When designing a batch system, engineers often select the control solution based on the size of the system. It is traditionally thought that small batch systems require a controller-based sequencing solution, while larger systems require a server-based solution. However, despite…
Compared to petroleum refining, the coal gasification process appears less complex. The chemistry behind the primary gasification reactions have been well known for around 100 years, and coal is more plentiful than petroleum in the U.S. and in some other…
When it comes to rotating machinery (pumps, compressors, gas turbines, steam turbines, turbo-expanders, and others) operating in the chemical process industries (CPI), installation, piping, support, pre-commissioning, commissioning and startup play crucial roles. Machinery maintenance and repair can be quite costly,…
Preventing dust explosions is not rocket science, and still these disasters occur. This article is written to help prevent these accidents. It describes how and why these explosions happen and what can be done to avoid them. Why they occur…
One of the most significant limitations on the operation of dynamic compressors (axial and centrifugal compressors) is the low-flow limit known as “surge”. A sudden valve closing, such as for emergency shutdowns or for a suction/discharge valve, presents significant challenges…
The prices of low-voltage variable frequency drives (VFDs) have declined substantially since they were introduced, while the cost of power has increased. Normal project economics will now justify these VFDs — which go up to 375 kW (500 hp) or…
Many CPI applications require the injection of chemicals, such as corrosion inhibitors, precipitation inhibitors, oxygen scavengers and countless others, into the process during operation. Follow these tips to design and operate a system that ensures accurate delivery of performance chemicals,…
For most solids-processing operations in the chemical process industries (CPI), particle-size reduction and screening (classification) to achieve the desired particle-size are required, since processes rarely produce the desired size directly. When designing processes, selecting equipment and looking for ways to…
This article covers permitting and directly related design issues associated with thermal processes used for drying and calcining, using the production of ceramic proppants as an illustrative example. While the magnitude of permitting issues varies significantly with air-quality attainment area…
Inorganic acids play a major role in the chemical process industries (CPI). They are used as raw materials, catalysts or finishing and pH control agents in the manufacture of a wide range of chemical products, from fertilizers to detergents, and…