I think you can configure that in you server.xml file and put 2 services :
<Service name="app1">
<Connector port="8081" protocol="org.apache.coyote.http11.Http11NioProtocol"
connectionTimeout="20000"
redirectPort="8443" />
<Engine name="Catalina" defaultHost="localhost">
<Host name="localhost" appBase="app1"
unpackWARs="true" autoDeploy="true">
</Host>
</Engine>
</Service>
<Service name="app2">
<Connector port="8082" protocol="org.apache.coyote.http11.Http11NioProtocol"
connectionTimeout="20000"
redirectPort="8443" />
<Engine name="Catalina" defaultHost="localhost">
<Host name="localhost" appBase="app2"
unpackWARs="true" autoDeploy="true">
</Host>
</Engine>
</Service>