquid waste by means of in-line injection of an alkalizing solution; e) promoting the volatilization of solubilized ammonia (NH3aq) in the pre-treated and alkalized liquid waste, changing the state of the solubilized ammonia (NH3aq) in aqueous solution to the gaseous state (NH3 gas); The resulting gas mixture is then subjected to a pumping step (f) to a reactor where a chemical reaction occurs between ammonia (NH3 gas) and sulfuric acid, generating a concentrated or saturated solution of ammonium sulfate, which is finally subjected to a batch conveying step (g) to a storage and quality control reservoir.
  6. 6- “PROCESS FOR AMMONIA RECOVERY FOR THE PRODUCTION OF AMMONIUM SULFATE”, according to claim 5, characterized by the fact that step d) of injecting an alkalizing solution is carried out in a controlled manner by a process pH meter, to reach the pre-established pH setpoint, situated between 9.5 and 12, depending on the chemical characteristics of the pre-treated liquid residue.
  7. 7- “PROCESS FOR RECOVERING AMMONIA FOR THE PRODUCTION OF AMMONIUM SULFATE”, according to claim 5, characterized by the fact that step e) of volatilization of ammonia solubilized in the alkalized liquid residue (NH3aq), combines the effects of mechanical energy transmission in the form of work by high-pressure spraying and/or by turbulent hydraulic agitation of the pre-treated and alkalized liquid residue, with a Reynolds number above 150,000; wherein the high-pressure spraying process, in addition to transmitting mechanical energy in the form of work to the liquid residue, allows the condensation of mist in a support medium with a high specific area; wherein the turbulent hydraulic agitation process employs a mechanical mixer dimensioned to achieve high turbulence (Reynolds > 150,000); seeking to transmit high rates of mechanical energy to the volume of pre-treated and alkalized liquid residue.

Description

[001] - This report refers to a system, installation and process for ammonia recovery for the production of ammonium sulfate, hereinafter referred to simply as URA. This system is intended for the production of a saturated ammonium sulfate solution, using ammonia in its gaseous form as input, which is recovered from liquid waste containing high concentrations of ammoniacal nitrogen, such as leachate from landfills. [002] - As is known to those skilled in the art, the industrial production of ammonium sulfate employs several techniques, among which are: - the reaction of ammonia gas with sulfuric acid, these industrial inputs being available on the market, called the synthetic route; - the co-production of ammonia in the production of chemical compounds such as caprolactam, acrylonitrile and methyl methacrylate used for the manufacture of synthetic fibers; and - from ammoniacal vapors from the destructive distillation of coal, reacting with commercial sulfuric acids. [003] - Currently, what is practiced, from the point of view of contaminated liquid effluents such as landfill leachate, industrial liquid waste or effluents resulting from treatment processes in Wastewater Treatment Plants (WWTPs), is to take these liquid wastes, containing nitrogen, to Wastewater/Liquid Waste Treatment Plants for specific biological and/or physicochemical processing, in order to allow their discharge into receiving water bodies. [004] - The attenuation of NH3 emissions into the environment is carried out in wastewater treatment plants, transforming it into nitrates and nitrites and/or nitrogen gas, as well as by dispersing ammonia gas (NH3 gas) into the atmosphere. [005] - It is also known, by experts in the field, that national and international legal standards establish maximum quality standards that limit the discharge of liquid waste containing nitrogen into receiving water bodies and/or the atmosphere. [006] - Therefore, it becomes necessary to take these wastes to Treatment Plants and subject them to processes to reduce concentrations. This way of solving the problem consists of treating liquid wastes containing nitrogen through biological/physico-chemical processes to reduce the nitrogen concentration and reach the qualitative standard required for discharge into the environment. [007] - Among these processes, the most commonly used are biological processes, which oxidize nitrogen at the cost of high electrical energy consumption. [008] - In a few cases, the treated effluent from biological processes is subjected to physicochemical processes to volatilize residual ammonia not removed by the biological processes. These ammonia volatilization processes via physicochemical routes are carried out in towers similar to industrial water cooling towers. It is worth adding that the ammonia gas volatilized in these processes is released into the atmosphere, which can result in dangerous air pollution incidents. [009] - In any case, these treatment processes significantly increase the investment and operating costs of conventional Wastewater Treatment Plants (WWTPs). [010] - Although these processes used in WWTPs are known, generally, public or private treatment systems are not prepared to reduce the nitrogen load contained in their effluents, which is the most evident cause of the high costs required for investments in WWTP modernization and operational costs due to the large increase in electricity consumption. [011] - This lack of preparedness of conventional public systems in reducing nitrogen load results in systematic non-compliance with environmental legislation in developing countries, especially pollution of inland waters with various environmental consequences, including the effect of nitrogen on the decline in the quality of water sources. [012] - In addition to water pollution, there can also be situations of air pollution. This occurs in landfills, due to the need to store leachate in lagoons, thus making the volatilization of ammonia gas inevitable, freely released into the atmosphere and generating significant environmental and social impacts in the vicinity of such lagoons. [013] - Even with the evolution, over the last 50 years, of techniques to mitigate the environmental impact of the release of nitrogen pollutants into water, the technical bases have remained fundamentally the same, while process management and control techniques have advanced more sharply. Therefore, treatment plants continue to have high investment and operating costs. [014] - Thus, the central objective of the present invention is to make available a technically and economically efficient ammonia recovery system for the production of ammonium sulfate, whose recovery of ammoniacal nitrogen and its conversion into a chemical product presents itself as an advantageous alternative both by reducing costs in investments in WWTPs, and by saving electrical energy used in these treatments, in addition to generating a chemical product of significant ec