SP – Chemical/Physical separations

Distillation

Figure 3.4 illustrates distillation equipment for normal pressure, elevated pressures or reduced pressures at SP Processum. The system consists of two connected columns, one packed column and one bubble cap column. The packed column has a portion that can heat the contents via an oil mantel, the other column relies on heating from a attached reactor (10 liter or 50 liter). The system is remotely operated through Delta-V (control software) and all parts of the system can be affected through regulators. The equipment can be operated continuously through a constant flow in and out or in batch mode. The system can easily be re-modelled to fit a desired process and specifications include: pumps max flow approx. 50 ml/min, mantled volume (packed column) 1.6 litres and pressures from -1 to +10 bar.

Figure 3.4 Scheme of the Distillation setup at SP Processum AB

The Biorefinery Demo Plant has a continuous distillation with a capacity of 500 L/h. The column is designed with bubble cap trays  below the feed stage and is packed above the feed. The column is heated with steam. The distillation column includes a reboiler, but typically direct steam injection is used.

Distillation is also routinely performed at SPPD. Equipment available range from lab scale packed columns to pilot plant packed columns and a glass distillation column with 20 stages (bubble cap design). For temperature sensitive material high vacuum thin film distillation/evaporation equipment at lab scale is available (Leybold-Heraeus GMBH KDL4, design pressure 0.001 mbar, operation pressure down to 2 mbar.). This equipment has been used to fractionate bio-diesel and to isolate the “heavy” fraction. Simulations are performed using Aspen Technology software.

Chromatography

In process development of chemical industries, e.g. in the manufacture of bulk chemicals, it is often important to isolate the individual molecules of a mixture in order to acquire reference substances for quality control in the large scale production.

In the design of chromatography processes for complex mixtures a stepwise combination of different separation modes is the most efficient.

 Liquid Chromatography(LC) is used for a wide range of compounds. Examples of applications are separation of a major or of a minor component from a complex mixture or chiral separations of enantiomers from a racemic mixture. Liquid chromatography is not suited for compounds which bind too tightly to the stationary phase. At SP Process Development there are two preparative liquid chromatography systems and one counter current system available for chromatography.

Table 3.2               Chromatography equipment available at SP Process Development

Counter Current Chromatography(CCC) is also used for a wide range of compounds and is especially good for compounds that bind tightly to, or are sensitive to degradation by a stationary phase since both stationary and mobile phases are liquids.

Extraction

SP Processum has a 3L stainless steel soxhlet extractor which can operated up to 230 C°. Batch extractions can also be done up to 50L, 15 bar, 230 C° in an ATEX classed area. A continuous liquid-liquid extraction unit is available with a 3mL/min capacity. It is a manufactured in hastelloy and teflon to withstand corrosive conditions.

Crystallisation

Development of crystallisa­tion methods att SP Process Development usually include the following activities: solvent screening, poly­morph screening, evalua­tion of purification obtained, particle design trials, measurement of solubility and construc­tion of phase diagrams. In some cases screening for suitable salts may be per­formed, and for the selected salt the above activities will then be carried out. When­ever possible, considerations for environmental effects are taken into account when selecting a suitable solvent system. Solid state properties are analysed and characterized. In addition, chemical analyses are carried out.

Crystallisation equipment and in-line measurements available at SP Process Development

• Batch reactors 100 mL-100L
• Multimax 50 mL reactors with turbidity and Lasentec FBRM Probes
• Continuous Flow reactors (Including Nitech continuous reactor – total capacity 3 liter)
• In-line measurements with Lasentec FBRM probesup to 0.5 L reactor scale
• Raman spectroscopy
• Solubility measurements
• In-line IR measurements

Dewatering

SP Processum has torrefaction pilot located in Umeå with a capacity of 4 t/day, a belt dryer with a capacity 5m³/h and a tornado dryer with a capacity of 300 kg/h. The evaporator system in the Biorefinery Demo Plant includes two steam-effects, and has a capacity of approximately 180 kg/h. Steam up to 7 bar can be introduced to both effects in parallel or in counter-current mode. The system includes flash tanks and surface condenser, and the DS content of the feed is typically between 1 – 5%.