Comprehensive treatment method and device for ship exhaust gas pollutants and ballast water

Abstract

The invention discloses a comprehensive treatment method and device for ship exhaust gas pollutants and ballast water. The device comprises a water pump I, a chlorine-containing oxidant tank, a lye tank, a fresh water tank, a water pump VI, a seawater pipe, a hydrocyclone, a sludge tank, a water pump V, a main washing liquid pipe, a water pump II, a water tank, a waste liquid storage tank, a ballast water chamber, a water pump III, a main spray pipe, a water pump IV, a stirrer, a washing tower, a cooler, a waste liquid discharge pipe, a stop valve I, a stop valve II, a stop valve III, a three-way valve and a stop valve IV. The ship exhaust gas pollutant treatment system provided by the invention adopts a wet washing technology, has two different operation modes, i.e. separate desulfurization and simultaneous desulfurization and denitrification, wherein the separate desulfurization mode can employ closed and open wet washing ways. According to different emission requirements of ship navigation areas to exhaust gas pollutants, the work mode and way can be switched freely, the operation is convenient, and the integration level, reliability and flexibility of the system can be greatly improved.

Description

technical field [0001] The invention belongs to the technical field of prevention and control of air pollution caused by ships and treatment of ballast water, and in particular relates to a comprehensive treatment method and device for ship waste gas pollutants and ballast water. Background technique [0002] In recent years, with the continuous development of global shipping trade, the average tonnage of ocean-going ships powered by large low-speed diesel engines has increased, while the number has declined slightly. In order to reduce transportation costs, marine diesel engines generally use poor-quality residual oil in the petroleum refining process as fuel, which has high sulfur content, high viscosity, and high residual carbon value, and the exhaust gas after combustion contains a large amount of nitrogen oxides (NO x ), sulfur oxides (SO x ), particulate matter (PM) and other pollutants have caused adverse effects on human health and the atmospheric environment. [0...

AI Technical Summary

Problems solved by technology

At present, the existing ship exhaust gas wet scrubbing technology can achieve efficient desulfurization of SOx in the flue gas, such as sodium-alkali seawater method, magnesium-based seawater method and other wet scrubbing post-treatment technologies. Using sodium alkali or magnesium hydroxide as an additive has a good desulfurization effect, but the denitrification effect of these wet scrubbing technologies for ship exhaust gas is not obvious

Some patents propose to use electrolysis of seawater to prepare strong oxidizing solution and strong alkaline solution, and at the same time realize the removal of NOx, SOx, particulate matter and other pollutants in ship exhaust gas Wet washing treatment, but this method requires high power consumption, which limits the feasibility of related technologies

There are also patents that propose the use of exhaust gas recirculation technology, that is, first remove SOx by wet scrubbing, and then mix part of the treated exhaust gas with fresh air before entering the diesel engine, by reducing the combustion temperature inside the combustion chamber of the diesel engine method to reduce NOx generation, but the desulfurization effect of this technology depends on the amount of bypass exhaust gas, and it will reduce the thermal efficiency of the diesel engine, resulting in increased HC and CO emissions

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