04-08-2012, 04:13 PM
LPG Recovery from Natural gas
Abstract
This project is an example of industrial application for the recovery of the natural gas into liquefied petroleum gas which is done by passing the natural gas extracted from the offshore structures through several processes and units contains many mechanical equipment such as boilers, air, coolers, heat exchangers, compressors and turbo expanders. The natural gas produced from the plant as (methane and ethane) which are compressed to the user and LPG as (propane and butane) which are stored in spherical tanks and are known by the name of butagas, later can be stored in cylinders for domestic usage in addition to production of some quantities of condensate oils. This is important in many industries such as:
a) Natural gas as fuel for public and domestic use (homes: heating , cooling ,furnaces)
b) LPG stored in cylinders for parts of the city which aren’t connected to the N.G network.
c) Production of ammonia, for use in fertilizer production.
d) Fuel for power stations.
e) Condensate oil used in the production of synthetic oils and to enhancing oil quality.
The project is composed of three major processes:
a) Dehydration unit. b) Cooling train unit. c) Depropanizer unit.
In order to deal with the case of low temperature in this project which reaches to (-78 ‘C), we depended on a software called Aspen Hysys for our calculations and re-design.
The project includes two important chapters:
1. Control systems: where all parameters should be under control such as flow rate pressure, temperature and level as well as safety requirements.
2. Design of heating and cooling equipment (Re-boiler and Air coolers).
Included in Depropanizer process (Fractionating tower)