Solvay Sodium Carbonate Production Process with Diemme Filter Press Technologies       

My readers know that I always talk about my 40 years in this engineering business solving process filtration and drying problems. Most recently I used this knowledge in my P&ID consulting for Diemme Filter Press Technology, a brand of the Aqseptence group. I wrote a paper entitled “Process Testing for Improving and Optimizing the Solvay Sodium Carbonate Production Process with Filter Press Technologies." The paper focuses on calcium carbonate/calcium chloride waste product initially discharged into the ocean. Using Diemme® Filtration filter press technology the client eliminated this environmental problem and created a salable product.

Discharging calcium carbonate / calcium chloride waste product into the sea created an environmental problem for the site. In addition, the calcium chloride waste represented lost revenue as the product has value for salt de-icing of roads, sidewalks, etc. in cold weather climates. The client contacted Diemme® Filtration to conduct laboratory test work to determine the optimum solid-liquid filtration technology to produce high-quality calcium chloride.

Testing Leads to Filter Press Technologies Improvements

The solution called for a two-step process. First, the calcium carbonate is filtered and dewatered. The dewatered cake is discharged to conveyor belts into a crusher and then into a downstream mix tank. There, cake is mixed with water and dissolved with hydrochloric acid to produce the final calcium chloride in liquid form. The calcium chloride liquid is filtered again before evaporation to produce the final product.

For the first slurry, testing showed excellent filterability with granular crystals forming a compact and homogenous cake. The well-formed cake discharged completely from the polypropylene filter cloths. The scale-up is based upon testing using membrane plates with a chamber/cake thickness of 50 mm. The sizing resulted in two (2) GHT 1200 x 1200 overhead beam-high performance filter presses with a filtration area of 210.24 m² each. The GHT 1200 has 46 membrane plates with 50 mm chambers and a total volume of 4,428 liters.

Figure 1. Diemme® Filtration GHT 1200 x 1200 Installed on the Top Floor of the Structure

For the second final product slurry, additional testing was conducted. In this case, the slurry contained magnesium as a precipitated magnesium-hydroxide. This slurry needs filtration to remove the hydroxides from the CaCl2 liquid before it can be evaporated, concentrated, and stored in big super sack bags. The scale up for this part of the process resulted in one (1) ME 1000 x 1000 side beam-versatile performance filter press with a filtration area of 36 m². The ME 1000 has 24 membrane plates with 20 mm chambers and a total volume of 1,000 liters.

filter press technologies
Figure 2. Diemme® Filtration GHT 1200 x 1200 Shown in the Process Step with Plate Stack Closed

Continuous Optimization

Diemme® Filtration provides continuing process support for their clients. As a result, after 18 months of operation, the client upgraded the process. Cake washing was incorporated into step 1 of the process to reduce the chloride concentrations to below 5 g/kg of cake. From the washing tests, the process was further optimized to reduce the chlorides to 0.62 g of Cl per kg of cake with a low wash ratio of only two chamber volumes.

The installed Diemme® Filtration Filter Press technologies in Figures 1 and 2 provided significant improvements for the client’s Solvay process. The most important is attaining a more sustainable process. Further, Diemme® Filtration has helped the client produce a high-quality product that generates revenue.

You can download the full paper and contact me for more information. P&ID can provide materials for your organization including white papers, market research, and case studies to increase your market penetration.

WFC13 Highlights the Latest in Solid-Liquid Separation.

Learning latest in solid liquid filtration in San Diego
Image source:


The World Filtration Conference 13 (WFC 13) in San Diego was a great opportunity to reconnect with friends and colleagues from North America and Europe. It has been over six years, and we picked up our conversations as if we had seen each other only yesterday. At the same time, the October conference was a chance to learn the latest in solid-liquid separation.

I enjoyed being a session moderator as well as a presenter on a topic of holistic and integrated chemical engineering. If you missed the conference, my presentation is available online: “Optimizing Downstream Final Drying with Upstream Solid-Liquid Filtration, Cake Washing & Dewatering.” This topic is also highlighted in my new book, Integration and Optimization of Unit Operations.” 

WFC 13 also provided an opportunity to learn about new and ground-breaking technology to help clients of Perlmutter & Idea Development (P&ID).

Digitalization & the Latest in Solid-Liquid Separation

Demonstrating digitalization of solid-liquid filtration, there were several presentations on the use of sensors to optimize the process. For example, the modernization/digitalization of filter presses using sensors embedded into the filter plate itself for cake moisture, cloth washing (conductivity), residual moisture, temperature profiles and cloth failure (filtrate quality). In addition, for vacuum belt technologies, the use of thermal cameras to determine cake cracking and cake dewatering was illustrated.

The use of steam pressure filtration as an alternative to gas/air pressure followed by drying is another interesting development. One presentation illustrated the use of low-pressure steam for solid-liquid filtration in a solvent slurry (i.e., toluene) followed by drying in an aqueous environment, resulting from the condensed steam. This approach can be used, for example, in specialty chemical, pharma with high-purity steam as well as for high viscous slurries.

There were also many studies discussing methods to improve cake washing in a production plant where the cake geometry is changing from hills, to valleys, to sloping.

Exhibitors also showed some interesting technologies for solid-liquid separation for lithium production, battery materials and recycling. These included rotating screens manufactured in alloys and synthetic materials to 1–5-micron, filter aids and speciality drying. For more information, please visit BPR (Brine, Powder, Recycling).      

Contact me to discuss these innovations via in-person or virtual meetings. Let’s optimize and improve together.

water usage

Chemical Plant Water Usage & Upcycling

water usage

Many industries rely on water. The USGS notes this valuable resource is used for fabricating, processing, washing, diluting, cooling, or transporting a product. Or it can be incorporated into a product. Or water may be needed for sanitation within the manufacturing facility. When it comes to chemical plant water usage, upcycling is particularly attractive. After all, this is one of the top industries drawing on our water resources.

Continuing my discussion of the circular economy — I’ve already discussed cold beers and the Caribbean as well as educating chemical engineers — I wanted to focus on chemical plants and their water usage. The first key question is always, “can we use less water?”

To answer this question, the chemical plant’s process engineers must analyze water sources including:

  • recycling your wastewater
  • creating large-scale rainwater collections
  • tapping new groundwater sources
  • or even desalinating seawater.

Next, the evaluation of chemical plant water usage must examine what contaminants might be present in the water. Also, how pure the water needs to be for the required process. Knowing these two things can help determine which technologies are needed to put a plan into action in the chemical plant.

Modifying Chemical Plant Water Usage

The fun part, today, though is also determining how to modify water usage in the process. Water is used for heating and cooling, chemical reactions, rinsing, making solutions, and even drinking. So, the options for transforming water usage plans considers filtration and separation units, ion exchange, treatment options, and more.

Plant operators can also lower water usage with diligent monitoring using automated technologies. Yet this approach is too often overlooked. Nevertheless, digital transformation is making it much easier to gather data. Plants can use this information to make their processes even more water efficient.

One new area for examination is “water accounting.”  In a recent article in Chemical Processing, Water Accounting Remains Fluid, Sean Ottewell, explained how various factoring the costs of water into the return-on-investment (ROI) calculations for a project. Each company may approach the calculation differently. Still, they are each trying to determine the “real” price of water usage. Water is not a free resource; the real price considers sourcing, treatment, distribution, maintenance and finally discharge.

Innovation in Chemical Plant Water Usage

Further reflecting the importance of tracking water usage, there is now a tradable index on the price of water.  NASDAQand Veles Water have partnered with West Water Research, LLC, the leading economic and financial consulting firm in water trading, to develop the Nasdaq Veles California Water Index (NQH2O Index), which will really help to drive water efficiency.

The index tracks the price of water rights across the five largest and most actively traded regions in the state of California including California’s surface water market and the four adjudicated groundwater basins.  This first-of-its-kind water index provides a spot price benchmark and offers unparalleled transparency. This initiative fosters greater price discovery and allows for the creation of new tradable financial instruments to serve water market needs.

Of course, my hope is to see this type of Index expand to other parts of the US. With the ability to better account for the true cost of water, we’ll be able to improve chemical plant water usage and find ways to produce more efficiently.

Reducing industrial water consumption is an important step in addressing the global water crisis. Let’s do our part by pursuing these new avenues in chemical plant water usage and innovating new ones as well.




Holistic Optimization of Unit Operations at WFC 13


WFC13Like the Olympics, the World Filtration Conference is held every four years. Only, in the case of WFC 13, it’s been six years since we’ve all been able to meet. The event, postponed twice by the pandemic, is on for October 6 – 9 2022 in San Diego. This conference will be one of the largest Congresses for Filtration & Separation welcoming many speakers from around the world. I'm looking forward to great conversation about holistic optimization of unit operations.

I am fortunate to be a session moderator as well as a presenter on a topic of holistic and integrated chemical engineering. The presentation is “Optimizing Downstream Final Drying with Upstream Solid-Liquid Filtration, Cake Washing & Dewatering.  This topic is also highlighted in my new book, Integration and Optimization of Unit Operations.” 

Most often when analyzing a new process development project, engineers take a “silo” approach and look at each step independently. The presentation illustrates that by taking an integrated and holistic approach and looking at each step not individually but as a continuum, the process solution becomes much more efficient.

Practical Look at Holistic Optimization of Unit Operations

We’ll discuss three examples illustrating an integrated and continuum approach. The discussion looks at the solid-liquid separation technologies of continuous pressure filtration:

  • with either a “single-drum” or “drum with individual cells”
  • with centrifuges either vertical peeler or horizontal inverting
  • followed by final dryer technologies including either conical vacuum and “Nauta-type” dryers.

The standard approach would be to first look at the solid-liquid filtration or centrifugation step and optimize this step for the maximum washing and drying efficiency. Then, with this information in hand, optimize the downstream drying. However, a new and different approach is to look at the process as a continuum from solid-liquid filtration/centrifugation through cake washing and dewatering to final drying.

The “Integrated and Continuum Approach” results in operational energy and nitrogen savings as well as lower capital and installation costs for a more efficient and reliable process.

You can read the full technical article or view the presentation slides if you can't attend. Contact me if you will be in San Diego or otherwise let’s schedule a virtual meeting. Let’s get more efficient together.


Accessible Running Shoes: Great Steps in Innovation


FlyEaseIn November 2020, I wrote a blog about my two favorite topics of innovation and running  I was sharing my thoughts on the new carbon fiber running shoes and how Nike’s innovation led to new and improved running shoes. Well, they are at it again. This blog will focus on their latest steps in innovation.

In a recent BusinessWeek article, “How Nike Designed Hands-Free Sneakers for People With Disabilities,” we learn about a new shoe called “Go FlyEase.” This breakthrough is Nike’s attempts to make a sneaker that is effortless to put on and take off.

Instead of lying flat on the ground, a band squeezes the shoe so its sole bends in the middle, creating an unusually large opening for a person’s foot. You’d just slide your toes down into the gap and press down with your heel. That makes the band contract to close the shoe into its proper shape and hold the foot firmly in place.

Removing the shoe is a little more complicated than putting it on—wearers use a hand or the other foot to engage a built-in kickstand—but the band system makes a significant difference for many people with disabilities who struggle to lace up Air Jordans. If the technology can be integrated into other sneaker designs, the Go FlyEase could open up all sorts of possibilities.

Innovation in Every Step

The innovative design team was led by Sarah Reinertsen. The accomplished distance runner and triathlete who has represented the U.S. at the Paralympic Games and set marathon records, had her left leg was amputated almost four decades ago, when she was seven.

Nike’s work in this area began in the mid-2000s, when Nike’s Tobie Hatfield started tinkering with custom gear for a colleague who had suffered a stroke. His focus on ease of use coalesced in 2012, when he read a letter from a teenager with cerebral palsy who wanted to be self-sufficient but couldn’t tie his shoes.

Three years later the first FlyEase hit the market in the form of a LeBron James high-top that used a wraparound zipper to open the rear of the shoe. Now, 10 years later, there is a shoe on the market that may begin a revolution for individuals with disabilities.

Learn more about the FlyEase story in this short video.

Moral for my readers?

These steps in innovation are for the consumer market. Still, the takeaway for my readers is this: “listen to customers.” Technology suppliers must continually listen to the market and develop disruptive process technologies to meet the future needs for innovation in the chemical process industries.