Environmental Engineering Reference
In-Depth Information
cooled help the cold streams (sinks) that are to be heated to enable both hot and cold process
streams reach their heating and cooling targets.
This approach of “Integration” of heat sources and sinks in industrial facilities reduces
the need for external hot thermal energy utility that mostly come from fossil materials
combustion processes. This methodology in turn attacks, at the source, the main contributor
to the atmospheric emissions problem by reducing the heating utility requirement. In this
paper a step-by-step modifications are applied to an actual oil and gas separation plant to
minimize its environment-footprint via GHG emissions reduction using heat integration. The
approach give the process owner the facility to select scheme based upon not only capital but
also energy resources sustainability and environmental impact on the world.
Oil and Gas Separation Plant Process Description
The un-stabilized crude oil is pumped to the stabilizer unit through a pipeline. The
stabilizer is fed after removing some light ends. These light ends are combined with
overheads from the column to the compression system. Light end gases from other stabilizers
and low pressure and high pressure production traps, not shown in this graphs but by arrows
only, are also directed to the gas compression section.
The fractionation capability provides a well defined split between the light ends and the
crude oil. This tight split ensures maximization of stabilized crude and minimization of crude
oil quality loss (API Gravity).
Heat input to the stabilizer bottom is provided through reboilers utilizing a heating oil
media in a closed loop circulation system. A furnace is used to heat up the return cold heating
oil. Light ends from the stabilizer overhead system is used as fuel for the heating oil furnace;
flare pilot and purge gas process blanketing.
Net light gases are then compressed, condensed and pumped to the natural gas liquid
pipeline.
The stabilized crude flowing from the bottom of the stabilizer column is cooled before
going to its final destination partially by heat exchange with the stabilizer bottoms and
completely in a final cooling stage using air coolers.
Heat Integration Application in Oil and Gas Separation Facility
Pinch Analysis techniques have been applied taking into consideration legitimate process
constraints such as safety and operability to evaluate the possibility of improving heat
recovery in the process and consequently reducing energy-based GHG emissions. Major
streams in the process have been listed below with its supply temperatures. In this chapter
Pinch technology has been used for targeting purposes and HEN synthesis. However the
problem solved in this chapter is considering HEN sophistication as the primary dominant
objective and energy cost and/or GHG emissions reduction as the secondary one.
