Influence of a Catalyst in Obtaining a Post-Consumer Pet-Based Alkyd Resin That Meets Circular Economy Principles

The paper studied the influence of a catalyst, comparing it with its traditional counterparts, in the process of obtaining a polyethylene terephthalate (PET)-based alkyd resin from post-consumer beverage bottles and how it consumes raw materials and generates waste. The resin was obtained in two phases: 1) glycerol and soybean oil alcoholysis reaction, a renewable material, for polyalcohol production, and 2) polyalcohol and polyacid esterification reaction to obtain the alkyd resin (reaction via solvent). A lithium octoate catalyst (OctLi) was used, not traditional in the alcoholysis reaction, and a fraction of the polyacid replaced by post-consumer PET at a proportion of up to 24% by weight in the esterification reaction. The OctLi catalyst caused a reaction in 30 min, compared to zinc acetate (120 min) and lithium hydroxide (LiOH, 60 min). Using post-consumer PET in obtaining the alkyd resin also decreased the esterification reaction time by 22% (8% PET), 67% (16% PET) and 72% (24% PET), compared to esterification without PET. The reaction time, considering alcoholysis with OctLi and partial esterification with PET (with 24% PET), was 180 min. Adding alcoholysis time with the LiOH catalyst and esterification without PET raises the reaction time to 600 min. Process water formed during the esterification stage declined by 15% (8% PET), 50% (16% PET) and 77% (24% PET), compared to the reaction without PET. The shorter reaction time resulted in less equipment use and consequent lower energy consumption. Another result was that the alkyd resin obtained with 8% PET was adequate for paint formulations.

Experimental and theoretical studies on glucose conversion in ethanol solution to 5-ethoxymethylfurfural and ethyl levulinate catalyzed by a Brønsted acid

DFT calculations combined with experiments were used to discover the mechanism and reaction pathway of the glucose alcoholysis reaction.

ALCOHOL SOLUTIONS OF THE POTASSIUM/SODIUM SULFITES AND NITRITES

Рассмотрены опубликованные и представлены собственные данные о растворимости сульфитов и нитритов натрия и калия в метаноле и этаноле. Обсуждена невозможность реакции алкоголиза указанных солей в температурном диапазоне 20-50°С. The published and new experimental data on solubilities of the sodium / potassium sulfites and nitrites in methanol and ethanol have been considered and presented. The impossibility of alcoholysis reaction for the alkali metal sulfites and nitrites in the temperature range 20-50°С was discussed.

Bio-additives for CI engines from one-pot alcoholysis reaction of lignocellulosic biomass: an experimental activity

In the recent years the progressive decrease in fossil petroleum resources and gradual deprivation of the environment have attracted increasing interest towards the use of biomass as renewable carbon source for the production of chemicals and transportation fuels. In particular, lignocellulosic biomass represents an abundant and inexpensive renewable resource with high carbon sequestration ability and non-polluting. In this paper, the valorisation of mixtures made of n-butanol (n-BuOH), butyl levulinate (BL) and dibutyl ether (DBE), in different percentages, as additive fuel for compression ignition (CI) internal combustion engine (ICE) was studied. These mixtures can be directly obtained from the catalytic alcoholysis reaction of the cellulosic fraction of raw and pre-treated lignocellulosic biomasses. Moreover, the possibility to recycle and reutilize the excess alcohol (n-Butanol), during the catalytic alcoholysis reaction, has been considered since it represents an opportunity to reduce the overall costs of the process. Therefore, a blend constituted only by BL and DBE has been also tested. The model mixtures were prepared by using commercial reactants, characterized by compositions analogous to those of the reaction mixtures. These model mixtures were tested as blend with Diesel fuel in a CI-ICE with the measurement of pollutant emission and performance. Results have been compared with those obtained fuelling the engine with a commercial Diesel fuel. As a whole, tests results have evidenced the potentiality of these novel blending mixtures to reduce the emissions of particulate without any significant increase in the other pollutants and negligible changes in engine power and efficiency.

Deep Eutectic Solvents as New Reaction Media to Produce Alkyl-Glycosides Using Alpha-Amylase from Thermotoga maritima

Deep Eutectic Solvents (DES) were investigated as new reaction media for the synthesis of alkyl glycosides catalyzed by the thermostable α-amylase from Thermotoga maritima Amy A. The enzyme was almost completely deactivated when assayed in a series of pure DES, but as cosolvents, DES containing alcohols, sugars, and amides as hydrogen-bond donors (HBD) performed best. A choline chloride:urea based DES was further characterized for the alcoholysis reaction using methanol as a nucleophile. As a cosolvent, this DES increased the hydrolytic and alcoholytic activity of the enzyme at low methanol concentrations, even when both activities drastically dropped when methanol concentration was increased. To explain this phenomenon, variable-temperature, circular dichroism characterization of the protein was conducted, finding that above 60 °C, Amy A underwent large conformational changes not observed in aqueous medium. Thus, 60 °C was set as the temperature limit to carry out alcoholysis reactions. Higher DES contents at this temperature had a detrimental but differential effect on hydrolysis and alcoholysis reactions, thus increasing the alcoholyisis/hydrolysis ratio. To the best of our knowledge, this is the first report on the effect of DES and temperature on an enzyme in which structural studies made it possible to establish the temperature limit for a thermostable enzyme in DES.

Lipase-catalyzed synthesis of red pitaya (Hylocereus polyrhizus) seed oil esters for cosmeceutical applications: process optimization using response surface methodology

Optimization of the alcoholysis reaction between red pitaya seed oil and oleyl alcohol catalyzed by Lipozyme RM IM was carried out.

Recovery of the polymers formed during thermal cracking of N-substituted dicarbamates over Fe–Ni/Al2O3

Regenerated carbamate from the thermal cracking polymers via the alcoholysis reaction in the presence of ethyl carbamate.