ISWA Presentation 2010


Dordrecht breit 768


HVC, officially “NV Huisvuilcentrale N-H”, is a joint venture of 56 municipalities from the Dutch provinces of North Holland, Flevoland, South Holland and Friesland plus 5 water boards. HVC is committed to providing innovative and environmentally responsible waste management and energy production services. HVC is located in Alkmaar where HVC is also owner and operator of the Alkmaar WTE plant. The line 4 of the Alkmaar plant was commissioned in 2004, has a capacity of 75 MW thermal, a design throughput of 27 tons of waste per hour and became the example for line 5 in Dordrecht.

RGR, officially “RGR-Projecten BV“ is a Dutch Project Management Company focused mainly on building up integrated project teams, jointly with the client’s staff, by providing external expertise and manpower. RGR was recently involved in the projects Alkmaar, BEC Twence, Moerdijk and also Dordrecht. I work with RGR since the Alkmaar project.

“Gevudo” was the original name of the waste incineration plant in Dordrecht. The plant was built by local municipalities and operation started 1972. Later, Eneco owned Gevudo but finally sold the plant to HVC on 19 December 2005. The plant has 4 old incineration lines of which only number 1 and 4 are equipped with heat recovery boilers. The lines 1 and 2 are connected to one flue gas treatment (FGT) A. The lines 3 and 4 are connected to FGT B. The latest revamp of the FGT took place in 1997. The old plant’s capacity is:

  • Lines 1 and 4, each                   7.1            t/h
  • Lines 2 and 3, each                   5.7            t/h
  • Yearly incineration capacity      240,000     t/year (permission)

There were ongoing discussions with the neighbourhood and the authorities on odour problems and exceeding emission limits. Of course, the incinerators 2 and 3 without heat recovery did not fulfil the IPPC guidelines. This was the status when the city of Dordrecht asked HVC to become the new owner of the plant and to improve the shortcomings.


HVC realised the Alkmaar line 4 project with an integrated project team. The team consisted of external experts and internal members of the operational staff. By this, the experience from operation and maintenance was combined with modern project management methods. The team worked jointly together, without differing between internal and external members, during the whole week on site. The external members were not only acting as, but were also considered as HVC staff taking also part in social events of HVC.

As the experience gained during the Alkmaar line 4 project was excellent, HVC decided to follow the same approach for the Dordrecht project. When buying the Gevudo plant it was HVC´s intention to extend the plant by a new line, more or less similar to the line 4 in Alkmaar. HVC decided to establish an integrated project team under the leadership of Mr. Rick Lutkeveld from RGR-Projecten BV, as Project Director reporting directly to the HVC management. Mr. Maarten Bruggeman from HVC became the daily Project Manager. I worked on behalf of RGR as Project Manager being responsible for the process equipment. Further team members can be found in the organisation scheme (see on CD).

Approaching a project with an integrated team got the following main advantages:

  • Experience from operation and maintenance present in the team and can easily be brought into concepts in an early stage.
  • Advisors are within the team and not separately standing outside.
  • Information exchange between project team an operation is simple.
  • Client’s organisation is committed to project decisions.
  • Modern project management skills and tools are present within the team.
  • Work load is distributed on many shoulders.
  • Ideas from other projects can be discussed, evaluated and implemented.
  • Back office support from external engineering companies is available.
  • Working close together makes communication easy and keeps everyone informed.
  • Short lines for quick decisions within the team.
  • Per discipline one speaker towards the supplier for streamlining the information and decision flow.

On 3 February 2006 the initial integrated project team came together for the Dordrecht kick-off-meeting. Drafting of concepts begun with boundary conditions and general targets:

  • “Safety above all” for personnel, environment and plant.
  • Quality is most important looking for long term operation, this includes the request for “proven technology only“ and the choice of conservative process parameters.
  • Planning and milestones must be maintained.
  • Budget must not be exceeded.
  • The line 5 in Dordrecht should have the same key data as the line 4 in Alkmaar.
  • Close down lines 2 and 3 after takeover of the line 5.
  • Compliance with the site boundaries.
  • No disturbance of ongoing operation of existing lines and neighbouring plants.
  • Local immission must not exceed the present values.
  • No increase of external noise values.
  • Open communication with authorities, neighbours and the public.


HVC took over the existing plant “Gevudo” end of 2005 knowing the lines 2 and 3 needed to be modified or replaced by a Waste to Energy solution in order to comply with the IPPC legislation. HVC decided to build a new WTE line 5, next to the existing lines 1 to 4. After run out of the line 5 guarantee period, lines 2 and 3 will be shut down.

The location of the former “Gevudo” plant was and still is complex and compact. The neighbouring companies are a Hospital Waste Incineration plant called ZAVIN, a Municipal Wastewater Treatment plant and a Wastewater Sludge Incineration plant. In the east an open landfill with rubble breaking facility is situated and the DuPont chemical plant in the west. The zoning scheme, made in 1962 and still valid, defines the site as recreational area and up to now the whole industrial estate was realised with exemptions to this scheme. On top of this, a Natura 2000 area called “De Biesbosch” is within 1000 meters.

HVC started intensive talks with all parties involved, varying from Provincial to Local Authorities, environmentalist groups and citizens living in close vicinity of the plant. HVC found out in which fields the challenges and opportunities were. In general, HVC made a statement: The plant needs to be modernised to meet the IPPC requirements and be brought to a higher capacity in order to keep the gate fee for the local citizens as low as possible. At the same time maintain the emissions after the expansion at the same level or less than the current situation to bring no extra negative effects for the near surroundings.

Totally open and honest discussions concerning environmental impact of this project resulted in a covenant with the environmentalist group in which detailed agreements were made in various fields. Once there was this covenant, the government was willing to speed up the permissions processes, knowing there was a wide public support for this project.

In order to fulfil al the requirements, HVC had to modify the remaining old installation to gain some “space” for line 5, I.e. reducing noise, emissions to air, transport movements and so on. The new plant itself has one of the lowest emissions to the air in Europe. During the permission procedure there where no objections and the whole procedure including environmental study, environmental permit and building permit was finished quickly.


Total budget of the project including preparation works:    200 mill.   EURO

Waste treatment capacity:          

  • Old situation, lines          1, 2, 3, 4           240,000    t/year
  • Current situation, lines   1, 2, 3, 4, 5       503,000    t/year
  • Final situation, lines        1,        4, 5        396,000    t/year                                                                                                   

Calculated efficiency, combination of lines 1, 4, 5: R1 efficiency status achieved

Planning, milestones:

  • Kick-off-meeting, integrated project team    3 Feb. 2006
  • Concept finished                                              June 2006
  • Application for permission                             4 May 2007
  • Signing the EPC contract with VMI               7 Dec. 2007
  • Permission granted                                  31 March 2008
  • Preparation works                       June 2007 to mid 2008
  • Start of site works                                            April 2008
  • First waste fire                                              21 July 2010


After an European negotiation procedure the consortia “VMI“ was selected to become the EPC Contractor. VMI consists of Visser&Smit Hanab for the civil part and civil related equipment and their daughter company VSH Boiler Engineering for the boiler part, Martin for the grate, Imtech Netherlands for the electrical and control scope, Imtech Germany for the thermal cycle (with a Siemens turbine) and LAB for the flue gas treatment section.


Odour problems were under discussion since years and the open unloading area for trucks was the main source of odour. To solve this problem, it was decided to build a closed tipping hall. All the primary combustion air is taken from the bunker, thus keeping low pressure there. The air flows via the tipping hall into the bunker and by this the odour problem is solved. The bunker capacity was already too small in the old situation. Based on the Alkmaar experience it was decided to build a new bunker “as big as possible“ by considering minimum distances to the boundaries and lowering the bunker into the ground by 9.4 meters. All the waste will be tipped into the new bunker via 5 bays. They are equipped with hydraulically driven covers. For feeding the old lines, a part of the waste will be moved by two (one in stand-by) new waste cranes from the new into the old bunker. A new crane operator cabin is located between old and new bunker. By two operator-chairs (one in stand-by) all the four cranes, old and new, can be operated.

  • Peak waste delivery                         300 t/h, during 5 h/day
  • Tipping hall, dimensions            40 x 39 m, L x W
  • New bunker, dimensions    24 x 33 x 24 m, L x W x H
  • Waste storage capacity              22,000 m/9,000 t, approx.
  • Grapple size                                       10 m3


The line 5 in Dordrecht is designed for MSW having a heating value in the range of 7.5 up to 15.5 MJ/kg. Currently, after years of slow increase, the heating value is about 10 MJ/kg. Based on this, it was decided not to apply a water-cooled grate system. A grate, cooled by air, was considered being more simple and reliable as the risk of leakages is avoided. Furthermore, in case of need, an air-cooled grate could later easily be changed into a water-cooled system, if the heating value raises or extraordinary wear of the air cooled grate bars occurs. The reverse-acting grate from the company Martin was finally chosen.

The Martin reverse-acting grate is inclined in the direction of transport and comprises several stair-like grate steps. The up-and-down motion against the grate inclination of every second step constantly mixes the red hot mass with the newly fed waste and facilitates uniform and stable operation of the combustion process. It is not necessary to cool the MARTIN reverse-acting grate with water, even when heating values are very high. Its unique drive concept constantly maintains a stable covering on the grate and consequently the grate elements are protected from excessive thermal loads.

  • Grate dimensions, approx.  10 x 8 m, W x L
  • Grate tracks                         5, each with 5 separate air zones


To avoid odour problems, the primary combustion air is taken from the bunker to provide a slight negative pressure in that area. For heating up the primary air to 140°C steam from the neighbouring plant ZAVIN will be used, as their supply covers our demand. There is no secondary air heater, even though the plants efficiency would become a bit higher, to avoid too hot furnace temperatures. Flue gas recirculation, taken from downstream the 3-field electrostatic filter at a temperature of about 270°C, ensures proper mixing within the combustion chamber, keeps the furnace temperature low and reduces the total amount of combustion air. The flue gas recirculation nozzles are equipped with online water cleaning to ensure their function throughout long operation periods.


Different design concepts were discussed. Finally, a 4 pass boiler having three empty vertical radiation passes a fourth horizontal pass with convection bundles plus an external economizer was selected. The economizer section is divided between an internal and an external part. Between both parts the electrostatic precipitator and the SCR plant are located. This decision - 4 pass/horizontal - was based on the following reasons:

  • The turn from the 2nd into the 3rd pass of the boiler provides some fly ash separation by centrifugal force. Downstream of this turn, fouling will be reduced.
  • The height of a boiler with 3 vertical radiation passes is less compared with a boiler with only one vertical pass. This leads to less visual impact of the total plant.
  • The horizontal 4th pass allows using pneumatically operated hammers for cleaning the bundles, so avoids soot blowers, consuming superheated, “expensive“ steam.
  • The horizontal 4th pass allows exchanging complete bundles via the roof of the boiler without major cutting works. In a vertical boiler, the bundles would be taken out via the boiler side walls, which need to be cut open for this purpose.
  • All boilers of HVC in Dordrecht and of the line 4 in Alkmaar are of the 4 pass design with a horizontal convection pass. The experience of HVC with regard to operation and especially maintenance with this type of boilers is good. The 3 older lines in Alkmaar have 2 passes, 1 vertical radiation plus 1 horizontal convective pass.

“Reliability comes first” is a general guideline within HVC. Contractual obligations must be fulfilled, waste needs to be incinerated. For this, reliable plants are essential. Within Alkmaar and Dordrecht all boilers produce steam of 40 bar and 400°C. These conservative parameters are well proven within the waste incineration sector. In the last years, higher steam parameters were discussed and also realised. In some cases this was due to connections with power stations or requests by external steam consumers. In other cases this was for increasing the thermal efficiency of the total plant. But higher parameters increase the risk of corrosion of boiler walls and especially superheater bundles. “No pilot plants - proven technology only“ is a second general HVC guideline. Still, most plants with higher steam parameters have a either a short track record or have to exchange bundles more often or spend high maintenance efforts in overlay welding. For the thermal cycle it is beneficial to combine the produced steam of all lines - 1, 4 and 5 - and to operate only one common turbine (see chapter thermal cycle). Considering all this factors, it was decided to go for conservative steam parameters - reliability first.

The refractory protects the evaporation walls of the combustion chamber against erosion and attack by corrosive flue gas elements and ensures the minimum combustion conditions required by law (850ºC, 2 seconds) even at part load all possible load. The main area of the 1stboiler pass is covered by nitride bonded SiC-tiles. HVC intends to operate line 5 for two years without interruption. But during such a long period, refractory damages can not be ruled out. The evaporation walls are basically low grade steel pipes. Failure of just one tile could cause damage to the pipes resulting in raptures. To avoid this risk, the whole 1st boiler pass, including the area underneath the refractory, is protected by inconel overlay welding. Then, having the walls protected, the purpose of the refractory tiles changes to keeping the temperature conditions only. As the refractory doesn’t need to be gas tight any more, a large area of the tiles - as from the burner level - is attached to the walls only with anchors. This will significantly reduce the time to exchange tiles after they are worn. Discussion with the refractory supplier finally lead to the agreement that online shower cleaning is allowed even in the 1st boiler pass.

If during two years of operation the fouling of the boiler exceeds our expectation - and experience will show - online shower cleaning devices could be installed later for cleaning all three radiation passes. The 4th pass may also be cleaned online with explosives.

  • Thermal capacity, design      75 MW, peaks up to 82.5
  • Feedwater temperature        140°C
  • Flue gas temperature            170°C
  • Steam temperature               400°C
  • Steam pressure, abs.              42 bar
  • Steam flow                              94 t/h


Since 2004 HVC gained good experience with the FGT of line 4 in Alkmaar. Said line has 75 MW thermal capacity and the waste is similar to the waste in Dordrecht. The Alkmaar line 4 FGT mainly consists of: Electrostatic precipitator (ESP, 3 fields) / selective catalytic reduction (SCR) / external economiser / spray dryer / 2nd ESP, 2 fields / two-stage scrubber / induced draught fan (ID-fan) / stack. For Dordrecht, a FGT with the same efficiency as in Alkmaar was a must. Any concept resulting in higher emissions than in Alkmaar would have resulted in strong public opposition against the line 5 project. It was also promised to the public, not to raise the total immission by line 5. This became possible by building a high efficient FGT and will finally be achieved by closing down the two old lines 2 and 3. The possibility of a dry FGT was discussed as well. But the requested emission values were not guaranteed by suppliers.

A major difference between the Alkmaar line 4 and the Dordrecht line 5 is the possibility to discharge effluent water to the Municipal Wastewater Treatment plant. Because of this, the spray dryer and the second ESP are not necessary. This is also space saving.

In Dordrecht NaOH was already in use as neutralisation agent. FGT processes using NaOH and limestone were economically compared. Even though the process based on NaOH resulted in marginal higher total cost, this chemical was chosen. This decision was based on the fact that NaOH was already in use in Dordrecht, the process is simple to handle and no space consuming reagent storage became necessary. 

Possible concepts have been discussed with potential plant suppliers during the conceptual phase. Based on evaluated investment and operational costs including consumables and residues the final concept became the following:

The ESP, arranged downstream of the internal economiser in line with the 4th boiler pass, protects the downstream SCR from dust deposits. Sedimentation of fly ash and dust from the gas stream out of the boiler would affect SCR efficiency, service interval and lifetime.

For NOX removal the selective catalytic reduction process, SCR, was chosen as a low figure of 70 mg NOX per m3 (dry, stp) must be achieved. The positioning of the SCR upstream of the external economiser is cost and energy effective as the flue gas does not need reheating up to adequate catalytic reaction temperatures. The entire SCR unit is fitted with a bypass, in order to avoid damage to catalyst elements due to overheating or in case of unacceptable gas conditions. The SCR also got an electrical heated circuit for heating up the catalyst prior to the start of the waste combustion. Downstream of the SCR there is the external economiser for cooling down the flue gas.

Prior to entering the quench the flue gas is cooled down in the gas/gas heat exchanger by already cold flue gas coming from the scrubbing process. This leads to a lower temperature in the washing process and results in an improved Hg recovery.

The quench serves for gas cooling and removal of HCl and HF acid gas components. The separate two-stage scrubber removes the remaining HCl and HF and additionally SO2. The first stage is operated in the acid range and without addition of reagent during normal operation, but with possibility to add reagent during peak loads. The second stage is operated at neutral condition. Reagent for neutralisation is prepared from caustic soda. Water excess of each stage is added to the cycle of the stage upstream. Wash water of the quench is discharged to the water treatment depending on the conductivity. Electro-Filtering-Modules (EFM, venturi-like wet electrostatic filter) provide the capture of the remaining fine particles to ensure the requested low emission limits.

After the scrubbing, the flue gas is reheated by the gas/gas heat exchanger. This reduces plume forming at the stack and improves the flue gas distribution in the atmosphere. Thanks to the gas/gas heat exchanger the downstream ID-fan runs in dry condition. Finally, a new flue, connected to the existing stack structure, releases the totally cleaned flue gas into the air.

Permission values             

Emission, mg/m3                 average period                    
(dry, 11% O
2, stp)     sample     daily      yearly            
Total dust                                   3            1.5
CO                                           30
TOC                                         10           10
X                                          20            5
HCl                                             8            3
HF                                              0.5         0.2
X                                        200         70 (monthly)
3                                            5
Hg                                0.01                   0,005
Sum Cd, Tl                   0.02
Sum heavy metals       0.05
Dioxines, Furanes        0.05 ng/m
3 TE, toxic equivalents


The existing turbine has a capacity of about 10 MW electric and was fed by steam from the boilers 1 and 4. The expanded steam was condensed by a wet cooling tower. The cooling tower did not comply with the state of the art, as defined by the IPP guideline. MP steam from ZAVIN was used for feedwater preheating.

Several scenarios of different thermal cycle concepts were prepared. Combinations of two turbines, existing plus new, wet and dry cooling, separate and combined thermal cycles. The use of water from the nearby river for direct cooling was considered as well. At the end of the conceptual phase, talks with a neighbouring chemical company started about the supply of medium pressure steam. These talks finally resulted in an intention declaration for future cooperation, but it was not possible to decide on final data in due time.

Further items considered in the concept were the following:

  • The existing turbine was due to a major maintenance.
  • Combination of all steam in one system makes future steam supply more reliable.
  • Maintenance costs for 1 turbine are lower compared to 2 turbines, old plus new.
  • Avoidance of dependencies from external companies. 

All evaluations resulted in the following thermal cycle concept:

  • Steam production of all boilers, 1, 4 and 5 is collected in one header.
  • All boilers have separate start up reducers.
  • One single new turbine.
  • Possibilities (extraction flanges) for future external steam use.
  • One new air cooled condenser.

Due to lack of space, the new turbine house is located in the former area of DRSH offices which had been relocated. For the same reason, the air cooled condenser is placed on the roof of the new turbine house.

  • HP steam from boiler 1 and 4        22      t/h, per boiler
  • HP steam from boiler 5                  94      t/h
  • Steam conditions                  400 / 40    °C / bar, abs.
  • MP steam from ZAVIN                     6      t/h, 12 bar sat. 
  • Turbine / Generator power             32      MW electric
  • Steam outlet pressure                      0.08 bar, abs.
  • Design ambient temperature          13     °C


The site plan shows the boundaries as well as the neighbouring plants. It is obvious that the site is very narrow. The photos give a good impression too. The bunker in the west of the site has been designed to achieve the maximum possible dimensions. The small free area between bunker and boundaries still allows for a street around the plant.

It was not possible to draft the main process building, with boiler and flue gas treatment, in a straight line. The turn within the plant, provides the minimum necessary length for the process equipment and allows the arrangement of one common stack structure. A passage underneath the boiler’s horizontal pass provides access to the existing plant.

Belt conveyors, arranged inside the northern conveyor bridge along the DRSH boundaries, transport the slag from the existing lines and from line 5 to the intermediate buffer.

The turbine house in the east is located on the former DRSH office location. The pipes, for all connections between boiler and turbine area, are on top op the conveyor bridge. Due to lack of space, the air-cooled condenser is located above the turbine house.


To make line 5 possible, some of the existing buildings were demolished or relocated. In 2007, during this phase of preparation works also the tie-in points to the existing plant were prepared. All these points were duly defined in an early phase and prepared in order to allow for later connection without stops of the existing lines. The preparation works were mainly the following:

  • New storage for slag, the temporary slag storage, the “TOS“.
  • Conveyor system with bridges to the new temporary slag storage.
  • Demolishing the existing slag storage.
  • New warehouse for all the parts on stock and demolishing the old one.
  • New pump room for the water-cooled condenser system.
  • Relocation the water-cooled condenser system.
  • Temporary updating the cooling unit with new droplet separators.
  • Relocation of existing silos for zeolite and fly ash.
  • Connecting the existing lines to the relocated silos via a new pipe bridge.
  • Demolishing old waste water collecting basins.
  • Demolishing the existing slag storage building.
  • Relocation of the DRSH office building.
  • Preparation of tie-in points to the existing lines.


HVC also decided to become owner of the landfill site and used a part of that area for the temporary site facilities as well as for the TOS. By becoming owner of that landfill, HVC also got the responsibility to cover the landfill according the current standards. Now, the temporary site facilities are almost gone and works on the landfill will be finished soon.

By protective coverage of transport belts and pipe bridges, building line 5 around that equipment became possible. Now, new concrete structures support the pipe bridge and the belts.

Equipment from the pre-mounting area was transported to the line 5 site via streets - partly - belonging to the neighbouring companies. Also some heavy lift cranes needed to be erected on the premises of neighbours. As from the early beginning of the line 5 project, talks were started with the neighbours to keep them informed and to agree about this temporary use of their sites. Having a good relationship with them since years, this use did not become a hinder. During the erection phase, regular meeting were held for information and agreement as early as possible.

As a conclusion, no stop of any existing plant became necessary during the building of line 5. HVC thanks the neighbouring companies for their close cooperation and willingness to accept work in close vicinity of their plants.


When writing this presentation in August 2010, the performance data have not yet officially been measured. Due to this, no data can be given in this document. Currently, all involved project partners from VMI strongly believe that line 5 will meet its contractual obligations. Based on the unofficially recorded data, HVC got no doubts in this statement. The latest information will be given in the verbal presentation during the ISWA conference.


The work in Dordrecht did not yet come to an end. Activities for further improvements are ongoing, of which the following are the more important:

  • HVC is obliged to demolish the old lines 2 and 3 within the next 2 years.
  • After this, the FGT lines A and B will work under part load conditions - below 50% of flue gas flow. For process improvement, the ducting of the FGT will be rearranged to treat all the flue gas in only one FGT.
  • The optimisation of the remaining FGT, A or B, is now under discussion. There are first concepts about additional heat exchangers to improve the plants efficiency.
  • with the neighbouring chemical factory about steam supply will be continued. Such steam supply would significantly increase the efficiency of the plant.


Good communication is essential for an effective project team, the trustful relationship with neighbours, citizens and authorities. An integrated project team, with members from the final client and enforced with external experts provide a good basis for effective project management and is able to handle such complex projects. By short communication and decision lines, concepts can be tailored, unforeseen events can be handled and further improvements can be considered during the execution of the project. Under difficult circumstances - no space, no extra emissions - but with joint efforts, it became possible to extend the Dordrecht plant by the line 5.

 © Buchhorn-Projects GmbH 2018