UKERC EDC: Publications

DTI_BW2008080000_file18124.pdf

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Abstract:

This document is a report for the project titled 'Harvester Development for New High Yielding SRC Crops and Markets'.

The objectives of this work are:

Higher Yielding Crops: To develop harvester drive chain and feeding systems to cope with larger higher yielding modern crops.

Harvesting Cycles: To assess by harvesting sites of different ages of the most recently planted varieties the most economic harvesting cycle for SRC crops. Focus on maximising machinery and crop output thus minimising delivered cost per tonne whilst still maximising grower return.

Co-firing fuel production: To produce in one pass fuel that can be directly fired with coal in pulverised fuel systems.

Gasification fuel production: To produce in one pass large grade fuel suitable for gasification.

Overall: To achieve a harvesting cost of ANY fuel specification of £10-£11/oven dried tonne (odt).

The project has consisted of a number of engineering and field trials. Key amongst these has been development of robust harvester drive mechanisms that are able to withstand the larger crops that the UK now produces and the modification of the chipping system to allow different fuels specifications to be produced. Throughout a method of research into the specific area has been followed by engineering adaptations that have then been field tested and reviewed. Clearly with cost objectives, trials involving the assessment of cost of production through workrate and expense have been necessary and these have been incorporated. Finally consolidation of the knowledge and results gained has been made and incorporated in guidance notes and recommendations for further work.

The conclusions of this project are:

Harvesting of SRC crops using the technology developed as part of this project is technically robust.

Fuel specification can be altered to suit the requirements of different markets and can be produced economically.

In production of fuel for co-firing in large coal combustion plant using pulverised fuel there are a series of complex economics involving secondary processing and haulage that will dictate the most cost effective method of delivering product.

As the scale of market grows the ability to harvest SRC over the majority of the year is essential to the economic viability of the crop as a fuel source in order to meet the desired tonnages of end users and to maintain a continual level of supply on a year round basis.

Harvesting of crops that have grown beyond the normal scale is extremely costly (may be over three times the normal cost at £35/odt) and not recommended.

This report contains an executive summary, and is divided into the following sections:

Manufacture and Installation of New Components for Large Crop Harvesting
Activity Summary and Results of Initial Field Testing on SRC Crops
Activity Summary and Results of Field Testing and Yields of Different Ages of Crops
Remanufacture of Chipping Drum and Production of Market Chip Samples
Economic Analysis and Harvesting Guidance
Conclusions and Recommendations for Further Work