Evaluation of pure rapeseed oil as a renewable fuel for agricultural machinery based on emission characteristics and long-term operation behaviour of a fleet of 18 tractors

Abstract

The usage of locally produced pure rapeseed oil fuel (R100) according to fuel standard DIN 51605 in agricultural machinery can contribute to protecting the climate, water, and soil. Besides economic aspects, uncertainties concerning the long-term operation reliability and limited exhaust emissions of R100-operated agricultural machinery are hindering market entry. Thus, the aim of this research is to evaluate field experiences, such as downtimes and repairs, engine oil quality, and cold start behaviour, over a total period of more than 50,000 operation hours with 18 tractors. The tested tractors range from European Union exhaust gas stages I to IV and were configured for the use of R100. Additionally, performance, nitrogen oxides, and particulate matter were measured on a tractor test stand. The tractors demonstrated their full functionality under usual Bavarian farm conditions in daily use. Within the tractor fleet, no serious engine damage was observed, while minor malfunctions and necessary repairs occurred just occasionally. The operational reliability of the tested rapeseed-oil-fuelled tractors seemed to be comparable to that of diesel-fuelled tractors. The results of recurrent power and fuel consumption measurements gave no indication of engine deterioration. Furthermore, measurements proved that differences in exhaust gas emissions between R100 and diesel operation were marginal. Tractor models with exhaust gas after treatment systems were characterized by low emissions of nitrogen oxides and particulate matter in particular. With the 18 tractors running on R100, about 220 tonnes of CO2eq per year were saved on average from 2015 to 2017. It can be concluded that the usage of pure rapeseed oil fuel (R100) in compatible agricultural machinery is an implementable alternative to diesel fuel and can make an important contribution to reducing greenhouse gas emissions in agriculture. Nevertheless, there are some challenges to solve, particularly for modern agricultural machines with engines with exhaust gas aftertreatment systems.

A Technical Review on Performance and Emission Characteristics of Diesel Engine Fueled with Straight Vegetable Oil

“…The investigators [77][78][79][80][81][82][83][84][85][86] noticed elevated EGT with different loading conditions and operational hours. All investigator [77][78][79][80][81][82][83][84][85][86] analyzed the affecting variables and after-effects of SVOs on lubricating oil during the long-term test of 250 to 50000 cumulative hours (refer Table 7). Almutairi et al 80 performed 300 hours of durability tests on a 1C, DE to study the effects of preheated crude Jatropha oil (90°C) as engine fuel.…”

“…In the same context, Sahu et al 76 reviewed the engine's output adopting a variable compression ratio DI DE engine using SVO for shortrun operations. However, some researchers [77][78][79][80][81][82][83][84][85][86] performed their investigation for short-run and long-run operation hours using SVOs. Acharya et al 87 also found that KO (PH) produces higher CO, HC lower CO2 at low load, and lower NOx at all loading conditions.…”

“…However, problems arise with the DE running for long-duration operations with unprocessed, unblended SVO. [77][78][79][80][81][82][83][84][85][86] Table 7 can be referred to for summarized results of investigators using SVOs during long operations.…”

An Experimental Study on the Injection Characteristics and the Macroscopic Spray Characteristics of Rapeseed Oil-Diesel Fuel Blends

“…Ettl et al [8] evaluated rapeseed oil (R100) as a renewable fuel for agricultural machinery based on long-term operation behavior and emissions of a fleet of tractors over more than 50,000 operation hours under Bavarian farm conditions. The tractors demonstrated their full functionality, and no serious engine failures were observed, while minor malfunctions and repairs occurred just occasionally.…”

The experimental verification of the multi-fuel IC engine concept with the use of jet propellant-8 (JP-8) and its blends with pure rapeseed oil

“…Pure rapeseed oil as fuel for CI engines was tested and gave some positive results, especially in agriculture. The tests showed that modified tractor engines reliable operation fueled with it is possible and provide some benefits [12,13]. Rapeseed oil is approximately a C57 compound with one mole having an atomic mass of 890 [14].…”