Marine Emissions Control Unit with Ionizing Wet Scrubber and SCR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current maritime emissions control systems face inefficiencies and operational challenges when dealing with high-sulfur diesel exhaust from Ocean Going Vessels, particularly due to the formation of ammonium bisulfate and sulfuric acid, which can clog and corrode Selective Catalytic Reducer (SCR) systems, and the placement of SCR upstream of Ionizing Wet Scrubber (IWS) exposes it to particulates and sulfur compounds, reducing its performance and longevity.
Innovation Solution
A mobile platform-mounted emissions control unit featuring an Ionizing Wet Scrubber (IWS) and a Selective Catalytic Reducer (SCR) system, where the IWS processes exhaust prior to entering the SCR to improve efficiency and service life, and heat from a diesel generator is used to convert urea to ammonia and heat the exhaust flow, with a heat exchanger capturing and reusing heat to optimize SCR operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SCR system is placed upstream of IWS system, then NOx reduction is achieved, but the SCR system is exposed to particulates and sulfur compounds that clog and corrode the catalyst
Solution Approach 1:
The IWS system performs preliminary cleaning of the exhaust stream by removing particulates and sulfur compounds before the gas enters the SCR system. This pre-treatment action protects the SCR catalyst from clogging and corrosion, extending its operational life and maintaining performance.
Solution Approach 2:
The IWS system acts as an intermediary component between the exhaust source and the SCR system. It serves as a protective barrier that filters out harmful substances (particulates and sulfur compounds) that would otherwise damage the SCR catalyst, while still allowing the NOx reduction function to proceed.
2Reliability
If IWS system is used to clean exhaust, then particulates and sulfur compounds are removed, but the system requires significant cooling of the exhaust gas stream
Solution Approach 1:
The heat exchanger continuously transfers heat from the hot exhaust stream to the incoming exhaust gas, maintaining a steady-state temperature profile throughout the system. This continuous heat transfer enables the IWS system to operate effectively at lower temperatures without requiring intermittent heating interventions.
Solution Approach 2:
The system recovers waste heat from the exhaust stream by using a heat exchanger to transfer thermal energy to the incoming exhaust gas before it enters the IWS system. This heat recovery approach reduces the cooling requirement for the IWS operation while still achieving effective particulate and sulfur removal.
3Reliability
If SCR system operates with high-sulfur diesel exhaust, then NOx reduction is achieved, but sulfur and ammonia combine to form ammonium bisulfate that clogs the SCR
Solution Approach 1:
The IWS system extracts and removes sulfur compounds and particulates from the exhaust stream before the gas enters the SCR system. By taking out these harmful substances in advance, the system prevents sulfur from reacting with ammonia to form clogging ammonium bisulfate deposits within the SCR.
Solution Approach 2:
The IWS system performs preliminary anti-action by pre-removing sulfur compounds and particulates that would otherwise cause harmful reactions in the SCR system. This preventive measure stops the formation of ammonium bisulfate clogs before they can occur, protecting the SCR catalyst.
4Reliability
If urea is converted to ammonia for SCR operation, then NOx reduction is enabled, but heating energy is required for the conversion process
Solution Approach 1:
The system uses the waste heat from the exhaust stream itself to provide the thermal energy needed for urea conversion to ammonia. The hot exhaust gas directly heats the urea solution in the conversion chamber, allowing the system to be self-sufficient and eliminating the need for external heating energy sources.
Solution Approach 2:
The system converts the waste heat in the exhaust stream—a previously useless thermal energy—into a useful resource for driving the urea-to-ammonia conversion process. This transforms a harmful waste product (hot exhaust) into a beneficial energy source for SCR operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the efficiency and longevity of the SCR by pre-processing exhaust with the IWS, reducing clogging and corrosion issues, and optimizes energy use by leveraging waste heat, effectively managing high-sulfur diesel exhaust emissions from Ocean Going Vessels and similar sources.
Implementation Method 1
The first system is an Ionizing Wet Scrubber (IWS)
Implementation Method 2
The first system is an Ionizing Wet Scrubber (IWS)
Implementation Method 3
The second system is a Selective Catalytic Reducer (SCR)
Implementation Method 4
The second system is a Selective Catalytic Reducer (SCR)
Implementation Method 5
a heat exchanger to transfer heat from a hot clean flow out of the SCR to the main exhaust flow entering the SCR
Implementation Method 6
heat from exhaust of the diesel generator is used to convert urea to ammonia used by an SCR system
Data Source
AI summary
A platform mounted emissions control unit includes a first system to reduce Particulate Matter (PM), Sulfur Dioxide (SO2), and Volatile Organic Compounds (VOCs), and a second system to reduce Oxides of Nitrogen (NOx). The systems serially process exhaust from a mobile or stationary pollution source. In one embodiment, first system is an Ionizing Wet Scrubber (IWS) and the second system is a Selective Catalytic Reducer (SCR), wherein the IWS processes the exhaust first to improve efficiency and service life of the SCR. A generator produces power required by the IWS and SCR, and heat from exhaust of the generator may be used convert urea to ammonia for use by the SCR, and to heat the exhaust flow into the SCR. The SCR may further include a heat exchanger to capture heat in the flow out of the SCR and use the captured heat to heat the flow into the SCR.