Logistics of Biomass Long Haul Transportation
Logistics of Biomass Long Haul Transportation
In the relentless drive to reduce greenhouse gas emissions from electricity generation the EU and the USA in particular are presently leading the field in the development of carbon neutral power plant replacing or augmenting existing fossil fuel stations. A wide range of fuels are available depending upon location including Agri-Biomass as by-products of agricultural operations but to fuel the rapid expansion of Biomass solutions in general only Wood Chip offers the required availability and sustainability of supply.
Wood chip is considered carbon neutral since the carbon released by burning in the kiln or power plant is balanced by the carbon absorbed by photosynthesis during the growing phase. The rapidly escalating use of wood chip in particular has opened opportunities for the expansion of sustainable forestry and even dedicated tracks of forest can be grown economically for this specific purpose. With over 100 new power plants planned for the USA and a similar number in Europe local supplies of wood chips cannot accommodate this expansion creating a demand for the bulk handling, shipment, import and large volume storage of this relatively low density material.
For example in the UK numerous very large power plants are currently under construction or planned which will demand around between 20 and 30 million tons of wood chip annually, far outstripping the present UK capacity to supply. By 2020 it is projected the EU will require a minimum of 60,000 million tons (120 million m3) of imported wood pellets to close the gap between projected demand and even an optimistic view of available European production. In terms of Woodchip this could equate to as much as 250 million m3 of raw wood chip after correcting for relative density and calorific value. If we consider a typical vessel of say 50,000 m3 this would represent some 5,000 Panamax vessel movements per year distributed around EU deep water ports demanding a considerable upgrading of existing infrastructure capacity.
These enormous quantities from sustainable resources can only be grown in southern latitudes where the climate is suited to fast growing species such as eucalyptus pine, willow and poplar. Wood chip from these sources will be transported by Panamax class vessels (up to 80,000 tons) and imported through major deep sea terminals requiring storage and onward transportation plus intake and storage facilities at the power plant, combined heat and power plant or process plant to accept economical volumes.
In reality the number of ship movements will probably be much greater since the number of European ports with sufficient depth of water and infrastructure to handle Panamax ships is relatively limited and as a result shippers will be limited to Handy or Handymax size vessels.
For many years now SCHADE, part of the AUMUND Group since 2001, has produced stacker and reclaimer solutions, mainly for the paper industry, handling large volumes of wood chip for pulp with the first delivery going back to 1978. Either in the form of longitudinal or circular pattern storages the chain scraper reclaimer by SCHADE offers automated stacking and reclaim of wood chip and other fuels.
The circular storage offers the benefit of least cost per ton stored and maximum stored volume per m2 of total footprint plus simplified enclosure using a light weight Geodesic dome. Enclosed storage eliminates any fugitive dust nuisance, windage losses and local pollution of water courses or aquifers by leaching of pollutants from the stored material with the obvious benefit of keeping the fuel dry...
By comparison longitudinal storage offers the benefit of easy and economical extension if, in the future, the process may be expanded in phases demanding additional storage capacity... In either case, controlled and automated storage facilities offer a safe and economical alternative to exposed ground stockpile with reduced cost of handling and also improved safety by significantly reducing fire risk, a major hazard in this industry.
With the possibility of imported Woodchip in particular from many sources and of many differing characteristics the blending of the various fuels will be critical in the same manner as for imported coals. For this purpose the SCHADE Bridge Reclaimer blending bed system, either longitudinal or circular in format, is an ideal solution particularly for larger volumes and continuous operation in major terminals or larger Biomass Power Plant. The largest Biomass power plants are presently planned up to 300 mW. on a single site and in terms of electrical output are compatible with many medium sized coal fired CHP plants and will demand a similar level of storage and blending capability but handling around double the volume of wood pellets or four times the volume of wood chip for the same steam output. This represents a considerable challenge both at the power plant and for the logistics chain between producer and consumer...
SCHADE delivered their first chain scraper reclaimer going back to the early 1950s and have developed their range of equipment significantly over the years covering applications in mining preparation plants, coal fired power plant and in the chemical and cement industries where there are large volumes of solid fuels and raw materials to store and reclaim.
In recent years SCHADE have delivered some 50 circular storages to Chinese utilities in particular serving coal imports to power plant with capacities to 180,000 tons live storage and handling rates to 4,000 tons per hour. Whilst this is far away from the handling rates required in a typical wood chip power plant, normally less that 100 tons per hour, there remains the need to discharge large seagoing vessels rapidly to reduce demurrage costs and then reclaim rapidly to transfer the wood chip to trains or barges for inland distribution. To cover both the power plant and the sea terminal SCHADE have a standardised range of designs that may be tailored to suit the specific combination of stacking and reclaim rates required for any application.
To ship the Wood Chip requires terminal facilities including Shiploaders such as the mobile equipment offered by B&W Mechanical Handling Limited of the UK (Aumund Group since 2002) based on their standard range of cambered boom machines with integrated trimming and powered travel facilities. In the project illustrated, at the Port of Panama in Florida, the Shiploader is linked to the on-port Wood Chip storage facility by a radial and telescopic conveyor supplied in the Shiploader package and integrated to the overall control system. In this first example the scheme enjoys the benefit of local storage but no fixed equipment could be installed on the actual berth. By using the radial and telescopic Link Conveyor concept to join the fixed storage to the Mobile Shiploader the entire vessel could be trimmed, avoiding expensive vessel movement during the loading operation. The radial and telescopic functions allow easy alignment between the units avoiding spillage and ensuring proper functioning of the dust control systems. Using the Shiploader powered travel system allows the unit to be easily moved off the berth, under its own power, leaving the area free of any obstruction for the import or export of other cargoes or container traffic.
A second similar set of equipment is presently under constriction for the port of Eastport in Maine USA comprising a mobile Shiploader with multiple mobile link conveyors to move Wood Chip from a new 40,000 ton capacity storage facility, adjacent to the berth, out to the Shiploader. For hold trimming and rapid movement along the berth between holds the Shiploader is equipped with the latest B&W In-Line, Parallel and Radial powered travel system. As with the Port of Panama this Shiploader is fully autonomous and may be moved off the berth during the handling of other cargoes.
Mobile Shiploaders are extremely flexible offering the shipper high handling rates and environmental performance but avoiding the need for expensive and permanent civil works and dedicated port infrastructure, and, very often much simplifying the required permitting. Mobile equipment may be fast tracked and the facility put into operation in between 6 to 9 months from the order placement. Furthermore the Mobile Shiploader is not necessarily dedicated to a single bulk cargo and the same equipment may be used for a wide range of bulk materials with minimum or no modification whatsoever.
Similarly the equipment may be easily moved between berths in a large port or even from one port complex to another perhaps even in a different country if trading patterns change. This flexibility in application and operation is very attractive for investors, particularly for short term contracts or in regions of political instability as, in the event the export contract is terminated for any reason, the equipment retains intrinsic value and may be moved on for another purpose altogether.
Of course in most projects there is no luxury of on-port storage and in this situation the B&W mobile Shiploader is supplied with integrated SamsonTM feeders allowing material delivery by tipping truck which is also an option for wood chip providing direct export from truck to ship without double handling. Generally two SamsonTM units are supplied, one each side of the Shiploader boom, allowing two trucks to discharge simultaneously for maximum performance. In this manner spot or peak loading rates of up to 1,500 m3 per hour and an average “through the ship” rate of 1,000 m3 per hour can be comfortably achieved with good vehicle management.
This level of performance can only be achieved by integrating the core features required of a high performance Shiploader into a single autonomous machine able to move quickly, as an integrated unit, along the vessel and within each hold for effective ship trimming. In the included illustrations the Shiploader is shown with a Cascade trimming chute including radial distributor plus full enclosures for the feeder units and conveyor boom with reverse jet dust filters at the transfer points to minimise this risk of fugitive dust causing local environmental pollution.
Where dust generation is not an issue, handling clean chip, the “Jet-Slinger” manufactured by B&W is an interesting option since it provides for easy hold trimming from a single machine position. The Jet-Slinger has a trajectory of 15 to 20 metres allowing the cargo to be delivered to any point in the hold and under the decks to maximise the stowage of this very light material. Of course the same equipment may be used in a fixed installation for stockpiling, combined with a stacking conveyor the Jet-Slinger will generate a huge radial stockpile at rates to 3,000 m3 per hour or 1,000 tons per hour.
By incorporating all of these facilities into a single mobile unit the exporter may enjoy the performance and environmental benefits of a dedicated fixed installation but with the flexibility and economy of a fully portable machine operating independent of any fixed port infrastructure.
Biomass Import by Ship or Barge:
Import from deep sea vessels requires substantial handling facilities at the port of entry which would generally include grab cranes discharging to hoppers before transfer to storage either by conveyor or trucks operating on a merry-go-round basis. To control the dust generated from such operations B&W have developed a range of Eco-Hoppers with integrated dust control and feeder equipment. Particularly for Wood Chip the combination of Eco-Hopper and SamsonTM feeder provides for steep hopper sides to prevent bridging and blockage plus reduced free fall to limit the velocity of displaced air thereby minimising the size of dust filters necessary to control any local pollution.
The Eco-Hopper matched with a Mobile Harbour Crane as shown in the included illustration, offers significant benefits for Biomass fuel imports in that no dedicated port infrastructure is required and the equipment may be simply travelled to a storage area when not in use thus freeing the berth of other port operations. With truck haulage from the berth to a local storage facility close to the port the operator has maximum flexibility. As with the mobile Shiploaders at Panama (illustrated herein) and Eastport mobile Link Conveyors may be employed to transfer Wood Chip from the Eco-Hopper to a fixed conveyor and storage system located adjacent to the berth, in this manner the operator has the benefit of an on-port storage facility with the flexibility of clearing the berth when not importing Wood Chip.
Of course in an ideal world the Biomass would be imported through a dedicated facility with on-port storage and conveyor transfer... An example of such a dedicated import facility is illustrated herein showing a specially constructed finger jetty where geared vessels discharge using their on-board grab cranes to a pair of rail mounted Eco-Hoppers. From the rail mounted units the bulk cargo is conveyed inland to a dedicated enclosed storage facility from where it may be distributed by truck, train or barge or used locally if the power plant is close to the port.
Regardless of the location of the storage it is very likely the final leg of the logistics chain from source to power plant will involve the use of road trucks. With any type of truck the SamsonTM provides an effective solution for the intake of Wood Chip at the power plant as it does at the Shiploader.
Typically the Samson provides a surface mounted intake facility incorporating a buffer storage and fast intake rate to release the truck quickly combined with a controlled discharge rate to match the ongoing conveyor systems. For dedicated Biomass power plant the fuel may be conveyed from the Samson to SCHADE storage but for existing coal fired plant the Biomass fuel may be bled onto the coal intake belts in a typical ratio of up to 10%.
Biomass Import by Road and Rail:
The SamsonTM feeder associated with the mobile Shiploader is also supplied as an independent fixed or mobile unit for the intake of Biomass direct from tipping or walking-floor road trucks. Similarly this equipment may be supplied in a different guise for installation under rail for the intake of bulk material from hopper bottom rail wagons. The wide belt feature of the SamsonTM is the key benefit in any application of this type permitting easy surface mounting for truck delivery with no risk of bridging or blockage handling wet and sticky Agri-Biomass for example in any implementation either above or below ground.
However, to maximise the efficiency and economy of railborne shipment woodchip is often conveyed in flat bottom or Gondola style unit trains or even random wagons which are discharged through a Wagon Tippler as illustrated herein.
This device inverts the rail wagon such that the Biomass material falls freely into a hopper beneath the rail track, various designs are provided by SCHADE based on the “O” Frame as shown in a bulk terminal in Poland or the “C” frame as illustrated with Wagon Charger allowing automated operation. Wagon Chargers and Indexers are available to fully automate the handling of unit trains allowing up to 60 wagons per hour to be discharge with a “Tandem Tippler” that is a Tippler that can discharge two wagons simultaneously.
Combining the flexibility of mobile harbour solutions for the logistics operation between producer and power plant with the permanence and assured continuous reliability of the SamsonTM intake and SCHADE wagon unloaders and storage systems at the power plant or terminal the AUMUND Group are able to offer tailored equipment packages appropriate for every application and combination of facilities.