The gasification process is vital to various applications, such as the manufacture of products in the petrochemical industry, and its importance to the coal industry calls for continuous research in order to achieve optimal operation. Continuous research ultimately results in the progress of the industry, including (a) environmentally cleaner operations that aim at protecting the green heritage, (b) effective material selection that leads to shorter residence times, and (c) the prolonged existence of equipment that in turn leads to stronger economical viability. The main objective of this publication was to investigate the agglomeration phenomenon which occurs inside the gasifier, causing problems such as pressure fluctuations, hindered bed permeability and possible downstream explosions. This research investigated the agglomeration phenomenon within a nitrogen atmosphere, using four South African coals. The novelty of this research is embedded firstly in the technique which this author developed for assessing coals, and secondly in the fact that this technique was aimed at screening coals to determine propensity for causing problems in a gasifier.