A laboratory scale fixed-bed coal conversion reactor part 1: Operation, reaction zone identification and industrial representativeness

Abstract

Fixed bed coal gasification and combustion operations form an important part in the global energy supply, and these processes are characterized by complex interactions which are difficult to study on an industrial scale. A laboratory scale fixed-bed coal conversion reactor (LSR) was therefore constructed and used to mimic pilot and industrial scale fixed bed combustion and gasification. The initial design aims were to establish operating conditions comparable to that of previous pilot and commercial scale work. Secondary design aims were to keep operations less expensive, more flexible, while using smaller samples and particle sizes and maintaining representativeness. The laboratory scale reactor is 1200mm in length and has an internal diameter of 104mm. A 500mm coal bed is initially loaded into the reactor and converted to produce an ash bed of 100mm. The coal loading for this reactor was on average 3.6kg in comparison to the 240kg of the pilot scale reactor (PSR). A maximum temperature of 1250°C was maintained to assure similarities to pilot and industrial operations. Seven thermocouples measured the axial temperature profile in the reactor. Measurement capabilities inside the reactor and post experiment bed dissection have shown that bed temperature profiles and reaction zones were representative of both a pilot scale reactor (PSR) and a commercial scale reactor (ISR).