What is Advanced Process Control (APC) and why does it matter?
In industrial manufacturing, small variations in environmental conditions can disrupt operations, causing inefficiencies, wasted energy, and inconsistent product quality. Traditionally, human operators manually adjust settings to compensate for these changes, but this approach is slow, reactive, and prone to human error.
Through this white paper, you will learn what Advanced Process Control (APC) is and why it plays a critical role in modern manufacturing, drawing inspiration from the intelligent automation in automotive innovations.
Advanced Process Control (APC) solves this problem by using intelligent automation to continuously adjust and optimize industrial processes in real time. Just like modern cars automatically regulate fuel injection for maximum efficiency, APC enables spray drying systems to self-optimize, ensuring stable production and energy savings without manual intervention. Since 2018, GEA has been offering its APC solution, GEA OptiPartner®.
The evolution of Spray Drying: Why APC is needed
Advancing Spray Drying: From Two-Stage to Three-Stage Technologies

The traditional two-stage spray dryers from GEA were once the industry standard, but they had limitations in producing powders with optimal properties. The resulting powders were typically spherical, non-agglomerated, and often difficult to dissolve due to weak inter-particle adhesion. To overcome these challenges, GEA introduced the three-stage MSD® and FSD® dryers in the early 1980s, marking a significant leap in spray drying technology. These systems enhanced product quality, improved energy efficiency, and reduced facility space requirements, making dust-free, easy-to-reconstitute powders widely accessible for industries such as:
- Dairy (infant formulas, milk ingredients)
- Food (flavors, sweeteners)
- Chemicals (dyestuffs, agrochemicals)
How the Three-Stage Dryer solved these challenges?
- The three-stage dryer, with an added static fluid bed (SFB) at the base of the drying chamber cone, changed the game by:
- Producing agglomerated powders with an open, porous structure, making them easier to dissolve.
- Reducing energy consumption by ~25% compared to two-stage drying.
Enhancing product consistency for various industries.
Yet, with greater complexity comes more variables to control. The increased number of control points and time delays in fluidized layers means that traditional PID (Proportional Integral Derivative) control loops struggle to maintain optimal running conditions when disturbances occur.
This is where APC comes in.
APC vs. Conventional Control
The comparison between MPC-based APC (GEA OptiPartner®) and conventional PID control assumes that, before the change at t = 0, the system was stable and optimized.
To illustrate the limitations of conventional feedback control, a simulation was conducted on a three-stage spray drying system to observe its response to a disturbance as a sudden drop in ambient air humidity.
Click the video below to view the simulation in action:
The key performance indicators were:
- Powder production rate
- Powder moisture content
- Energy consumption
Based on the graph, the following conclusions can be drawn:

Without APC (Conventional Control):
- Production rate drops, reducing efficiency.
- Powder becomes too dry, leading to energy waste and quality issues.
- Manual operator adjustments are needed to fix errors, introducing delays.
With APC (GEA OptiPartner®):
- Moisture content remains stable, ensuring product consistency.
- Production rate increases by ~10%, using favorable drying conditions efficiently.
- No human intervention needed; the system self-adjusts in real time.
As a conclusion, the simulation clearly shows that APC eliminates the need for manual corrections, increases production capacity, and prevents energy waste.
Lessons From Automative Innovation.
Bridging industries: what Spray Drying can learn from the road ahead
As the simulation shows, APC offers clear advantages such as, greater efficiency, consistency, and responsiveness with no manual intervention. So why hasn’t it become the standard across spray drying operations? To answer that, it helps to look outside our industry. By exploring how the automotive sector tackled similar challenges in process control and efficiency, we can uncover valuable lessons that could accelerate APC adoption in spray drying.
What can the Spray Drying Industry learn from Automotive innovation?
The 1973 oil crisis forced the automotive industry to rethink fuel efficiency. As consumer demand shifted toward better miles per gallon (Mpg), automakers responded in a phased approach:
- First, they focused on mechanical solutions—designing more aerodynamic and lightweight vehicles.
- Next, they turned to engine optimization, developing more complex technologies to improve combustion efficiency.
- Finally, they introduced advanced control systems, such as APC, to enable precise fuel management through Direct Fuel Injection (DFI).
DFI was a major breakthrough because it precisely controlled fuel supply in real-time, optimizing combustion and eliminating inefficiencies of older carburetor-based systems. This marked a shift not just toward more sophisticated mechanical engineering, but toward a new level of intelligent control over existing equipment.
The result?
✔ Mpg increased from 12 in the 1970s to 20+ today.
✔ Every modern gasoline/diesel vehicle now operates with DFI.

APC in Spray Drying: Why adoption is still low?
Despite being introduced over 25 years ago, Model Predictive Control (MPC)-based Advanced Process Control (APC) is still only applied in about 25% of industrial spray drying operations. In contrast, the automotive industry has achieved 100% adoption of Direct Fuel Injection (DFI) by demonstrating clear efficiency gains and cost benefits.
This raises a critical question: What is holding APC back in spray drying, and how can the industry overcome these challenges?
In the next episodes of our Whitepaper series, we will explore:
- The barriers preventing widespread APC adoption in powder manufacturing and drying technologies.
- How lessons from the automotive sector’s success with DFI can accelerate APC implementation.
- Actionable strategies for manufacturers to optimize production and improve efficiency.
The automotive industry proved that process control innovation can drive higher efficiency, improved quality, and reduced energy consumption, and spray drying has the same opportunity.
The real question is no longer whether APC works, but how quickly will the industry embrace its full potential.
With solutions like GEA OptiPartner®, the industry has the technology to make APC the standard for efficiency and process optimization, just as DFI did for fuel efficiency. Learn more on GEA OptiPartner® Powder Plants.

