A new biofuel from wood waste for sustainable transportation

Most biofuels in use today are obtained from feedstock that can also be used for food-grade agriculture, creating an ever growing ethical problem. In the search for so-called second-generation (2G) sustainable transportation fuels that are not in competition with food production, a woody biomass-based biofuel production technique is currently under development. The process development is integrated in the Belgian federal government funded Ad-Libio project and its process outcome is mainly consisting of hydrocarbons containing five to six carbon atoms, that differ significantly from gasoline or diesel fuel. Since the Ad-Libio fuel composition can be changed, a fuel blend calculator with integrated fuel database has been developed. This tool enables fast fuel property calculations, so quick decisions can be made on the fuel production process outcome. After a first screening with the calculator, a fuel research engine was used to evaluate the combustion properties of the promising fuel blends, enabling quick in-house experimental verification of the calculations. The ultimate goal is to produce a drop-in fuel, made out of wood waste, that can be fully interchanged with the gasoline fuels in use today, enabling sustainable transportation for modern and legacy combustion engine-powered vehicles

Investigation of naphtha-type biofuel from a novel refinery process

In order to reduce the carbon footprint of the Internal Combustion Engine (ICE), biofuels have been in use for a number of years. One of the problems with first-generation (1G) biofuels however is their competition with food production. In search of second-generation (2G) biofuels, that are not in competition with food agriculture, a novel biorefinery process has been developed to produce biofuel from woody biomass sources. This novel technique, part of the Belgian federal government funded Ad-Libio project, uses a catalytic process that operates at low temperature and is able to convert 2G feedstock into a stable light naphtha. The bulk of the yield consists out of hydrocarbons containing five to six carbon atoms, along with a fraction of oxygenates and aromatics. The oxygen content and the aromaticity of the hydrocarbons can be varied, both of which have a significant influence on the fuel’s combustion and emission characteristics when used in Internal Combustion Engines. When used as a blend component, this novel 2G biofuel could help increase the sustainability of vehicle fuels. But, while exhaustive experimental and, although lesser in number, numerical investigations on combustion behavior have been performed for 1G biofuels, less information is available for 2G biofuels and especially this novel naphtha-like fuel. An extensive fuel compound property database and a fuel blend property calculator is readily available in literature, but their validity has not been tested for the novel 2G biofuel components. This article provides a first screening of the usability of these light naphtha components as blend components for gasoline and diesel drop-in fuels, by means of a freely available fuel component database and fuel blend calculator, concluding with an initial assessment of achievable blends and pointing out where further work is needed

Methanol Evaporation in an Engine Intake Runner under Various Conditions

Methanol has recently emerged as a promising fuel for internal combustion engines due to its multiple carbon-neutral production routes and advantageous properties when combusting. Methanol is intrinsically more suitable for spark-ignition (SI) operation thanks to its high octane number, but its potential in heavy-duty applications also encourages engine manufacturers in this field to retrofit their existing compression-ignition products into methanol/diesel dual-fuel (DF) operation. For both SI operation and DF operation, injecting methanol into the engine’s intake path at low pressure is a relatively simple and robust method to introduce methanol into the cylinders. However, the much higher heat of vaporization (HoV) of methanol compared to conventional SI fuels like gasoline can be a double-edged sword. On the one hand, its enhanced cooling effect may increase volumetric efficiency and lower knock tendency, on the other hand, the extra heat it absorbs when evaporating may pose cold-start issues and lead to unstable combustion. To further investigate, a special experimental setup was built. Multiple thermocouples were mounted on an intake runner where the fuel is injected to monitor the temperature changes of the flow before and after injection. The temperature of the runner itself was also monitored to assess the heat taken from the metal wall of the runner pipe. Different air-fuel ratios, air temperatures, air pressures, and air mass flow rates were tested to evaluate their influences on methanol evaporation. The test results were then compared with conventional gasoline operation. It was found that the temperature drop after fuel injection is strongly dependent on the flow temperature, and that the evaporated fraction of methanol was far lower than that of gasoline even with higher flow temperature. Their very different evaporation behaviors are thoroughly discussed

Development of a novel drop-in naphthenic spark ignition biofuel by means of a fuel blend calculator and a simplified octane number verification method

In the search for sustainable transportation fuels that are not in competition with food production, considerable efforts are made in the development of so-called second-generation (2G) biofuels. This paper looks into the results of a novel 2G biofuel production technique that is based on a catalytic process that operates at low temperature and that converts woody biomass feedstock into a stable light naphtha. The process development is integrated in the Belgian federal government funded Ad-Libio project and the process outcome is mainly consisting of hydrocarbons containing five to six carbon atoms. Their composition can be altered, resulting in a large amount of different possible fuel blends. The ultimate goal is to produce a drop-in fuel that can be fully interchanged with the gasoline fuels in use today. This is a challenge, since the Ad-Libio fuel components differ significantly from gasoline fuel components. For an initial assessment of the suitability of a novel blend, a fuel blend calculator with integrated fuel database has been developed. This tool enables fast SI fuel property calculations, so quick decisions can be made on the fuel production process outcome. The blend’s research octane number (RON) is one of the important properties to be checked for a blend’s suitability as a spark ignition engine fuel. After a first screening with the calculator, the average peak pressure pulsation (APPP) method was used on a CFR engine to evaluate the octane number of the blends, enabling quick in-house experimental octane number verification of the calculations before the blends can ultimately be sent to an ASTM-compliant testing laboratory. This article describes the calculation and verification methodology of the first blends that have been used to design a new and fully sustainable SI engine fuel blend, ultimately aiming for a sustainable second-generation drop-in gasoline fuel replacement