Biofuel Engine Research Facility

Overview

Research team

QUT

• Associate Professor Richard Brown
• Professor Doug Hargreaves
• Professor Zoran Ristovski

External collaborators

• The Dalby Town Council
  
• Peak 3 P/L
• SkillPro P/L
  

Organisational unit

Lead unit Science and Engineering Faculty Other units

• Science and Engineering Faculty

Details

Project background

There is an urgent global need to reduce the use of fossil fuels, yet demand for their use continues to grow (eg. the present demand for transport is predicted to double by 2050 (Dearing, 2000)). Compression ignition (diesel) engines dominate the heavy transport sector as well as stationary energy generation. They are the most efficient of all reciprocating internal combustion engines.

Alternatives fuels are currently readily available to reduce dependence fossil fuels. There are two fundamental approaches to the use of alternative fuels in conventional internal combustion engines:

1. fuel blends (such as E10 or B20 where fuels are physically mixed), and
2. dual fuel technologies (where the fuels are not mixed and introduced into the engine separately).

 

Dual-fuel technology has existed since the very beginnings of engine development with Rudolph Diesel (1901).

A method and arrangement of supplying a supplementary fuel (8) to a compression ignition internal combustion engine wherein an air supply (3) to the engine is first caused to pass through a natural vortex creator (1), and a supply of supplementary fuel (8) to the engine is supplied into a low pressure area the natural vortex (1) which provides a substantially constant ratio of supplementary fuel to main fuel through varying load conditions.

This technology involves the addition of an apparatus to the air intake of a standard compression ignition engine, requiring no modification of the engine, either hardware or software (Kruger 2006b).  This technology offers the option to reduce the use of fossil fuels (diesel), to increase the use of renewable fuels (methanol/ethanol), and to reduce the greenhouse emissions and fine particulate emissions from compression ignition engines, whether in transport or for stationary energy generation.

Project aims

Developing a fundamental understanding of the combustion of dual-fuel engines.

Investigating the fundamental processes underlying ultrafine particle formation in dual fuel engines.

Developing quantitative understanding of the influence of different engine parameters and  fuel/water ratio on (a) the performance and (b) emissions of a dual fuel engine.

Optimising dual fuel engine performance for methanol/ethanol blend fuels.

Achieving the project goals

To achieve this purpose, the group will undertake a two pronged investigation.

The fundamental operation of a dual fuel compression ignition engine

Compression ignition (Diesel) engines dominate the heavy transport sector as well as stationary energy generation. They are the most efficient of all reciprocating internal combustion engines. In a dual fuel engine the primary fuel is mixed with air in the intake manifold before it inducted into the cylinder. The mixture is then compressed in the cylinder and a pilot quantity of diesel fuel is injected to initiate combustion. The combustion processes of dual fuel engines lie between that of the compression ignition and spark ignition engines fuel results in further increases in ignition delay, compared to the pure diesel condition (Lee et al. 2003). Thus use of dual fuels enables a potentially improved ability to control the combustion characteristics and ultimately the performance of the compression ignition engine.

Characterisation of gaseous/particulate emissions from dual fuel compression ignition engines

While emissions from motor vehicles operating on any type of fuel contribute to elevated concentration of airborne pollutants, emissions from compression ignition engines are considered to be of particular significance. It has been reported that emission levels of particles could be significantly higher from compression ignition than from spark ignition engines, both in terms of mass and particle number. Although some work has been published on the emissions of regulated pollutants from dual fuel engines only one reference so far by this group (Ristovski et al 2006) has considered aspects of ultrafine particle emissions. This work has shown that ultrafine particle emissions are reduced in LPG/Diesel dual-fuel engines at the expense of increased emissions of unburned hydrocarbons and carbon monoxide. A reduction in the most important greenhouse gas, CO2, was also observed. Further work is needed in better understanding the fundamental processes underlying ultrafine particle formation in a complex system such as in dual fuel engines.

Project overview

The project will consist of five interlinked modules.

Developing a framework for dual fuel engine evaluation

Within this module we will develop a high level framework for quantitatively assessing dual fuel engine performance using ethanol substitution in a compression ignition engine as a pilot case. Use will be made of multivariate analysis to facilitate on the optimum engine operating parameters and dual fuel/water ratio that will minimise the multicriteria decision making harmful environmental emissions and maximize power output and performance. CI Brown has conducted a comparable comprehensive optimisation for outboard motor (Kelly et al, 2005) emissions to water (All CIs).

Thermodynamic modelling

This model will be used as a starting point for further model development. It has a full CFD solution for flow field coupled with a reduced chemistry module which is known to predict NOx emission well.

Laboratory evaluation, optimisation and performance and emission testing

This module will consist of several submodules with some running in parallel.

• Engine performance testing - Field testing using salt water to identify differences introduced by saltwater (will occur in year 3 of program).
• Laboratory fuel/water optimisation and performance testing - This testing will measure the performance of the engine over the full range of operating parameters with a range of dual fuel ratios and ethanol water content. The primary measurements will be of brake horsepower, peak and mean effective pressures (using an in head pressure transducer). The experimental matrix obtained will enable optimisation of the Clean Future Technology for retro fitting to existing compression ignition engines. (CIs Brown and Hargreaves).
• Emission testing - The main emission parameters measured can be classified into 2 groups: gaseous emissions and particulate emissions. The gasses measured will be: CO, CO2, NOx and unburned hydrocarbons (HCs).  Special care is taken that the dilution system mimics as close as possible 'real world' dilution conditions.
• Standard industry 200 hour test - The engine will initially be stripped down and the state of wear will examined using optical microscopes and surface roughness instrumentation in the Tribology Lab at QUT. Following the 200 hour test the procedure will be repeated to determine if the new technology results in any abnormal engine wear. An industry standard such as the D-13B Cummins ISM Lubricant Test or ASTM D 5290 test will be used. (CI Hargreaves).

Identifying optimal engine/fuel parameters

Engine operating conditions will be adjusted so an optimal engine performance is achieved without a significant increase in emissions of any of the measured parameters. If this is not possible different after-treatment technologies (i.e. oxidation catalyst) will be applied and their performance tested. Elimination of knock (preignition) will be included on the overall optimisation. The degree of knock depends on the period of ignition delay but there are in fact three types of knock that have been identified in dual fuel engines (Nwafor 2002).

Field testing

This module will be conducted with the facilitation of the industry partner who has a relationship with Dalby City Council as part of their program to become the most sustainable local government area in Australia, and transfer of knowledge to the industry to promote dual fuel technology to regulatory authorities to assist in the development of effective legislation to cover emissions and safety for dual fuel engine operation.

Partnerships

The Dalby Town Council

In its bid to enhance the economic and environmental sustainability of their region, the Dalby Town Council is committed to hosting the field trials. This has been negotiated on behalf of QUT by A/Prof David Hood. On behalf of the industry partner, Mr A Spock will facilitate this as part of the research in the latter part of the project including a regional analysis of diesel use and the potential for ethanol replacement, negotiation with local businesses and interested parties regarding participation with field trials in year 3 (including negotiations with Dalby BioRefinery for the supply of ethanol with controlled water content) and local facilitation of the field trials in Year 3.  The inkind contribution also includes the use of local compression ignition engines and fuel for the purpose of the trials.

QUT already has developed a deep relationship and a Memorandum of Understanding exists covering a range of issues around this project and other future development of this technology, most importantly covering intellectual property issues.  This project is expected to cement and further develop a long-term alliance between all organisations.

QUT also works with Peak 3 P/L and SkillPro P/L on this research project.

Publications and output

Research group publications

Surawski, N. C., Miljevic, B., Roberts, B. A., Modini, R. L., Situ, R., Brown, R. J., Bottle, S., Ristovski, Z. D., Particle emissions, volatility, and toxicity from an ethanol fumigated compression ignition engine, Environmental Science and Technology, accepted 5th Nov. 2009

Situ, R., Brown, R. J., Ristovski, Z. D., Kruger, U., Hargreaves, D., Analysis of dual fuel compression ignition (diesel) engine, In: The Seventh International Conference on Modeling and Diagnostics for Advanced Engine Systems, 28-31 July 2008, Sapporo, Japan

Ristovski, ZD, E.R. Jayaratne and L. Morawska (2006) “Particle Number and Regulated Gas Emissions from Heavy Duty Vehicles Operating on Diesel and LPG/Diesel Blend Fuels and the Influence of Oxidation Catalysts” ,  in press Particle & Particle Systems Characterization.

Ristovski, ZD, Jayaratne, E. R.; Lim, M.; Ayoko, G. A. and Morawska, L. (2006) “Influence of Diesel Fuel Sulfur on Nanoparticle Emissions from City Buses”, Environ. Sci. Technol., 2006; DOI: 10.1021/es050094i

Kruger, U. (2006) Clean Future - Technology

Kruger, U. (2006) “Compression Ignition Engines”.  United States Patent Office. No: 20040206329

Kelly, C.A., G.A. Ayoko, R.J. Brown and C.R. Swaroop (2005) “Underwater emissions from a two-stroke outboard engine: a comparison between an EAL and an equivalent mineral lubricant”. Materials & Design, 26: 609,617.

Ristovski, ZD, L. Morawska, N. Bofinger and J. Hitchins (1998) “Submicron and Supermicron Emission from Spark Ignition Vehicles”, Environment Science & Technology, 32(24), 3845