Combustion of fuel blends containing digestate pyrolysis oil in a multi-cylinder compression ignition engine

FUEL

卷:171

Article

Hossain, A. K.¹  Serrano, C.²  Brammer, J. B.²  Omran, A.²  Ahmed, F.¹  Smith, D. I.¹  Davies, P. A.¹ 

[1] Aston Univ, Sch Engn & Appl Sci, Sustainable Environm Res Grp, Birmingham B4 7ET, W Midlands, England

[2] Aston Univ, European Bioenergy Res Inst, Sch Engn & Appl Sci, Birmingham B4 7ET, W Midlands, England

关键词: CI engine;    Anaerobic digestion;    Intermediate pyrolysis;    Digestate;    Combustion;    Emission;   

DOI  :  10.1016/j.fuel.2015.12.012

来源: Elsevier

【 摘 要 】

Digestate from the anaerobic digestion conversion process is widely used as a farm land fertiliser. This study proposes an alternative use as a source of energy. Dried digestate was pyrolysed and the resulting oil was blended with waste cooking oil and butanol (10, 20 and 30 vol.%). The physical and chemical properties of the pyrolysis oil blends were measured and compared with pure fossil diesel and waste cooking oil. The blends were tested in a multi-cylinder indirect injection compression ignition engine. Engine combustion, exhaust gas emissions and performance parameters were measured and compared with pure fossil diesel operation. The ASTM copper corrosion values for 20% and 30% pyrolysis blends were 2c, compared to 1b for fossil diesel. The kinematic viscosities of the blends at 40 degrees C were 5-7 times higher than that of fossil diesel. Digested pyrolysis oil blends produced lower in-cylinder peak pressures than fossil diesel and waste cooking oil operation. The maximum heat release rates of the blends were approximately 8% higher than with fossil diesel. The ignition delay periods of the blends were higher; pyrolysis oil blends started to combust late and once combustion started burnt quicker than fossil diesel. The total burning duration of the 20% and 30% blends were decreased by 12% and 3% compared to fossil diesel. At full engine load, the brake thermal efficiencies of the blends were decreased by about 3-7% when compared to fossil diesel. The pyrolysis blends gave lower smoke levels; at full engine load, smoke level of the 20% blend was 44% lower than fossil diesel. In comparison to fossil diesel and at full load, the brake specific fuel consumption (wt.) of the 30% and 20% blends were approximately 32% and 15% higher. At full engine load, the CO emission of the 20% and 30% blends were decreased by 39% and 66% with respect to the fossil diesel. Blends CO2 emissions were similar to that of fossil diesel; at full engine load, 30% blend produced approximately 5% higher CO2 emission than fossil diesel. The study concludes that on the basis of short term engine experiment up to 30% blend of pyrolysis oil from digestate of arable crops can be used in a compression ignition engine. (C) 2015 Elsevier Ltd. All rights reserved.

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