Pilot testing reveals the feasibility of separation processes
Pilot testing enables our customers to verify the feasibility of the proposed separation processes. In addition, innovative solutions and new developments can be elaborated and optimized to supply our customers with the best and most cost-effective solution to their separation problem.
The equipment in our test centers covers the whole range of unit operations that can be supplied to our customers. Our analytical laboratory equipment enables us to measure and monitor the relevant quantitative and qualitative parameters in order to ensure that the required specifications can be met.
Our modern test facilities are continuously upgraded and expanded. All our pilot plants are highly automated and allow complete logging of all relevant test parameters.
Laboratory and pilot size equipment for all separation technologies
Test halls of 3 000 m3, with up to 15 m useable height, explosion proof zone 1
Process control system (S7 PLC with WinCC visualization and Hitec-Zang LabVision)
Laboratories for bench scale tests and analyses: 200 m2
Distillation and absorption are well established separation technologies, and column performance can usually be accurately predicted by theoretical models. In many cases, however, tests are still recommended, for example for:
Mixtures with impurities or by-components (for example, salts)
Foaming systems or products containing solids
Systems with an unknown (and not measurable) vapor-liquid equilibrium (VLE)
Extreme requirements (related to, for instance, very high product purity)
Processing of sensitive products in term of color, smell, or taste
Test procedure
Tests are usually carried out on the basis of results from simulations or clients’ data. The column is configured according to the process requirements (continuous operation, batch, total reflux). The sensitive parameters are varied during the test:
Type of internals, tray height, number of stages
Position of feed and side streams
Feed flow
Operating pressure
Reflux ratio
Testing Equipment
Depending on the test plant, the temperature can be adjusted up to 320°C and the pressure from 1 mbar to 16 bar. Throughput ranges from 1 kg/hr to several hundreds of kg/hr.
Column sizes:
- Glass: Ø 50 mm
- SS316L: Ø 100, 250 mm
In many cases it is not possible to accurately predict film evaporation performance from first principles, especially when the products are temperature-sensitive or viscous. Tests are therefore carried out to:
Examine flow and wetting characteristics
Evaluate and optimize evaporator type
Determine optimum achievable concentrations (often on ppm level)
Test procedure
Tests are set up based on the first results using a rotary evaporator, on estimates of partial pressures, or on customer’s data. After selection of the type of evaporator, the test parameters are established:
Operating pressure / feed flow
Recirculation ratio
Cocurrent/countercurrent
Stripping gas
For wiped film evaporators:
- Wiper geometry
- Product take-off system
Testing equipment
The pilot plants can be operated with temperatures ranging from 20 to 320°C and pressures from 0.01 to 1 000 mbar (1 Pa to 100 000 Pa). Feed rates are between 0.5 kg/hr and about 200 kg/hr.
Rotary evaporator: 1 lt (0.001 m3)
Flash evaporator: Ø 250 mm (0.250 m)
Falling film evaporators:
- In glass: 0.12 m2
- In SS316L: 0.4, 0.8, 1.2 m2
Wiped film evaporators:
- In glass: 0.025 m2, 0.06 m2
- In SS316L: 0.14 m2
Short path evaporators:
- In glass: 0.05 m2
- In SS316L: 0.14 m2
Agitated liquid-liquid extraction column in pilot scale
Liquid-liquid extraction
Tests are normal practice for countercurrent extraction. An additional difficulty here is the complex scale-up of most extractors. Tests are necessary for the following reasons:
Feasibility study (to investigate dispersion, droplet size, and phase separation)
Evaluation and optimization of extractor type, and phase ratio
Measurement of achievable concentrations
Test procedure
The selection of the solvent is the first step and determines the feasibility of the extraction process. Pilot trials are based on physical properties and equilibrium data. If necessary, mini-plant tests with recycle streams are carried out first to check the accumulation of impurities. Whenever possible, tests are performed on small extractors, with small feed samples. Typical test parameters are:
Internals (geometry, number of stages), energy input
Loading, phase ratio
Turn down
Testing equipment
Tests are usually carried out at temperatures between 20 and 100°C and at normal pressure. Feed rates range from 1 kg/hr to 300 kg/hr.
Crystallization is often used because of the advantage for high-purity separation of a substance. Data obtained from pilot trials are mandatory for the design and sizing of crystallization units. These pilot tests allow for optimization of the crystallization process with respect to the unit(s) to be employed. In the cases of new separation problems, where no experience with crystallization is available, bench scale tests are employed to check the feasibility of the separation.
Test procedure
Between 2 and 10 kg of sample material are sufficient to carry out bench scale tests for a preliminary assessment on crystallization behavior, product quality and process feasibility. For pilot scale tests 100 to 800 kg are required. As a result of these investigations, a detailed proposal can be submitted, which will include a preliminary process flow diagram, an equipment list, and plant performance data.
Testing equipment
Falling film crystallizers (with 1, 4, 12 and 18 m height)
Static melt crystallizers (1, 1.5, 6, 40 and 67 lt / 0.001, 0.0015, 0.006, 0.040 and 0.067m3)
Freeze concentration and suspension crystallizer with wash column
For the evaluation of tests simultaneous analyses of samples are essential. Existing customers’ methods are used, or adapted when necessary. Modern, computer-controlled analytical equipment is available in-house in our test centers. For special analytical requirements, we cooperate with competent contract laboratories.
