This research investigates ethanol production from waste lignocellulosic material (sugarcane bagasse). The bagasse was first pretreated using chemicals and ultrasound techniques. These pretreatment techniques were applied separately and combined. The pretreated bagasse was then fermented anaerobically for biofuel production without enzymatic hydrolysis. The results showed higher ethanol production than those reported in the literature. The maximum ethanol production of 820 mg/L was achieved with a combination of ultrasound (60 amplitude level, 127 W) and acid (3% H₂SO₄ concentration). The combination of two-step pretreatment such as an ultrasound (50 amplitude level, 109 W) with acid (3% H₂SO₄ concentration) and then an ultrasound with alkaline (23% NaOH concentration) generated 911 mg/L of ethanol.

Optimising the combustion process in compression ignition (CI) engines is of interest in current research as a potential means to reduce fuel consumption and emission levels. Combustion optimisation can be achieved as a result of understanding the relationship between spraying technique and combustion characteristics. Understanding macroscopic characteristics of spray is an important step in predicting combustion behaviour. This study investigates the impact of injector hole diameter on macroscopic spray characteristics (spray penetration, spray cone angle, and spray volume) of butanol-diesel blends. In the current study, a Bosch (0.18 mm diameter) and a Delphi (0.198 mm) injector were used. Spray tests were carried out in a constant volume vessel (CVV) under different injection conditions. The test blends were injected using a solenoid injector with a common rail injection system and images captured using a high-speed camera. The experimental results showed that the spray penetration (S) was increased with larger hole diameter. Spray penetration of a 20% butanol-80% diesel blend was slightly further than that of neat diesel. Spray penetration of all test fuels was increased as a result of increased injection pressure (IP), while spray cone angle (θ) was slightly widened due to the increase in either hole diameter or injection pressure. Spray volume of all test fuels was increased as a result of increased hole diameter or injection pressure. Thus, an efficient diesel engine performance can be achieved as a result of controlling injection characteristics, especially when using a promising additive like butanol blended with diesel.

The objective of this review is to provide a deep overview of liquid biofuels produced from sugarcane bagasse and to address the economic challenges of an ethanol and acetone-butanol-ethanol blend in commercial processes. The chemistry of sugarcane bagasse is presented. Pretreatment technologies such as physical, chemical pretreatment, biological, and combination pretreatments used in the fermentation process are also provided and summarised. Different types of anaerobic bacteria Clostridia (yeast) are discussed to identify the ingredient best suited for sugarcane bagasse, which can assist the industry in commercializing ethanol and acetone-butanol-ethanol biofuel from biomass sugarcane. The use of an acetone-butanol-ethanol mixture and ethanol blend in internal combustion engines is also discussed. The literature then supports the proposal of the best operating conditions for fermentation to enhance ethanol and acetone-butanol-ethanol plant efficiency in the sugar waste industry and its application in internal combustion engines.

This paper evaluates and compares the effect of using three types of alcohol as additives butanol (B), Acetone-butanol-ethanol (ABE) and Butanol-acetone (BA) each blended with diesel (D). The test was conducted on a single-cylinder diesel engine at 10% and 20% of B, ABE, BA and D by volume at different engine speeds of 1400, 2000 and 2600 rpm. Diesel fuel was also tested as a baseline for comparison. This study has shown that the brake power (BP) was like all B, ABE and BA-diesel blend ratios and comparable with the brake power of diesel fuel at all engine speeds. Brake-specific fuel consumption (BSFC) was increased in all alcohol blend. The maximum reduction of exhaust gas temperature (EGT) compared to D100 was by 5% for 20BA. The maximum reduction of NO_x emission by 7% was observed for 10B90D and 10BA90D at all engine speeds. However, the mixture with 10% ABE showed a higher NO_x emissions at all engine speeds. The maximum reduction in CO emission was observed in 20B80D, 20ABE80D and 20BA80D blend at all engine speeds when compared with pure diesel. The mixture with 10% and 20% ABE presented a significant decrease in unburnt hydrocarbon (UHC) emission with a 20% reduction compared to those of D100. However, the mixture with 10% BA and 20BA showed a significant increase in UHC emissions in all engine speeds when compared with those of D100.

This study investigates the impact of an acetone-butanol-ethanol (ABE) mixture on spray parameters, engine performance and emission levels of neat cottonseed biodiesel and neat diesel blends. The spray test was carried out using a high-speed camera, and the engine test was conducted on a variable compression diesel engine. Adding an ABE blend can increase the spray penetration of both neat biodiesel and diesel due to the low viscosity and surface tension, thereby enhancing the vaporization rate and combustion efficiency. A maximum in-cylinder pressure value was recorded for the ABE-diesel blend. The brake power (BP) of all ABE blends was slightly reduced due to the low heating values of ABE blends. Exhaust gas temperature (EGT), nitrogen oxides (NO_x) and carbon monoxide (CO) emissions were also reduced with the addition of the ABE blend to neat diesel and biodiesel by 14–17%, 11–13% and 25–54%, respectively, compared to neat diesel. Unburnt hydrocarbon (UHC) emissions were reduced with the addition of ABE to diesel by 13%, while UHC emissions were increased with the addition of ABE to biodiesel blend by 25–34% compared to neat diesel. It can be concluded that the ABE mixture is a good additive blend to neat diesel rather than neat biodiesel for improving diesel properties by using green energy for compression ignition (CI) engines with no or minor modifications.