Direct Convective Heating with Recycled Pyrolysis Gasses in the Ecoshale Process and Potential Implications for Design, Construction, and Production Efficiencies

摘要

One of the most significant evolutions in the Ecoshale technology that is under investigation is the implementation of direct heating by recycled gasses produced by pyrolysis. This involves a change in the heat exchanger architecture from the earlier configuration while retaining convective heating. The concept is to inject externally heated produced gas into the rubble bed through perforated pipes. This process gas then heats the shale bed through convection, as before. Produced gas is extracted from the capsule and cooled to remove condensable hydrocarbon products, but the non-condensable produced gas is externally re-heated and recirculated or re-injected into the capsule to continue convective heating and hydrocarbon production. This approach moves the heat exchanger from inside the capsule to outside the capsule. This could substantially reduce capsule construction cost and complexity, and dramatically reduce the amount of pipe in the capsule and the associated costs. It would allow the elimination of pipe bedding material, which would dramatically reduce materials costs and increase the average grade (kerogen content) in the capsule and also allow the option for internal pipe temperatures to be reduced. It would further allow for a much more robust internal piping system, and would allow the heat exchanger to be re-used rather than left behind in every capsule. The potential danger associated with potential piping leaks would also be eliminated, as no gas entering the capsule would contain any oxygen in this direct heating architecture.