A New Distillation Process for the Upgrading of Acid Gas

Topics: Gas conversion (LNG/GTL)
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In this work, the potential of a new low-temperature distillation process for natural-gas sweetening has been investigated. The proposed technology consists of a dual pressure-distillation scheme designed to avoid the formation of a solid phase in all parts of the process while remaining able to fulfill the required natural-gas-purity specifications. The new process offers the competitive advantages of low-temperature technologies while avoiding carbon dioxide (CO2) solidification and solvent addition.

Introduction

The industry must find technologies that allow the profitable exploitation of low-quality and high-CO2-content gas reserves in order to meet increasing demand while still decreasing production costs. Low-temperature processes are preferred to traditional chemical or physical absorption for gas purification when the CO2 concentration in natural-gas streams is high. For this reason, attention on low-temperature processes for CO2 ­removal has increased in recent years.

In this work, an analysis has been carried out to determine the trade-off between classical methyldiethanolamine (MDEA) gas-sweetening units, still representing the industry benchmark for acid- and sour-gas purification, and a low-­temperature distillation process. The MDEA unit typically requires steam at the reboiler of the regeneration column, while the low-temperature distillation processes consume electric energy to drive the refrigeration cycle. In amine regeneration units, the steam consumption is a significant part of the total energy demand of the process and thus of the total operating costs. The complete paper defines a merit-index function to determine the trade-off between the two considered technologies.

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 183154, “The Potential of a New Distillation Process for the Upgrading of Acid Gas,” by L.A. Pellegrini, G. De Guido, S. Langé, and S. Moioli, Politecnico de Milano, and B. Picutti, P. Vergani, G. Franzoni, and F. Brignoli, Tecnimont, prepared for the 2016 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 7–10 November. The paper has not been peer reviewed.
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A New Distillation Process for the Upgrading of Acid Gas

01 April 2017

Volume: 69 | Issue: 4