Control of exhaust emissions from an internal combustion engine

摘要

Exhaust gas emissions from an internal combustion engine are controlled through the use of a heat exchanger, a sulfur oxide absorbent, and a catalytic converter. The exhaust gas is contacted with the sulfur oxide absorbent before it is passed to the catalytic converter, and the heat exchanger is used to extract heat from the exhaust gas before the exhaust gas is contacted with the sulfur oxide absorbent. The heat extracted from the exhaust gas by the heat exchanger is then used to heat the catalytic converter. In a preferred embodiment, the exhaust gas is also contacted with a hydrocarbon adsorbent which: (1) adsorbs organic compounds, such as hydrocarbons, from the exhaust gas at the low temperatures which are typical of an engine cold-start, and (2) desorbs them at the higher temperatures which are reached after sustained engine operation.