Special Report : Importance of effective temperature control

Special Report : Importance of effective temperature control
Martin Menachery, editor, Refining & Petrochemicals Middle East.
Published: 30 August 2017 - 5:05 a.m.
By: Martin Menachery

A modern refinery is a highly complex and integrated unit separating and transforming crude oil into a wide variety of products like transportation fuels, residual fuel oils and lubricants.

While, in the simplest refinery, the crude oil is separated into lighter and heavier fractions through distillation, the modern refineries have developed much more complex and integrated systems in which hydrocarbon compounds are not only distilled but also converted and blended into a wider range of products. Heat transfer and temperature control paly critical roles in the refining processes.

Heat energy is transferred between two media by virtue of temperature difference. When there are two media with different temperatures in contact with each other, heat transfer will take place from the body at higher temperature to the one at lower temperature, until the temperatures of both become the same. This fundamental concept of thermodynamics is the basis of all heating processes.

In a typical heating process, steam loses its latent heat, which is then transferred to the medium being heated by the virtue of temperature difference. There are two ways for heat transfer, direct and indirect. In a direct heating process, the hot medium is mixed with the cold medium and as a result, temperature of the mixture increases. Indirect heat transfer is used in many cases, in which hot and cold media are not allowed to mix with each other, but are separated by a conducting material and heat transfer takes place through this conducting separating medium.

Effective temperature control is very critical to process safety since it can prevent runaway reactions, equipment failure, fires and explosions. Normally, process temperature is monitored by temperature control systems, which are in place to achieve and maintain a target temperature. These systems are made up of several elements that send and receive signals, which result in the adjustment of heat transfer rate through the process. In case control systems cannot keep the process temperature within the safe limits, safety instrumented systems can provide a second level of protection.

A typical temperature control system consists of transmitters, controllers and control elements. While the transmitters contain sensing elements that measure the process temperature and send a corresponding signal to the controller, the controller compares the actual temperature to the set point temperature and sends a control signal to the control element. The control element alters heat transfer rates to adjust the process temperature to match the set point temperature.

Heat transfer fluid (HTF) market is estimated to grow from over 480 kilo tons in 2015 with a compound annual growth rate of more than six percent up to 2023. Oil and gas leads the overall application segment for HTFs and was valued at over US$470 million in 2015. Growing gas production in the GCC may boost synthetic lubricants demand in HTF form over the next seven years.

Increased prospects for large-scale oil and gas exploration in Saudi Arabia and Kuwait due to discoveries in proven oil reserves are projected to fuel the GCC HTF market growth. HTFs play an important role in oil and gas processing. These fluid systems are used for facility heating and regeneration of glycols to remove water from the natural gas produced in offshore platforms. HTFs are also used in cooling and offshore heating processes in the oil and gas platform utilities, floating production units, and in LNG in liquefaction and regasification terminals.

Expansions in the oil and gas and petrochemical industries are projected to stimulate the HTF market over the next few years. Growing oil and gas industry and increasing number of LNG terminals and offshore production facilities are promising factors to fuel HTF market growth. Effective temperature control is critical to the success of oil and gas refining and petrochemicals manufacturing processes since it can help companies boost productivity, improve product quality, reduce process downtime and extend the lifetime of the operating equipment.

Click here to add your comment

Please add your comment below
Name
Country
Email
Your email address will not be published
Captcha