Solids Recovery

Background

Gone are the days when companies could just dump their waste. Coupled with limited landfill sites the rising cost for disposal and the limitation of some of our earth’s resources, it is essential for companies to invest in Solids Recovery Systems to minimize resource consumption and assess the potential for recovery and recycling of previously ‘waste’ material.

Until fairly recently it was not uncommon for most companies in the Food and Beverage industry to undertake just Primary Treatment, normally separating out un-dissolved solids, which could then be picked up by a local farmer and spread on his field, or even in some instances fed to livestock.

The problem with this is that if only using a Primary Treatment, the solids content is only likely to be between 2- 5% Solids, therefore over 95% of the waste being taken away would be Water!

Nowadays it is more likely that the companies will undertake some form of Solids Recovery, solids will have to be concentrated before being transported to a specialist treatment centre for either landfill or burning.

Below are some of the specific market sectors we have assisted clients with in Solids Recovery:

Metals Recovery

In some processes what was previously classed as waste, might be a high-value reactant and if extracted from the rest of the waste stream the Solids Recovery could be recycled or sold. Within the glass industry darkened and one-way glass uses precious metals such as Palladium and Silver, the former commanding prices over €7,000/kg. Similarly, Lithium Chloride (LiCl) is used in the car manufacturing industry as the flex material in soldering Aluminum. In these processes and many more it is now commercially viable to investigate the potential Return on Investment (ROI) to recover and recycle these materials. Technologies such as vacuum evaporation can have a very important role when these reactants, and due to their small foot-print are relatively easy to retrofit into existing plant rooms.

Calorific Value Waste

Within some waste solids, there could be material which has some value. This might be due to the calorific value of the material, rendering it suitable for burning in systems such as Combined Heat & Power (CHP) or as material for Anaerobic Digestion (AD). By reducing the volume of the water in the waste solids, not only does this increase the total solids loading, but it also may increase the calorific value of the material and make it more attractive to companies operating CHP and AD plants.  By using technologies available from Condorchem Envitech, on the one hand, wastes are considerably reduced and, on the other hand, potentially a significant amount of thermal and electrical energy is produced.

Fertilisers

The rise in prices, around the world, of fertilizers in the market makes Condorchem Envitech approach of proposing ecological and natural fertilizers production source very interesting.

Some industrial fertilizers contain contaminants that can be recovered or commercialized once purified and concentrated, becoming products that can produce a source of income.

The recovery of products to obtain fertilizers or other recoverable products takes place through the application of separation technologies that enable us to reach this goal. These separation processes are different on a case-by-case basis, usually involving the use of solid separation, filtration and membrane concentration technologies and, finally, a vacuum evaporation stage with or without a dryer.

Fertilizer production from the liquid fraction that comes from livestock waste bio-digestors (slurry, poultry manure, etc.) or from the co-digestion of these wastes with animal or plant organic matter, allows an ideal binomial: thermal energy production (from the bio-digestor´s biogas) and nutrient-rich liquid fraction (Nitrogen, Phosphates, and Potassium N,P&K), as well as very valuable soluble carbonaceous compounds from organic soil substances such as Humic and Fulvic acids.

Available Technologies

Having highlighted some areas where previous waste solids might nowadays be de-watered, what technologies are available?

Condorchem Envitech are one of the leading companies in the evaporation and crystallization of materials. Starting with material with a low Dry Solids (DS) value, typically as highlighted earlier post Primary Treatments at 2 – 5% Solids, using their expertise Condorchem Envitech will evaluate for the client the best technology for their particular application, this might range from evaporation of some of the liquid in the waste, or taking the process further to remove the majority of the liquid phase and be left with predominately dry solids. Crystallization can achieve over 95% solids.

At the initial stage Condorchem Envitech will work with the client to assess which technologies lend themselves to treating the waste material. Samples can be sent to the laboratory for further assessment, particularly where the client might be interested in how much of a precious material can be recovered. Further assessment can be undertaken with the client with on-site trial rigs which can be delivered to site and provide the client with live data.

Below are therefore some examples of the types of systems which Condorchem Envitech can work with the client to ensure that the correct cost effective solution is found

  • Physical- Chemical Purificators – In some cases it will be necessary to separate out the solids required for further treatment from the liquid phase, rather than put all the waste through the evaporation or crystallisation phase straight off.
  • Evaporation Technologies – Condorchem Envitech are one of the leading companies in offering Evaporation Technologies to water that is heavy in water salts, smaller units have a small footprint and be located near to the extraction or delivery source.
  • Crystallization ProcessesCrystallizers are equipment that allow full remove of liquid from a solution, transforming the paste into a dry solid, usually crystallized. Its function is based on heat application with the aim of evaporating the liquid until a consistent solid is obtained.
  • Vacuum Concentrators – Theses systems are characterized by concentrating with low power consumption, dissolved liquid or solid products. The concentrated product can become the final product of the production process or a by-product to be reused or recycled.