New Syngas Reforming Solutions for Enhanced Gas-to-Diesel Conversion

Abstract

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 177660, “New Syngas Reforming Solutions for Enhanced Gas-to-Diesel Conversion,” by Conrad Ayasse and Rob Ayasse, Verdis Synthetic Fuels, prepared for the 2015 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 9-12 November. The paper has not been peer reviewed. This paper presents an overview of the challenges of using traditional synthesis gas reforming methods for efficient gas-to-liquids (GTL) conversion. A second objective is to show how newly emerging reformer technologies, such as those based on plasma or catalytic partial oxidation, will provide significant improvements. A case also will be made for how these new technologies, when paired with a high-efficiency Fischer-Tropsch (FT) process, provide a profitable alternative to the environmentally damaging, and wasteful, practice of flaring or venting associated gas. Introduction Given the limitations of footprint, weight, safety, cost, and other factors for platform operations, the use of the FT process for flared-gas conversion to liquids is challenging. This study shows that the best process uses a catalytic partial-oxidation reformer, a unique wax-free FT catalyst, and an advanced FT reactor to meet all platform criteria while cutting traditional capital expenditures (Capex) and operational expenditures (Opex) in half. Criteria for Platform Operations The following criteria were considered for the selection of equipment on a platform: Small footprint (space limitations) Low weight (weight limitations) Low pressure (safety considerations) High gas hourly space velocity (GHSV) (to enable small reactors) Low pressure drop at high GHSV (reactor shape) High gas conversion (process efficiency) High gas selectivity to carbon monoxide (process efficiency) No water needed (simplicity) No pure oxygen needed (platform requirement for safety) No feed-gas preheat needed (simplicity) No reformer tail-gas heat exchanger needed (simplicity) At the heart of the list are footprint, weight, and safety. From the safety perspective, temperature, pressure, and oxygen concentration are important. Equipment footprint and weight affect the platform cost and the ability to add equipment to existing platforms. This means that the number of process-unit operations must be kept at a minimum.