Technology to convert municipal waste to coal
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- MACAWBER BEEKAY PVT LTD
- Filing Date
- 2024-01-15
- Publication Date
- 2026-05-13
AI Technical Summary
Municipal solid waste incineration generates toxic pollutants and unwanted ash, posing environmental and health risks, and current methods lack an efficient, environmentally friendly way to utilize all by-products for energy generation.
A waste conversion system that processes municipal solid waste into charcoal and volatile gas, using a reactor with temperature zones and hydraulic feeders to produce self-sustaining charcoal and fuel for the process, with the volatile gas used for heating and further processing into hydrogen and dimethyl ether.
The system converts municipal waste into environmentally friendly charcoal and volatile gas, reducing pollutant emissions, utilizing all by-products for energy and minimizing ash disposal issues, while being economically sustainable and eco-friendly.
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Figure IN2024050037_09012025_PF_FP_ABST
Abstract
Description
[0001]TECHNOLOGY TO CONVERT MUNICIPAL WASTE TO COAL TECHNICAL FIELD This invention relates to the conversion of Municipal Solid Waste (MSW) into charcoal and, more particularly, to a system and associated method of processing such municipal waste into usable charcoal and volatile gas in an environmentally friendly manner. Charcoal can be used as coal in industrial establishment by replacing fossil fuel whereas the volatile gas shall be used in burners of system itself for heating of reactor and other accessories. This makes the system self- sustained and more economical for commercial use. Further by applying suitable technology, this volatile gas can be used in the production of hydrogen (H2) and dimethyl ether (DME) to make it more economical and eco-friendlier. BACKGROUND Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced in prior art. Municipal solid waste is commonly incinerated in a combustion process at high temperatures such as 900 Deg Celsius. In this incarnation process solid waste directly fetches to the combustor in oxygen rich environment and the amount of heat generated from burning is utilized for generation of steam for further electricity generation. One potential problem with such incineration is emission. The incinerator may contain toxic and other unwanted pollutants dangerous to human health and the environment. Another problem with incarnating municipal solid waste is that the resultant ash must be sent to a particular type of landfill subject to restrictive environmental regulations. In case if it is dumped at landfill site, then it has very adverse effect over the environment, soil, and underground water. Therefore, there is a need in the industry for a process of treating municipal solid waste in an environmentally friendly manner which uses all the residual by product of the process. There is also a need for a process of treating municipal solid waste in an environmentally friendly manner which can generate electricity. SUMMARY The following presents a simplified summary of the subject matter in order to provide a basic understanding of some aspects of subject matter embodiments. This summary is not an extensive overview of the subject matter. It is not intended to identify key / critical elements of the embodiments or to delineate the scope of the subject matter. Its sole purpose is to present some concepts of the subject matter in a simplified form as a prelude to the more detailed description that is presented later. A waste conversion system disclosed here addresses the above-mentioned need a process of treating municipal solid waste in an environmentally friendly manner which uses all the residual by product of the process. The waste conversion system disclosed here comprises a hopper, a coarse feeder, a weigh feeder, a reactor, and a cooling segment. The hopper stores the segregated municipal solid waste MSW as buffer feed stock for a reactor, where the hopper provides a constant feed of the MSW to the reactor for continuous operation of the reactor. The coarse feeder is connected to the hopper, where the coarse feeder feeds definite amount of MSW into the reactor. The weigh feeder is connected to the coarse feeder to receive the MSW, where the weigh feeder pushes the MSW feed into the reactor. The weigh feeder measures weight of the MSW that is fed into the reactor. The reactor is configured to receive the MSW via a set of hydraulic pushers and heats the segregated MSW to a predefined temperature in an oxygen deficient space, which causes the MSW to lose moisture and changes phase of the MSW to charcoal. The cooling segment receives the charcoal from the reactor and cools down the charcoal to avoid auto ignition. In an embodiment, the coarse feeder is connected to an exit gate of the hopper, and is operated using a hydraulic pusher, where the coarse feeder feeds a predefined quantity of MSW from the hopper via the hydraulic pusher. The feed of the MSW is controllable with the number of operation cycle of coarse feeder through a logic control. In an embodiment, the coarse feeder pushes the MSW forward and the MSW falls into the weigh feeder, and the weigh feeder comprises the hydraulic pusher to push the MSW feed into the reactor. The weigh feeder measures weight of the MSW entering inside the reactor by means of load cells equipped at the weigh feeder, which provides feedback to plant PLC programmable logic control system to control the process. In an embodiment, the hydraulic pusher is positioned in the coarse feeder and the weigh feeder, where the hydraulic pusher comprises feeder plates. The hydraulic pusher consists of a piston rod which moves back and forth using a power pack assembly, where the coarse feeder and the weigh feeder are operated by the power pack assembly that uses enclosed fluid to transfer energy to subsequently create rotary motion, linear motion, and force. In an embodiment, the waste conversion system further comprises tubes through which pressurized hydraulic oil is transferred. The tubes are connected to the hydraulic pusher to provide to and fro motion to the hydraulic pusher and the feeder plate. In an embodiment, after the weigh feeder measures the weight of the MSW, the weigh feeder pushes the MSW inside the first zone of the reactor through an inlet chute. Moving baffles and fixed baffles are provided to prevent the ingress of air inside the reactor, where the moving baffle is hinge supported and moved up along the MSW to make way and return when the feeding is not in process. In an embodiment, the reactor comprises: the first zone defining a pre-heating zone with a temperature range of 50 degree Celsius to 150 degree Celsius), a second zone defining heating zone with a temperature range of 100 degree Celsius to 200 degree Celsius, a third zone defining torrefaction zone with a temperature range of 250 degree Celsius to 350 degree Celsius, and a fourth zone defining cooling zone with a temperature below 60 degree Celsius. In an embodiment, the reactor comprises a rotary inner shell connected with a girth gear for conversion process of the MSW, and the girth gear is positioned adjacent to the rotary inner shell. The girth gear is connected with a main electric drive and a gear box, which facilitates rotary motion for the reactor. The gear box provides rotary torque and reduced rpm to the reactor and the main electric drive transfers rotary motion through a belt and pulley arrangement. The reactor rotates between 1-6 rpm based on operational capacity and parameter of the reactor, which is controlled through a variable frequency drive VFD. In an embodiment, the reactor comprises an outer stationary shell that is positioned over a rotary inner shell for movement of hot air in space between outer stationary shell and the rotary inner shell. The outer stationary shell is insulated for thermal efficiency of the heating system and the reactor, and where the outer stationary shell is sealed using layers of leaf seal that prevent ingress of air between stationary outer stationary shell or adopter and the rotary inner shell. In an embodiment, the rotary inner shell is fitted with one or more guide rings, which rotates over rollers positioned alongside a bracket for seamless rotation of the rotary inner shell. The rollers are positioned alongside the bracket of the reactor on which the guide ring rotates and prevents the reactor from derailing. In an embodiment, the waste conversion system further comprises a discharge feeder that is connected to the cooling segment, where the charcoal is discharged through the discharge feeder, which operates through the power pack assembly provided at discharge gate of the reactor, where the discharge feeder maintains sealing of the reactor to avoid any ingress of air and leakage of volatile gases, where the charcoal discharged from reactor falls on the discharge feeder through a discharge chute. The discharge feeder pushes the discharged charcoal to either side of the discharge feeder. In an embodiment, the waste conversion system further comprises a cyclone separator that is connected to outlet of the cooling segment and the discharge feeder to separate dust, mist and solid particles from volatile gases that are generated in the waste conversion system. The dust, mist and solid particles are pushed based on their respective masses to outer edges of the cyclone separator due to centrifugal force and any incoming volatile gas is forced to adopt a fast- revolving spiral movement, which causes the separation of the dust, mist and solid particles from the volatile gases. In an embodiment, the waste conversion system further comprises a set of burners and a centrifugal volatile gas blower. The burners are installed below the outer stationary shell of the reactor to provide required heat energy for the conversion process in the reactor that uses the volatile gas as a fuel in the burners. The centrifugal volatile gas blower is positioned in line from the cyclone separator to regulate the flow of the volatile gas towards the burners. The centrifugal air blower is positioned adjacent to the burners to supply required amount of air for complete and efficient combustion of volatile gas in the burners. In an embodiment, the waste conversion system further comprises a flue gas blower that transfers the flue gases towards the chimney. The flue gases are generated after combustion in the burner and travels across the reactor via space between the outer stationary shell and the rotary inner shell, and the flue gas blower maintains pressure within combustion section of the reactor and draws the flue gases to escape via the chimney. In an embodiment, the waste conversion system further comprises a cooling system and a specially designed moving joint. The cooling system is positioned to maintain sufficient flow and pressure inside the cooling segment. The moving joint that comprises a fixed water inlet and outlet, which facilitates water connection through moving pipes that are attached with the rotating cooling segment. The fixed water inlet and outlet are provided at discharge chute of the reactor where cooling water is required to cool down the coal temperature and avoid any self-ignition. In an embodiment, the waste conversion system further comprises thermocouple IR sensors that are connected to the outer stationary shell to measure the temperature of the rotary inner shell, and the measurement is used as a reference to control the burner and resulting temperature from the burner. In an embodiment, the process involved in the reactor comprises the following steps. Heating the reactor using the external source of heating. In response to internally generated inflammable volatile gas after heating inside inner shell, switching off the external heat source and heating with internally produced volatile or syn gas and burners installed, where the external heat source is switched OFF automatically between external heat source and internal source of heating though volatile gas. Setting operation of the external heat source is in standby mode and the external heat source is switched ON only when volatile gas generation inside the inner shell is low or insufficient and the external heat source is switched OFF once a definite temperature is achieved. Controlling the ON and OFF operation of the external heat source via the thermocouple IR sensors that are installed adjacent to the burner and the reactor, where the controlled operation makes the process self-sustainable in terms for fuel for heating and reduces reduce dependency upon external heat source or fuel to reduce cost. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS The foregoing and further objects, features, and advantages of the present subject matter will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings, wherein numerals are used to represent like elements. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter, and are, therefore, not to be considered for limiting of its scope, for the subject matter may admit to other equally effective embodiments. Figure 1A illustrates a schematic view of the or the waste conversion system used to practice the method of the present invention, as an example embodiment of the present disclosure. Figure 1B illustrates a left-side portion along the axis XX of the Figure 1A to provide a clear view of the components of the waste conversion system, as an example embodiment of the present disclosure. Figure 1C illustrates a right-side portion along the axis XX of the Figure 1A to provide a clear view of the components of the waste conversion system, as an example embodiment of the present disclosure. Figure 2 illustrates a feeder assembly of the waste conversion system as shown in Figure 1A, as an example embodiment of the present disclosure. Figure 3 illustrates moving joint arrangement within the waste conversion system as shown in Figure 1A, as an example embodiment of the present disclosure. Figure 4 illustrates a schematic flow of process involved in the waste conversion system as shown in Figure 1A, as an example embodiment of the present disclosure. DETAILED DESCRIPTION The following presents a detailed description of various embodiments of the present subject matter with reference to the accompanying drawings. The embodiments of the present subject matter are described in detail with reference to the accompanying drawings. However, the present subject matter is not limited to these embodiments which are only provided to explain more clearly the present subject matter to a person skilled in the art of the present disclosure. In the accompanying drawings, reference numerals are used to indicate like components. The specification may refer to “an”, “one”, “different” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and / or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It will be understood that when an element is referred to as being “attached” or “connected” or “coupled” or “mounted” to another element, it can be directly attached or connected or coupled to the other element or intervening elements may be present. As used herein, the term “and / or” includes any and all combinations and arrangements of one or more of the associated listed items. The figures depict a simplified structure only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. In general, the concept of this type of Waste-To-Energy plant is basically a waste management facility that converts waste to produce Charcoal, which can be further used as a coal in conventional thermal power plant. This type of plant is sometimes called a Waste-to Coal, municipal waste conversion, energy recovery, or resource recovery plant. Waste-to-coal is being increasingly looked at as an alternative against conventional coal which is fossil fuel. The biggest advantage is utilization of waste into conversion of energy without depleting the carbon loaded fossil fuel. Thus, saving natural resources and solving the eco-social issue by processing municipal waste. Due to lack of practice at source segregation of waste, Indian MSW is typically composed of a wide variety of materials, including plastics, paper, food waste, and other organic materials. It also contains metals, construction material (inert), utensils, cans, aluminium foils, and other pollutants. These metals and inert materials are not ideal for making into Charcoal. With MBPL technology, now it is possible to convert municipal solid waste (MSW) into charcoal (which is later termed as Green Coal) using heat reaction process and efficient method of sorting and processing to separate the waste and metals / inert particles. It is important to note that MSW contains a diverse range of materials that are not typically found in biomass feedstock. Due to this reason, the process of charcoal generation is more complex and requires a different approach to the process. This process of charcoal generation is basically torrefaction process in which thermal treatment process takes place inside a rotating large drum (which is termed as the REACTOR). The process inside the Reactor involves heating of segregated MSW to a high temperature (up to 350°C) in the oxygen deficient atmosphere. This causes the MSW to lose moisture and causes phase changes in the material that make it more similar to conventional coal. After heating of reactor, the flue gas is cleaned by using gas cleaning system in which the temperature gets cooled down and passed through cleaning system in which the contaminants such as SO2 and NOx gases along with particulate matter are removed. It also continuously monitors the level of emissions being discharged from chimney. The process to convert Municipal Solid Waste (MSW) to Green Coal (charcoal) via reactor, involves the following steps: a. Pre-Sorting: This is first step is where the MSW is churned inside store pit to remove some moisture in natural way. Also, the waste is mixed to make it homogenous. The large inert materials or metals can be sorted out here itself. b. Preheating: This is required to remove the maximum moisture content at this stage by using specially designed Rotary Drum Dryer cum pre-shredder. After heating, the moisture that remains here is approximately 10% in the MSW. c. Sorting: The next step is to sort and separate the waste into different categories by mechanical segregation method. Most of the metals and inert materials are sorted out here itself. This increases the efficiency of the reactor to the optimum level. d. Pre-treatment: The next step would be to shred, chop or grind the sorted waste into small pieces, to make it easier to handle and process. This step is also important to make it homogeneous material and thus improve the heat transfer during process inside reactor. e. Heating of Reactor: Initially reactor is heated with external source which can be biomass fired gasifier burners or Biomass burners. The hot gasses are generated to the temperature of 600 deg. C. Once torrefaction process starts, it starts producing volatile gas. This volatile gas, once become flammable, is diverted to the burners and the external source will be automatically switch-off in phased manner. This process makes system self-sustainable. The external heat source is required only when the required temperature is dipping. f. Charcoal Reaction: The pre-treated waste would then be fed into a Reactor. The Reactor is sealed to the level to allow minimum amount of air and heated to a temperature between 50-350°C, to remove moisture and break down the waste into its component parts as high GCV charcoal. This is indirect heating where the outer shell is heated by firing a set of burners and material which are heated inside the reactor. The reactor is divided in following zones as per different temperature zones. o Pre-heating zone (500C to 1500C) o Heating Zone (1000C to 2000C) o Torrefaction Zone (2500C to 3500C) o Cooling Zone (Less than 600C) g. Cooling and conditioning: Once the torrefaction process is complete, the material would need to be cooled and conditioned before it can be used as charcoal. This is done in last zone of reactor with external cooling water. h. Pelletising and packaging: The cooled Charcoal is then be mixed with binder, pelletised, dried and packaged for transport and storage. This final product can be termed as MBL Green Coal. MBL Green Coal is used as a fuel in power plants, as well as in other industrial processes. It burns more cleanly and efficiently than raw biomass or RDF (Refuse Derive Fuel) and has a higher energy density than RDF. It also can be stored and transported more easily than raw biomass or RDF. Additionally, charcoal pellets have better grindability and more suitable for use in pulverized coal-fired power plants. Referring to Figures 1A-1C, Figure 1A illustrates a schematic view of the or the waste conversion system (60) used to practice the method of the present invention, Figure 1B illustrates a left-side portion along the axis XX of the Figure 1A to provide a clear view of the components of the waste conversion system (60), and Figure 1C illustrates a right-side portion along the axis XX of the Figure 1A to provide a clear view of the components of the waste conversion system (60), as an example embodiment of the present disclosure. As shown in Figures 1B and 1C, the waste conversion system (60) disclosed here comprises a hopper (1), a coarse feeder (2), a weigh feeder (5), a reactor (50), and a cooling segment (17). The hopper (1) stores the segregated municipal solid waste (MSW) as buffer feed stock for the reactor (50), where the hopper (1) provides a constant feed of the MSW to the reactor (50) for continuous operation of the reactor (50). Main objective of this MSW hopper (1) is to facilitate enough feed stock for constant feed and continuous operation of the reactor (50). The coarse feeder (2) is connected to the hopper (1), where the coarse feeder (2) feeds a definite amount of MSW into the reactor (50). The coarse feeder (2) is specially designed and mounted at just bottom / exit of MSW hopper (1) and operated via hydraulically assisted pusher members. The coarse feeder (2) feeds a definite quantity of material (equivalent to volume of box) from MSW hopper (1) to the coarse feeder (2). The coarse feeder (2) decides the amount of feed material to be fed into the reactor (50). The feed can be controlled with the number of operation cycles of coarse feeder (2) through logic controls. As shown in Figures 1B and 1C, the weigh feeder (5) is connected to the coarse feeder (2) to receive the MSW, where the weigh feeder (5) pushes the MSW feed into the reactor (50). The weigh feeder (5) measures weight of the MSW that is fed into the reactor (50). The coarse feeder (2) pushes the material forward and it falls into the specially designed weigh feeder (5) basket, where a feeder pusher plate (3) (Figure 2) is provided to push the feed material inside of reactor (50). The weigh feeder (5) also measures the weight of feed material entering inside the reactor (50) by means of load cells (5a). The reactor (50) is configured to receive the MSW via a set of hydraulic pushers (3a) and heats the segregated MSW to a predefined temperature in an oxygen deficient space, which causes the MSW to lose moisture and changes phase of the MSW to charcoal. In an example, MSW is fed into the reactor (50) inlet by means of hydraulic pusher (3a). There are two hydraulic pushers (3a) provided, one for coarse feeder (2) and other for weigh feeder (5). A hydraulic cylinder (explained later) is equipped with hydraulic pusher (3a) to provide adequate movement to the feeder plate (3). The hydraulic pusher (3a) consists of a cylinder barrel, in which a piston is connected to a piston rod (3b) that moves back and forth with the help of a power pack assembly (4). Finally, the cooling segment (17) receives the charcoal from the reactor (50) and cools down the charcoal to avoid auto ignition of charcoal. As described previously, the coarse feeder (2) is connected to an exit of the hopper (1) and is operated using a hydraulic pusher (3a), where the coarse feeder (2) feeds a predefined quantity of MSW from the hopper (1) via the hydraulic pusher (3a). The feed of the MSW is controllable with the number of operation cycle of coarse feeder (2) through a logic control. The coarse feeder (2) pushes the MSW forward and the MSW falls into the weigh feeder (5), and the weigh feeder (5) comprises the hydraulic pusher (3a), as shown in Figure 2, to push the MSW feed into the reactor (50). The weigh feeder (5) measures weight of the MSW entering inside the reactor (50) by means of load cells (5a) equipped at the weigh feeder (5), which provides feedback to plant PLC (programmable logic control) system to control the process. As shown in Figures 1C and 2, the hydraulic pusher (3a) is positioned in the coarse feeder (2) and the weigh feeder (5), where the hydraulic pusher (3a) comprises feeder plates (3). The hydraulic pusher (3a) consists of a piston rod (3b) which moves back and forth using a power pack assembly (4), where the coarse feeder (2) and the weigh feeder (5) are operated by the power pack assembly (4) that uses enclosed fluid to transfer energy to subsequently create rotary motion, linear motion, and force. In an example embodiment, both the feeders are operated by an individual or common power pack system (4) which is a hydraulic system that employs enclosed fluid to transfer energy from one source to another, and subsequently create rotary motion, linear motion, or force. The power pack system (4) provides sufficient power needed for this transfer of fluid. After the weigh feeder (5) measures the weight of the MSW, the weigh feeder (5) pushes the MSW inside the first zone (10a), as shown in Figure 1B, of the reactor (50) through an inlet chute (6). Moving baffles (6a) and fixed baffles (6b) are provided to prevent the ingress of air inside the reactor (50), where the moving baffle (6a) is hinge (6c) supported and moved up along the MSW to make way and return when the feeding is not in process. The reactor (50) comprises: the first zone (10a) defining a pre-heating zone with a temperature range of 500degree Celsius to 150 degree Celsius), a second zone (10b) defining heating zone with a temperature range of 100 degree Celsius to 200 degree Celsius, a third zone (10c and 10d) defining torrefaction zone with a temperature range of 250 degree Celsius to 350 degree Celsius, and a fourth zone (17) defining cooling zone with a temperature below 60 degree Celsius. As shown in Figure 1B, the rotary inner shell (10) is fitted with one or more guide rings (13), which rotates over rollers (14) positioned alongside a bracket (14a) for seamless rotation of the rotary inner shell (10). The rollers (14) are positioned alongside the bracket (14a) of the reactor (50) on which the guide ring (13) rotates and prevents the reactor (50) from derailing. The waste conversion system (60) also comprises a discharge feeder (18) that is connected to the cooling segment (17), where the charcoal is discharged through the discharge feeder (18), which operates through the power pack assembly (4) provided at discharge gate of the reactor (50). Here, the discharge feeder (18) maintains sealing of the reactor (50) to avoid any ingress of air and leakage of volatile gases, where the charcoal discharged from the reactor (50) falls on the discharge feeder (18) through a discharge chute (18a), and where the discharge feeder (18) pushes the discharged charcoal to either side of the discharge feeder (18). As shown in Figure 1C, the waste conversion system (60) also comprises a cyclone separator (21) that is connected to outlet of the cooling segment (17) and the discharge feeder (18) to separate dust, mist and solid particles from volatile gases that are generated in the waste conversion system (60). The dust, mist and solid particles are pushed based on their respective masses to outer edges of the cyclone separator (21) due to centrifugal force and any incoming volatile gas is forced to adopt a fast-revolving spiral movement, which causes the separation of the dust, mist and solid particles from the volatile gases. Furthermore, a water seal safety valve is provided to prevent the rotary inner shell (10) from over pressurization. Water in the tank seals the gas and atmospheric air, thus allowing the water seal to break whenever the rotary inner shell (10) is pressurized. As shown in Figure 1C, the waste conversion system (60) also comprises a set of burners (16) and a centrifugal air blower (15b). The burners (16) are installed below the outer stationary shell (11) of the reactor (50) to provide required heat energy for the conversion process in the reactor (50) that uses the volatile gas as a fuel in the burners (16). The centrifugal volatile gas blower (15a) is positioned in line from the cyclone separator (21) to regulate the flow of the volatile gas towards the burners (16). The centrifugal air blower (15b) is positioned adjacent to the burners (16) to supply the required amount of air for complete and efficient combustion of volatile gas in the burners (16). In an example embodiment, after the combustion, the generated flue gas shall travel across the reactor (50) via space between outer stationary shell (11) and the rotary inner shell (10) and to maintain the proper pressure within combustion chamber, a flue gas blower (15c) is provided, also it transfers the flue gas towards chimney (24). As shown in Figure 1C, the waste conversion system (60) also comprises the flue gas blower (15c) that transfers the flue gases towards the chimney (24). The flue gases are generated after combustion and travels across the reactor (50) via space between the outer stationary shell (11) and the rotary inner shell (10), and the flue gas blower (15c) maintains pressure within combustion section of the reactor (50) and draws the flue gases to escape via the chimney (24). Furthermore, flue gas is treated further in gas cleaning tank (23), in which dust particles, aerosols and harmful chemical washed out within this tank via treating with some catalyst. Cleaned flue gas is further transferred to chimney (24) where escape draft is maintained where flue gas can easily evacuate from the system. As shown in Figure 1B, the waste conversion system (60) also comprises thermocouple IR sensors (25) that are connected to the outer stationary shell (11) to measure the temperature of the rotary inner shell (10), and the measurement is used as a reference to control the burner (16) and resulting temperature from the burner (16). Referring to Figures 1A-1C, the process involved in the reactor (50) comprises the following steps. Heating the reactor (50) using the external heat source (26). The external heat source (26) is, for example, 1) a biomass burner, which is an external burner operates by using biomass as fuel. This generates high temperature flame / flue gas which is used for eating of reactor (50), and b)a Gasifier that generates volatile or syn gas which is fed to the reactor burners for heating of reactors. The gas is generated by heating of biomass / coal RDF etc in gasifier to generates inflammable gas. In response to generation of inflammable volatile gas after heating, the external heat source (26) is switched OFF, where the volatile gas line (16a) is switched ON. Setting operation of the external heat source (26) in standby mode and the external heat source (26) is switched ON only when volatile gas generation is low and the external heat source (26) is switched OFF after a definite temperature is generated from the burner (16) using volatile gas line (16a). Controlling the ON and OFF operation of the external heat source (26) via the thermocouple IR sensors (25) that are installed adjacent to the burner (16) and the reactor (50). Here, the controlled operation makes the process self-sustainable in terms for fuel for heating and reduces reduce dependency upon external fuel or external heat source (26) to reduce cost. In addition to the above, dedicated ducts are routed across the plant, which are used to carry volatile gas, flue gas, and air according to the process requirement. The whole reactor (50) rests on the steel structure frame also known as reactor brackets. The load cells (5a) that are positioned equipped below weigh feeder (5) measures the weight of feed material to be fed into the reactor’s (50) inlet in cyclic manner. A cooling system (22) is also provided to maintain sufficient flow and pressure inside the cooling segment (17) as described in Figures 3 and 4. Figure 2 illustrates a feeder assembly of the waste conversion system (60) as shown in Figure 1A, as an example embodiment of the present disclosure. The waste conversion system (60) also comprises tubes (4a) through which pressurized hydraulic oil is transferred. The tubes (4a) are connected to the hydraulic pusher (3a) to provide to and fro motion to the hydraulic pusher (3a) and the feeder plate (3). The reactor (50) comprises of a rotary inner shell (10) connected with a girth gear (7) for conversion process of the MSW, and the girth gear (7) is positioned adjacent to the rotary inner shell (10). The girth gear (7) is connected with a main electric drive (9) and a gear box (8), which facilitates rotary motion for the reactor (50). The gear box (8) provides rotary torque and reduced rpm to the reactor (50) and the main electric drive (9) transfers rotary motion through a belt (8b) and pulley (8a) arrangement. The reactor (50) rotates between 1-6 rpm based on operational capacity and parameter of the reactor (50), which is controlled through a variable frequency drive (VFD) (9a). Furthermore, a screw arrangement is provided 1 / 3rd of length of the reactor (50) for forward movement of material. This screw is welded with the rotary inner shell (10) of reactor (50). In the remaining area, a lifter plate is provided for forward movement of material till discharge and this lifter plate is welded with the rotary inner shell (10) of the reactor (50). Also, specially designed lifter chutes are provided at the end of the reactor (50) to uplift the charcoal material from inside of reactor (50) to discharge feeder (18). The reactor (50) comprises an outer stationary shell (11) that is positioned over the rotary inner shell (10) for movement of hot air in space between outer stationary shell (11) and the rotary inner shell (10). The outer stationary shell (11) is insulated for thermal efficiency of the heating system and the reactor (50), and where the outer stationary shell (11) is sealed using layers of leaf seal (12) that prevent ingress of air between the outer stationary shell (11) or adopter (6) and the rotary inner shell (10). As an example embodiment, after measuring the weight of feed material, the weigh feeder (5) pushes the feed material inside the first zone (10a) of reactor (50) assembly through the inlet chute (6), as shown in Figure 3. To prevent the ingress of air inside the reactor (50), moving and fixed baffles (6a) and (6b) are provided. The moving baffle (6a) is hinge supported and moved up with the feed material to make way and comedown in case feeding is not in process and this is to seal the entry for air. Referring to Figures 3 and 4, Figure 3 illustrates moving joint arrangement within the waste conversion system (60) as shown in Figure 1A, as an example embodiment of the present disclosure. Figure 4 illustrates a schematic flow of process involved in the waste conversion system as shown in Figure 1A, as an example embodiment of the present disclosure. The waste conversion system (60) also comprises a cooling system (22) and a specially designed moving joint (19). The cooling system (22) is positioned to maintain sufficient flow and pressure of cold water inside the cooling segment (17). A specially designed moving joint (19) that comprises a fixed water inlet (19a) and outlet (19b) , which facilitates water connection through moving pipes (19c) that are attached with the rotating cooling segment (17), wherein the fixed water inlet (19a) and outlet (19b) are provided at discharge chute (18a) of the reactor (50) where cooling water is required to cool down the coal temperature and avoid any self-ignition. In other words, the specially designed moving joint (19) is provided to cater the requirement of fixed water inlet / outlet connection with moving pipe attached with rotating reactor cooling section. Stationary water entry and exit ports are provided at discharge chute (18a) of the reactor (50) where cooling water is required to cool down the coal temperature and avoid any self-ignition. Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is, therefore, contemplated that such modifications can be made without departing from the scope of the present invention as defined.
Claims
We Claim:
1. A waste conversion system (60) comprising: a hopper (1) that stores the segregated municipal solid waste (MSW) as buffer feed stock for a reactor (50), wherein the hopper (1) provides a constant feed of the MSW to the reactor (50) for continuous operation of reactor (50); a coarse feeder (2) that is connected to the hopper (1), wherein the coarse feeder (2) feeds definite amount of MSW into the reactor (50), a weigh feeder (5) that is connected to the coarse feeder (2) to receive the MSW, wherein the weigh feeder (5) pushes the MSW feed into the reactor (50), and wherein the weigh feeder (5) measures weight of the MSW that is fed into the reactor (50); the reactor (50) configured to receive the MSW via a set of hydraulic pushers (3a), wherein the reactor (50) heats the segregated MSW to a predefined temperature in an oxygen deficient space, which causes the MSW to lose moisture and changes phase of the MSW to charcoal; and a cooling segment (17) that receives the charcoal from the reactor (50) and cools down the charcoal to avoid auto ignition.
2. The waste conversion system (60) as claimed in claim 1, wherein the coarse feeder (2) is connected to an exit of the hopper (1), and is operated using a hydraulic pusher (3a), wherein the coarse feeder (2) feeds a predefined quantity of MSW from the hopper (1) via the hydraulic pusher (3a), and wherein the feed of the MSW is controllable with the number of operation cycle of coarse feeder (2) through a logic control.
3. The waste conversion system (60) as claimed in claim 2, wherein the coarse feeder (2) pushes the MSW forward and the MSW falls into the weigh feeder (5), wherein the weigh feeder (5) comprises the hydraulic pusher (3a) to push the MSW feed into the reactor (50), wherein the weigh feeder (5) measures weight ofthe MSW entering inside the reactor (50) by means of load cells (5a) equipped at the weigh feeder (5), which provides feedback to plant PLC (programmable logic control) system to control the process.
4. The waste conversion system (60) as claimed in claim 2, wherein the hydraulic pusher (3a) is positioned in the coarse feeder (2) and the weigh feeder (5), wherein the hydraulic pusher (3a) comprises feeder plates (3), and wherein the hydraulic pusher (3a) consists of a piston rod (3b) which moves back and forth using a power pack assembly (4), wherein the coarse feeder (2) and the weigh feeder (5) are operated by the power pack assembly (4) that uses enclosed fluid to transfer energy to subsequently create rotary motion, linear motion, and force.
5. The waste conversion system (60) as claimed in claim 4, further comprising tubes (4a) through which pressurized hydraulic oil is transferred, wherein the tubes (4a) are connected to the hydraulic pusher (3a) to provide to-fro motion to the hydraulic pusher (3a) and the feeder plate (3).
6. The waste conversion system (60) as claimed in claim 2, wherein after measuring the weight of the MSW, the weigh feeder (5) pushes the MSW inside the first zone (10a) of the reactor (50) through an inlet chute (6), wherein moving baffles (6a) and fixed baffles (6b) are provided to prevent the ingress of air inside the reactor (50), wherein the moving baffle (6a) is hinge (6c) supported and moved up along the MSW to make way and return when the feeding is not in process.
7. The waste conversion system (60) as claimed in claim 6, wherein the reactor (50) comprises: the first zone (10a), which is a pre-heating zone with a temperature range of 50 degree Celsius to 150 degree Celsius, a second zone (10b), which is a heating zone with a temperature range of 100 degree Celsius to 200 degree Celsius,a third zone (10c and 10d), which is a torrefaction zone with a temperature range of 250 degree Celsius to 350 degree Celsius, and a fourth zone (17), which is cooling zone with a temperature below 60 degree Celsius.
8. The waste conversion system (60) as claimed in claim 2, wherein the reactor (50) comprises a rotary inner shell (10) connected with a girth gear (7) for conversion process of the MSW, wherein the girth gear (7) is positioned adjacent to the rotary inner shell (10), wherein the girth gear (7) is connected with a main electric drive (9) and a gear box (8) which facilitates rotary motion for the reactor (50), wherein the gear box (8) provides rotary torque and reduced rpm to the reactor (50) and the main electric drive (9) transfers rotary motion through a belt (8b) and pulley (8a) arrangement, wherein the reactor (50) rotates between 1-6 rpm based on operational capacity and parameter of the reactor (50), which is controlled through a variable frequency drive (VFD) (9a).
9. The waste conversion system (60) as claimed in claim 8, wherein the reactor (50) comprises an outer stationary shell (11) that is positioned over the rotary inner shell (10) for movement of hot air in space between outer stationary shell (11) and the rotary inner shell (10), wherein the outer stationary shell (11) is insulated for thermal efficiency of the heating system and the reactor (50), and wherein the outer stationary shell (11) is sealed using layers of leaf seal (12) that prevent ingress of air between stationary outer stationary shell (11) or adopter (6). and the rotary inner shell (10) 10. The waste conversion system (60) as claimed in claim 1, wherein the rotary inner shell (10) is fitted with one or more guide rings (13), which rotates over rollers (14) positioned alongside a bracket (14a) for seamless rotation of the rotary inner shell (10), and wherein the rollers (14) are positioned alongside the bracket (14a) of the reactor (50) on which the guide ring (13) rotates and prevents the reactor (50) from derailing.
11. The waste conversion system (60) as claimed in claim 1, further comprising a discharge feeder (18) that is connected to the cooling segment (17), wherein the charcoal is discharged through the discharge feeder (18), which operates through the power pack assembly (4) provided at discharge gate of the reactor (50), wherein the discharge feeder (18) maintains sealing of the reactor (50) to avoid any ingress of air and leakage of volatile gases, wherein the charcoal discharged from reactor (50) falls on the discharge feeder (18) through a discharge chute (18a), and wherein the discharge feeder (18) pushes the discharged charcoal to either side of the discharge feeder (18).
12. The waste conversion system (60) as claimed in claim 11, further comprising a cyclone separator (21) that is connected to outlet of the cooling segment (17) and the discharge feeder (18) to separate dust, mist and solid particles from volatile gases that are generated in the waste conversion system (60), wherein the dust, mist and solid particles are pushed based on their respective masses to outer edges of the cyclone separator (21) due to centrifugal force and any incoming volatile gas is forced to adopt a fast-revolving spiral movement, which causes the separation of the dust, mist and solid particles from the volatile gases.
13. The waste conversion system (60) as claimed in claim 11, further comprising: a set of burners (16) installed below the outer stationary shell (11) of the reactor (50) to provide required heat energy for the conversion process in the reactor (50) that uses the volatile gas as a fuel in the burners (16); and a centrifugal volatile gas blower (15a) that is positioned in line from the cyclone separator (21) to regulate the flow of the volatile gas towards the burners (16); and a centrifugal air blower (15b) that is positioned adjacent to the burners (16) to supply required amount of air for complete and efficient combustion of volatile gas in the burners (16).
14. The waste conversion system (60) as claimed in claim 11, further comprising a flue gas blower (15c) that transfers the flue gases towards the chimney (24), wherein the flue gases are generated after combustion and travels across the reactor (50) via space between the outer stationary shell (11) and the rotary inner shell (10), and wherein the flue gas blower (15c) maintains pressure within combustion section of the reactor (50) and draws the flue gases to escape via the chimney (24).
15. The waste conversion system (60) as claimed in claim 11, further comprising: a cooling system (22) that is positioned to maintain sufficient flow and pressure inside the cooling segment (17); a specially designed moving joint (19) that comprises a fixed water inlet (19a) and outlet (19b) , which facilitates water connection through moving pipes (19c) that are attached with the rotating cooling segment (17), wherein the fixed water inlet (19a) and outlet (19b) are provided at discharge chute (18a) of the reactor (50) where cooling water is required to cool down the coal temperature and avoid any self-ignition.
16. The waste conversion system (60) as claimed in claim 11, further comprising thermocouple IR sensors (25) that are connected to the outer stationary shell (11) to measure the temperature of the rotary inner shell (10), and wherein the measurement is used as a reference to control the burner (16) and resulting temperature from the burner (16).
17. The waste conversion system (60) as claimed in claim 11, wherein process involved in the reactor (50) comprises the following steps: heating the reactor (50) using the external heat source (26); in response to generation of inflammable volatile gas after heating the rotary inner shell (10), switching off the external heat source (26) and switchingON the volatile gas line (16a), wherein the external heat source (26) is switched OFF automatically; setting operation of the external heat source (26) in standby mode and the external heat source (26) is switched ON only when volatile gas generation is low and the external heat source (26) is switched OFF after a definite temperature is generated from the burner (16) using the volatile gas line (16a); and controlling the ON and OFF operation of the external heat source (26) via the thermocouple IR sensors (25) that are installed adjacent to the burner (16) and the reactor (50), wherein the controlled operation makes the process self- sustainable in terms for fuel for heating and reduces reduce dependency upon external fuel to reduce cost.