Effect of n-Butanol Additive on Bio-Mix Fuel Performance in Diesel Engines

The current experimental investigation describes a simple oil-diluting process, called as the bio-mix approach, to improve the properties of bio-mix test samples. Raw Tamarind and Waste cotton Oil (RTWO) samples were prepared through a method of bio-mix to enhance the quality of biodiesel from the raw mixture of edible and non-edible feedstocks.Five Raw Tamarind and Waste cotton Oil test samples (RTWO1, RTWO2, RTWO3, RTWO4, and RTWO5) were developed for this research by blending waste cotton and tamarind seed oils.Among these test samples, RTWO4 and RTWO5 were chosen as the optimum blends due to their low acid values. The selected raw bio-mix oils were transesterified using KOH as a catalyst to produce the bio-mix biodiesel samples (BMTW1 and BMTW2).10% of n-butanol additive blended with optimal blends, referred as BMTW1Bu10 and BMTW2Bu10 were selected for further experimental investigation. The fatty acid content and fuel characteristics of the bio-mix fuels with additives were examined and compared with the optimal bio-mix sample. A singlecylinder, stationary diesel engine has been used to evaluate each of the bio-mix test fuel.The experimental results indicated that the n-butanol blended bio-mix fuel samples showed significant improvements. At full engine load (4.42 kW), the BMTW2Bu10 blend enhanced brake thermal efficiency by 22.2% and reduced brake-specific fuel consumption by 23.6% when compared to the BMTW1 blend. Additionally, hydrocarbon (HC), carbon monoxide (CO), and smoke emissions decreased by 27.2%, 45.4%, and 35.4%, respectively.Overall, BMTW1Bu10 and BMTW2Bu10 exhibit improved engine performance, combustion characteristics and reduced emissions than BMTW blends. Major Findings: Adding 10% n-butanol to bio-mix fuels (BMTW1 and BMTW2) boosted engine performance by improving brake thermal efficiency and lowering brake-specific fuel consumption, HC, CO, and smoke emissions. The n-butanol blends (BMTW1Bu10 and BMTW2Bu10) also increased saturated fatty acid content and cetane number.