Removal of polyfluoroalkyl and perfluoroalkyl substances (PFAS) in a wastewater biosolid gasification process using a thermal oxidation device and slaked lime injection.

Abstract

An apparatus and method for removing PFAS from wastewater biosolids by fluidized-bed gasification. The gasifier decomposes PFAS in the biosolids at temperatures between 900 and 1800°F. Synthesis gas (syngas) exits the gasifier and is coupled to a thermal oxidizer where it is combusted at temperatures between 1600 and 2600°F, thereby decomposing the PFAS in the syngas and producing a flue gas. Heat can be recovered from the flue gas by cooling it to a temperature between 400 and 1200°F in a heat exchanger coupled to the thermal oxidizer. The cooled flue gas is mixed with hydrated lime to promote the decomposition of PFAS. Spent lime is filtered from the cooled flue gas using a filter system that may incorporate a catalyst-impregnated filter element. The apparatus and method thereby remove PFAS from the wastewater biosolids and control the resulting flue gas emissions.

Description

Technical Field

[0001] Cross - reference to Related Applications This application is an international application based on U.S. Patent Application No. 17 / 406,188, filed on August 19, 2021.

[0002] This disclosure generally relates to the gasification of wastewater biosolids and the removal of polyfluoroalkyl substances and perfluoroalkyl substances.

Background Art

[0003] Polyfluoroalkyl substances and perfluoroalkyl substances (PFAS) are a type of chemical substances widely used in products such as anti - sticking coatings for cooking utensils, water - repellent and stain - resistant additives for clothing, and fire - fighting foams. These chemical substances are very stable and non - biodegradable, so they are nicknamed "forever chemicals". In recent years, it has been found that these chemical substances cause significant health concerns. And the presence of PFAS in the wastewater discharged from wastewater treatment facilities is increasing concerns about environmental problems.

[0004] The processes available for reducing PFAS in wastewater biosolids are limited. Most of the technologies used to reduce PFAS in wastewater biosolids are inefficient, achieving only partial decomposition and / or generating other harmful by - products. So far, the most promising methods used to reduce PFAS in biosolids include incineration and thermal decomposition.

[0005] Incineration is a somewhat effective solution for reducing PFAS in biosolids, but high temperatures over a long residence time are required. Some incineration processes lack the combination of temperature and residence time to completely decompose some of the more stable PFA compounds. Incineration also generates pollutants such as furans and dioxins. Furthermore, incineration requires expensive pollution prevention systems and may be difficult to permit depending on the location.

[0006] On the other hand, pyrolysis is a process that follows similar principles to gasification. For example, gasification may include a pyrolysis step. In pyrolysis, the feedstock may be heated sufficiently to expel volatile compounds and break them down or "crack" them into smaller molecules. To remove PFAS and control emissions, feedstock gasification apparatus and methods are needed that not only expel volatile compounds by treating the feedstock with additional heat, but also react many of the non-volatile carbon molecules in the feedstock to produce fuel gas. [Overview of the project] [Means for solving the problem]

[0007] Apparatus and method for removing PFAS from wastewater biosolids by fluidized bed (FB) gasification are disclosed. In one embodiment, the biosolids are supplied to a fluidized bed gasifier. The gasifier decomposes the PFAS in the biosolids at a temperature of 900–1800°F. The syngas exits the gasifier and enters a thermal oxidizer coupled to the gasifier, where it is combusted at a temperature of 1600–2600°F. This decomposes the PFAS in the syngas and produces fuel exhaust gas. Heat can be recovered from the fuel exhaust gas by cooling it to a temperature of 400–1200°F in a heat exchanger coupled to the thermal oxidizer. The cooled fuel exhaust gas is mixed with slaked lime to promote the decomposition of PFAS. The spent lime is filtered from the cooled fuel exhaust gas using a filter system which may incorporate a catalyst-impregnated filter element. The apparatus and method thereby remove PFAS from wastewater biosolids and control the discharge of the resulting fuel exhaust gas. [Brief explanation of the drawing]

[0008] [Figure 1] This shows an exemplary apparatus for removing PFAS from wastewater biosolids using a fluidized bed gasification system. [Figure 2]This shows an exemplary apparatus process flow for removing PFAS from wastewater biosolids using a fluidized bed gasification system. [Figure 3A] This section illustrates various exemplary implementations of filter systems. [Figure 3B] This section illustrates various exemplary implementations of filter systems. [Figure 3C] This section illustrates various exemplary implementations of filter systems. [Figure 4A] Both diagrams show schematic representations of exemplary filter units. [Figure 4B] Both diagrams show schematic representations of exemplary filter units.

[0009] Similar reference numbers in various drawings refer to the same elements. [Modes for carrying out the invention]

[0010] In one embodiment, a fluidized bed gasifier is used, in which the oxidizer is blown through a bed of solid particles at a rate sufficient to keep the solid particles suspended. The feedstock is introduced into the gasifier, mixed very quickly with the bed material, and heated to the bed temperature almost instantaneously, either externally or using a heat transfer medium. Most fluidized bed gasifiers are equipped with a cyclone to remove the fluidized medium from the generator gas and minimize by-products such as char and ash (which may be introduced into the generator gas flow). In exemplary cases, if the by-product is mainly mineral material with low carbon content (e.g., less than 12% carbon) and is from biosolids, the by-product is more accurately called ash. By-products with high carbon content (e.g., more than 85% carbon) are more accurately called char or biochar. The carbon level is determined by the conversion rate and ash content. Key advantages of using an FB gasifier include the flexibility of the feedstock and the ability to easily control the reaction temperature, which allows for the gasification of fine-grained materials (such as sawdust) without the need for pretreatment. Fluidized bed gasification systems are very well adapted to large sizes.

[0011] A brief description of fluidized bed (FB) gasification and a brief example of a fluidized bed gasifier are provided below. Other types of gasifiers, such as downdrafts, may also be used. An exemplary downdraft gasification may be carried out using the downdraft gasification technique disclosed with reference to Figures 1-21 of U.S. Patent No. 10,662,386 by Kelfkens et al., filed on December 6, 2019, entitled “Method for gasifying feedstock with high yield production of biochar,” which is incorporated herein by reference in its entirety. An exemplary fluidized bed gasification may be carried out using the fluidized bed gasification technique disclosed with reference to Figures 1-8 of U.S. Patent No. 10,696,913 by Kelfkens et al., filed on December 20, 2019, entitled “Gasification reactor with pipe distributor,” which is incorporated herein by reference in its entirety.

[0012] In one embodiment, the apparatus may include an FB gasifier configured to gasify a feed material and release synthesis gas produced by the gasification of the feed material; a thermal oxidizer operably coupled to the gasifier to receive and burn the synthesis gas and release the heated fuel exhaust gas; and a heat exchanger operably coupled to the thermal oxidizer to receive and cool the heated fuel exhaust gas and release the cooled fuel exhaust gas as a gas stream from the heat exchanger.

[0013] The supplied raw materials may further contain wastewater biosolids.

[0014] The supplied raw materials may further contain biosolids.

[0015] The biosolid may further contain PFAS.

[0016] The supplied raw materials may further contain wastewater biosolids containing PFAS.

[0017] The feedstock may further include, but is not limited to, granular activated carbon, reverse osmosis resin, other adsorbents, and other PFAS-containing solids such as automotive shredder residue.

[0018] The apparatus may further comprise a conveyor configured to transfer the feedstock to the gasification device via a feed bin configured with a live bottom.

[0019] The apparatus may further comprise a gasification device configured to receive the feedstock.

[0020] The apparatus may further comprise a drying device operably coupled to the gasification device for feeding the dried feedstock dried by the drying device to the gasification device.

[0021] The drying device may be configured to dry the feedstock received by the drying device.

[0022] The drying device may be coupled to the device to dehydrate the biosolid.

[0023] The apparatus may further comprise a drying device operably coupled to the gasification device.

[0024] The apparatus may further comprise a gasification device configured to operate at a temperature of 900 - 1800°F.

[0025] The apparatus may further comprise a gasification device operating at a temperature of 900 - 1800°F.

[0026] The apparatus may further comprise a gasification device configured to operate to convert the feedstock into low-calorific value synthesis gas.

[0027] The apparatus may further comprise a gasification device configured to operate to devolatilize PFAS in the feedstock, liberate PFAS from the solids in the feedstock, and decompose the PFAS liberated from the solids.

[0028] The apparatus may further include a cyclone operably coupled to the gasifier in order to receive the synthesis gas coming out of the gasifier.

[0029] A cyclone may further include two or more cyclones.

[0030] The apparatus may further include two or more cyclones operably coupled with the gasifier.

[0031] The apparatus may further include a cyclone configured to operate to remove entrained particles from the gas held by the cyclone.

[0032] The apparatus may further include a cyclone operably coupled to a thermal oxidation apparatus in order to supply the synthesis gas, from which particulate matter has been separated by the cyclone, to the thermal oxidation apparatus.

[0033] The apparatus may further include a thermal oxidation apparatus configured to burn the synthesis gas at a temperature of 1600 to 2600°F.

[0034] The apparatus may further include a thermal oxidation apparatus for burning synthesis gas at a temperature of 1600 to 2600°F.

[0035] The apparatus may further include a thermal oxidation unit configured to burn the synthesis gas for a residence time of 1 to 5 seconds.

[0036] The apparatus may further include a thermal oxidation device for burning the synthesis gas over a residence time of 1 to 5 seconds.

[0037] The apparatus may further include a thermal oxidizer configured to operate for the thermal decomposition of PFAS remaining in the synthesis gas after gasification, wherein the operating temperature of the thermal oxidizer is higher than that of the gasifier.

[0038] The apparatus may further include a heat exchanger configured to cool the heated fuel exhaust gas to a temperature of 400-1200°F.

[0039] The apparatus may further include a heat exchanger configured to recover heat captured based on the cooling of heated fuel exhaust gases from the thermal oxidation unit and to provide the recovered heat to surrounding systems and devices.

[0040] The apparatus may further include a device configured to inject slaked lime or other calcium-based adsorbent into the cooled fuel exhaust gas passing through the heat exchanger.

[0041] The device may further include an exhaust pipe operably connected to an induced draft fan, and the device may be operably coupled to the exhaust pipe to discharge cooled fuel exhaust gases through the exhaust pipe.

[0042] The apparatus may further include one or more heat exchangers configured to recover residual heat in the cooled fuel exhaust gas.

[0043] The device may further include an induced draft fan configured to draw fuel exhaust gas from the thermal oxidation device and push this fuel exhaust gas out of the exhaust pipe.

[0044] The apparatus may further include a filter operably coupled to the heat exchanger to filter the cooled fuel exhaust gas flow exiting the heat exchanger. The apparatus may further be configured to periodically clean the filter with pulses of air passing through the filter in the opposite direction to the cooled fuel exhaust gas flow exiting the heat exchanger.

[0045] The device may be equipped with a filter system.

[0046] The exhaust stack may be operably coupled to the filter.

[0047] The filter system may include multiple filter units.

[0048] The filter may include a catalyst-impregnated filter element.

[0049] In one embodiment, the process includes gasifying a feedstock containing PFAS to produce synthesis gas exiting a gasifier, burning the synthesis gas in a thermal oxidizer to produce heated fuel exhaust gas exiting the thermal oxidizer, and cooling the fuel exhaust gas using a heat exchanger and discharging the cooled fuel exhaust gas from the thermal oxidizer.

[0050] The gasification apparatus may be a fluidized bed gasification apparatus.

[0051] Gasification of the raw materials may include supplying raw materials containing PFAS to a gasification unit.

[0052] The supplied raw materials may further contain wastewater biosolids.

[0053] The process may further include drying the feedstock, which contains wastewater biosolids, using a drying device.

[0054] The drying apparatus may be operably coupled to the gasifier in order to supply the feed material dried by the drying apparatus to the gasifier.

[0055] The process may further include dewatering the feedstock containing wastewater biosolids using a dewatering machine.

[0056] The dewatering machine may be operably coupled with a drying machine in order to supply the raw material from the dewatering machine to the drying machine.

[0057] The process may further include configuring the gasifier to operate at a temperature of 900–1800°F.

[0058] The process may further include configuring and operating a gasifier to convert the feedstock into a low-calorific-value synthesis gas.

[0059] The process may further include removing entrained particles from the synthesis gas held in the cyclone using a cyclone.

[0060] The cyclone may be operably coupled to the gasifier to receive the synthesis gas coming out of the gasifier.

[0061] The process may further include burning the synthesis gas received from the gasifier using a thermal oxidation unit.

[0062] The thermal oxidation apparatus may be operably coupled to the gasifier to receive the synthesis gas coming out of the gasifier.

[0063] The process may further include burning the synthesis gas received from the gasifier using a thermal oxidation unit.

[0064] The thermal oxidation apparatus may be operably coupled to a cyclone to receive synthesis gas from which particulate matter has been separated by the cyclone.

[0065] The process may further include configuring and operating a thermal oxidation apparatus to burn the synthesis gas at a temperature of 1600–2600°F.

[0066] The process may further include configuring and operating a thermal oxidizer or similar device to burn the synthesis gas with a residence time of 1 to 5 seconds.

[0067] The process may further include configuring and operating a thermal oxidizer to thermally decompose the PFAS remaining in the synthesis gas after gasification, wherein the operating temperature of the thermal oxidizer is higher than the operating temperature of the gasifier.

[0068] The process may further include cooling the fuel exhaust gas heated by the synthesis gas combustion in the thermal oxidizer by a heat exchanger operably coupled to the thermal oxidizer.

[0069] The process may further include configuring and operating a heat exchanger to cool the heated fuel exhaust gas to a temperature of 400–1200°F.

[0070] The process may further include injecting slaked lime or other calcium-based adsorbents into the cooled fuel exhaust gas passing through the heat exchanger.

[0071] The process may further include filtering the gas flow exiting the heat exchanger by a filter operably coupled to the heat exchanger.

[0072] The filter may include, but is not limited to, a catalyst-impregnated filter element, such as a ceramic filter element in which a catalyst is embedded in a ceramic material.

[0073] The process may further include configuring and operating a filter to remove spent lime from the gas flow exiting the heat exchanger.

[0074] The process may further include periodically cleaning the filter with pulses of air passing through the filter in the opposite direction to the gas flow exiting the heat exchanger.

[0075] The process may further include filtering lime from the fuel exhaust gas and releasing the filtered, cooled fuel exhaust gas through an exhaust stack operably coupled with a heat exchanger.

[0076] The process may further include configuring piping, ducts, pumps, valves, conduits, sensors, and wiring to carry out the steps described by the algorithm controller.

[0077] In one embodiment, an exemplary process may include recovering heat from fuel exhaust gas heated by the combustion of synthesis gas produced from a gasified biosolid containing PFAS.

[0078] In one embodiment, an exemplary process may include recovering heat from fuel exhaust gas heated by the combustion of synthesis gas in a thermal oxidation unit using a heat exchanger, wherein the synthesis gas is produced from a biosolid containing PFAS gasified by a gasifier.

[0079] In one embodiment, an exemplary process may include generating synthesis gas by gasifying a biosolid containing PFAS, burning the synthesis gas to obtain heated fuel exhaust gas, and recovering heat based on the cooling of the heated fuel exhaust gas.

[0080] In one embodiment, an exemplary process may include generating a generator gas based on the gasification of a biosolid containing a PFAS, burning the generator gas to obtain heated fuel exhaust gas, and recovering heat based on the cooling of the heated fuel exhaust gas.

[0081] Details of various embodiments are clearly shown in the attached drawings and the following description. Other features and advantages will be apparent from the description and drawings, as well as from the claims.

[0082] This disclosure teaches the removal of PFAS from wastewater biosolids. Exemplary implementations of PFAS removal according to this disclosure may involve a combination of gasification, combustion, and reaction with lime to remove PFAS from biosolids and other feedstocks. In an exemplary example, the exemplary gasification step may include feeding the PFAS-contaminated feedstock to a gasifier. In some cases, the wastewater biosolids may be dehydrated and dried to make them suitable fuel for the gasification step of the PFAS treatment.

[0083] In exemplary cases, since pyrolysis may be one step in the gasification process, the gasifier attacks PFAS in a similar manner to pyrolysis. The operating temperature of the gasifier defolates PFAS in the feedstock and pyrolyzes them. In addition to the thermal effect, the strong reducing atmosphere in the gasifier provides additional pathways for the breakdown of PFAS, such as hydrogen cracking and hydrolysis reactions. The more stringent the conditions required to convert fixed carbon compounds in the feedstock into fuel gas, the higher the rate of defolatation and decomposition of PFAS compared to pyrolysis alone, instead of simply driving out volatiles and cracking in pyrolysis.

[0084] The feedstock to the gasifier is not limited to wastewater biosolids and may include other PFAS-contaminated materials that can be used as fuel for the gasifier. These other feedstocks include, but are not limited to, used activated carbon, reverse osmosis resins, and automotive shredder residues. The decomposition reaction in the gasifier can be accelerated by adding small amounts of lime (up to 5%) to the floor individually or continuously, or by mixing it with the fuel. The lime may be mixed with the fuel before being fed into the gasifier, before or after drying, or it may be supplied directly to the floor via a separate supply system. The calcium in the lime reacts with the fluorine in the PFAS to break down more stable chain materials, enabling the formation of hydride alkanes rather than fluoride alkanes, which are far less stable and more easily decomposed.

[0085] After leaving the gasifier, the synthesis gas flows through a cyclone to remove entrained particles. These entrained particles are residual ash and char from the feedstock from which PFAS have been removed through the gasification process in the gasifier. A cyclone is a control device that uses centrifugal force to separate dust from the gas flow. A cyclone is typically a vertical cylinder with a conical outlet at the bottom. Gas and solids enter tangentially from near the top of the cylinder, the separated solids exit through the cone at the bottom, and the purified gas exits through a vertical pipe at the roof of the cylinder. After the cyclone, the synthesis gas proceeds to a thermal oxidizer or other device for burning the synthesis gas.

[0086] Following the removal of entrained particles from the synthesis gas by cyclone, the synthesis gas is burned in a thermal oxidizer, which provides a much higher temperature than gasification, operates with excess oxygen, and gives sufficient residence time at these higher temperatures to thermally decompose the more stable PFAS compounds. This step is similar to the incineration process, however, the main difference is that the thermal oxidizer burns only the synthesis gas produced in the gasification process, rather than directly burning the solid feedstock. This is not considered incineration, and this process avoids the adverse environmental impacts such as the generation of furans and dioxins that plague the incineration process. Without solid fuel, the thermal oxidizer operates at a higher temperature than incineration, which eliminates the possibility of ash slag in the feedstock and significantly increases the rate of PFAS decomposition.

[0087] After exiting the thermal oxidation unit, the fuel exhaust gas passes through a heat exchanger to remove heat that can be used elsewhere. The cooled fuel exhaust gas is then injected with slaked lime to control sulfur emissions from the process. After lime injection, the fuel exhaust gas flows through a duct to a filter system to remove spent lime from the gas flow. As the spent lime accumulates on the filter surface, it forms a thin layer of spent lime called a filter cake, which can be periodically removed by pulses of air flowing in the reverse direction through the filter. To further accelerate decomposition, the filter element may be impregnated with a catalyst. At this point, the gas temperature is in the same range as in the low-temperature incineration process enhanced with lime addition. A final polishing step is performed by mixing the remaining PFAS compounds with the fuel exhaust gas and passing it through the lime filter cake in the filter system used to remove spent lime from the gas flow, allowing the calcium in the lime to attack the fluorine bonds in the PFAS. This reaction is slow and is not expected to contribute significantly to the control of PFAS, but it provides a finishing polishing step.

[0088] Compared to existing PFAS processing technologies, the exemplary PFAS removal implementations described herein may have the potential to operate under more stringent conditions than existing methods by combining multiple pathways for PFAS destruction while avoiding the environmental impacts of some existing methods.

[0089] Figure 1 shows an exemplary implementation of PFAS removal configured to recover heat from fuel exhaust gas heated by the combustion of synthesis gas produced from a gasified biosolid containing PFAS, using a fluidized bed gasifier. In Figure 1, the exemplary PFAS removal system 100 comprises a gasifier 120, a cyclone 135, a thermal oxidizer 140, and one or more heat exchangers 145. The gasifier 120 shown in Figure 1 is a fluidized bed gasifier. As shown in Figure 1, the fluidized bed gasifier 120 is configured to gasify the feed material 105 supplied to the fluidized bed gasifier 120.

[0090] In the illustrated example, the feed material 105 contains PFAS. In the illustrated example, dried biosolid or other PFAS-containing feed material 105 may be stored in a biosolid storage bin 205. In the illustrated example, a conveyor 110 may be used to transfer the feed material 105 to the gasifier feed bin 115. In the illustrated configuration, the live bottom 210 feeds the feed material 105 from the gasifier feed bin 115 to the feed screw 215, and the feed screw 215 feeds the feed material 105 to the fluidized bed gasifier 120.

[0091] The synthesis gas flows from the fluidized bed gasifier 120 to a cyclone 135 which is operably coupled to the fluidized bed gasifier 120. In the cyclone 135, biochar that remains mixed in the synthesis gas after gasification is removed. After the cyclone 135, the synthesis gas is combusted in a thermal oxidizer 140 which is operably coupled to the cyclone 135. The energy from the heated fuel exhaust gas resulting from the combustion of the synthesis gas in the thermal oxidizer 140 is removed in a heat exchanger 145 which is operably coupled to the thermal oxidizer 140.

[0092] The heat exchanger 145 cools the fuel exhaust gas heated by the thermal oxidizer 140. The heat recovered by the heat exchanger 145 can be used as heat and / or electricity in the plant. The feed material 105 supplied to the fluidized bed gasifier 120 can be dried by a dryer (described with reference to Figure 2) operably coupled to the fluidized bed gasifier 120. The dryer may be operably coupled to the heat exchanger 145 and configured to dry the feed material using the heat recovered by the heat exchanger 145. In the example shown, lime is injected into a filter unit duct 150 at the outlet of the heat exchanger 145. Used adsorbent is removed in the filter unit 155 and the filtered cooled fuel exhaust gas is discharged through the exhaust port 160. In one embodiment, the apparatus further comprises a filter 155 operably coupled to the heat exchanger to filter the cooled fuel exhaust gas flow coming out of the heat exchanger, wherein the filter includes a catalyst-impregnated filter element 156.

[0093] Figure 2 shows a process flow of an exemplary PFAS removal implementation configured to recover heat from fuel exhaust gas heated by the combustion of synthesis gas produced from a gasified biosolid containing PFAS using a fluidized bed gasifier. In Figure 2, the illustrated flowchart of the exemplary process 200 shows PFAS removal using a fluidized bed gasifier 120, a cyclone 135, a thermal oxidizer 140, and a heat exchanger 145. Figure 2 shows a block flow version of the process described with reference to Figure 1. In the fluidized bed gasifier 120, PFAS is separated from the PFAS-containing feedstock 105 by high temperature, and the PFAS is decomposed through various pathways, including pyrolysis.

[0094] Particulate matter mixed into the synthesis gas formed in the fluidized bed gasifier 120 is separated by a cyclone 135 and then combusted in a thermal oxidizer 140 at a temperature higher than the operating temperature of the fluidized bed gasifier 120, where additional thermal decomposition occurs. The fuel exhaust gas from the thermal oxidizer 140 is cooled by a heat exchanger 145 and then mixed with slaked lime. The feed material 105 supplied to the fluidized bed gasifier 120 can be dried by a dryer 220 operably coupled to the fluidized bed gasifier 120. The dryer 220 may be operably coupled to a heat exchanger 145 and configured to dry the feed material using the heat recovered by the heat exchanger 145. The slaked lime further decomposes any remaining PFAS by chemically attacking the fluorine bonds in the material.

[0095] Figures 3A to 3C show various exemplary implementations of filter systems.

[0096] In Figure 3A, the exemplary filter system includes three exemplary filter units 155. In the shown implementation, each of the three filter units 155 consists of at least one of the catalyst-impregnated filter elements 156 shown in the exemplary cross-sectional view.

[0097] In Figure 3B, a cross-sectional view of an exemplary filter unit 155 includes a filter unit duct 150 leading to the filter unit 155. In the example shown, the filter unit duct 150 is connected to a filter inlet 305. The filter inlet 305 can receive fuel exhaust gas to be filtered by the filter unit 155 using a catalyst-impregnated filter element 156 configured in the filter unit 155. In the illustrated configuration, the filter unit 155 includes a filter outlet 310. In the illustrated configuration, the filter outlet 310 is configured to discharge fuel exhaust gas filtered by the filter unit 155. The exemplary configuration of the filter unit 155 shown in Figure 3B also includes an air manifold 315. In the exemplary configuration, compressed air may be injected into the air manifold 315 for reverse pulse jet cleaning of the filter unit 155. The filter unit 155 may be periodically cleaned by pulses of air passing through the filter in the opposite direction to the direction of the cooled fuel exhaust gas flow entering the filter inlet 305 of the filter unit 155. In the illustrated implementation, the exemplary filter unit 155 includes a waste hopper 320 configured to collect waste discharged from an airlock waste outlet 325 by air injected into an air manifold 315 to clean the filter unit 155. In the example shown in Figure 3B, the container of the filter unit 155 is shown as cut open to show exemplary filter elements hanging inside the filter unit 155. In the illustrated example, the filter elements are ceramic filter elements. In the illustrated implementation, the filter elements are shown inside a housing. In some implementations, the illustrated filter elements may be about 3 inches in diameter. In various implementations, the illustrated filter elements may be about 2.5 meters in length. In the exemplary example, the filter unit 155 shown in Figure 3B may consist of several hundred filter elements. The filter elements may be ceramic. The filter elements may be suspended inside the filter unit 155.

[0098] Figure 3C shows the operational performance of an exemplary filter unit 155. In the illustrated example, the inlet 305 of the filter unit 155 receives a gas flow containing fuel exhaust gas with mixed contaminants through the filter unit duct 150. In the illustrated example, the mixed contaminants include parts, dust, HCl, SO2, and NO X , and further containing dioxins. In the illustrated example, filter unit 155 filters the fuel exhaust gas flow using a catalyst-impregnated filter element 156. In the illustrated example, filter unit 155 discharges the filtered fuel exhaust gas flow through the outlet 310 of filter unit 155. In the illustrated implementation, the filtered fuel exhaust gas flow discharged by the outlet 310 of filter unit 155 has a concentration of 0.0001 gr / dscf (2 mg / m³). 3 Includes outlet particles less than ). In the example shown, the performance of filter unit 155 allows for up to 97% HCl, up to 95% SO2, and up to 95% NO X And 97-99% of dioxins are removed.

[0099] Figures 4A and 4B both show schematic diagrams of exemplary filter units. Figure 4A shows various components of the filter unit 155 related to the housing of the filter unit 155 that holds the filter elements shown in Figure 4B.

[0100] While various features are described with reference to the drawings, other features are possible. For example, various exemplary implementations of this disclosure can provide a novel process for PFAS removal, which removes and decomposes PFAS from biosolids using a gasification system and a three-step process, which is more effective than other control means and has no potential environmental impacts as some other methods. In an exemplary example, the first step in the decomposition of PFAS in wastewater biosolids may include supplying the biosolids to a gasification unit. After exiting the gasification unit, the synthesis gas may be burned in a thermal oxidizer or similar device at a temperature of 1600–2600°F and for a residence time of 1–5 seconds. This exemplary step following gasification may help to thermally decompose any PFAS remaining in the gas after the gasification step. After exiting the thermal oxidizer, the fuel exhaust gas may be cooled in a heat exchanger to provide heat and / or power to the plant or surrounding users. This fuel exhaust gas, cooled to 400-1200°F, can be mixed with slaked lime as a polishing step in the decomposition of PFAS and to control emissions of sulfur oxides and other substances from the plant.

[0101] In exemplary examples, an exemplary system for PFAS removal according to the present disclosure may comprise a gasifier, a thermal oxidizer, and a dry adsorbent injection system utilizing lime or slaked lime having a catalyst-impregnated filter.

[0102] In exemplary examples, exemplary methods for PFAS removal according to the present disclosure may include: drying a PFAS-containing feedstock to a moisture content suitable for gasification; supplying the PFAS-containing feedstock to a gasifier, in which the PFAS is defolatable from the feedstock and partially decomposed through various pathways; passing the synthesis gas produced by the gasifier through a cyclone to remove the accompanying solids from which the PFAS has been removed; burning the synthesis gas in a thermal oxidizer to complete the removal of PFAS by thermal decomposition; and polishing any remaining PFAS by reaction with slaked lime, which is injected into the fuel exhaust gas flow and removed in a catalyst-impregnated filter system.

[0103] PFAS-containing solids may be dried until their moisture content is less than 20%.

[0104] The gasification device can operate at temperatures between 900 and 1800°F.

[0105] Lime, limestone, or dolomite may be added to the gasification unit floor to promote the decomposition of PFAS.

[0106] The synthesis gas produced by the gasification unit may contain entrained solids that are removed via a cyclone or other separation device.

[0107] Synthesis gas can be burned at temperatures of 1600–2600°F in a thermal oxidation apparatus or similar combustion device.

[0108] The gas residence time in the thermal oxidation apparatus may be 1 to 5 seconds.

[0109] Fuel exhaust gas from the thermal oxidation unit can be mixed with lime at a temperature of 400-1200°F as a polishing step.

[0110] Used adsorbent can be removed via a filter system comprising a unit containing a filter element into which the solid is filtered and collected, the unit being cleaned periodically using a backflow of air or other gas, and the unit having a system for transporting the solid from the filter to a storage unit.

[0111] The filter system may, but is not limited to, use catalyst-impregnated filter elements, such as ceramic filter elements in which a catalyst is embedded in a ceramic material.

[0112] PFAS removal may be carried out by a PFAS removal apparatus. The PFAS removal apparatus may include a gasifier. The gasifier may be any gasifier known to those skilled in the art. The gasifier may be a downdraft gasifier or a fluidized bed gasifier. The gasifier may be configured to receive feed material. The gasifier may be configured to receive feed material supplied to the gasifier. The apparatus may include a dryer. The dryer may be configured to operate to dehydrate and dry the feed material. The feed material may contain wastewater biosolids. The gasifier may be operably coupled with the dryer. The feed material may contain PFAS. The gasifier may operate at temperatures of 900 to 1800°F. The gasifier may be configured to operate to defolarate PFAS, release PFAS from the solid, and decompose PFAS. The gasifier may be configured to operate to convert the feed material into low calorific value synthesis gas.

[0113] The gasifier may be operably coupled to a cyclone. The cyclone may be configured to operate to remove entrained particles from the gas held by the cyclone. The cyclone may be operably coupled to the gasifier to receive the synthesis gas exiting the gasifier. The apparatus may include a thermal oxidizer or a similar device. The thermal oxidizer or a similar device may be operably coupled to the gasifier. The thermal oxidizer or a similar device may be operably coupled to a cyclone. The thermal oxidizer or a similar device may be operably coupled to the gasifier to receive the synthesis gas exiting the gasifier. The thermal oxidizer or a similar device may be operably coupled to a cyclone to receive the synthesis gas exiting the gasifier. The thermal oxidizer or a similar device may be configured to burn the synthesis gas. The thermal oxidizer or a similar device may be configured to burn the synthesis gas at a temperature of 1600–2600°F. The thermal oxidizer or a similar device may be configured to burn the synthesis gas at a temperature higher than the operating temperature of the gasifier. A thermal oxidizer or similar device may be configured to burn the synthesis gas for a residence time of 1 to 5 seconds. The thermal oxidizer or similar device may also be configured to operate to thermally decompose any PFAS remaining in the synthesis gas after gasification.

[0114] The apparatus may include a heat exchanger. The heat exchanger may be operably coupled with a thermal oxidizer. The heat exchanger may be configured to receive fuel exhaust gas from the combustion of synthesis gas in a thermal oxidizer or similar device. The heat exchanger may be configured to cool fuel exhaust gas heated by the combustion of synthesis gas in a thermal oxidizer or similar device. The heat exchanger or similar device may be configured to operate to cool heated fuel exhaust gas. The heat exchanger or similar device may be configured to operate to cool heated fuel exhaust gas coming out of a thermal oxidizer or similar device. The heat exchanger may be configured to operate to recover heat based on the cooling of heated fuel exhaust gas coming out of a thermal oxidizer or similar device to provide heat and / or power to the plant or surrounding devices or systems. The heat exchanger may be configured to operate to cool heated fuel exhaust gas to a temperature of 400–1200°F.

[0115] The apparatus may be configured to inject slaked lime into the cooled fuel exhaust gas passing through the heat exchanger. The apparatus may be configured to be operably coupled to the exhaust stack to discharge the cooled fuel exhaust gas through the exhaust stack. The apparatus may include a filter. The filter may be operably coupled to the heat exchanger to remove spent lime from the gas flow coming out of the heat exchanger. The apparatus may be configured to periodically clean the filter with pulses of air passing through the filter in the opposite direction to the gas flow coming out of the heat exchanger.

[0116] The apparatus may include a mixing chamber configured to be coupled to a heat exchanger to receive cooled fuel exhaust gas. The mixing chamber may include a duct operably coupled to the heat exchanger. The mixing chamber may be configured to operate to receive fuel exhaust gas cooled to a temperature of 400–1200°F. The mixing chamber may be configured to operate to mix the cooled fuel exhaust gas with slaked lime injected into the mixing chamber. The slaked lime may be filtered from the fuel exhaust gas. The mixing chamber may be configured to be fluidly coupled to the exhaust pipe to discharge the cooled fuel exhaust gas after the lime has been filtered from the fuel exhaust gas. The mixing chamber may be configured to operate to mix cooled fuel exhaust gas with slaked lime as a polishing step in the decomposition of PFAS and to control emissions of sulfur oxides and other substances from the plant.

[0117] The device may include piping, ducts, pumps, valves, conduits, sensors, and wiring configured to implement the described functions. The device may include a control system. The control system may be operably coupled with the piping, ducts, pumps, valves, conduits, sensors, and wiring to implement the described functions. The control system may include an algorithmic controller. The control system may include a processor. The control system may include memory configured to be operably coupled with the processor. The memory may be operably coupled with the processor. The memory may include encoded processor-executable program instructions and data, the instructions and data together program and configure the device, and when the instructions are executed by the processor, they cause the device to perform operations that implement the described functions.

[0118] PFAS removal may be carried out by a PFAS removal process. The PFAS removal process may include gasifying the feedstock containing PFAS using a gasifier. The gasifier may be any gasifier known to those skilled in the art. The gasifier may be a downdraft gasifier or a fluidized bed gasifier. Gasifying the feedstock may include feeding the feedstock containing PFAS into the gasifier. The feedstock may include wastewater biosolids. The process may include drying the feedstock containing wastewater biosolids using a dehydrator. The dehydrator may be operably coupled with the gasifier to feed the feedstock dried by the dehydrator into the gasifier. The process may include configuring the gasifier to operate at a temperature of 900 to 1800°F. The process may include configuring and operating the gasifier to defolarate PFAS, release PFAS from the solid, and decompose PFAS. The process may include configuring and operating the gasifier to convert the feedstock into low calorific value synthesis gas.

[0119] The process may include removing entrained particles from the synthesis gas held by the cyclone using a cyclone. The cyclone may be operably coupled to the gasifier to receive the synthesis gas exiting the gasifier. The process may include burning the synthesis gas received from the gasifier using a thermal oxidizer. The thermal oxidizer may be operably coupled to the gasifier to receive the synthesis gas exiting the gasifier. The thermal oxidizer may be operably coupled to the cyclone to receive the synthesis gas from which particulate matter has been separated by the cyclone. The process may include configuring and operating the thermal oxidizer to burn the synthesis gas at a temperature of 1600–2600°F. The process may include configuring and operating the thermal oxidizer or similar device to burn the synthesis gas at a temperature higher than the operating temperature of the gasifier. The process may include configuring and operating the thermal oxidizer or similar device to burn the synthesis gas with a residence time of 1–5 seconds. The process may include configuring and operating a thermal oxidation apparatus to thermally decompose any PFAS remaining in the synthesis gas after gasification.

[0120] The process may include cooling the fuel exhaust gas heated by the combustion of synthesis gas in the thermal oxidizer by a heat exchanger operably coupled to the thermal oxidizer. The process may include configuring and operating the heat exchanger to cool the heated fuel exhaust gas to a temperature of 400–1200°F. The process may include injecting slaked lime into the cooled fuel exhaust gas passing through the heat exchanger. The process may include mixing the slaked lime injected into the mixing chamber with the cooled fuel exhaust gas in a mixing chamber operably coupled to the heat exchanger to receive the cooled fuel exhaust gas from the heat exchanger. The process may include filtering the gas flow out of the heat exchanger by a filter operably coupled to the heat exchanger. The process may include configuring and operating the filter to remove spent lime from the gas flow out of the heat exchanger. The process may include periodically cleaning the filter with pulses of air passing through the filter in the opposite direction to the gas flow out of the heat exchanger. The process may include releasing cooled fuel exhaust gases through an exhaust stack operably coupled to a heat exchanger.

[0121] The process may include configuring piping, ducts, pumps, valves, conduits, sensors, and wiring to perform the steps described. The process may include configuring a control system operably coupled with the piping, ducts, pumps, valves, conduits, sensors, and wiring to perform one or more of the steps described by the control system. The steps described may be performed by an algorithmic controller. The control system may include a processor. The control system may include memory configured to be operably coupled with the processor. The memory may be operably coupled with the processor. The memory may include encoded processor-executable program instructions and data, the instructions and data together program and configure the device, and when the instructions are executed by the processor, the device performs an operation that performs one or more of the steps described.

[0122] Various implementations can achieve one or more technical effects. For example, some implementations can improve the decomposition rate of PFAS. This enhancement may result from burning the synthesis gas at a higher temperature rather than directly burning the solid feedstock. For example, burning the synthesis gas at a higher temperature instead of directly burning the solid feedstock can avoid the environmental impact that can occur with incineration. In some implementations, PFAS removal may be more effective than gasification. Such improved PFAS removal may result from burning the synthesis gas in a thermal oxidizer at a higher temperature for a sufficient residence time to thermally decompose more stable PFAS compounds. Various implementations can improve the energy efficiency of PFAS removal. Such improved energy efficiency may result from recovering heat from the fuel exhaust gas heated by the combustion of the synthesis gas and providing the recovered heat to the surrounding plant. Some implementations can reduce emissions from PFAS removal. This enhancement may result from mixing cooled fuel exhaust gas with slaked lime to accelerate the decomposition of PFAS and control the emission of harmful substances such as sulfur oxides from the plant.

[0123] An exemplary implementation of PFAS removal according to this disclosure may remove PFAS through a process comprising three exemplary steps. In the exemplary example, the first exemplary step in the decomposition of PFAS in a biosolid may be feeding the biosolid to a gasification unit. In the exemplary example, the gasification unit may operate at a temperature of 900–1800°F. The gasification unit works to defolatory the PFAS, freeing it from the solid and decomposing the PFAS. The gasification unit converts the feed material into a low-calorific synthesis gas. After exiting the gasification unit, the synthesis gas may be burned in a thermal oxidizer or similar device at a temperature of 1600–2600°F and for a residence time of 1–5 seconds. This exemplary second step may thermally decompose any PFAS that may remain in the synthesis gas after the gasification step. After exiting the thermal oxidizer, in an exemplary third step, the fuel exhaust gas may be cooled in a heat exchanger to supply heat and / or power to the plant or surrounding users. This fuel exhaust gas, cooled to 400-1200°F, can be mixed with slaked lime as a polishing step in the decomposition of PFAS and to control emissions of sulfur oxides and other substances from the plant.

[0124] The implementation of PFAS removal described herein may provide a system or method for removing PFAS from wastewater biosolids and other feedstocks using a process comprising three exemplary steps for decomposing PFAS: gasification, combustion in a thermal oxidation apparatus, and reaction with lime.

[0125] The above summary of the invention, the modes for carrying out the invention, the following claims, and the accompanying drawings refer to specific features of various implementation modes. It should be understood that the disclosure of various specific features herein should be interpreted as including all possible combinations of such specific implementation features. For example, if a particular feature is disclosed in a particular aspect or implementation mode or in the context of a particular claim, that feature may also be used, as far as possible, in combination with and / or in the context of other particular aspects and implementation modes, and in general in implementation modes.

[0126] While several implementation modes are disclosed, further implementation modes will become apparent to those skilled in the art from the modes for carrying out the invention. The disclosed implementation modes can be modified in countless obvious ways without departing from the spirit and scope of the disclosed implementation modes. Therefore, the drawings and descriptions should be considered illustrative and not limiting.

[0127] Features shown in the drawings are not necessarily depicted to a fixed scale, and it should be noted that, as those skilled in the art will recognize, features of one implementation mode may be used in conjunction with other implementation modes, even if not explicitly stated herein. To avoid unnecessarily obscuring implementation features, descriptions of well-known components and processing techniques may be omitted.

[0128] In this disclosure, various features may be described as optional, for example, through the use of the verb “may,” or through the use of any of the phrases “in some practical implementations,” “in some designs,” “in various implementations,” “in various designs,” “in an exemplary example,” or “for example.” For brevity and readability, this disclosure does not expressly describe all the changes that can be obtained by selecting from a set of optional features. However, this disclosure should be interpreted as expressly disclosing all such changes. For example, a system described as having three optional features may be implemented in seven different ways: by one of the three possible features, by any two of the three possible features, or by all three of the three possible features.

[0129] In various implementations, elements described herein as coupled or connected may have effective relationships that can be achieved through direct connections or indirectly with one or more other intervening elements.

[0130] In this disclosure, the term “any” can be understood as specifying any number of each element, i.e., one, at least one, at least two, each or all of each element. Similarly, the term “any” can be understood as specifying any set of each element, i.e., a set containing one or more sets of each element, one, at least one, at least two, each or all of them. Each set does not need to contain the same number of elements.

[0131] While various implementations are disclosed and described in detail in this specification, it will be apparent to those skilled in the art that various modifications can be made to the disclosed configurations, operations, and forms without departing from their spirit and scope. In particular, note that each implementation feature can be combined in any configuration, except those that are obviously meaningless to those skilled in the art, even if disclosed simply in combination with other implementation features. Similarly, the use of singular and plural forms is for illustrative purposes only and should not be interpreted as limiting.

[0132] The abstract is provided in accordance with 37 C. FR § 1.72(b) so that readers can immediately confirm the nature of the technical disclosure, and is submitted with the understanding that it is not to be used to interpret or limit the claims or their meaning.

[0133] In this disclosure, all descriptions using “including” may alternatively have “essentially consist of” or “consist of.” In this disclosure, any implementation of any method or apparatus may omit one or more process steps or components. In this disclosure, implementations that employ negative limitations are expressly disclosed and are considered part of this disclosure.

[0134] Certain technical terms and their derivatives may be used in this disclosure for convenience only, and are not limited to them. For example, words such as “up,” “down,” “left,” and “right” refer to the direction being referenced in the drawings unless otherwise specified. Similarly, words such as “inward” and “outward” refer to the direction toward and away from the geometric center of a device or area and a designated part thereof, respectively. Unless otherwise specified, singular references include plural forms and vice versa.

[0135] The term “includes” and its grammatical equivalents are used herein to mean, among other things, that other components, ingredients, or steps are optionally present. For example, an implementation “includes” (or “contains”) components A, B, and C may consist of components A, B, and C (i.e., include only those components) or may include not only components A, B, and C but also one or more other components.

[0136] Where this specification refers to a method comprising two or more defined steps, the defined steps may be performed in any order or simultaneously (unless the context excludes such possibility), and the method may include one or more other steps performed before any of the defined steps, between two of the defined steps, or after all of the defined steps (unless the context excludes such possibility).

[0137] The term “at least” followed by a number is used herein to indicate the beginning of a range that starts with that number (which may be a range with an upper limit or an upper limit, depending on the defined variable). For example, “at least 1” means 1 or 2 or more. The term “maximum” followed by a number (which may be a range with a lower limit of 1 or 0, or an upper limit, depending on the defined variable). For example, “maximum 4” means 4 or less than 4, and “maximum 40%” means 40% or less than 40%. In this specification, when a range is given as “(first number) to (second number)” or “(first number) ~ (second number)”, it means a range with the second number as the upper limit. For example, 25~100mm means a range with a lower limit of 25mm and an upper limit of 100mm.

[0138] Many suitable methods and corresponding materials for manufacturing each of the individual components of a mounting device are known in the art. As will be apparent to those skilled in the art, one or more mounting components may be formed by machining, 3D printing (also known as “additive” manufacturing), CNC machined parts (also known as “subtractive” manufacturing), and injection molding. The metals, woods, thermoplastics and thermosetting polymers, resins, and elastomers mentioned herein may be used. As will be apparent to those skilled in the art, many suitable materials are known, available, and can be selected and mixed according to the desired strength and flexibility, preferably the manufacturing method, and the specific application.

[0139] Elements in these claims that do not explicitly describe “means” or “steps” for performing a particular function should not be construed as “means” or “steps” as defined in 35 U.SC § 112(f). Specifically, the use of “steps” in the claims herein is not intended to invoke the provisions of 35 U.SC § 112(f). Elements enumerated in means-plus-function form are intended to be construed in accordance with 35 U.SC § 112(f).

[0140] The use of the term "first" in relation to a feature or element in a claim does not necessarily imply the presence of a second or additional feature or element.

[0141] The phrases “to be connected,” “to be bonded,” and “to communicate with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interactions. Two components may be functionally bonded to each other even if they are not in direct contact with each other. The terms “to be in contact” or “mechanically fused” refer to items that are in direct physical contact with each other, even if they are not necessarily attached together.

[0142] The term “exemplary” is used herein to mean “serving as an example, illustration, or reference.” Any implementation or design described herein as “exemplary” should not necessarily be construed as preferable to other implementations or designs. Various aspects of this disclosure are presented with reference to the drawings, which are not necessarily drawn to a certain scale unless otherwise indicated.

[0143] Throughout this specification, any reference to “implementation mode” or “the said implementation mode” means that any particular feature, structure, or characteristic described in relation to that implementation mode is included in at least one implementation mode. Therefore, not all quotations or variations thereof cited throughout this specification necessarily refer to the same implementation mode.

[0144] Similarly, it should be understood that in the above description, for the purpose of streamlining the disclosure, various features may be grouped into a single implementation mode, figure, or description thereof. However, the manner of the disclosure should not be interpreted as reflecting an intention that any claim of this application or an application claiming priority to this application requires more features than those expressly described in its claims. Rather, as reflected in the claims below, a novel mode may be a combination of fewer features than all the features of any single aforementioned disclosed implementation mode combined. Thus, the claims following the modes for carrying out the invention are incorporated into the modes for carrying out the invention, and each claim exists in itself as a separate implementation mode. This disclosure is intended to be interpreted as including all substitutions of independent claims with their dependent claims.

[0145] Implementations of the systems or methods described herein can be achieved through the use of one or more computing devices. Those skilled in the art will understand that exemplary systems suitable for use in the implementations described herein generally include one or more central processing units (CPUs) (e.g., random access memory (RAM), storage media (e.g., hard disk drives, solid-state drives, flash memory, cloud storage), operating systems (OS), one or more application software, display elements, one or more communication means, or one or more input / output devices / means. A control system may be an algorithm controller implementing one or more algorithms. Examples of computing devices usable in the implementations of this disclosure include, but are not limited to, proprietary computing devices, personal computers, mobile computing devices, tablet PCs, mini PCs, servers, or any combination thereof. The term computing device may also describe two or more computing devices that are communicably linked in a manner that distributes and shares one or more resources, such as clustered computing devices or server banks / farms. Those skilled in the art will understand that any number of computing devices can be used, and that the implementations of this disclosure are intended for use with any computing devices.

[0146] In various implementations, communication means, data storage devices, processors, or memory may interact with other components on the computing device to provision and display various functions related to the systems and methods detailed herein. Those skilled in the art will understand that numerous configurations are available for implementations of the disclosure, and that the implementations of the disclosure are intended for use in any suitable configuration.

[0147] According to one implementation of the present disclosure, the communication means of the system may be any means for performing data communication, for example, over one or more networks or to one or more peripheral devices connected to the system. Suitable communication means include, but are not limited to, circuits and control systems for providing wireless, wired, cellular, data port, Bluetooth®, or any combination thereof. Those skilled in the art will understand that there are many communication means that can be used in the implementation of the present disclosure, and that the implementation of the present disclosure is intended to be used with any communication means.

[0148] Throughout this disclosure and thereafter, block diagrams and flowcharts illustrate methods, apparatus (i.e., systems), and computer program products. Each element of a block diagram and flowchart, as well as each combination of elements in a block diagram and flowchart, illustrates a function of a method, apparatus, and computer program product. Any and all such functions ("Described Functions") can be implemented by computer program instructions, dedicated hardware-based computer systems, combinations of dedicated hardware and computer instructions, combinations of general-purpose hardware and computer instructions, and any and all such may be commonly referred to as "circuits," "modules," or "systems."

[0149] The aforementioned drawings and descriptions illustrate functional aspects of the disclosed system; however, unless explicitly stated or otherwise evident from the context, no specific arrangement of software for implementing these functional aspects should be inferred from these descriptions.

[0150] Each element of a flowchart may represent a step or group of steps of a method implemented by a computer. Furthermore, each step may include one or more substeps. For illustrative purposes, these steps (as well as any and all other steps identified and described above) are shown in order. It will be understood that implementations may include alternative orders of steps that are suitable for specific uses of the technology disclosed herein. All such changes and modifications are intended to be within the scope of this disclosure. The illustration and description of steps in any particular order is not intended to exclude implementations having steps in a different order, unless required by a particular application, expressly stated, or otherwise evident from the context.

[0151] Traditionally, a computer program consists of a series of computational instructions or programming instructions. It should be understood that a programmable device (i.e., a computing device) can accept such a computer program and process its computational instructions to produce further technological effects.

[0152] A programmable device may include one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors, programmable devices, programmable gate arrays, programmable array logic, memory devices, application-specific integrated circuits, etc., which can be appropriately used or configured to process computer program instructions, execute computer logic, and store computer data. Throughout this disclosure and / or throughout, a computer may include at least one general-purpose computer, a dedicated computer, a programmable data processing device, a processor, a processor architecture, etc., in any or all appropriate combination.

[0153] A computer may include computer-readable storage media, which may be internal or external, removable and replaceable, or fixed. A computer may also include a basic input / output system (BIOS), firmware, operating systems, databases, etc., which may include, interface with, or support the software and hardware described herein.

[0154] The implementations of the systems described herein are not limited to applications involving conventional computer programs or programmable devices that execute them. For example, the implementations of the disclosure claimed herein may include optical computers, quantum computers, analog computers, and the like.

[0155] Regardless of the computer program or type of computer involved, it is possible to manufacture a specific machine capable of loading a computer program into a computer and performing any and all of the illustrated functions. This specific machine provides means for performing any and all of the illustrated functions.

[0156] Any combination of one or more computer-readable media may be used. Computer-readable media may be computer-readable signal media or computer-readable storage media. Computer-readable storage media may be, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. More specific examples (non-exclusive list) of computer-readable storage media include electrical connections with one or more wires, portable computer diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In the context of this document, computer-readable storage media may be any tangible medium that contains or can store programs for use by or in connection with an instruction execution system, apparatus, or device.

[0157] Computer program instructions can be stored in computer-readable memory that enables a computer or other programmable data processing device to function in a particular way. Instructions stored in computer-readable memory constitute a product containing computer-readable instructions for implementing any and all of the illustrated functions.

[0158] A computer-readable signaling medium may include, for example, a propagated data signal having computer-readable program code encoded therein, either in the baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including but not limited to electromagnetic, optical, or any suitable combination thereof. A computer-readable signaling medium may be any computer-readable medium that is not a computer-readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0159] Program code encoded in a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, fiber optic cable, RF, or any suitable combination thereof.

[0160] The elements shown in the flowcharts and block diagrams throughout the drawings suggest logical boundaries between them. However, according to software or hardware engineering techniques, the shown elements and their functions may be implemented as part of a monolithic software structure, as standalone software modules, or as modules employing external routines, code, services, or any combination thereof. All such implementation modes are within the scope of this disclosure.

[0161] Unless explicitly stated or otherwise made clear from the context, the verbs “execute” and “process” can be used interchangeably to mean execute, process, interpret, compile, assemble, link, load, or any combination thereof. Thus, any implementation that executes or processes computer program instructions, computer executable code, etc., may operate appropriately according to the instructions or code in any and all of the described ways.

[0162] The functions and operations presented herein are not inherently related to any particular computer or other device. Various general-purpose systems may also be used with programs following the teachings herein, or it may be convenient to construct more specialized devices to carry out the necessary method steps. The structures required for various such systems, along with equivalent variations, will be obvious to those skilled in the art. Furthermore, the implementations of this disclosure are not described with reference to any particular programming language. Various programming languages ​​may be used to carry out the teachings described herein, and any reference to a particular language is provided for the applicability and best-form disclosure of the implementations of this disclosure. The implementations of this disclosure are well suited to a wide variety of computer network systems across numerous topologies. In this art, the configuration and management of large-scale networks include storage devices and computers that are communicatively coupled to different computers and storage devices over networks such as the Internet.

[0163] The reference numbers and descriptions of each element shown in the drawing are summarized below. 100 Systems 105 Material 110 Conveyor 115 Gasification equipment supply bin 120 Gasification equipment 135 Cyclone 140 Thermal Oxidation Device 145 Heat exchanger 150 Filter Unit Duct 155 Filter Unit 156 Catalyst-impregnated filter element 160 exhaust port 200 processes 205 Biosolids Storage Bin 210 Live Bottom 215 Supply Screw 220 Drying equipment 305 Filter Inlet 310 Filter Outlet 315 Air Manifold 320 Waste Hopper 325 Airlock waste exit

[0164] Several implementation modes have been described. Nevertheless, it will be understood that various modifications are possible. For example, the steps of the disclosed technology may be carried out in a different order, the components of the disclosed system may be combined in different ways, or components may be supplemented with other components. Therefore, other implementation modes are contemplated within the scope of the following claims.

Claims

1. A gasifier having an operating temperature, configured to defolarate PFAS in a feed material containing polyfluoroalkyl substances and substances contaminated with PFAS, to release and decompose PFAS from the feed material, to gasify the feed material, and to release synthesis gas produced based on the gasification of the feed material. A thermal oxidizer operably coupled to the gasifier for receiving the synthesis gas, the thermal oxidizer having an operating temperature, configured to burn the synthesis gas and discharge heated fuel exhaust gas generated based on the combustion of the synthesis gas, A heat exchanger operably coupled to a thermal oxidation device for receiving the fuel exhaust gas, wherein the heat exchanger is configured to cool the heated fuel exhaust gas and release the cooled fuel exhaust gas as a gas flow out of the heat exchanger, and the heat exchanger cools the heated fuel exhaust gas to a temperature of 400 to 1200°F, Equipped with, The system is configured to inject slaked lime into the cooled fuel exhaust gas flowing from the outlet of the heat exchanger. A filter unit operably coupled downstream of the heat exchanger, further comprising a slaked lime cake formed within the filter unit, which filters the flow of the cooled fuel exhaust gas, and the slaked lime cake has the function of decomposing the fluorine bonds of PFAS, At the time of adding the slaked lime to the filter unit, the gas temperature is maintained in a range lower than the gas temperature at the outlet of the heat exchanger. The apparatus is characterized in that the mixing of the remaining PFAS compound into the cooled fuel exhaust gas and the passage of the slaked lime cake formed in the filter unit provide conditions in which the calcium in the slaked lime acts to attack the fluorine bonds of the PFAS.

2. The apparatus according to claim 1, wherein the thermal oxidation apparatus is configured to thermally decompose the PFAS remaining in the synthesis gas after gasification, and the operating temperature of the thermal oxidation apparatus is higher than the operating temperature of the gasification apparatus.

3. The apparatus according to claim 1, wherein the filter unit comprises a catalyst-impregnated filter element.

4. The apparatus according to claim 1, wherein the substance contaminated with PFAS is a biosolid.

5. The apparatus according to claim 1, further comprising the supply material biosolids.

6. The apparatus according to claim 1, wherein the supplied raw material is at least partially composed of wastewater.

7. The apparatus according to claim 1, wherein the gasification apparatus further comprises a fluidized bed (FB) gasification apparatus.

8. The apparatus according to claim 1, further comprising a conveyor configured to transfer the supply material to the gasification apparatus via a supply bin comprising a live bottom.

9. The apparatus according to claim 1, further comprising a drying device, wherein the drying device is operably coupled to the gasification device and supplies the gasification device with dried feed material to be dried by the drying device.

10. The apparatus according to claim 9, wherein the drying apparatus is configured to dry the raw material to be received by the drying apparatus.

11. The apparatus according to claim 1, further comprising a drying device operably coupled with the gasification device and the heat exchanger.

12. The apparatus according to claim 1, further comprising the gasification apparatus configured to operate at a temperature of 900 to 1800°F.

13. The apparatus according to claim 1, further comprising the gasification device configured to operate for converting the supply material into a low-calorific value synthesis gas.

14. The apparatus according to claim 1, further comprising a cyclone operably coupled to the gasifier for receiving the synthesis gas discharged from the gasifier.

15. The apparatus according to claim 14, further comprising the cyclone configured to operate for removing entrained particles from the gas held by the cyclone.

16. The apparatus according to claim 14, further comprising a cyclone operably coupled to the thermal oxidation apparatus, which supplies the synthesis gas from which particulate matter has been removed by the cyclone to the thermal oxidation apparatus.

17. The apparatus according to claim 1, further comprising the thermal oxidation apparatus configured to burn the synthesis gas at a temperature of 1600 to 2600°F.

18. The apparatus according to claim 1, further comprising the thermal oxidation device configured to burn the synthesis gas for a residence time of 1 to 5 seconds.

19. The apparatus according to claim 1, further comprising a heat exchanger configured to recover heat captured based on the cooling of the heated fuel exhaust gas discharged from the thermal oxidation device and to provide the recovered heat to surrounding users.

20. The apparatus according to claim 1, further comprising an exhaust pipe, the exhaust pipe being operably coupled to the heat exchanger to discharge the cooled fuel exhaust gas.

21. The apparatus according to claim 1, wherein the apparatus is configured to periodically clean the filter unit with pulses of air passing through the filter unit in the opposite direction to the direction of the cooled fuel exhaust gas flow coming out of the heat exchanger.

Images