Description:TECHNICAL FIELD:

The present invention relates to the field of emission control and environmental sustainability. More specifically, the invention pertains to a novel and adaptive alkaline-based emission capture system designed to effectively capture and mitigate carbon dioxide (CO2) and other harmful gases emitted from various industrial processes using artificial intelligence.

BACKGROUND OF THE INVENTION:

One of the most pressing global challenges is climate change, driven primarily by the increase in greenhouse gas emissions such as CO2 including other harmful emissions such as NOx, CO, and SOx. Since the energy consumption of the world is increasing still fossil fuels contribute to the major portion of this energy demand. Many countries are signatories to international agreements like the Paris Agreement, which commits them to reducing greenhouse gas emissions. Carbon capture utilization and sequestration (CCUS) is a key tool to help countries meet their emissions reduction targets and fulfill their climate commitments. Carbon capture coupled with emission control systems are instrumental in reducing the concentration of CO2, NOx, CO, and SOx from any gases. By capturing these emissions from power plants, factories, and other industrial processes, the carbon capture systems can significantly reduce Scope 1 emissions and help countries meet their climate targets. Many countries rely heavily on fossil fuels for energy production. Carbon capture technology allows these nations to continue using their indigenous energy resources while reducing their carbon footprint. This enhances energy security by reducing dependence on energy imports and reducing greenhouse gas emissions. Numerous industrial processes, such as cement and steel production, emit substantial amounts of CO2. Implementing carbon capture in these hard-to-abate sectors can help reduce their carbon footprints, making them more environmentally sustainable

Further, various combustion platforms such as diesel generators, incinerators, gas turbines, and boilers generate exhaust gas containing a high concentration of pollutants. To remove contaminants contained in the exhaust gas, an absorption tower or a wet-type dust collector/ scrubber is generally used.

Specifically, the wet-type dust collecting apparatus or scrubber is a device for removing contaminants in the exhaust gas by spraying water at a high-temperature exhaust gas. However, flue gas discharged from the wet type dust collecting apparatus has high temperature and high humidity.

The flue gas contains a variety of pollutants including greenhouse gases such as SOx, NOx, PM10, and PM2.5 so the flue gas condensation and falling water contains a large amount of substances including carcinogens that are harmful to the human body, causing the the water to become polluted. This water requires subsequent treatment in an effluent treatment plant.

The various prior art systems that are used to remove CO2 gases from the exhaust of DG sets, boilers, incinerators, kilns, etc. concentrate a pure form of CO2. However, users have to bottle and store the captured CO2 until it is transported with no end in sight for warehousing costs.

Such CO2 capturing systems use amine-based chemicals which may be released as air pollutants if not adequately controlled. Particularly, volatile nitrosamines released in such systems are carcinogenic when inhaled or ingested with water. Further, the CO2 generated using these systems has to be compressed.

However, the compression of CO2 is an energy-intensive process that adds to the parasitic load and indirect emissions. It has been estimated that about 60% of the energy penalty is contributed by the capture process, 30% from the compression of CO2, and the remaining 10% is contributed by the pumps and fans.

Accordingly, there exists a need to provide a system and process for capturing gaseous emissions, which overcomes the above-mentioned drawbacks.

BRIEF DESCRIPTION OF THE DRAWINGS AND FIGURES:

Figure 1 is a schematic layout of a multi-gas emissions capturing system according to the present invention.

Figure 2 is a schematic layout of the multi-gas emissions capturing system in an embodiment of the present invention.

DETAILED DESCRIPTION:

The present invention is elucidated comprehensively with reference to the accompanying drawings. It is essential to note that the embodiment exemplified herein is not meant to impose any restrictions on the breadth of the present invention. Moreover, this embodiment is to be interpreted as encompassing structural elements that may be readily conceived by individuals skilled in the relevant field or those which are essentially indistinguishable.

The terms "an embodiment," "embodiment," "embodiments," "the embodiment," "the embodiments," "one or more embodiments," "some embodiments," and "one embodiment" signify "one or more (but not all) embodiments of the invention(s)" unless explicitly specified otherwise.

The terms "including," "comprising," and "having," and their variations signify "including but not limited to," unless explicitly specified otherwise. The enumeration of items does not imply mutual exclusivity unless explicitly specified otherwise. The terms "a," "an," and "the" indicate "one or more" unless explicitly specified otherwise.

Unless specifically defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by someone with ordinary skill in the relevant field. While various processes and materials similar or equivalent to those described herein may be used in practicing the present invention, the preferred materials and processes are disclosed in this document.

The system incorporates artificial intelligence (AI) enhancement to optimize its performance and adaptability, offering a comprehensive solution for reducing greenhouse gas emissions and promoting cleaner industrial practices aligned with the United Nations Sustainable Development Goal of Climate Action. The technology finds applications in diverse industrial sectors, including power generation, manufacturing, chemical processing, and any other activities contributing to harmful emissions.

The present invention relates to an emission-capturing system utilizing alkaline solutions to effectively capture and mitigate harmful emissions from various industrial processes. As concerns about environmental pollution and greenhouse gas emissions continue to escalate, there is an urgent need for innovative technologies to combat these challenges and promote sustainable practices. Conventional processes for emission control have often proven inadequate, and existing solutions often entail high costs, complex installations, or limited effectiveness in capturing emissions across a broad spectrum of industries.

The emission-capturing system described herein addresses these limitations by harnessing the power of alkaline solutions and wastes as a highly efficient and environmentally friendly absorbent material. Alkaline solutions and wastes have demonstrated exceptional capability in capturing carbon dioxide (CO2) and other noxious gases, making them a promising candidate for wide-scale emission reduction. The novel apparatus combines cutting-edge design and engineering principles to offer a versatile and scalable solution adaptable to diverse industrial settings, such as power plants, cement manufacturing facilities, and chemical processing units, among others.

The process and system of the present invention with its unique design and functionalities showcases its ability to achieve substantial reductions in greenhouse gas emissions and pollutants. By harnessing the potential of alkaline solutions and wastes, this technology aims to revolutionize emission control practices, aligning industries with sustainability goals and contributing to a cleaner and more ecologically balanced future.

For illustrative purposes, the present invention embodied in the system is shown and described herein with reference to Figures 1 and 2. The present invention discloses a process and system for capturing multi-gaseous emissions and optimizing its operation using artificial intelligence. The system comprises absorber (s), hopper unit, chemical tank-1, sludge tank, electronic circuit, artificial neural network, and fluid circuit. In the description herein, where certain chemicals are presented in the Sodium and Calcium form, such as Sodium Hydroxide (NaOH) and Calcium Hydroxide (Ca(OH)2, the chemicals applied to the present invention can be in any Alkali metal form. For example, where NaOH and Ca(OH)2 are used, the invention can use MOH and M(OH)n, wherein M is an alkali metal. However, the present invention is described in conjunction with NaOH and Ca(OH)2. In a preferred embodiment, the present invention provides the use of a homogenous mixture of alkali fly ash and slaked lime.

In one aspect, the present invention provides a process for capturing multi-gas emissions from a boiler, genset, incinerator exhaust, and any other exhaust containing CO2. Specifically, the primary constituents of combustion gas and similar exhaust emissions are water and carbon dioxide, with additional impurities including sulfur oxides, nitrogen oxides, carbon monoxide, and hydrocarbon as well as a minor presence of soot, dust (particulate matter), and other such substances. These impurities need to be removed from the exhaust before emitting into the atmosphere. The process of the present invention is used to remove all the above-mentioned emissions from the exhaust.

The process comprises passing multi-gas emissions received from the exhaust of the boiler, genset, and incinerator or any similar means through a reactor unit. Specifically, the reactor unit is configured for a flow rate for multi-gas emissions of 25000 kg/h and 10000 kg/h and is modular in nature to accommodate larger flow rates.

The process further comprises spraying any one of sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture, over the multi-gas emissions of the reactor unit. For the purpose of clarity the sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture (hereinafter referred as “the spray adsorber mixture), either alone or in combination are used to spray over the mutigaseous emmisions the In an embodiment, wherein the reactor unit is any one absorber unit and fluidized bed reactor. In an embodiment, 1 part slaked lime and 9 parts fly ash to make up a total of 10 parts of the mixture used.

Specifically, any one of sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture, over the multi-gas emissions in the reactor unit is sprayed over the multi-gaseous emission to carbonate the metal oxides in fly ash using the heat generated during the exothermic reaction between any one of quicklime and slaked lime with water.

In an embodiment, maximum 5 parts of slaked lime and 5 parts of fly ash to make up a total of 10 parts of the mixture is used.

In another embodiment, only fly ash (without slaked lime) can be sprayed over the multi-gas emission of the reactor unit.

In ane embodiment, the proportion of slaked lime to fly ash is 20:80. In another embodiment, the proportion of fly ash- steelmaking residue mixture is 80:20. In yet another embodiment, the proportion of slaked lime- steelmaking residue mixture 20-80.

In an embodiment, the fly ash is any one of coal fly ash and biomass fly ash.

In an embodiment, the red mud used is bauxite residue and the steelmaking residue is stainless steel- basic oxygen furnace slag, blast furnace slag or corex process slag.

Specifically, the absorber unit with packed column is used to spray water to leach out metal oxides from the multi-gas emission before spraying a solution of the water and the spray solution mixture Specifically, 50 to 80 % by weight water and balance the spray solution mixture as described above, wherein carbonated metal oxide precipitates in the reactor unit when the water- the spray solution is sprayed. The carbonated metal oxides precipitate and are separated by gravity because of differences in densities.

In an embodiment, the the spray solution is continuously sprayed within the reactor unit.
As discussed above, the spray solution contains sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture, in accordance with an exemplary embodiment of the present invention. However, for the sake of clarity and conciseness, the system is described with the fly ash-slaked lime mixture hereinafter and should not be construed as limiting.

Specifically, the steel making residues including blast furnace slag (BFS), COREX process slag, electrical arc furnace slag, and aluminium making residue when mixed with water shows alkaline nature which shows their potential to capture CO2. However, their affinities towards CO2 capturing are weak. Howver, a strong alkaline mixture is created by adding these steel making residue with a small proportion of slaked lime or quicklime. Other combinations like BFS+ Slaked lime+ Flyash are also added because they may be found in the same complex (Flyash produced from Power plant and BFS produced from Steel plant, make it one of the suitable candidate for CO2 absorption material.

In an embodiment, the operating temperature of the system is at least 60 °C and at most 250 °C. In an alternate embodiment, a heat exchanger is needed to recover waste heat before the flue gases enter the reactor unit.

Other metal oxides including but are not limited to ferric oxide (Fe2O3), Aluminum oxide (Al2O3), calcium oxide (CaO), Magnesium Oxide (MgO), Sodium Oxide (Na2O), Potassium oxide (K2O) capture the carbon dioxide at varying temperatures with the efficiency of the carbonation reaction increasing with increasing temperatures. The addition of slaked lime or quick lime, its subsequent hydration and carbonation reaction is exothermic, which in turn increases the temperature, resulting in increased CO2 capture by other metal oxides within the packed bed of the absorber unit of the present invention

Specifically, when the water-fly ash-slaked lime mixture or the spray solution is sprayed over the multi-gas emissions in the absorber unit, the water leaches out metal oxides, and then this water in combination with fly ash and slaked lime and or the spray solution captures carbon dioxide. The carbonated metal oxides form a precipitate that settles at the bottom of a settling tank by gravity which can then be used in building material. Specifically, carbonates formed in the process are sequestered in the building material.

In an embodiment, the fly ash-slaked lime mixture is the solution of water-fly ash-slaked lime. In another embodiment, the fly ash-slaked lime mixture is a solid fly ash-powdered quicklime mixture.

Specifically, the carbonated fly ash in solid form is obtained when a solid fly ash-powdered quicklime mixture is passed over incoming exhaust gases in the fluidized bed reactor.

In the case of a solid fly ash-slaked lime mixture where a fluidized bed is used as the reactor, the fluidized bed reactor increases the particle-to-particle contact between exhaust gases, fly ash, and powdered quicklime bed. In this embodiment, no water is used. Fly ash is introduced to the fluidized bed reactor as a solid and carbonated fly ash is removed from the reactor as a solid. Both mass flow rates are precisely controlled using an electronic control unit. Exhaust gases are allowed to pass through the bed of fly ash causing the bed to fluidize. Specifically, eliminating water helps in heating the fluidized bed so that carbonation of exhaust gases occurs with greater efficiency. Fluidization increases the particle-to-particle contact between exhaust gases fly ash and powdered quicklime bed.

The process furthermore comprises capturing water droplets coming along the multi-emissions using a demister unit.

In another aspect, the present invention provides a system (1000) for capturing multi-gas emissions from a boiler, genset, and incinerator exhaust.

The system (1000) comprises a reactor unit (100) configured for passing multi-gas emissions therethrough. In an embodiment, the reactor unit (100) is any one absorber unit (200) and fluidized bed reactor (200).

In an embodiment, the absorber unit (200) with a packed column is used to spray water to leach out metal oxides from the multi-gas emission before spraying a mixture of solution of any one of sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture. Specifically, the carbonated metal oxide precipitates in the absorber unit (110) when any one of sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture is sprayed.

The system (1000) further comprises a hopper unit (300) supplying any one of sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture to the reactor unit (100) to pass over the multi-gas emissions of the reactor unit.

The system (1000) furthermore comprises a demister unit (107) for capturing water droplets coming along the multi-emissions in the reactor unit.

The system (1000) also comprises a separator tank (400) for collecting water from the absorber unit (200). Specifically, the separator tank (400) separates sludge from the absorber unit (200) utilizing gravity allowing water to recirculate within the system, wherein the sludge has a setting time of 1-2 days and hardens under ambient atmospheric conditions to have a compressive strength of 90 to 110 kg/cm2. Also, the recharged water is pumped back to the top of the absorber unit (200) to react with CO2 incoming flue gases.

As shown in Figure 1, the system (1000) comprises the absorber unit (200), a hopper (300) for holding the spray solution including but not limited to sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture, a separator tank (400), an ECU (500), and a cloud storage (600). The absorber unit (200) is configured to receive exhaust from any type of combustion system such as a boiler, genset, incinerator, and the like through its inlet (101), which flows upwards in the absorber unit (200).

The spray solution contains sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture, in accordance with an exemplary embodiment of the present invention. However, for the sake of clarity and conciseness, the system is described with the fly ash-slaked lime mixture hereinafter and should not be construed as limiting.

The absorber unit (200) contains one or more levels of the packed bed (103) and a liquid distributor (108) on the exhaust flow rate, the concentration of gases, and the required capturing efficiency. The exhaust gas (11) flows are counter-current with respect to the mixture of fly ash and slaked lime coming from liquid distributor-1 (109). The mixture of fly ash and slaked lime flows over the packed bed-1 (103) which increases the surface area for mass transfer between exhaust (11) and the mixture of fly ash and slaked lime (22). The packed bed (103) is arranged over packed bed support (102) in structured and/or random order. The exhaust gas moves to the packed bed-2 (105), which is placed over the packed bed support (104) in structured and/or random order.

In an embodiment, the fly ash-slaked lime mixture is the solution of the water-fly ash-slaked lime mixture. In another embodiment, the fly ash-slaked lime mixture is a solid fly ash-powdered quicklime mixture.

When the water-fly ash-slaked lime mixture is sprayed over the multi-gas emissions in the absorber unit (200), the water leaches out metal oxides, and then this water in combination with fly ash and slaked lime captures carbon dioxide. The carbonated metal oxides form a precipitate that settles at the bottom of a settling tank (400) by gravity which can then be used in building material. Specifically, carbonates formed in the process are sequestered in the building material.

In another embodiment, the solid fly ash-slaked lime mixture when passed through the fluidized bed is used as the reactor (100), the fluidized bed reactor increases the particle-to-particle contact between exhaust gases, fly ash, and powdered quicklime bed. In this embodiment, no water is used. Fly ash is introduced to the fluidized bed reactor as a solid and carbonated fly ash is removed from the reactor as a solid. Both mass flow rates are precisely controlled using an electronic control unit. Exhaust gases are allowed to pass through the bed of fly ash causing the bed to fluidize. Specifically, eliminating water helps in heating the fluidized bed so that carbonation of exhaust gases occurs with greater efficiency. Fluidization increases the particle-to-particle contact between exhaust gases fly ash and powdered quicklime bed.

Specifically, the carbonated fly ash in solid form is obtained when the solid fly ash-powdered quicklime mixture is passed over incoming exhaust gases in the fluidized bed reactor.

Specifically, the exhaust gas (11) flows counter-current with respect to the mixture of fly ash and slaked lime (22). The exhaust gas then moves to the demister unit (107), which is used to remove small liquid droplets moving along with the exhaust. The demister unit (107) is placed above the demister support (106). The clean exhaust, as harmful constituents of gases removed from the exhaust, moves out from the outlet of the absorber (200) to the atmosphere. In an embodiment, the outlet of the absorber unit (200) is incorporated with a gas sensor to calculate the captured efficiency of the gas constituents.

Further, the mixture of fly ash and slaked lime (22) coming out from the liquid distributor-2 (108) falls on the packed bed-2 (105) and it moves down with absorbed gases. Also, the mixture of fly ash and slaked lime (22) coming out from the liquid distributor-1 (109) falls on the packed bed-1 (103) and moves down to the bottom of a second absorber (116). The lean solution collects at the bottom of the second absorber (116) and moves from the absorber (200) to the hopper unit (200) through the liquid discharge pipe (111) using a pump (213) or gravity flow.

Specifically, the inlet (101) connected to the second absorber (116) is slightly offset to the center of the absorber (200) to improve the gas and liquid interaction as well as reduce the flow resistance. Further, the inlet (101) is slightly inclined to the axis of the absorber (116) to improve the vertical movement of fluid. The inlet (101) is incorporated with various sensors such as a gas flow measurement sensor (112), gas sensor (113), temperature sensor (114), and any other sensor. The gas flow measurement sensor (112) measures the volumetric flow rate of the exhaust gas (10) and the data signal goes to the ECU (500). The gas sensor (113) measures the gas constituents in the exhaust gas (10) and the data signal goes to the ECU (500). The temperature sensor (114) measures the temperature of the exhaust gas (10) and the data signal goes to the ECU (500).

The hopper unit (300) is connected to ECU (500) to control its speed and to power ON/OFF. An electronic valve (212) is connected to the hopper unit (300) for more precise control of the mixture of fly ash and slaked lime to the absorber (200). The hopper unit (300) consists of an ultrasonic sensor (302) to sense the level of fly ash and slaked lime in the hopper (300).

For proper mixing of chemicals in the tank, an agitator (202) is used. The agitator (202) is connected to a motor (203) for the precise control of speed and timing. The hopper unit (300) senses the level of mixture of fly ash and slaked lime and its temperature using an ultrasonic sensor and temperature sensor, respectively, and provides data to the ECU.

Specifically, the absorber unit with a packed column is used to spray water to leach out metal oxides from the multi-gas emission before spraying a mixture of a solution of a water-fly ash-slaked lime mixture, wherein carbonated metal oxide precipitates in the absorber unit when the water-fly ash-slaked lime mixture is sprayed.

Fly ash includes but is not limited to ferric oxide (Fe2O3), Aluminum oxide (Al2O3), calcium oxide (CaO), Magnesium Oxide (MgO), Sodium Oxide (Na2O), and Potassium oxide (K2O) capture carbon dioxide at varying temperatures with the efficiency of the carbonation reaction increasing with increasing temperatures. The addition of slaked lime or quick lime, its subsequent hydration and carbonation reaction is exothermic, which in turn increases the temperature, resulting in increased CO2 capture by other metal oxides within the packed bed of the absorber unit of the present invention.

The multi-gas capturing system works smartly and optimally captures gas emissions using an electronic control unit (500). The electronic control unit (500) senses data from various components of the system such as the absorber unit (200), the hopper unit (300), the settling tank (400 and the like. The sensed data is used for controlling pump 211, flow valve 212, sludge pump 204, and agitator motor 203.

Whenever the combustion system starts, the exhaust flows to the inlet of the absorber (200). The flow meter (112), the gas sensor (113), and the thermocouple (114) measure exhaust flow rate, exhaust temperature, and concentration of gaseous emission, respectively, of the exhaust gas, and the data goes to the electronic control (500). The ECU (500) checks if the exhaust temperature or gas concentration is higher than the critical limit, then it will start the pump 211 and agitator motor 203. Further, the ECU (500) acquires various data from other sensors such as the turbidity sensor (206), TDS sensor (207), pH sensor (208), temperature sensor (209), and the ultrasonic sensor (210) incorporated with the hopper unit (300).

The ECU (500) controls the speed of the pump (211), the flow valve (212), the timing of the agitator motor (203), and the timing of the sludge pump (204) using the artificial intelligence model (700. The ECU (500) notifies the user to remove sludge from the sludge tank (400) by sensing the ultrasonic sensor’s (402) data and if the level of sludge is above the critical level. Moreover, The ECU (500) notifies the user to add fly ash and slaked lime to the hopper (300) by sensing the ultrasonic sensor’s (302) data and if the level of the fly ash-slaked lime is below the critical level. The ECU (500) detects the signals from the ultrasonic sensor (210) incorporated into the hopper unit (300) and determines the level of the fly ash-slaked lime solution in the hopper unit (300). If the level of solution is below the critical limit, then it notifies the user to fill the water and add the desired amount of chemicals in the hopper unit (300).

The ECU (500) sends the required information to the cloud, which can be accessed using a suitable cloud platform. Further, the desired parameters can given as inputs to the ECU (500).

Figure 2 shows a schematic diagram of a multi-gase capturing system with a multi-absorber in accordance with an embodiment of the present invention.

As depicted in Figure 2, the multi-gases capturing system with multi-absorber of this embodiment incorporates, in addition to the components mentioned in the first embodiment, multiple units of absorber 200. The rest of the components in the multi-gases capturing system for this embodiment remain identical to those in the first embodiment of Figure 1. Consequently, the identical components are denoted by the same reference numbers, and their detailed description is omitted.

Considering large flow rates of exhaust and space constraints in the industries mainly for already installed combustion systems. The multi-gas capturing system has been designed considering the limitation of height. Thus, there are four or multiple absorbers (200) in a multi-gases capturing system. The exhaust gas (11) coming from a combustion system enters the manifold which divides the flow into 2 parts and enters the absorber (200) and absorber (200a). The manifold consists of various sensors such as the gas flow measurement sensor (112), gas sensor (113), temperature sensor (114), and any other sensor, as discussed in the first embodiment. The processes in the absorbers (200) and (200a) are similar as discussed in the first embodiment. The exhaust coming out from the absorbers (200) and (200a) moves to another absorbers (200b) and (200c), respectively through pipe arrangements 120. The processes in the absorbers (200b) and (200c) are similar as discussed in the first embodiment. The exhaust moves out from the absorbers (200b) and (200c) through the outlet pipe (110). The outlet pipe (110) incorporates the gas sensor (115) to detect the gas species in it and send the signal to ECU (500) for calculating gas captured efficiency.

In yet another embodiment, a few combustion systems such as coal-fired boilers and incinerator produces exhaust gas which also contains a high amount of soot is shown to be used with the system. The high amount of soot in the exhaust gas can lower the capturing efficiency of the multi-gas capturing system. Then, arrangements need to be made to remove soot from the exhaust before the absorber.

The multi-gases capturing system with a soot separator, in addition to the components mentioned in the first embodiment of Figure 1, added equipment to remove soot. The rest of the components in the multi-gases capturing system for the third embodiment remain identical to those in the first embodiment. Consequently, the identical components are denoted by the same reference numbers, and their detailed description is omitted.

The exhaust gas coming out from the coal-fired boiler moves to the inlet (701) of the electrostatic precipitator (700). There are two electrodes in the electrostatic precipitator (700), which is connected to a high-voltage supply. The soot captured on the wall of the electrostatic precipitator (700) scraps down to the soot collection box (703). After some time, soot can be removed from the collection box (703) from the collection box outlet (704).

The below table shows absorber material Composition of various absorber materials used in the present invention.
Table 1 Composition of various absorber materials used in NZM
MgO Na2O Cao SiO2 Al2O3 Fe2O3 TiO2 K2O SO2 MnO P2O5
Flyash 4.5 6.1 9.7 39.7 21.1 13.6 0.9 3.4 - 0.2 -
BFS 9.2 0.4 47.9 18.8 14.5 4.2 1.7 1.7 1.2 0.3 -
Corex Slag 8.8 0.6 43.8 27.5 17.7 0.6 0.7 0.4 - 0.1 -
BOF* 7.8 - 40.9 14.1 2 23 1.4 - - 4.9 1.7

Below are the examaples of the adsorbent used in the process for capturing multi-gaseous components and their effects.

Coal Fly Ash (100%)

Figure 2 shows CO2 concentration of the exit gas from a diesel generator with time in seconds. The concentration of the CO2 reduced by 8% in 80 seconds when a slurry of coal flyash with water. Oxides alkali and alkaline earth metals e.g., Ca, Mg, Na etc are the major components of flyash which are responsible for capturing the CO2. As the proportion of these elements are less (as shown in Table 1), the capturing efficiency is also limited to 8%. As the size of the reactor is fixed, hence the residence time of the gas and thus the contacting time of the gas is also limited. For increase the conversion proportion, either reactivity of the slurry with CO2 should be increased (by adding more reactive material like Quick/slaked lime) or the residence time of the reactants should be increased by increasing the size of the reactor.

Figure 1 CO2 concentration of gas with time when coal fly ash is used as solid absorber

Biomass Fly Ash (100%)
An alternative way of increasing the reactivity of the absorbing material is to choose material which has higher proportion of reactive constituents. For example, the proportion of alkali and alkaline earth metal (as given in Table 1) which are responsible for capturing CO2 is higher in biomass flyash that makes it more suitable for capturing CO2 from the flue gas. A sample result of experiment carried out using biomass flyash is given below in

Figure 3. The CO2 concentration by volume is reduced by 9.61 % as compared to coal flyash where the reduction of 8% has been achieved.

Figure 2 CO2 concentration of gas with time when biomass flyash is used as a solid absorber
Blast furnace slag
Other than biomass and coal ash, the blast furnace slag also consists a huge proportion of CaO as determined by XRF and given in Table 1. The CaO is added to the furnace to remove impurity present in the iron ore and the unutilized CaO can be potentially be helpful in capturing CO2. The reduction in CO2 concentration ~18%, i.e., higher than coal and biomass flyash.

Figure 3 CO2 concentration of gas with time when blast furnace slag is used as a solid absorber
A mixture of coal flyash and slaked lime

To increase the reactivity of the coal flyash, 20% portion of the flyash has been replaced by slaked lime (Ca(OH)2). The presence of Ca(OH)2 increases the pH value of the aquous solution making it more suitable for capturing CO2 [3]. The evidence of increased absorption capacity is evident in the experiemntal results of using coal flyash with slaked lime in 20% in proportion and shown in Figure 5. The efficiency of capturing CO2 for this mixture is jumped from 8% ( only coal flyash) to 87%.

Figure 4 CO2 concentration of gas with time when mixture of 20% slaked lime with flyash is used as a solid absorber
A mixture of blast furnace slag and slaked lime
Increase in proportion of the slaked lime results in to boost up the pH level. However, as the Ca proportion of the BFS was higher as shown in the Table 1, initially only 10% of the slaked lime has been added 10% which is increased to 20% for comparison as shown in Figure 6 below. Also, as this part has been added from our previous claim, two levels of mixing of slaked lime is done to evaluate the effect.

Figure 5 CO2 concentration of gas with time when mixture of 0, 10 and 20% slaked lime with BFS is used as a solid absorber

As expected, the proportion of the slaked lime has been helpful to increase the CO2 capturing efficiency. However, increasing the slaked lime proportion does not reflect linear increase in the capturing efficiency. As discussed, only BFS can achieve ~18% efficiency, which increased to 84% when 20% Slaked lime added. Further addition of 10% more slaked lime (20% slaked lime) only fetches 88% efficiency. An optimal proportion of slaked lime can only boost the efficiency of the mixture.

Table 2 shows maximum efficiencies and time required to achieve the same for different absorbers in the system of the present invention.

Solid Feed Efficiency Time (sec)
100 % Biomass Fly Ash 7.98% 128
100 % Coal Fly Ash 9.61% 168
100 % Blast Furnace Slag (Sieved, not ground) 18.75% 77
20 % Slaked Lime + 80 % Coal Fly Ash 79.84% 199
20 % Slaked Lime + 40 % Coal Fly Ash 88.33% 318
100 % Slaked Lime 92.71% 210
20 % NaOH + 80 % Slaked Lime 99.64% 174
20 % Slaked Lime + 80 % Blast Furnace Slag 84.50% 445

Advantages of the invention.

1. The system and process of the present invention is a unique after-treatment system aimed at capturing gaseous emissions of CO2, CO, SOx, NOx, and HC from stationary sources of combustion like Diesel Generator sets, incinerators, and boilers (Solid, liquid and gas fueled).

2. The system when attached to a source of biogas, syngas, or natural gas, removes CO2, CO, H2S, NOx, and SOx allowing only methane (CH4) or hydrogen(H2) and nitrogen to pass through increasing their concentration in the fuel mixture and improves fuel quality.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the processes disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the scope of the invention.
, Claims:We claim

1. A process for capturing multi-gas emissions, the process comprising:
passing multi-gas emissions through a reactor unit;
spraying any one of sodium hydroxide, fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture, over the multi-gas emissions in the reactor unit; and
capturing water droplets coming along the multi-emissions using a demister unit.
2. The process as claimed in claim 1, wherein the proportion of slaked lime to fly ash is 20:80.
3. The process as claimed in cliam 1, wherein the proportion of fly ash- steelmaking residue mixture is 80:20.
4. The process as claimed in claim 1, wherein the proportion of slaked lime- steelmaking residue mixture 20-80.
5. The process as claimed in claim 1, wherein the fly ash is any one of coal fly ash and biomass fly ash.
6. The process as claimed in claim 1, wherein the red mud used is bauxite residue.
7. The process as claimed in claim 1, wherein the steelmaking residue is stainless steel- basic oxygen furnace slag, blast furnace slag or corex process slag.
8. The process as claimed in claim 1, wherein the reactor unit is any one absorber unit and fluidized bed reactor.
9. The process as claimed in claim 1, wherein fly ash-slaked lime mixture is a solution of water-fly ash-slaked lime mixture.
10. The process as claimed in claim 1, wherein the fly ash-quicklime mixture is a solid fly ash-powdered quicklime mixture.
11. The process as claimed in claim 1, wherein the carbonated fly ash in solid form is obtained when solid fly ash-powdered quicklime mixture is passed over incoming exhaust gases.
12. A system for capturing multi-gas emissions, the system comprising:
a reactor unit configured for passing multi-gas emissions therethrough;
a hopper unit supplying any one of fly ash, fly ash-slaked/quick lime mixture, fly ash- steelmaking residue mixture, slaked lime- steelmaking residue mixture, red mud and red mud-fly ash mixture to the reactor unit to pass over the multi-gas emissions of the reactor unit;
a demister unit for capturing water droplets coming along the multi-emissions in the reactor unit; and
a separator tank for collecting water from the reactor unit.

13. The system as claimed in claim 12, wherein the reactor unit is any one packed bed absorber unit and fluidized bed absorber.

14. The system as claimed in claim 12, wherein the separator tank separates sludge utilizing gravity allowing water to recirculate within the system, wherein the sludge has a setting time of 1-3 hrs and hardens under ambient atmospheric conditions to have a compressive strength of 90 to 110 kg/cm2.

15. The system as claimed in claim 12, wherein recharged water is pumped back to the top of the reactor unit to react with CO2 of incoming flue gases.

16. The system as claimed in claim 12, wherein an electronic control unit triggers the addition of fly ash-slaked lime mixture to the reactor unit.