FuelCal® is a technology for processing concentrated municipal sludge, agri-food industry sludge, expellers, dregs, biodegradable waste and some animal waste (category 2 and 3) into OrCal® fertilizer or into OrCal®En fuel that can be used for desulfurization in power industry. The technology meets the requirements specified in Polish Waste Management Act of 14 December 2012.

The technology developed by Evergreen Solutions Sp. z o.o. company has a wide range of applications and may contribute to the improvement of the waste balance. Apart from municipal sewage treatment plants and biogas plants, the technology may be used by agri-food industry companies such as abattoirs, packing plants, breeding farms, food production companies, breweries, distilleries, dairies and other.

As of today, the technology is used by 16 companies operating in various areas.
The problem of organic waste can be solved in numerous ways, but only one of them deals with the issue in a comprehensive, efficient and environmentally friendly way. It is called FuelCal®, a technology developed and distributed by Evergreen Solutions Sp. z o.o. company from Pyrzyce, Poland.
FuelCal® makes it possible to completely process the wastes into organo-mineral fertilizer or fuel components - the products that are ready to be introduced to the market.


Food producers
Breeding farms
Packing plants


  • animal wastes, category 2 and 3
  • feathers
  • bones
  • bristle
  • poultry litter
  • manure
  • sediments from sewage pretreatment plants
  • scum


Municipal sewage treatment plants


  • sludge, code 190805
  • digestate


Paper industry
Biogas plants


  • biomass
  • digestate
  • grain stillage
  • cellulose
  • etc.


The biggest advantage of this technology lies in the fact that the plants that decide to implement it, cease to generate any wastes and consequently do not need to observe the regulations specified in the Waste Management Act anymore. In accordance with the EU Directive on Wastes of November 2008, every company needs to operate in such a way, to minimize the waste production and limit the necessity of waste utilization.
In the case of FuelCal® technology, the utilization process is not required, because the process line is applied as a natural extension of the technological process.

The system is installed in direct proximity to the centrifuge, press or any place where the wastes are produced. This way, the modular structure allows for a significant decrease of the investment costs. Therefore, the technology becomes an additional source of income for the producer, and not a problem.


Due to the thermal, physico-chemical processing of the wastes, the FuelCal® technological process makes it possible to manufacture a product of homogeneous particle size distribution, which is easy to store and transport.
FuelCal technology is completely hygienic and eliminates such pathogenic bacteria as Ascaris, Toxocara, Trichuris and other, as well as insects and live eggs of intestinal parasites. Waste odors and pathogens are completely eliminated. FuelCal® is a patented, Polish technology. The official producer and distributor of the technology, Evergreen Solutions Sp. z o.o. company, offers Rcal120 and Rcal250 devices, which can be adjusted to the amount of wastes produced in the given facility. The technology has numerous advantages.
The wastes are processed directly at the place where they are produced.
The technological process uses the heat that is generated by the chemical reaction (no external sources of heat).

The technological process may be performed in the temperature between 50ºC and 145ºC, which makes the technology environmentally friendly, due to the lack of emissions of harmful products (sulfur oxides, nitric oxides and other) typical for processing technologies that require high temperatures.

FuelCal® technology is environmentally friendly. Emission measurements performed by the expert appointed by the Polish Minister of the Environment are very positive and do not show any adverse influence on the environment or any gas and odorous emissions.


Products from the series OrCal® and OrCal® pHregulator can only be manufactured using FuelCal® technology consistent with the patent p.400268 `` Fertilizer with controlled release of ingredients, method of producing controlled release fertilizer and the method of fertilizer application ``, using a reagent WapCal® in accordance with the R292513 standard and the license granted to the producer by the Licensor. FuelCal®, OrCal®, WapCal® and pHregulator® trademarks are registered trademarks in the Patent Office of the Republic of Poland, protected by patent law.

The residence time of the WapCal® reagent mixture and waste at temperatures exceeding 55 ° C is above 20 minutes, including inside the reactor for not less than 8 minutes. These guarantees result from the size of the reactor, the efficiency of the production installation, the way the raw materials migrate through the reactor and the fact that the exothermic reactions started in the mixer are also continued in the product leaving the production line (so-called maturation process). The product can not leave the reaction node without full sterilization and thus reaching the desired temperature.

The pH of the chemical reaction medium: pH > 12,0

The presence of a concentrated hot solution of milk of lime in the reaction mixture providing access to the inside of the particles of the processed pulp.

No possibility of wandering of waste subjected to processing by the processing line, omitting the node of the processing reactor.

Registration and archiving of technological parameters of the processing process (graph of processing temperatures over time).

The processing efficiency is not less than 0.2 Mg/h and a maximum of 4 Mg/h of concentrated sewage sludge per hour, while ensuring that sewage sludge contains min. 2% dry weight.
Consumption of WapCal® reagent per 1 MG of waste is not more than 400 kg, while ensuring by the operator a continuous supply of raw material in an amount ensuring continuous operation of the processing plant, with a capacity not less than 0.2 Mg/h and a maximum of 4 Mg/h of waste per hour per reaction node and with a content of dry matter not less than 20%. The fulfillment of this requirement is closely related to the reactivity of the WapCal® reagent.
The production line guarantees full sterility of the manufactured product. The chemical composition of OrCal® fertilizers is valuable due to the nitrogen, phosphorus and lime added in the waste.
The amount of supplied WapCal® reagent, an average of 150 – 250 kg per ton of waste, determines full sterilization, reaching temperatures above 55 ° C and drying with the simultaneous creation of a valuable OrCal® fertilizer with reduced moisture.


FuelCal® technology was implemented in the sludge processing line at one of the sewage treatment plants located in Upper Silesia, Poland, where the system complements the existing wastewater purification process.
Its task is to conclude the whole sewage treatment process. As far as the legal regulations are taken into consideration, the line is supposed to meet the requirements set forth in art. 14 of the Council Directive 91/271/EEC concerning urban waste water treatment: “Treated waste water shall be reused whenever appropriate.
Disposal routes shall minimize the adverse effects on the environment”. Moreover, the technology fulfills the requirements specified in the Council Directive 86/278/EEC on the protection of the environment, and in particular of the soil, when sewage sludge is used in agriculture, which aim is to regulate the use of sewage sludge in agriculture in such a way as to prevent harmful effects on soil, vegetation and man, while encouraging its correct use. The technology meets all requirements specified in Polish regulations, namely in art. 17 and art. 18 of the Waste Management Act of 14 December 2012 and in the Environmental Law of 27 April 2001.


The technology enables the production of organo-mineral fertilizer known as OrCal®, certified by the Ministry of Agriculture and Rural Development (certificate no. 183/07/2007). The product manufactured with the use of FuelCal® technology is accordant with the patent P.400268 “Fertilizer of controlled release of chemical compounds to the soil and method of its production”.

Distributed by Evergreen Solutions Sp. z o.o. company, OrCal® is a fertilizer that quickly increases the pH of the soil and contains app. 30% of natural organic matter. OrCal® neutralizes soil acidification, both natural and caused by farming industry.This property is caused by active hydrated form of calcium of high water solubility, much better than the solubility of lime chalk or calcium carbonate. OrCal® contains app. 4.7% of nitrogen, which is released gradually and works for long periods of time. Due to its specific properties, OrCal® fertilizer improves the structure and fertility of the soil, providing the plants with amino acids, minerals and other trace elements. Studies conducted by the Institute of Soil Science and Plant Cultivation proved that the fertilizer “improves the factor of plant biomass growth from 20% to 40%”.
Our clients who use OrCal® fertilizers confirm that the product increases the amount of protein in cereals by app. 30% in comparison to the crops cultivated without OrCal®.
For instance, protein constitutes 18% of weight of spring wheat fertilized with our product, in comparison with 13% obtained with the use of traditional methods.

Organo-mineral OrCal® fertilizer has excellent chemical composition:

  • amount of nitrogen (N)– app. 4,7%
  • calculated amount of phosphorus (P2o5)– app 2,56%
  • amount of phosphorus – app. 1,12 %
  • amount of potassium (K)– app 1,15 %
  • amount of potassium (K2O)– 1,38%
  • amount of calcium and CaO– min. 25%
  • amount of organic substance in dry mass  – app 20%


Popularity of OrCal® fertilizer is constantly increasing, while the price of the product itself is kept on a constant, high level. Therefore, the companies that invest in FuelCal® technology have the opportunity to generate additional sales income. OrCal® is promoted by Farming Consultancy Centers in whole Poland and by Regional Chemical-Agricultural Stations.

FuelCal® technology was recognized by the Polish Ministry of the Environment and was awarded at the Green Technology Accelerator competition “GreenEvo”. “GreenEvo” is a project launched by the Polish Ministry of the Environment to enable international transfer of technologies that could be used to improve environmental protection and economic development. The technology distributed by Evergreen Solutions Sp. z o.o. company was positively evaluated by numerous scientific authorities and institutes, for instance: Institute of Soil Science and Plant Cultivation in Puławy, Poland, Institute for Building, Mechanization and Electrification of Agriculture, Rural Medicine Institute or Institute of Environmental Protection.
Opole University of Technology voiced an independent opinion on the technology, proving the economic and environmental advantages of FuelCal® technology used in waste processing facilities.


The fertilizer improves plant biomass growth from 20% to 40%


Increases the amount of protein in cereals by app. 30%.


Save up to 40% on the purchase

Evergreen Solutions sp. z o.o. – member and founder of the Key Cluster “Green Chemistry”


We are the laureate


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