Direct Production of Coal Tar Pitch

Direct Production of Coal Tar Pitch Technical Abstract The increased attractiveness of carbon composites, in particular carbon/carbon composites, to the aerospace industry requires abundant, domestic and secure sources of pitch. With its high carbon content and resulting density advantages coal-based pitch is of prime interest. The ability to produce coal-based pitch from a wide-variety coals, even waste coal piles, is particularly desirable. A novel, continuous, clean and energy efficient coal processing technology (Ekocoke process) has been designed and tested to convert coal into it basic solid, liquid and gas components for production of a variety of coal-based materials. The coal to be utilized in this study is western high-volatile bituminous coal which is abundant and has a high tar yield. The Ekocoke process starts with a continuous thermal coal treatment which devolatilizes the coal. The coal volatiles are collected and processed as various salable products. The basic process has been evaluated at the pilot scale and is ready for commercial application. It is envisioned that high-quality coal tar pitch can be produced directly from the process, avoiding costly post-processing of tar which is the common practice. In order to accomplish this, design of stepwise condensation of hot coal volatile matter is required. This Phase I effort is to determine optimum operating conditions for direct high-quality pitch production from a stepwise condensation process in a bench-scale environment. Pitch will be collected under various temperature conditions in the first step of a multi-step condensation process. The characteristics of the various temperature pitches will be measured including aromaticity, molecular weight range, QI value, softening point and viscosity at the University of Utah who maintains a high level of experience in coal and coal products analysis, including pitch. The applicability of the pitches to military uses will be determined by comparing their properties with acceptable pitch specifications. Northrup Grumman Corp will make actual test panels of carbon/carbon composites using optimized pitch. They will then evaluate the panels through a series of performance tests. The results will be used to design a direct pitch production system for the Ekocoke process. The successful completion of this Phase I effort will demonstrate and optimize the ability to directly produce a qualified coal-based pitch for military applications from the Ekocoke process, a commercial-ready process, using abundant domestic coal. It will also provide the design for inclusion of the optimized pitch collection step directly into the Ekocoke process.