Assessment of wild cherry (Prunus avium L.) chopping and utilization for biofuel and investigation of chaff properties

Abstract

Lithuania medium rotation plant plantations are started to breed relatively recently, so reliable data on suitability of these crops for biofuel production cannot be found. Studies have established wild cherry chop physical properties. 8-16 mm particles make the main, chopped by a drum chopper, wood fraction; on the average, it makes 84 % of total chop mass. Experimental results show that humidity has greater impact on the wild cherry wood chop collapse angle: with decrease of the moisture content the collapse angle increased from 65 ± 1.0 to 82 ± 2.0 degrees, when humidity is lower, the influence on the natural slope angle is lower. It fell accordingly from 36 ± 1.0 to 42 ± 2.0 degrees. Chop bulk density variation with the change of wood humidity was determined; with increase of humidity of wild cherry from 35.1 ± 1.0 to 6.4 ± 0.1 % the density varied from 342.67 ± 4.81 to 236.67 ± 2.6 kg·m-3. Wild cherry ash content is low, and it does not increase 1.87 ± 0.18 %, and the calorific value of wood reached 18.70 ± 0.36 MJ·kg-1; it is close to the standard accepted in Lithuania – birch caloricity. The determined elemental composition of wild cherry wood showed that carbon (C) quantity reached 49.16 ± 1.10 %, nitrogen (N) quantity does not increase 0.23 ± 0.10 %, and quantity of sulphur (S) does not exceed 0.01 %. Having determined and evaluated the main criteria for biofuel (finesse of chop, calorific value, ash content, elemental composition), it is possible to state that wild cherry wood fully complies for production of qualitative biofuel. However, from the economic point of view, it is purposeful to use only branches and tops of wild cherry trees for biofuel, and valuable part of wood may be used for production of furniture or in other industry branches.