Pilot Plant Testing for Mass Transfer Processes & Full-Scale Separation Equipment
Koch Modular maintains a state-of-the-art pilot plant in Houston, Texas, dedicated to the testing of mass transfer processes including including distillation, liquid-liquid extraction, stripping and reaction chemistry. The pilot plant is extremely flexible and equipment setups are customized for the particular problem at hand.
Our facility has more than 5,000 square feet of floor space and 32 ft of headroom. We have a strong commitment to safety in the workplace and are dedicated to being environmentally conscious. The pilot plant is equipped for both bench and pilot-scale testing. In addition, an in-house analytical department supports the pilot tests. On-site analysis provides customers with on-the-spot feedback and reduces time spent in the pilot plant. Analytical methods include gas chromatography, high-pressure liquid chromatography, spectrophotometry, wet chemistry and Karl Fischer Titration.
One of the essential elements of a good pilot plant trial is flexibility. Separation problems are not always as they seem on the surface, so the ability to modify column internals and/or auxiliary equipment is necessary to quickly arrive at an optimum solution. Our pilot plant staff has the experience and expertise to solve your most difficult mass transfer problems.
Our pilot plant is used to study the processes, as well as develop vapor-liquid and liquid-liquid equilibrium data. Accurate VLE and LLE data, fundamental for the design of mass transfer processes, is often not available in literature and must be developed prior to the design effort. Koch Modular employs a staff of experienced process engineers who design the test programs and then interpret the resulting experimental data.
How We Do It
Tests are conducted in the smallest columns that will give reliable scale-up data. The advantage of using small columns is that it minimizes the amount of material required. Most tests require only 5 to 50 gallons of material. In addition, small equipment minimizes test time by reaching equilibrium conditions more rapidly.
Extractor ScaleupPilot tests are performed over a range of operating conditions to measure mass transfer efficiency and determine optimum conditions. Additional observations, such as foaming, fouling, thermal degradation and overall operating stability provide important information used in design of commercial production equipment.
Sufficient data for scale-up is routinely generated within one week of testing for each process step. With our many years of experience, Koch Modular has developed proven correlations that provide accurate scale-up from pilot to commercial size.
The final product of the pilot plant test is a report that contains the operating data necessary to allow Koch Modular to design and supply the commercial scale equipment with a Process Performance Guarantee.
Customized Distillation Pilot Test Services Offered in TX
Every distillation pilot test involves a setup customized for the application at hand. Varying configurations are available for flashing, steam stripping, vacuum, azeotropic, multi-component and non-ideal processes. Column internals can be either trays or packing. Flanged column sections are used to provide maximum flexibility for arrangement of internals. Both stainless steel and glass sections can be used. Provisions can be made for multiple feed point locations, as well as vapor or liquid sidedraw.
Reboilers can be kettle, thermosiphon, forced circulation or falling film, heated by steam, hot oils, or electricity. Alternatively, direct steam addition can be utilized.
Operating pressures from 30 PSIG to 1 mmHg absolute are possible. Heat loss is minimized by means of heat tracing and insulation.
The pilot column is run over a range of operating conditions to measure separation performance and help determine optimum conditions. Other observations, such as operating stability, foaming, fouling, or thermal degradation, are also made and recorded. This type of data and information is extremely important for process scale-up.
Packed, Trays, Multiple Feeds, Sidedraw
Sizes range from 1″ to 4″ and up to 60 theoretical stages
Pressure to 30 PSIG, Vacuum to 1 mmHG
Kettle, Thermosiphon, Forced Circulation, Falling Film
Each of the columns has particular strengths and weaknesses, which must be taken into consideration to ensure the proper extraction device is selected. If necessary more than one type of extraction column is tested to help optimize performance.
During the pilot tests, the columns are run over a wide range of operating conditions, and separation performance is measured. In addition, observations on droplet formation and dispersion, coalescence, interface control, entrainment, and emulsion tendencies are also made. Test data and observations are then used with Koch Modular proven scale-up correlations to arrive at the optimum extractor design.
With nearly 50 years of LLE testing experience, Koch Modular has learned how to streamline the testing procedures, minimizing the time and amount of raw material required. This results in significant cost savings for our clients. When it is not possible to test in our Houston Pilot Plant, then Koch Modular can supply pilot scale columns for on-site testing at the client facility.
In a number of applications, liquid-liquid extraction must be tested at elevated pressure due to the temperature and the vapor pressure of the material handled. Koch Modular has available for rental a 1″ diameter KARR® Column and 3″ diameter SCHEIBEL® Column, both in 316SS construction. These columns can be sent to the clients facility for on-site testing, along with operating and engineering personnel.
Customized Steam Stripping Setups Available at Pilot Plant
There are multiple process design questions that must be answered to properly define a steam stripping application, such as: What impact will the hydrocarbons and their range of respective concentrations have on the separation? Does the wastewater have a foaming tendency? Does the wastewater tend to foul equipment? The answers to these questions can be developed through pilot testing.
By processing drum quantities of ‘actual’ wastewater, developed in our customer’s processes, a real world understanding of the stripping process characteristics (foaming tendency, fouling propensity, impact of ‘bad players’ and overall operating stability) can be determined. Often, several different wastewater feeds are provided, representing a range of worst case conditions for design.
Pilot plant equipment setups are customized for each of our clients’ unique steam stripping applications. Test plans are established, with the input of our clients, to maximize the benefit of the development activities. Concurrently, Koch Modular’s process development capabilities and insightful pilot plant staff strive to answer the design questions of your wastewater stripper application.
Pilot Testing a Reaction Process is Vital for Plant Design
Pilot testing a reaction process, alone or as part of a multi-step process, is often a vital part of the design for the commercial scale plant. Even with available reaction kinetics there is additional information that can be gathered from testing. Koch Modular has experience in the following types of reaction studies:
Homogeneous Batch / Semi-batch Reactions
Homogeneous batch/semi-batch are the most common reaction type. They can be as simple as adding measured quantities of two or more reactants to a vessel and mixing. Heat is normally removed or added through a jacket, heating mantle or external heat exchanger. Often they require constant removal of a product via distillation in order for the reaction to progress.
Homogeneous Batch / Semi-batch Reactions
Homogeneous continuous reactions are typically plug-flow. The liquid reactants are mixed together continuously and residence time in the reactor is very short. This style is very useful for fast reactions where high throughput is essential. A reactor for this service could be as simple as a piping loop, with or without an in-line mixer. It could also be an agitated extraction column such as SCHEIBEL®or KARR®column. Miscible or non-miscible reactants are fed to the bottom of the column, flow up through the agitated zone and exit at the top of the column. Heating or cooling jackets are used to control the reaction temperature. In one application, a KARR®Column reactor has replaced a series of CSTR’s and is providing higher yield and higher purity.
Reactive Distillation – Homogeneous
Homogeneous reactive distillations make use of the good mixing and heat transfer inside a distillation column. The residence time can be adjusted and the rate of reaction can be enhanced by constant removal, via distillation of the resulting products.
Typically tray columns are used for homogeneous reactive distillation. Two unit operations, reaction and distillation are performed in the same piece of equipment, which can be a considerable cost savings.
Reactive Distillation – Heterogeneous
Heterogeneous reactive distillations are performed in distillation columns that have three sections. The reactor section is the middle section where a special packing Katamax® is used which contains a solid catalyst. The liquid phase reaction takes place as the liquid film passes across the surface of the packing / catalyst. Above and below the reaction section is a rectifying and stripping section of traditional packing. Once again, two unit operations, reaction and distillation are performed in the same piece of equipment, which can be a considerable cost savings.
In addition to liquid-liquid extraction (LLE) and distillation, Koch Modular can evaluate and test a number of other unit operations for separation processes. In general these other unit operations are evaluated for processes that include LLE or distillation steps as well. However, if necessary Koch Modular will work with our clients for these operations on an individual basis.
Some of the processes we can evaluate in our pilot plant are:
Heat Transfer Coefficient Studies
Thin Film Evaporation (partnership with LCI Corporation)
Ion Exchange Beds
Koch Modular LLE columns have also been applied to a number of unique applications that can be tested in our pilot plant.
Single Stage Mixer / Settler
Both the KARR® and SCHEIBEL® columns can be used as co-current, mixer/settlers. The typical mixer/settle used industrially will only generate up to 85% of a theoretical stage due to backmixing inefficiency. However, operating in plug-flow mode, the co-current KARR® or SCHEIBEL® Column can achieve essentially 100% of a theoretical stage at extremely high capacity.
Koch Modular has demonstrated that the KARR® Column can effectively handle slurries with up to 50% solid’s concentration. The perforated plates with 55-60% open area allow solids to flow through without accumulating. Slurry feed must be such that the solids will “sink” through the up-flowing solvent and accumulate in the bottom chamber of the column. The agitation provides the means for maximizing solid-to-liquid mass transfer.
VLE and LLE Equilibrium Studies via Pilot Plant Testing
The first step in the process of pilot plant testing is often the development of vapor-liquid or liquid-liquid equilibrium data.
Due to the non-ideal nature of many of the systems encountered, experimental equilibrium data is required for design. If this data is not in literature it must be measured in the laboratory. Thus, it is often necessary to perform bench scale tests to fill gaps in the available data. LLE data for extraction and VLE data for distillation can be developed in our pilot facility.
This data is then incorporated into computer models to optimize the process and establish operating conditions for the pilot plant tests to follow.
Also important during LLE and VLE tests are observations by Koch Modular’ss trained experts. For example, observations such as foaming or fouling often prove to be extremely valuable in avoiding potential operating problems in the pilot plant and/or commercial equipment.
The primary goal for most tests performed in the Koch Modular Pilot Plant is to generate the data required for successful scale-up to production equipment. Scale-up from Pilot Plant data forms the basis of our process performance guarantees. In this section are a number of recent applications where testing has led to the design and implementation of production equipment. These pilot testing columns include fragrance fractionation, product recovery through fractionation, solvent recovery and other extraction techniques for mass transfers.
Koch Modular has successfully fractionated orange oil and other citrus oils to produce many commercially desirable components. Pilot tests have included batch and continuous folding and fractionation steps to recover compounds such as octanal, pinene, limonene, linalool, citronella, dodecanal, valencene, and nootkatone. These tests typically require high vacuum to limit the operating temperature.
Pilot Plant Testing of Fractional Extraction for Product Recovery
Koch Modular successfully tested a fractional extraction application involving a light “tar” feed stream from a refinery operation using a SCHEIBEL® Column. For this application, the organic feed was added in the middle zone of the column. A polar solvent was added at the top of the column to preferentially extract the more polar, aromatic components (product stream). A straight-chain hydrocarbon was added at the bottom of the column and preferentially extracted the non-polar organics (impurities). The test program successfully demonstrated greater than 92% product recovery with less than 1% impurities. A production column was designed, built, installed and started-up with excellent product recovery and purity achieved.
Koch Modular has successfully recovered Biodiesel (methyl esters) from a crude Biodiesel feed stream. The process was piloted in three steps. The first step was an evaporation step which removed methanol and lights. The second step was removal of remaining glycerin. The last step collects the Biodiesel as a distillate product. All three steps are performed under vacuum. A commercial system was designed, built and started up by Koch Modular. The modular system is currently in operation.
Pilot Testing an Replacement for a Poorly Performing Extraction Column
Koch Modular successfully tested the extraction of organic components including nitrated organics from an aqueous feed stream using an aromatic, organic solvent. Prior to testing, the client was using an antiquated RDC column in their production process, but leaving a high level of nitrated organics in the aqueous effluent. Testing in a SCHEIBEL® Column demonstrated higher extraction efficiency (lower nitrated organic level in the aqueous effluent) at a reduced solvent to feed ratio. Testing also demonstrated that changing the continuous phase resulted in significantly improved process hydraulic behavior (minimized emulsion formation and entrainment losses). A production column has been designed, built, installed, and successfully started-up.
Pilot Testing Partially Water Soluble Solvent Recovery and Drying
Koch Modular has successfully recovered a high-boiling partially water-soluble solvent from both phases of a decanted product. This was done in a multi-step process, processing both phases individually. After a wet solvent-rich stream was recovered, the water was stripped out. A commercial system was designed, built and started up by Koch Modular. The modular system is currently in operation.
Pilot Test for Extracting Salts from an Organic Feed Stream
Koch Modular successfully tested the extraction of inorganic, chloride, salts from a chlorinated organic feed stream, using water as the solvent. A KARR® Column with PTFE perforated plates was tested for this application. The testing demonstrated that greater than 99% removal of the inorganic salts can be achieved for solvent to feed ratios as low as 0.07 (i.e. 0.07 weight of water to 1.0 weight of organic feed).
Pilot Plant Full Analytical Capabilities
Content should consider expansion The analytical department provides on-site analysis of process streams to assist with pilot/laboratory testing. Rapid analytical results are available to help direct the tests so that results can be obtained in the shortest time possible. Our analytical chemist is dedicated to supporting the pilot plant activities, and we always welcome input from the client’s analytical staff to assist in these tests.
The pilot plant testing team at Koch Modular Process Systems is fully capable of providing analytical support for the following equipment systems: