Reduction in Operating Costs and Environmental Impact Consisting in the Modernization of the Low-Power Cylindrical Wood Chipper Power Unit by Using Alternative Fuel

Abstract

Alternative fuel within the meaning of Directive 2014/94/EU is, among others, LPG (liquefied petroleum gas), characterized by a lower purchase cost and lower emissions of toxic exhaust compounds in comparison to the combustion of classic gasoline. In wood chippers, intended for chopping branches, with low-power internal combustion engines that meet the emission standards in force in 2019 in the European Union, in accordance with Regulation 2016/1628/EU, carburetor fuel supply systems are commonly used. Innovative trends in the development of these drives are: electronic fuel injection, systems supporting the adaptation of the working elements to the conditions of use and the use of alternative fuels. The first two solutions significantly affect the cost of purchasing a power unit or modernizing it. The authors of this article indicate, as a beneficial alternative, a cheap (EUR 105) possibility of modernizing the carburetor fuel supply system. It is based on a modification that will allow for the use of LPG instead of gasoline to drive the working system of the wood chipper. This article presents the results of tests on the fuel consumption of a wood chipper powered with gasoline (3.04 L h−1) and LPG (3.65 L h−1) during continuous chipping. The cost of an hour of chipping related to fuel consumption was determined, which was equal to 3.89 € h−1 while using gasoline, and 2.19 € h−1 when using LPG. The mass flow rate (0.66 t h−1) and volumetric flow rate (3.5 m3 h−1) of a wood chipper powered by a low-power (9.5 kW) internal combustion engine with spark ignition were determined. In addition, we determined the cost of producing 1 m3 of biomass from chipping freshly cut oak branches (Quercus robur L. Sp. Pl. 996 1753) with a maximum diameter of 80 mm and a humidity of 25%. The branches were selected earlier in such a way that their dimensions as as similar as possible. This amounted to EUR 1.11 for a gasoline-powered drive and EUR 0.63 for a LPG powered one. The benefits of using an alternative fuel supply system, the installation of which increases the cost of the machine by 8.4%, have been confirmed.