Unlike the by-product type of coke plant, in non-recovery coke-making, coke oven slag and other by-products released from coking process are combusted within the oven. This provides the heat required for the coke-making process. The oven is a horizontal design and operates under negative pressure. Primary combustion air is introduced though ports in the oven doors which partially combusts the volatiles in the oven chamber. Secondary air is introduced to complete the combustion process into the sole flues which run in a serpentine fashion under the coal bed. Heat can still be recovered from hot exhaust gases and be used for the production of heat and electricity – in such arrangements the system is called Heat Recovery Coke Making.

As most of the by-products are combusted in the oven this technique eliminates the need tor costly flue gas and wastewater treatment infrastructure. Heat recovery coking has a smaller output of blast furnace coke as compared to conventional coke-making systems, but provides more flexibility for coal selection than conventional slot ovens. The operational costs are also generally lower due to reduced labour requirement and due to the ability of using lower grade coals.

This technology requires significantly larger footprint and investment costs are higher if a cogeneration plant is included. It is, therefore, only economical where emission reduction requirements are strict, electricity prices are high, and/or there is demand for high quality steam.