Evaluation of potential improvements to coking process energy efficiency as a consequence of implementing a coal blend pre-drying operation

The policy of sustainable development, increasing societal awareness, and as result the ambitious targets of European Union energy policy are both forcing and inspiring companies to improve the energy efficiency of applied technologies. The coke making industry in Poland and Europe as a whole have been doing so by looking for optimal technological development leading to improved energy efficiency, and as consequence to higher profitability. Poland’s domestic coke making industry is also searching for a technology which will allow for even more intensive exploitation of domestic coals, thus making it possible to benefit from geographical rent. One of the more interesting development opportunities for Polish coke plants, meeting all the existing demands, is the implementation of the coal blend pre-drying operation. Associating this technology with a coke dry quenching installation significantly improves the effectiveness of the coke making process. The unit consumption of coke oven gas could be decreased by as much as 12.6%. This article provides an analysis of improvements to energy efficiency in the coke making process after the implementation of a pre-drying operation - both independently and in conjunction with a dry quenching installation. In the first case, it is possible to decrease coke making heat consumption by 2.8%, while combining these two technologies, apart from other positive effects, leads to higher savings of up to 12.6%. Total coking heat of approximately 2,600MJ/t wet coal blend needed to performthe coking of a coal blend decreases to about 2,527.5 MJ/t wet coal blend in the case when only the pre-drying operation is being applied. Applying this installation in conjunction with dry quenching technology will allow for a decrease in integral coking heat to 2,273.6 MJ/t wet coal blend. Combining both technologies seems to have significant potential, especially from the point of view of energy consumption. It allows for the use of hot coke physical enthalpy with a very high level of efficiency. The final part of the article presents a comparison of coke making process energy parameters for different technological systems with coal blend pre-drying and/or dry coke quenching.