The invention discloses a
trapping method for
tar in
coal gas. The
trapping method comprises steps as follows: gas-gas heat exchange: low-temperature gas exchanges heat with high-temperature
coal gas, heat of the high-temperature gas is recovered, and the use amount of spray
tar is reduced;
trapping: low-temperature
tar is sprayed on the high-temperature
coal gas subjected to heat exchange, so that tar gas in the
coal gas is condensed, separated out and recovered through trapping; defogging: tar
fog drops about to escape are recovered gradually by use of a two-stage
defogger. With the adoption of the tar trapping method, tar can be removed from the
coal gas repeatedly, that is, the better tar
recovery effect is realized in a tar washing manner. Compared with an existing technology for trapping tar through washing, firstly, the tar trapping method cannot produce a large amount of
refractory wastewater, so that the investment, production and operation costs of
wastewater treatment equipment are reduced; secondly, the trapping rate is high and secondary investment of an electrical tar precipitator is reduced. Besides, the invention further provides a trapping
system for the tar in the
coal gas.