Design and development of portable nitrogen generator for Oil & Gas installations

Abstract

In the oil and gas industry more applications are using nitrogen, nitrogen have normally been produce onshore and transported to an offshore installation, in bottle racks or liquefied in vessels. Since the demand after nitrogen has increased during the last decade, some installation is producing local nitrogen onboard. But this is stationary big units that have problems to serve the rest of the demands on the installation. Normal nitrogen generator that are in use now, are having separated systems, air compressor, nitrogen generator and sometimes high pressure compressors. This thesis is taking the nitrogen onboard production to the next level, designing a small compact unit for operations in hazardous areas including Atex Zone 1. Overall objective has been to develop an easy to use "plug & play" unit, utilizing only electrical power supply to produce nitrogen from the surrounding atmosphere and to deliver nitrogen at high pressure. This means that an air primary air compressor, nitrogen membrane and high pressure compressor have been integrated to one compact portable unit. In order to develop a nitrogen generator that are producing nitrogen and are portable, compact components and efficiency solutions has to be integrated together. In this master thesis a concept has been developed for a solution for nitrogen generation up to 300 bar discharge pressure. That is compact, designed with lifting arrangement and can be manual handled around on the installation. Prototype will be constructed and manufactured in September/October 2013.