A modular power generation fuel gas dealkylation and desulfurization treatment device and treatment method

Abstract

A kind of modular power generation fuel gas dealkylation desulfurization processing device and processing method, it is related to gas purification processing technical field, including desulfurization tower skid and dealkylation skid;Desulfurization tower skid is integrated with water injection separator, at least two desulfurization towers and supporting valve group on base, the desulfurization tower is filled with iron hydroxyl oxide desulfurizer;The base of dealkylation skid is integrated with heavy hydrocarbon removal tank, silica gel adsorption tower, mercury removal tower, program-controlled valve skid and filter, the silica gel adsorption tower is equipped with two, and its inside is filled with columnar silica gel;The present application solves the problem of low integration level of traditional equipment, inconvenient transportation and installation by modular design, realizes resource recycling by dry desulfurization and silica gel regeneration process, meets ASME standard and expands international market applicability;Device processing capacity covers 300-1000Nm³ / h, can be adapted to 1000kW-3600kW generator set, and no waste pollutant is generated, has economy and environmental protection, provides efficient solution for flare gas recovery power generation and small and medium-sized temporary station gas pretreatment.

Description

Technical Field

[0001] This invention relates to the field of gas purification and treatment technology, specifically to a modular power generation fuel gas dehydrocarbonization and desulfurization treatment device and method. Background Technology

[0002] With the increasing demand for energy recovery and utilization, the recovery of flare gas (containing combustible components such as methane and ethane) from power plants for power generation has become an important energy-saving direction. However, flare gas typically contains H2S (corrosive gas) and C4 and higher heavy hydrocarbons (which easily condense and clog equipment), requiring dehydrocarbonization and desulfurization treatment before being introduced into the generator set. Existing treatment equipment has the following problems: 1. Low integration: Desulfurization and dehydrocarbonization equipment are mostly independent units, with large equipment and complex process flow. They require on-site pipeline connection and have a long installation cycle, making them unsuitable for rapid deployment in temporary sites or overseas projects. 2. Poor adaptability: The processing capacity is fixed and cannot be flexibly adjusted according to the power of the generator set (1000kW-3600kW). Moreover, wet desulfurization (such as the complexed iron method) is mostly used, and the desulfurizing agent is not renewable. In foreign countries, the cost of treating waste desulfurizing agent is high and the environmental pressure is great. 3. Inconsistent standards: Domestic equipment mostly follows GB standards, which cannot meet the international market's requirements for ASME standards, thus restricting exports; 4. Inconvenient operation and maintenance: It is difficult to replace adsorbents and desulfurizers, the equipment pressure drop is large, which affects the power generation efficiency, and there is a lack of effective regeneration and recycling mechanisms, resulting in high operating costs.

[0003] To address the aforementioned issues, this invention designs a modular, renewable, and internationally compliant dehydrocarbonization and desulfurization treatment device and method, improving the portability, adaptability, and economy of the equipment. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a modular power generation fuel gas dehydrocarbonization and desulfurization treatment device and method, which can solve the above technical problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A modular power generation fuel gas dehydrocarbonization and desulfurization treatment device includes a desulfurization tower skid and a dehydrocarbonization skid; the base of the desulfurization tower skid integrates a water injection separator, at least two desulfurization towers and matching valve groups, and the desulfurization towers are filled with ferric hydroxide desulfurizing agent; the base of the dehydrocarbonization skid integrates a heavy hydrocarbon removal tank, a silica gel adsorption tower, a mercury removal tower, a programmable valve skid and a filter, and two silica gel adsorption towers are provided, one for standby and one for use, and their interiors are filled with columnar silica gel.

[0006] Preferably, the desulfurization tower has a single tower volume of 1.4-2.1 m³, a pressure safety valve is provided at the top of the tower body, and a discharge port is provided at the bottom.

[0007] Preferably, the heavy hydrocarbon removal tank is a vertical structure with a volume of 5-12 m³, and a baffle plate is installed inside the tank; the columnar silica gel particles have a diameter of 3-5 mm and a specific surface area ≥1000 m² / g; the top of the silica gel adsorption tower is connected to the exhaust gas outlet of the gas generator set's chimney through a pipeline; the programmable valve skid includes 8-12 standard valves, and the adsorption and regeneration processes are automatically switched through a PLC control system.

[0008] Preferably, the automatic switching cycle is 8-12 hours.

[0009] A treatment method using a modular power generation fuel gas dehydrocarbonization and desulfurization treatment device includes the following steps: S1: Fuel gas pretreatment The raw gas with a flow rate of 300-1000 Nm³ / h, a pressure of 0.8-1.0 MPa, and a temperature of 20-40℃ is introduced into the water separator of the desulfurization tower skid. After the free water is separated, the pressure is stabilized to 4-7 bar by the pressure regulating valve before entering the desulfurization tower. S2: Dry desulfurization The pretreated raw gas comes into contact with ferric hydroxide desulfurizer in the desulfurization tower, and H2S is removed through chemical adsorption reaction, controlling the outlet H2S content to ≤50ppm; when the desulfurizer reaches saturation after running for 0.65-1.2 months, the desulfurization tower discharge port is removed, and the saturated desulfurizer is transported to the factory for regeneration. S3: Desulfurizer regeneration Inside the factory, air is introduced into the saturated desulfurizing agent for aeration and circulated into the slurry, where it is oxidized and regenerated to produce elemental sulfur. The regenerated desulfurizing agent can be reused 2-3 times and is eventually disposed of for waste incineration, with no pollutant emissions. S4: Dehydrocarbonization treatment The desulfurized gas first enters the mercury removal tower, then enters the heavy hydrocarbon removal tank. After the heavy hydrocarbons are initially separated by the baffle plate, it enters the silica gel adsorption tower. At a pressure of 4-7 bar and a temperature of 20-40℃, the silica gel adsorbs C4 and above heavy hydrocarbons. The outlet heavy hydrocarbon content is controlled to be ≤4%, and the equipment pressure drop is ≤0.5 Barg. S5: Silicone Recycling When the silica gel reaches saturation after 10-12 hours of adsorption, the PLC system automatically switches to the standby adsorption tower. Engine chimney exhaust gas at 120-180℃ is introduced into the saturated adsorption tower and heated for 2 hours to desorb heavy hydrocarbons. The exhaust gas containing heavy hydrocarbons produced by desorption is introduced into a high-temperature regeneration gas absorption tower and treated by low-temperature methanol absorption before being discharged in compliance with standards. The regenerated silica gel has an adsorption efficiency of more than 90% of the initial efficiency and can be recycled. S6: Standardized gas supply After being dehydrocarbonized, the fuel gas passes through a filter again, with the flow rate maintained at 95%-98% of the feed gas, and is then fed into a gas generator set with appropriate power for power generation.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Integration and portability: The dual-module frame design is compatible with domestic and international land transportation, shortening the on-site installation cycle to within 3 days. No professional welding construction is required, meeting the rapid deployment needs of small and medium-sized temporary stations. The processing capacity covers 300-1000Nm³ / h and can be adapted to generator sets of different power from 1000kW to 3600kW, significantly improving adaptability.

[0011] 2. Environmental protection and economy: hydroxyl iron oxide desulfurizer can be regenerated 2-3 times, and silica gel can be recycled more than 10 times, reducing annual operation and maintenance costs by 40%; no waste pollutants are generated during the regeneration process, and the desulfurizer can be ultimately utilized as a resource, which meets international environmental protection requirements; silica gel is recycled from engine exhaust gas, requiring no additional energy consumption, further reducing operating costs.

[0012] 3. Standards Compatibility and Safety: The entire system complies with ASME standards and can be directly exported to the international market; measures such as pipeline hierarchical design, static grounding, and overpressure and overtemperature protection ensure safe operation of the equipment in flammable and explosive gas environments, with a pressure drop of ≤0.5 Barg, which does not affect power generation efficiency.

[0013] 4. High purification efficiency: After desulfurization, the H2S content is ≤50ppm, the C4 and above heavy hydrocarbon content is ≤4%, and the output gas flow rate is maintained at 95%-98% of the raw material gas, which fully meets the gas intake requirements of the gas generator set and ensures the stable operation of the power generation equipment. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a schematic diagram of the dehydrocarbonization and desulfurization treatment device of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1-Desulfurization tower skid, 2-Dehydrocarbon removal skid, 3-Water injection separator, 4-Desulfurization tower, 5-Heavy hydrocarbon removal tank, 6-Silica gel adsorption tower, 7-Mercury removal tower, 8-Programmable valve skid, 9-Filter. Detailed Implementation

[0017] The invention will now be described in detail with reference to the accompanying drawings, by way of example. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments.

[0018] Example 1 like Figure 1 As shown, this invention discloses a modular dehydrocarbonization and desulfurization treatment device for power generation fuel gas. The device adopts a detachable frame-type dual-module integrated structure, conforming to ASME standards (ASME VIII Div.1 Pressure Vessel Standard, ASME B31.3 Process Piping Standard), and is compatible with domestic and international land transport dimensions, requiring no welding work during on-site installation. Specifically, it includes a desulfurization tower skid 1 and a dehydrocarbonization skid 2. The desulfurization tower skid 1 uses dry desulfurization with iron hydroxyl oxide, while the dehydrocarbonization skid 2 uses a PSA dehydrocarbonization process combining silica gel adsorption with engine exhaust gas heating and regeneration. The overall design conforms to ASME standards, employs a frame structure, and allows for the regeneration and recycling of desulfurizing agents and adsorbents.

[0019] The desulfurization tower skid 1 has an integrated water separator 3, at least two desulfurization towers 4, and matching valve groups on its base. The desulfurization tower 4 is filled with ferric hydroxide desulfurizing agent. The volume of a single desulfurization tower 4 is 1.4-2.1 m³, which is adapted according to the processing capacity: 6 towers with a volume of 1.4 m³ are used for 300 Nm³ / h, and 8 towers with a volume of 2.1 m³ are used for 1000 Nm³ / h. The top of the tower is equipped with a pressure safety valve with an opening pressure of 8 bar, and the bottom is equipped with a discharge port to facilitate the replacement of the desulfurizing agent, overall disassembly and transportation, and return to the maintenance point for regeneration.

[0020] The base of the dehydrocarbon removal skid 2 integrates a heavy hydrocarbon removal tank 5, a silica gel adsorption tower 6, a mercury removal tower 7, a programmable valve skid 8, and a filter 9. The heavy hydrocarbon removal tank 5 is a vertical structure with a volume of 5-12 m³, suitable for a processing capacity of 300-1000 Nm³ / h. The tank is equipped with baffles to initially separate more than 20% of heavy hydrocarbons in the fuel gas. Two silica gel adsorption towers 6 are provided, one for standby and one for use. They are filled with columnar silica gel with a particle size of 3-5 mm and a specific surface area ≥1000 m² / g. The top of the silica gel adsorption tower 6 is connected to the exhaust gas outlet of the gas generator set's chimney through a pipeline, using the exhaust gas to regenerate the silica gel. The programmable valve skid 8 includes 8-12 ASME B16.34 standard valves, and the adsorption and regeneration processes are automatically switched by a PLC control system. The automatic switching cycle is 8-12 hours.

[0021] The structural principle of this device is as follows: The medium enters the device through the inlet pipe and then enters the water separator 3 to treat the free water in the raw gas. After passing through the internal filter, it enters the desulfurization tower 4 (the number is adapted according to the processing capacity) and comes into contact with the hydroxyl iron oxide desulfurizing agent. H2S is removed through chemical adsorption reaction, and the H2S content at the outlet after treatment is ≤50ppm. After passing through the desulfurization tower skid 1, the gas enters the mercury removal tower 7, and after treatment, it enters the heavy hydrocarbon removal tank 5 (for preliminary separation of heavy hydrocarbons), the silica gel adsorption tower 6 (for deep removal of heavy hydrocarbons), and the programmable valve skid 8. The adsorption tower is connected to the exhaust gas pipeline of the engine chimney, and the exhaust gas is used to regenerate the silica gel. At the same time, it integrates the key valve group required by the desulfurization equipment to ensure the stable operation of the system. Finally, it passes through the precision filter 9 and enters the generator set after filtration.

[0022] After the desulfurizing agent in this device is saturated, it can be disassembled and transported to the factory for regeneration through the "aeration circulation slurry oxidation" process (regeneration times 2-3 times). Elemental sulfur is generated during the regeneration process. After the desulfurizing agent is discarded, it can be used for waste incineration without generating waste pollutants, solving the problem of desulfurizing agent disposal abroad. The cost of desulfurizing agent regeneration is only 1 / 3 of that of new agent, and the silica gel can be recycled more than 10 times, reducing annual operation and maintenance costs by 40%.

[0023] This invention features a simple structure, compact device, small footprint, low requirements for customer site conditions, and a module weight of ≤30t, which can be transported via container. The installation cycle for overseas projects is shortened to 3 days, and no professional construction team is required.

[0024] Example 2 This invention also discloses a treatment method using a modular power generation fuel gas dehydrocarbonization and desulfurization treatment device, comprising the following steps: S1: Fuel gas pretreatment The raw gas (containing H2S≤5000ppm and C4 and above heavy hydrocarbons) with a flow rate of 300-1000Nm³ / h, a pressure of 0.8-1.0MPa, and a temperature of 20-40℃ is introduced into the water separator 3 of the desulfurization tower skid 1. After the free water is separated, the pressure is stabilized to 4-7bar through the pressure regulating valve and then enters the desulfurization tower 4.

[0025] S2: Dry desulfurization The pretreated raw gas comes into contact with ferric hydroxide desulfurizer in desulfurization tower 4, and H2S is removed through chemical adsorption reaction, controlling the outlet H2S content to ≤50ppm; when the desulfurizer reaches saturation after 0.65-1.2 months of operation (depending on the processing capacity: 1.2 months for the 300Nm³ / h model, 0.65 months for the 1000Nm³ / h model), the desulfurization tower discharge port is removed, and the saturated desulfurizer is transported to the factory for regeneration.

[0026] S3: Desulfurizer regeneration Inside the factory, air is introduced into the saturated desulfurizing agent for aeration at an intensity of 1.5-2 m³ / (m²・h), and the aeration is circulated into the slurry with a concentration of 0.5-2%. The slurry is oxidized and regenerated to produce elemental sulfur. The regenerated desulfurizing agent can be reused 2-3 times and is eventually disposed of for waste incineration, with no pollutant emissions.

[0027] S4: Dehydrocarbonization treatment The desulfurized gas first enters the mercury removal tower 7, then enters the heavy hydrocarbon removal tank 5. After the heavy hydrocarbons are initially separated by the baffle plate, it enters the silica gel adsorption tower 6. At a pressure of 4-7 bar and a temperature of 20-40℃, the silica gel adsorbs C4 and above heavy hydrocarbons. The outlet heavy hydrocarbon content is controlled to be ≤4%, and the equipment pressure drop is ≤0.5 Barg.

[0028] S5: Silicone Recycling Once the silica gel reaches saturation after 10-12 hours of adsorption, the PLC system automatically switches to the standby adsorption tower. Engine chimney exhaust gas at 120-180℃ is introduced into the saturated adsorption tower at a flow rate 1.2-1.5 times that of the raw material gas. The tower is heated for 2 hours to desorb heavy hydrocarbons. The heavy hydrocarbon-containing exhaust gas produced by desorption is introduced into a high-temperature regeneration gas absorption tower and treated by low-temperature methanol absorption before being discharged in compliance with standards. The regenerated silica gel has an adsorption efficiency restored to more than 90% of its initial efficiency and can be recycled.

[0029] S6: Standardized gas supply After being dehydrocarbonized, the fuel gas passes through filter 9 again, with the flow rate maintained at 95%-98% of the feed gas, and is then fed into a gas generator set with an appropriate power (1000kW and below, 1500kW and below, 2500kW and below, 3600kW and below) for power generation.

[0030] This invention solves the problems of low integration and inconvenient transportation and installation of traditional equipment through modular design. It achieves resource recycling by adopting dry desulfurization and silica gel regeneration processes, complies with ASME standards and expands its applicability in the international market. The device has a processing capacity of 300-1000 Nm³ / h, can be adapted to generator sets of 1000kW-3600kW, and generates no waste pollutants. It is both economical and environmentally friendly, and provides an efficient solution for flare gas recovery power generation and gas pretreatment for small and medium-sized temporary power plants.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and application concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A modular power generation fuel gas dehydrocarbonization and desulfurization treatment device, characterized in that, It includes a desulfurization tower skid (1) and a dehydrocarbon removal skid (2); the base of the desulfurization tower skid (1) is integrated with a water injection separator (3), at least two desulfurization towers (4) and matching valve groups, and the desulfurization tower (4) is filled with ferric hydroxide desulfurizing agent; the base of the dehydrocarbon removal skid (2) is integrated with a heavy hydrocarbon removal tank (5), a silica gel adsorption tower (6), a mercury removal tower (7), a programmable valve skid (8) and a filter (9), and two silica gel adsorption towers (6) are provided, one for standby and one for use, and the interior is filled with columnar silica gel.

2. The modular power generation fuel gas dehydrocarbonization and desulfurization treatment device as described in claim 1, characterized in that, The desulfurization tower (4) has a single tower volume of 1.4-2.1 m³, and a pressure safety valve is provided at the top of the tower body and a discharge port is provided at the bottom.

3. The modular power generation fuel gas dehydrocarbonization and desulfurization treatment device as described in claim 2, characterized in that, The heavy hydrocarbon removal tank (5) is a vertical structure with a volume of 5-12 m³ and a baffle plate inside; the columnar silica gel has a particle size of 3-5 mm and a specific surface area ≥1000 m² / g; the top of the silica gel adsorption tower (6) is connected to the exhaust gas outlet of the gas generator set's chimney through a pipeline; the programmable valve skid (8) includes 8-12 standard valves and automatically switches between adsorption and regeneration processes through a PLC control system.

4. The modular power generation fuel gas dehydrocarbonization and desulfurization treatment device as described in claim 3, characterized in that, The automatic switching cycle is 8-12 hours.

5. A processing method using the processing apparatus as described in claim 4, characterized in that, Includes the following steps: S1: Fuel gas pretreatment The raw gas with a flow rate of 300-1000 Nm³ / h, a pressure of 0.8-1.0 MPa, and a temperature of 20-40℃ is introduced into the water separator (3) of the desulfurization tower skid (1). After the free water is separated, the pressure is stabilized to 4-7 bar by the pressure regulating valve and then enters the desulfurization tower (4). S2: Dry desulfurization The pretreated raw gas comes into contact with ferric hydroxide desulfurizer in the desulfurization tower (4) and removes H2S through chemical adsorption reaction, controlling the outlet H2S content to ≤50ppm; when the desulfurizer reaches saturation after running for 0.65-1.2 months, the desulfurization tower discharge port is removed and the saturated desulfurizer is transported to the factory for regeneration. S3: Desulfurizer regeneration Inside the factory, air is introduced into the saturated desulfurizing agent for aeration and circulated into the slurry, where it is oxidized and regenerated to produce elemental sulfur. The regenerated desulfurizing agent can be reused 2-3 times and is eventually disposed of for waste incineration, with no pollutant emissions. S4: Dehydrocarbonization treatment The desulfurized gas first enters the mercury removal tower (7), then enters the heavy hydrocarbon removal tank (5) for removing heavy hydrocarbons. After the heavy hydrocarbons are initially separated by the baffle plate, it enters the silica gel adsorption tower (6). At a pressure of 4-7 bar and a temperature of 20-40℃, the silica gel adsorbs C4 and above heavy hydrocarbons. The heavy hydrocarbon content at the outlet is controlled to be ≤4%, and the equipment pressure drop is ≤0.5 Barg. S5: Silicone Recycling When the silica gel reaches saturation after 10-12 hours of adsorption, the PLC system automatically switches to the standby adsorption tower. Engine chimney exhaust gas at 120-180℃ is introduced into the saturated adsorption tower and heated for 2 hours to desorb heavy hydrocarbons. The exhaust gas containing heavy hydrocarbons produced by desorption is introduced into a high-temperature regeneration gas absorption tower and treated by low-temperature methanol absorption before being discharged in compliance with standards. The regenerated silica gel has an adsorption efficiency of more than 90% of the initial efficiency and can be recycled. S6: Standardized gas supply After being dehydrocarbonized, the fuel gas passes through a filter (9) again, with the flow rate maintained at 95%-98% of the raw material gas, and is then fed into a gas generator set with appropriate power for power generation.

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