\\ Gicom in Vessel Composting
Introduction
Brentwood have developed an exclusive arrangement with Gicom of Holland to distribute Gicom technology and plant in the in vessel waste composting market in Australia, New Zealand and South East Asia.
By incorporating Gicom composting technology with Brentwood’s solid waste size reduction, screening and materials handling manufacturing capabilities, Brentwood are able to realise projects including design, manufacture, construction, commissioning and training on a turn-key basis.
Since 1984 GICOM, a Dutch based company, has designed and realised computer controlled growing cells' and 'tunnel composting facilities' for both the mushroom growing and waste processing industries. |
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Tunnel composting facilities are used to:
- Compost different organic waste streams (biowaste, MSW, sewerage sludge, industrial sludge, manure, digested residue, etc.) into high quality compost;
- Produce different types of mushroom compost: phase 1,2 and 3;
The above mentioned 'GICOM products' are built upon 3 different technology fields:
- Measurement and control devices
- Biotechnological process control
- Air handling systems
The necessary soft and hardware systems have been developed and produced within the GICOM organisation. Brentwood / GICOM are able to realise projects on a turn-key basis, providing professional design and planning services and incorporating construction and management teams during construction on site.
As an innovative company GICOM owns and operate several pilot plants to maintain its position as provider of state of the art tunnel composting technology. Current and future customers can use the GICOM after sales service: a 24-hours-a-day service department able to answer questions and to solve problems.
GICOM composting systems is a company operating all over the world - from Europe to Australia and from America to Asia!
385 FACILITIES OF EXPERIENCE!
Since 1984 GICOM has designed and constructed tunnel composting facilities to convert organic materials into quality compost products. More than 385 GICOM facilities are in operation all over the world, with a total processing capacity of over 2.750.000 tons/year. About 80% of the facilities are operating in the mushroom market and 20% in the waste management market, where facilities for treating the following materials have been realised:
- Biowaste / Greenwaste
- Municipal Solid Waste (MSW)
- Sewerage sludge
- Manure
- Industrial sludges
- Contaminated Soil
- Anaerobic digestion process residue
The GICOM system can be adapted to every capacity needed:
- Modular and Semi-mobile Container System, for capacities of 1.000 - 10.000 tonnes/annum
These plants can be fully installed and commissioned within a few weeks.
- Fixed Concrete Tunnel System for capacities over 10.000 tonnes/annum
Tailor made and based on a long term operation.
System Description
The GICOM Tunnel Composting System is based on composting organic material in an enclosed vessel: the Tunnel.
After the tunnel has been filled with compost feedstock the door is closed and the tunnel climate control program is initialized. The composting tunnels will be managed with respect to temperature, oxygen and moisture levels to optimize the process, attain pathogen reduction requirements, and meet process objectives.
After tunnel filling and program initialization, the variable speed blower associated with the tunnel starts operating and air is pushed into the aeration floor system within the tunnel. The recirculation route for the air is as follows:
- Air is blown into the concrete plenum located behind each tunnel in the technical area;
- Into the floor piping system;
- Into the composting matrix;
- From the head-space into external recirculation loop ductwork through the open recirculation damper;
- Back through the blower and then back into the plenum.
As the air enters the circulation route, several parameters are measured at several positions in what is referred to as the Input, Return and Total Airstream:
- Air temperature
- Air humidity
- Oxygen / carbon dioxide concentration
- Pressure
* temperature of the composting matrix is measured at several points within the tunnel.
The above parameters are continuously monitored by the process computer software. The software is programmed to control certain variables at certain pre-determined times or points in the course of the tunnel cycle. The speed of the blower and recirculation rate will be manipulated to maintain the desired conditions in the composting matrix.
When called for, the damper arrangement, controlled by a servomotor, permits the continuously variable introduction of the Fresh Airstream (0-100%). This allows for mixing of the recirculated air in the ductwork upstreams of the plenum. When this occurs, a volume of used air equivalent to that newly introduced is exhausted out of the system from the headspace by a damper arrangement.
The Fresh Airstream for the tunnels is drawn from the receiving hall via an overhead ductwork system with managed controls. This system takes the air out of the building on a variable basis. Air is drawn from building space by a dedicated variable speed blower and controls.
The process air exhausted from the tunnel is transported directly to the odour control system.
Process Control
The entire process is controlled by the GICOM process computer (G-2000) equipped with custom designed,
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patented software which allows dynamic control and pre-programming of key process setpoints within each composting activity unit.
All monitored results are recorded and displayed by the computer on a continuous basis. As results are recorded, they are simultaneously compared with setpoint data.
Based on this comparison and the range tolerance specified for process variables, the computer adjusts air- and water flows and conditions effecting respectively the composting cycle in the tunnels, set values for the building area, operation parameters for the waterscrubber and biofilter.
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The process computer records and stores all instantaneous measurements and cumulative data for each tunnel for each of the following parameters:
| Oxygen consumption | (g/kg;g/h) |
| Total oxygen consumption | (tons) |
| Water evaporation | (g/kg;g/h) |
| Total water evaporated | (tons) |
| Energy content of different air flows | (J/kg;J/h) |
| Total amount of emitted energy | (J) |
| Total amount of circulated air | (m³) |
| Total amount of fresh air input | (m³) |
| Water content of composting material | (%) |
During the process all the different process parameters can be shown in different tables on the computer screen. The user can create any graphic needed with the mentioned parameters. This facilitates rapid review, evaluation and adjustments (if necessary) of the composting process.
Water Management
All condensate and leachate (process water) is lead to a collection tank. This process water will be used to humidify exhaust airstreams within the scrubber and to moisture the compost within the tunnels. The overall water balance is negative, which means that no waste water has to be treated at a waste water sewage plant!
Odour Control System
All exhaust process air (the Overpressure Airstream) is directed to the (acid) scrubber where it is humidified prior to being exhausted to the biofilter. At several positions in the Odour Control System the airstream is monitored for the following parameters in order to be able to control essential setpoints in the Odour Control System:
After the scrubber, the exhausted, humidified process air is transported via a valve system and a pressure controlled blower, through an enclosed ductwork to the biofilters. The temperature of the biofilter matrix is also monitored. With these measurements, the temperature of the biofilter matrix can be controlled to remain within the optimum range for the cleaning and degradation of odorous compounds.
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The GICOM system is able to meet the high odour standards in The Netherlands and Germany, based on the technic of olfactometry. Following biofilter emission numbers are based on multiple measurements done at several GICOM composting plants in Germany and The Netherlands and show that the average emission level is 250 europeanOU/m³ (=500 dutchOU/m³ and =50 germanOU/m³)
The European Odour Unit is described in a recent directive (EN publication summer 1997)
Working Environment
To protect workers at the composting facility the GICOM system encloses several protection measurements:
1. The entire (closed) facility has extensive air conditioning, so the total air volume can be refreshed one or several times per hour;
2. At several positions in the facility, where dust, keimes and spores have possibilities to come into the working environment (f.e. at screens, conveyors, shredder etc.), special climatisation units (including dust and spore filters) are installed;
3. In case frontend loaders are used, they are equipped with special overpressure units to protect the driver;
4. Detailed safety procedures for personnel.
The GICOM plant at Deurne, the Netherlands is the first composting plant in Europe where all measurements to protect workers are being installed and where at the same time the new (European) regulations are being met!
Variations in System Setup
Each Brentwood / GICOM compost facility design is developed individually to suit the needs of a particular client. Considerations include waste stream quantity and quality, compost quality required, and economic considerations. Brentwood / GICOM can provide the client with a full range of options, including the following:
- simple or complex processing
- (semi) automatic waste processing
- (semi) automatic un/loading of the tunnels
- open/closed biofilters
- co-composting of different waste streams
- ability to manage different quality waste streams separately
- re-use of process energy
Advantages of the tunnel composting system
- Excellent process control
- Decreased detention time to produce nature compost (stability IV-V) : 14-21 days
- Flexibility towards input material (organic waste, sewage sludge, manure etc.)
- Flexibility towards end product (different kinds of compost can be produced)
- Sophisticated odour control
- No devices in the process room: no corrosion
- Working environment: meeting new (European) regulations!
- Automatic process handling
- No waste water effluent
- Fully enclosed active processing
- Worldwide experience with 385 full scale plants
- Re-use of process energy
- Price competitive for both investments and operational costs
Input Materials
Composting / MSW
Composting period |
5-7 days |
Dry matter content |
80-85% |
Mass reduction |
35% |
No pathogens |
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Odour free |
Handling
The MSW is screened at 70 mm and brought into the tunnel without the need to improve the structure. The handling takes place automatically and as an alternative, it can be done with a loader. There are 3 possible goals:
- Production of fuel (RDF)
- Production of compost (soil improves, landscaping)
- Production of first class compost (gardening, nursing)
Retention time in tunnel depends on the set goal.
Composting / Biological Drying of Sludges
| Composting period | 7-14 days |
| Dry matter content sludge | 18-25% |
| Dry matter content compost | 60% |
| Overall mass reduction composting | 85% |
| Organic matter reduction | 60% |
| No pathogens |
Handling
The sludge is mixed with f.e woodchips, sawdust and freshmade compost to improve the structure. The handling of the sludge mixture is done automatically, as an alternative it can be done with a frontend loader. The compost can be used for agricultural purposes and landscaping or as a daily and/or top cover on landfills.
| Composting period | 5-7 days |
| Dry matter content | 80-90% |
| No pathogens | |
| Odour free |
Handling
On a daily basis the manure is transported into the tunnel where the composting process takes place. Depending on the type and the composition of the manure, one can add a processing step to the process (for example mixing).
The exhaust air coming from the process needs to be cleaned with a (chemical) scrubber and a biofilter.
Reference Sites
MSW + Greenwaste
| 1988 | VAM | Wijster | NL | 1.000 t/a |
| 1990 | Heidemij | St. Oedenrode | NL | 3.000 t/a |
| 1991 | Ferm-o-feed | Zeeland (NB) | NL | 1.000 t/a |
| 1991 | Kaathoven | St. Oedenrode | NL | 10.000 t/a |
| 1992 | Kaathoven | St. Oedenrode | NL | 25.000 t/a |
| 1992 | VAM | Zeeland (NB) | NL | 10.000 t/a |
| 1992 | RAZOB | Deurne | NL | 25.000 t/a |
| 1993 | Kaathoven | Bladel | NL | 30.000 t/a |
| 1993 | Twente | Boeldershoek | NL | 60.000 t/a |
| 1993 | OGAR | Pekela | NL | 25.000 t/a |
| 1993 | AVL | NL | 75.000 t/a | |
| 1994 | RAZOB | Acht | NL | 25.000 t/a |
| 1994 | WKG | Würzburg | D | 20.000 t/a |
| 1994 | WGV | Quarzbichl | D | 20.000 t/a |
| 1995 | Schneider | Gießen | D | 30.000 t/a |
| 1995 | Kaathoven | St. Oedenrode | NL | 10.000 t/a |
| 1996 | RAZOB | Deurne | NL | 10.000 t/a |
| 1996 | Emsland | Meppen | D | 17.000 t/a |
| 1997 | BSR | Berlin | D | 70.000 t/a |
| 1997 | PROAV | Rotterdam | NL | 70.000 t/a |
| 1997 | HRA | Jevnaker | N | 4.000 t/a |
| 1997 | Intradel | Liege | B | 3.000 t/a |
Digested Residue
| 1994 | GeVuLei | Leiden | NL | 1.000 t/a |
| 1996 | SMB | Tilburg | NL | 1.000 t/a |
| 1997 | BSR | Berlin | D | 70.000 t/a |
Industrial-Agricultural Waste
| 1995 | Trentini | Rovereto | I | 10.000 t/a |
| 1995 | Lesage | Zutphen | B | 70.000 t/a |
| 1995 | Prechamp | Heusden Zolder | B | 50.000 t/a |
| 1995 | Kristjanson | Reykjavik | ICE | 10.000 t/a |
| 1996 | Billio | Porcellego Di Paese | I | 60.000 t/a |
| 1996 | La Lande | St. Laurent de Lin | F | 40.000 t/a |
| 1996 | Fleuren | Middelharnis | NL | 225.000 t/a |
| 1996 | Theeuwen | Blitterswijck | NL | 200.000 t/a |
| 1996 | Walkro | Maasmechelen | B | 150.000 t/a |
| 1997 | Wanganui | Wanganui | NZ | 5.000 t/a |
| 1997 | Wrona | Psczyna | PL | 60.000 t/a |
| 1997 | Van Werven | Hattumerbroek | NL | 25.000 t/a |
| 1997 | Hensby | Huntingdon | UK | 7.000 t/a |
| 1997 | Theeuwen | Blitterswijck | NL | 100.000 t/a |
Sewage Sludge
| 1991 | GMB/ZOG | Zutphen | NL | 6.000 t/a |
| 1993 | GMB/ZOG | Zutphen | NL | 50.000 t/a |
| 1993 | GMB | Tiel | NL | 25.000 t/a |
| 1993 | BFI | Unity, Maine | USA | 35.000 t/a |
| 1994 | GTR | Barcelona | E | 30.000 t/a |
| 1994 | GMB | Tiel | NL | 30.000 t/a |
| 1995 | Rutte | Woerden | NL | 10.000 t/a |
| 1995 | AW | Ipswich | UK | 12.500 t/a |
| 1996 | GTR | Blanes | E | 15.000 t/a |
| 1996 | Te Wierik | Raalte | NL | 10.000 t/a |
| 1997 | XY | Mass. | USA | 12.000 t/a |
Semi-Mobile Container System General Description
The GICOM Tunnel Container system for small capacities (500 - 7500 t/a) is based on composting organic material in a semi-mobile closed box: - the container tunnel.
The composting facility comprises a system of corrosion free air and water tight modular units, which are transported to the site pre-assembled. The facility which consists of composting containers with scrubber and biofilter, can be fully installed and commissioned within a few weeks period.
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The stainless steel container tunnel is divided by a perforated floor (based on the GICOM spicket system©) into two parts: the aeration plenum and the composting matrix.
When the composting container is filled with organic material the process air is blown from the aeration plenum into the composting matrix. The process air is via ducts recirculated into the container. When needed, fresh air can be added and (percolate) water can be sprinkled.
By circulating the process air it is possible to control parameters important to the composting process, such as temperature, humidity and oxygen concentration. |
The outgoing process air is cleared from ammonia, odour and dust by use of a water scrubber and a biofilter.
A GICOM composting container installation will normally be built up out of 3 modules:
- composting containers
- technical container
- biofilter container
The technical container contains the ventilators, ducts, pumps, switch boxes and the scrubber.
The configuration of the facility is most flexible. The simplest/minimum configuration holds 3 modules: 1 composting container, 1 biofilter container and 1 technical container. Every other combination of these three modules is also possible, depending on the needed capacity.
The range of material to be treated with the container composting system is wide. One can handle the following materials, also in a co-composting situation:
- Foodwaste / green- and yardwaste
- Municipal Solid Waste (MSW)
- Sewage sludge/Industrial sludges
- Manure
- Anaerobic digestion process residue
- Contaminated soil
For further information refer to the system description of tunnel composting system information.
Independent Compost Quality Certifications
Testing compost quality to conform to the German compost quality regulations (LAGA M10) at the GICOM composting facility 'Quarzbichl' (Germany)
Planotec Report Summary
To test the hygienic component of the German compost qualification regulation (LAGA M10) there were three tests done by the independent research institute Plancotec (Witzenhausen) at the GICOM composting facility 'Quarzbichl', Germany.
The LAGA M10 subscribes the following sensor organisms to be tested:
- human/veterinarian hygiene:
- Salmonella senftenberg W775
- native Salmonella
- phytohygiene:
- Plasmodiophora brassicae
- Tabak-Mosaik-Virus (TMV)
- Tomato seeds
The tests have been done during one year at three different moments (November, April, July) to cover the different situations (climate, compostion waste) at the facility. The tests have been done during normal operation with biowaste from source separation (< 60mm) mixed and shredder green waste. The water content of the initial input mix was :65%, 55% and 60%.
During the different tests the following temperature regime in the composting matrix was being followed: the first 24-36 hours temperature between 60-65° C, starting at day 3 the temperature level was decreased to 50-60° C by manipulating the air flow through the matrix; important to mention that there was a flat temperature development over the composting time.
The mentioned organisms are being re-introduced in the composting matrix at different positions (top, middle, bottom). After the tunnel retention time (2 weeks) the different inoculated samples are taken out and tested at the laboratory on the existence and activity of the sensor organisms.
The results show that during the three tests over the year all four organisms where de-activated:
- Salmonella senftenberg W775 and the Tomato seeds were eliminated completely.
- Plasmodiophora brassicae was eliminated completely during two tests and showed very low activity at the third test. This activity level was way down below the tolerated level mentioned in LAGA (0.08/0.25 where as LAGA tolerates 0.5)
Also Tabak-Mosaik-Virus (TMV) was inactivated completely during one test, but showed very low activity in two tests at a level of 1.4/4, whereas LAGA tolerates 8. The produced compost was tested on native Salmonella (25 samples), in which no Salmonella was found at all.
The conclusion from the 'around the year' testing is that the GICOM tunnel composting system is able to meet the German regulations for compost quality (LAGA M10) for all the mentioned test organisms after a retention time of two weeks. After two weeks the compost produced with the GICOM tunnel composting system at the Quarzbichl composting plant can be used for any purpose, based on arguments in the field of human-, vegetarian- and pytho-hygiene.
ITA Final Report
Research concerning the composting process at the Quarzbichl facility, Germany
4.2 Remarks to the results.
The following details are worth mentioning:
- After 14 days of tunnel composting the input material shows a very high grade of stability (German Rottegrad IV- V) . The digested residue (digested for 14 days) shows a lower grade of stability
- The input material to the second stage shows in some occasions a lower organic matter content then the second stage output material.
- Most samples of the second stage output material show the highest grade of stability: V (German Rottegrad V).
- The C/N ratio shows a strong correlation with the change of the grade of stability during the composting process.
- There is a clear change in granular distribution: the longer the retention time in the tunnel system, the smaller the aggregates.
5. Process parameters.
5.1 First stage composting
During the 14 days 'first stage composting process' the graphs of the Air Temperature(s), Compost Temperature and the Water Content looked very stable.
Air Temperature.
The Air Temperature has been in the following intervals:
1. circulation air 54-60° C
2. input air 50-55° C
The Air Temperature only changes when there is major change in the Air Mixing Factor: Air Temperature (circulation) = Air Temperature (input) + Air Temperature (fresh).
Compost Temperature.
The temperature change over the entire composting process shows great stability. The maximum temperature difference measured was 5 degrees Celsius (?T £ 5° C).
Air Volume.
The Air Volume changes over the time and varies with the Air Temperature Changes and the amount water sprinkled over the compost. There is a negative correlation between the retention time and the Air Volume: the Air Volume decreases during the process. At the end of the composting process the Air Volume will increase to cool down the compost. The Air Volume changes between 3.000 - 15.000 m3/h.
5.2 Second stage composting
During the second stage composting the process parameters show similar graphs as during the first stage. The major difference is the Air Volume, which is more or less constant at the level of 4.000 m3/h.
6. Summary.
6.1 First stage composting
Analysing the compost coming out of the tunnel showed the following results:
- Stability IV-V (German Rottegrad)
- Water Content Decrease 38%
- Dry Matter Decrease 25%
- Organic Dry Matter Decrease 40%
The high Decrease of Organic Matter during the 14 days of tunnel composting has to do with the following factors:
- Air Volume: The GICOM tunnel composting process uses high volumes of air (38 - 180 m3/h,t material).
- The Air Control shows a very stable profile, no significant pressure drop over the material during the process.
- Last but not least, the Temperature Profile looks very
stable indeed (?T £ 5° C).
Water management: Sprinkling the water over the compost, based on the Amount of Water Evaporated out of the tunnel, works out very positively. It keeps the water content of the material at a, for microbiological activity, optimum level.
Input material: During 30 minutes the biowaste (from source separation) is mixed with bulking agent. The bulking agent (green waste from parks) has been shredded and piled for tree weeks.
6.2 Second stage composting
Analysing the compost after the second stage showed the following results:
- Stability IV-V (German Rottegrad)
- Water Content Decrease 33%
- Dry Matter Decrease 8%
- Organic Dry Matter Decrease 16%
The second stage shows lower Degradability Rates because of the absence of easy degradable components and the change in process control. The Air Volume is much lower as during the first stage (4.000 m3/h compared with 3.000 - 15.000 m3/h during first stage). After one week water sprinkling was stopped.
7. Discussion
The results show that the test runs at the Quarzbichl tunnel facility (Germany, system GICOM) were successful: after 14 + 14 days compost stability reached Rottegrad IV-V.
To the opinion of ITU Berlin the results are extraordinary: Stability IV after 14 days of composting is the best thinkable result (!) and only possible because of a superior process control in combination with a good water sprinkling regime.
To the expectation of ITU Berlin changes in Input Material will not change the possible results of the facility when the operator fine-tunes the process control and will give strong attention to the pre-processing of the (different) input materials.
Berlin, 24th June 1996.