According to the jboss_3_2.dtd:
The age after which a bean is automatically passivated
<!ELEMENT max-bean-age (#PCDATA)>
The max-bean-life specifies the period of the remover
task that removes stateful beans (that normally have been passivated)
that have age greater than the specified max-bean-life element.
<!ELEMENT max-bean-life (#PCDATA)>