Lakhya Jyoti Konwar

Sulfonated carbon as a new, reusable heterogeneous catalyst for one-pot synthesis of acetone soluble cellulose acetate

A sulfonated carbon (SO3H/PhSO3H-carbon) catalyzed novel process was developed for the solvent free synthesis of acetone soluble-cellulose acetate (CA) via acetylation of cellulose with acetic anhydride. The SO3H/PhSO3H functionalized carbons easily outperformed the traditional solid acids (zeolites, heteropoly acids, Amberlyst-15 etc.) producing acetylated products with DS values between 1.6 and 2.94, in high yield (48–77% isolated yield) and under solvent free conditions, in a one-pot process. Further, it was possible to produce the commercially desired, soluble CA (DS values 2–2.7) in excellent yields (∼70%) from microcrystalline cellulose under optimized reaction conditions over the highly active mesoporous sulfonated catalyst (AC500S). A catalyst-to-cellulose (w/w) ratio of 1, acetic anhydride-to-AGU (anhydroglucose unit) mole ratio of 4.5 and reaction time of 12 h was applied. Additionally, the sulfonated catalyst could be easily recovered by centrifugal separation of the reaction mixture (diluted with acetone) and subsequently applied in the next reaction cycle with no significant reduction in yield and DS of CA over multiple reaction cycles.

Performance, combustion and emission characteristics of a direct injection VCR CI engine using a Jatropha curcas oil microemulsion: a comparative assessment with JCO B100, JCO B20 and petrodiesel

A Jatropha curcas oil (JCO) based hybrid microemulsion fuel (MHBF) comprising pretreated JCO–1-butanol–ethanol was prepared. The fuel characteristics of the hybrid microemulsion fuel (MHBF) were determined as per standard tests methods recommended by ASTM and compared with JCO B20, JCO B100 and petroleum diesel. The performance, combustion and emission characteristics of MHBF were studied for the first time in a variable compression ratio (VCR) direct injection CI engine. The fuel properties of the MHBF formulation were comparable to that of JCO B100 (viscosity of 5.9 mm2 s−1, density 0.872 g cm−3 and higher heating value of 38.25 MJ kg−1), while the cold flow properties were found to be superior than JCO B100 and JCO B20. In terms of engine performance, the brake specific fuel consumption (BSFC) of MHBF was comparable to B100 and B20 but higher than petrodiesel; while brake thermal efficiency (ηbte) was close to that of JCO B100 but slightly lower than petrodiesel at almost all load conditions. In terms of emission quality, MHBF was found to be superior to all other tested fuels under all conditions of loading. Most significantly it was observed that up to 80% NOx reduction as compared to petrodiesel was achieved when operated at full load with the MHBF at the maximum compression ratio of 17.5. Obviously, this is a significant finding and a factor of motivation and investigation for future biofuel applications.

A comparative study of Mesua ferrea L. based hybrid fuel with diesel fuel and biodiesel.

ABSTRACT The study presents preparation of a Mesua ferrea L. seed-oil-based emulsion hybrid fuel system by blending with alcohols (ethanol and butan-2-ol) in which butan-2-ol was employed as a surfactant. The study also deals with the investigation of the effect on fuel properties of the hybrid fuel due to the variation in surfactant amount and analysis of the prepared hybrid fuel system by 1H nuclear magnetic resonance (1H NMR). The experimental results show that the properties of the hybrid fuels were comparable to that of diesel and biodiesel.

Activated Carbon Supported CaO from Waste Shells as a Catalyst for Biodiesel Production

ABSTRACT In the wake of increasing environmental constraints, this work is aimed at developing a catalyst purely prepared from waste biomass source as the raw material. The catalyst is investigated for its applicability in transesterification of vegetable oil with the objectives: (i) to use waste shells of mollusk as raw material for the preparation of activated carbon and CaO; (ii) to use it as heterogeneous catalyst in the transesterification of waste cooking oil; (iii) to optimize the different parameters affecting the transesterification reaction; and (iv) to study its reusability. Under optimized conditions it was observed that a conversion >90% was possible and the catalyst could be reused five times with a slight loss in activity. This study indicates that the biomass source could also be used as a potential raw material in the synthesis of environmentally benign catalysts.

Sidestreams From Bioenergy and Biorefinery Complexes as a Resource for Circular Bioeconomy

One of the main drivers for the establishment of biorefineries and the drive toward bioeconomy is the call for sustainability. However, the modern-day biorefinery must embrace on the concept of who ...

Efficient C–C coupling of bio-based furanics and carbonyl compounds to liquid hydrocarbon precursors over lignosulfonate derived acidic carbocatalysts

This paper demonstrates the catalytic potential of novel Na-lignosulfonate (LS) derived meso/macroporous solid protonic acids upon C–C coupling of bio-based furanics and carbonyl compounds. The mat ...