PELLETS Compact pelletising requires no building The modular compact design is in response to demands from pellet manufacturers for a solution with a small footprint that can reduce capital costs for buildings while increasing mobility for best onsite location. According to Rudnick & Enners achievable production capacities are available from 2 to 4 tonnes per hour with 8 tonnes or more feasible by using modular designed extensions. NEWP acquires Allegheny Pellet Bioenergy International No 78, 2-2015 33 RUDNICK & ENNERS GMBH, a German company specialised in the development and manufacturer of components and turnkey systems for pellet plants, sawmill equipment and wood processing solutions has announced the successful installation of its containerised “compact pelletising” wood pellet plant solution for an Austrian sawmill client. Site and size constraints The client processes locally sourced spruce and wanted to use wood residues from its sawmill operations, but had only a small space available for pellet production and storage. Furthermore pellet production capacity was limited to a maximun of 1 tonne per hour. Rudnick & Enners was awarded the contract to supply its compact pellet plant concept. The scope of the turnkey order included complete engineering, final layout, supply of full machinery and full commissioning and operational staff training. A key feature is that the pellet plant does not require a building to house the plant or even a concrete foundation as a flat surface will suffice. It is entirely modular with all the equipment fitted into 20 ft containers that are connected to each other and form the housing for the plant. Only external utility connections are needed. This approach reduces capital costs and the installa- tion footprint, lower energy costs due to short conveying distances while increasing mobility. Single belt dryer A wheeled loader loads wet sawdust and woodchips produced by the sawmill into a buffer bin designed in 20 ft container and fitted with a hydraulic push floor. A 4 kW power supply guarantees trouble-free operation 24 hours per day. An integrated chain conveyor transfers wet feedstock from the buffer bin to a rotating screener to separate fine and coarse fractions in order to feed homogenous sized material to a low temperature single belt dryer. Developed by SwissCombi in collaboration with Rudnick & Enners the 2 m wide belt dryer is equipped with a fine mesh polyester belt that keeps dust emissions under 8 mg/Nm3. This eliminates the need for additional dust separation equipment. Complete with a fan plus corresponding hot water-to-air heat exchangers, the incoming material is dried from about 50 percent moisture content down to around 10 percent on exiting the dryer. With available hot water of about 100° C feeding temperature a process drying temperature of about 90° C can be achieved and a return flow temperature of about 80° C. The homogenously dried sawdust or wood chips are transferred upwards by bucket elevator and then by a tube belt conveyor into a buffer storage bin on top. Ultrasonic sensors monitor and regulate the product level in the buffer bin. A screw conveyer feeds a 75 kW direct drive hammer mill that mills the material into a 0–10 mm size fraction. A starch dosing unit, a cyclone followed by a rotary valve and humidity mixer are stations that the material passes en route to the next process stage. Before pelletising, the material rests in a maturity bunker to ensure homogenous moisture content of 10-12 percent. A mixer with water injection is installed on top of a 75 kW CPM pellet press. The entire process operation and control is done from a single cabinet utilising its own PLC. Local markets first The pellets are transferred to a 275 m3 storage silo which is fitted with level sensors. When unloading, a chain trough conveyor followed by weighing cells take the pellets to a rotating screen to separate fines and broken pellets from the final product. The pellets are ENplus certified and are sold in bulk via distributors as well as to the local market. Text: Alan Sherrard Photo: courtesy Rudnick & Enners BI78/4760/AS US pellet producer Rentech, Inc., has announced that its subsidiary, New England Wood Pellet (NEWP), has acquired the assets of Allegheny Pellet Corporation. The acquisition expands NEWP’s market position as the largest producer of wood pellets for the US heating market. – Consistent with the growth strategy we outlined when we acquired NEWP, we are pleased to expand NEWP’s platform with the acquisition of Allegheny, said Sean Ebnet, Senior VP of Rentech’s wood fibre business. Using local sawmill residues Allegheny’s pellet plant in Youngsville, Pennsylvania has been operating since 1993. Pellet sales have been through big box stores, specialty retailers and bulk sales channels. Allegheny will be fully integrated into NEWP and will operate as its fourth pellet plant. NEWP intends to invest in environmental and safety improvements at the plant and expand its annual production from approximately 36,000 US tons under a four-day workweek to approximately 50,000 US tons under a seven-day workweek. The additional production will help meet strong demand for pellets in Pennsylvania and New York. BI78/4799/AS International technology group Andritz has received an order from Enviva, one of the leading producers of wood pellets, to supply woodyard equipment, engineering, and field services for two pellet plants, each with a capacity of 500 000 tonnes per annum, to be built in North Carolina, USA. Andritz will supply several innovative products for manufacturing high-quality mini-chips from round timber at high production rates. At the heart of the wood processing line is the HHQ30 chipper with TurnKnife system from Andritz Iggesund Tools. According to Andritz this combination of chipper and knife system produces the highest percentage of accept chips and the thinnest chip on the market. BI78/4802/AS Andritz to supply woodyard equipment to Enviva
Bioenergy no 2 - March 2015
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