Exhaust aftertreatment system with ammonia gas generator

An exhaust aftertreatment system may include a reductant tank, a gaseous ammonia source, an injector, first conduit and a second conduit. The injector may receive the liquid reductant from the reductant tank and the gaseous ammonia from the gaseous ammonia source and inject the liquid reductant into a stream of exhaust gas in a first mode, inject the gaseous ammonia into the stream of exhaust gasin a second mode, and both the liquid reductant and the gaseous ammonia into the stream of exhaust gas in a third mode. The first conduit may communicate liquid reductant from the reductant tank to the injector. The second conduit may communicate gaseous ammonia from the gaseous ammonia source to the injector. 种排气后处理系统可以包括还原剂箱、气态氨源、喷射器、第导管以及第二导管。该喷射器可以从该还原剂箱接收液态还原剂并且从该气态氨源接收气态氨并且在第模式下将该液态还原剂喷射到排出气体流中、在第二模式下将该气态氨喷射到该排出气体流中、并且在第三模式下将该液态还原剂和该气态氨两者喷射到该排出气体流中。该第导管可以将液态还原剂从该还原剂箱传输到该喷射器。该第二导管可以将气态氨从该气态氨源传输到该喷射器。