AGRO-EKO spol. s r.oObecní 811 735 43, Albrechtice, Czech Republic

AGRO-EKO Ltd. was founded in 1992. The Main business objects of AGRO-EKO Ltd. are above all these areas:

1. Building, technology and other services in the environmental area, where the firm concentrates on technology supply and processing of biologically degradable waste and its further use.

The main technological device is EWA (Ecological Waste Apparatus) fermenter for controlled aerobic thermophillic fermentation and accompanying facilities such as active biofilter. The EWA fermenter is certified by The Government Testing Laboratory of Agricultural, Food Industry and Forestry Machines, Join-stock-company. The EWA fermenter is the major part of the processing line for BDW (Biologically Decomposable Waste) treatment. Unique method of transformation is protected by patent No. 295922 (IPO Prague, 2005). The existing programs concentrate on "ordered" supply of biomass processing technology. Possible product of these processing lines is compost (mulch-compost) or bio-fuel.

2. Preparing of project documentation and studies in environmental, especially for biologically decomposable waste treatment and further preparing of feasibility study and project documentation of all stages.

3. Solving of science and research program - in this field, the firm successfully participates on solving of science and research programs of Ministry of Industry and Commerce of the Czech Republic and Ministry of Environment of the Czech Republic. They concern mainly ways of biologically compostable waste and biomass processing into fuel and compost, and development and production of machinery prototypes for their processing. The firm is a holder of patent and number of utility designs.

The company continually upgrades the process of ecological and economical obtaining of compost, biofuel, energy and biochar from biodegradable waste. AGRO-EKO Ltd. has let out an analysis of technology driven thermophilic aerobic fermentation in terms of environmental impact. The processed assessment shows that the technology is fully in line with BAT (Best Available Technique) and is an eco-innovative technology that can be operated with minimal costs in many localities (CENIA 2010).

Aerobic fermenter EWA

DETERMINATION

EWA fermenter (Ecological Waste Apparatus) is certified device for processing of biodegradable waste (BDW), including sewage sludge and animal products according to Edict 1069/2009 EC.

CONSTRUCTION
EWA fermenter consists of thermically insulated operation space, system of injectors for intensive airing of the fill, system of fill shovelling consisting of segmented floor and bucket (pocket) conveyer placed on the inside of the fermenter, and integrated device for loading and unloading. All technology points are placed inside ISO 40track container (ALL IN ONE).

EWA fermenter is protected by edict, doc. No. 295922. On November 16, 2005 an application was handed in at European Patent Office (EPO) named “The method of conversion of biodegradable hygienically non-stabilized substrate into hygienically stabilized product”. Beside this patent, four utility models, also registered by the ÚPV (Industrial Property Office) are used for the production of the fermenter. The fermenter is certified by State test-room of agricultural, forester and food-processing machinery in Prague, Certificate No. 6/2006, dated May 30, 2006.

PROCESSING PRINCIPLE

Mixture of biodegradable waste and structural (liquid-absorbing) biomass is loaded in the operation part of the fermenter. Optimal fill humidity (50-60%) and disposal of air oxygen activate the metabolism of aerobic bacteria. Aeration of the fill is done by airing and shovelling inside the fermenter. High level of metabolic activity and simultaneous reproducing of bacteria is demonstrated externally by rising temperature of the fill. Intensive thermofilic aerobic fermentation runs under the same conditions in the whole fill section. This accelerates composting processes. Complex organic matters are decomposed and transformed into others. Turbulent biological oxidation runs in the fermenter due to ideal conditions. The fill temperature rises above 70ºC and proteins are gradually denatured. High fill temperatures for defined time period cause inactivation of present bacteria and pathogenic organisms (viruses, bacteria, leaven, mould, protozoons, and worms). This process is called thermofilic aerobic stabilization and hygienization of the fill. Due to high temperature the number of microorganisms is decreasing and weed seeds loose their germinating capacity. Continuing fermentation at temperatures around 50ºC and intensive fill airing enable so-called biological final fill drying.

Common mixing rate is 30% weight ratio units of sludge component and 70% weight ratio of biomass. If the biomass input humidity is low (straw, wood-shavings) the mixing rate can be up to 50:50. The unloading humidity of the fermentate used for compost production is about 40%. If the fermentate is intended for energetic purposes the final humidity is usually below 30%. The time of fill delay in the EWA fermenter depends on the character of the fill and the final product. It takes 48 – 96 hours.

EXAMPLES OF USE OF FERMENTED AND TERMOPHILICLY HYGIENIZED BIOMASS
After the thermophilic aerobic fermentation is finished the fill is stabilized and hygienized. As its qualities have been essentially changed it is further on called fermentate. It can be used as compost for agrotechnical use or compost for energetic use (biofuel).

Compost for agrotechnical use (mulch-compost)

Mulch-compost is produced by a process of controlled aerobic composting (thermophilic fermentation). It is a mixture of agricultural and forester biomass with compostable waste. Its structure is fibrous even crumby with noticeable undegraded pieces of biomass (straw, wood chips, bark). Its color is brown or brown-grey, at the production humidity it is loose it smells like mushrooms or humid forest.Certification of the product was done by CZ BIOM, Biomass Association Prague.

Compost for energetic use (biofuel)

Compost for energy recovery is a fermented mixture of BDW, made according to company standards, in accordance with Decree No. 5 / 2007 Coll. consisting of the BRO (see catalog biowaste Decree No. 341/2008 Coll.)

The company standards provides standard production process, the range of inputs, the maximum values of controlled substances, quality attributes and recommended ways of use.

Fuel is intended for combustion in boilers for solid fuels. It is suitable for biomass boiler systems, but also for coal-fired boilers. Fuel can be used in the grate boilers, but very good results are achieved by burning in boilers with fluidized bed. Incineration may be carried out individually or in combination with fossil fuels. Produced fuel usually comes in bulk form.Compost for energy recovery has crumby, lumpy and fibrous structure; the color is brown to dark brown. In the mixture the input components of biomass are obvious - parts of plants, bark, branches, etc. The maximum length of the individual pieces of the biomass is 50 x 50 x 50 mm, very thin twigs may be up to 100 mm length, occasionally up to 200 mm.

OPERATION OF THE EWA FERMENTER AND CONTROL OF THE PROCESS
The operation cycle of the aerobic fermenter is controlled on the basis of operation reading of conditions and values which characterize the aerobic fermentation. One operation cycle consists of 3 or 4 time-separated phases.