| engineering how-to |
Determining Packing Height With Accuracy
By Kenneth Graf, Koch-Glitsch, LP
Equilibrium stage simulations are the nearly universal process design tool for mass transfer columns that contact vapor and liquid in countercurrent flow. Whether the service is absorption, stripping, distillation, fractionation, quench or evaporation, equilibrium stage models make mass and heat balances easy. They quickly estimate stream conditions and physical properties. They are easily altered, so a change to any design parameter can be instantly assimilated into equipment and stream properties. When it comes to the actual design of mass transfer columns, however, the use of theoretical stage simulations can leave engineers perplexed about what packing height to use, and can lead engineers to believe that packing efficiency is a bewildering art devoid of logic. A better procedure begins with process design by equilibrium stages, followed by conversion of theoretical stages to transfer units, followed by equipment choice and design. This procedure results in a complete process design, the correct expression of the mass transfer task and logical choice of equipment. » |
 |
PSA Technology: Beyond Hydrogen Purification
By Tobias Keller, Linde Engineering & Goutam Shahani, Shure-Line Construction
Pressure swing adsorption (PSA) technology is well known for H2 purification applications, but the technique can also be used for other gas-separation processes in petroleum refining facilities. PSA is a well-established process for the separation and purification of a wide range of industrial gases. PSA is generally safe, reliable and cost effective. In the petroleum refining industry, PSA systems are used to produce hydrogen from synthesis gas that is produced by steam-methane reforming (SMR), partial oxidation (POX) or gasification. Although well known for H2 purification, PSA technology can also be used for other gas-separation tasks. PSA systems can be used to recover H2 from refinery offgases, to capture CO2, and to generate O2 and N2 gases. This article provides an overview of PSA technology, including the scientific principles that dictate how it works, along with design considerations of PSA systems. Selecting the best technology for a given gas-separation problem requires a thorough understanding of the available production technologies, including SMR, POX and gasification, as well as available separation technologies, such as membrane, cryogenic, absorption and adsorption. Identifying the optimal solution, and whether PSA technology could be a benefit, also requires a detailed knowledge of the capital and operating costs for the relevant process. » |
|
|
| |
| latest news |
|
|
 |
ADVERTISEMENT
Process automation is highly complex. You’re being asked to improve process performance with fewer engineers, make split-second decisions on situations under stress, and guarantee product quality during changing conditions. Learn about how our six approaches can boost revenue and performance by enhancing operational efficiency.
|
|
| facts at your fingertips |
| Wet Scrubbers |
| Wet fluegas desulfurization (FGD), also known as wet-scrubbing, is a popular pollution-abatement technique for removing acid gases, such as SO2 and HCl from fluegas produced during coal-fired power generation and industrial combustion processes. Wet scrubbing is used in association with power generation, thermal oxidizers, kilns, incinerators, boilers, foundries and other combustion units. Also, wet-scrubbing can be used to treat other sulfur- or acid-laden fluegas streams. |
|
 |
|
| what's new |
|
In the process described in this month's Technology Profile, ammonia is synthesized following production of synthesis gas (syngas) from natural gas via steam reforming.
Join Chemical Engineering on June 8 for a webinar examining the current status of the U.S. chemical industry, as well as its outlook over the next several years. Register here.
Here are some recently published books for the CPI
Focus on Blast Overpressure and Blast Resistance with our newest Quiz |
|
| from our bookstore |
| Instrumentation (Volume 1): Controlling Temperature, Pressure, Level and Flow |
| Proper selection, specification and use of instrumentation is essential for optimal operation of chemical process industries (CPI) facilities. The detailed engineering articles contained in Volume 1 of this 2-volume set provide guidance on monitoring and controlling several key process variables — pressure, temperature, level and flow, and several articles are provided on the appropriate measurement of pH, as well. The engineering support on pressure monitoring focuses on the accurate measurement of low pressures, high pressures and overpressure, and several articles focus on the proper use of rupture disks and pressure-relief valves to manage high-pressure situations, too. The guidance on temperature monitoring provides coverage of competing methods, including RTD sensors, remote infrared thermal sensors, thermowells and other analytical options. Specific articles focus on addressing the challenges of temperature measurement in extremely cold climates. The articles on measuring flow focus on applications handling both fluids and bulk solids or particulate materials. [more] |
|
|
|
|
|
|
|
