This chapter gives a construction of finite nilmonoids, which is due to the author [1991N], [2001N] and expands earlier ideas of Arendt & Stuth [1970A]; a shorter account is given in Grillet [1995]. Unlike previous constructions for these semigroups, this is a global construction with a very geometric character, in which nilmonoids are obtained as quotient of free commutative monoids by suitable
... [Show full abstract] congruences. It accounts well for various structural features of nilmonoids, such as the greatest pure congruence and the universal group of N\0. A more general construction was given by Grillet [2001N] and applied to fully invariant congruences in [2001F].
