molecules Article Bio-Based Solvents and Gasoline Components from Renewable 2,3-Butanediol and 1,2-Propanediol: Synthesis and Characterization Vadim Samoilov 1,* , Denis Ni 1, Arina Goncharova 1, Danil Zarezin 1, Mariia Kniazeva 1 , Anton Ladesov 2, Dmitry Kosyakov 2 , Maxim Bermeshev 1 and Anton Maximov 1 1 A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences (TIPS RAS), 29 Leninsky Prospect, 119991 Moscow, Russia; [email protected] (A.M.) 2 Core Facility Center “Arktika”, Northern (Arctic) Federal University, 17 Severnaya Dvina Embankment, 163002 Arkhangelsk, Russia; [email protected] (A.L.); [email protected] (D.K.) * Correspondence: [email protected] Received: 4 March 2020; Accepted: 1 April 2020; Published: 9 April 2020 Abstract: In this study approaches for chemical conversions of the renewable compounds 1,2-propanediol (1,2-PD) and 2,3-butanediol (2,3-BD) that yield the corresponding cyclic ketals and glycol ethers have been investigated experimentally. The characterization of the obtained products as potential green solvents and gasoline components is discussed. Cyclic ketals have been obtained by the direct reaction of the diols with lower aliphatic ketones (1,2-PD + acetone ! 2,2,4-trimethyl-1,3-dioxolane (TMD) and 2,3-BD + butanone-2 2-ethyl-2,4,5-trimethyl-1,3-dioxolane 0 0 0 ! (ETMD)), for which the DH r, DS r and DG r values have been estimated experimentally. The monoethers of diols could be obtained through either hydrogenolysis of the pure ketals or from the ketone and the diol via reductive alkylation. In the both reactions, the cyclic ketals (TMD and ETMD) have been hydrogenated in nearly quantitative yields to the corresponding isopropoxypropanols (IPP) and 3-sec-butoxy-2-butanol (SBB) under mild conditions (T = 120–140 ◦C, p(H2) = 40 bar) with high selectivity (>93%). Four products (TMD, ETMD, IPP and SBB) have been characterized as far as their physical properties are concerned (density, melting/boiling points, viscosity, calorific value, evaporation rate, Antoine equation coefficients), as well as their solvent ones (Kamlet-Taft solvatochromic parameters, miscibility, and polymer solubilization). In the investigation of gasoline blending properties, TMD, ETMD, IPP and SBB have shown remarkable antiknock performance with blending antiknock indices of 95.2, 92.7, 99.2 and 99.7 points, respectively. Keywords: renewable solvents; ketals; ethers; 2,3-butanediol; renewable fuel; propylene glycol; Kamlet-Taft 1. Introduction The use of fossil fuel feedstocks for the production of energy carriers and chemicals has been developed a lot during the XXth century, and can now be considered as one of the main sources of current ecological problems. Among the latter there are environmental pollution (particularly, air, water and soil contamination) and climate change, which influence each other. One of the possible solutions to the aforementioned problems could be the extensive development of the biomass processing industry that provides the chance to replace fossil-based fuels and chemicals with bio-based renewable analogues. Renewable glycols such as 1,2-propanediol (1,2-PD) and 2,3-butanediol (2,3-BD) are of great interest as potential starting materials for chemical conversions for several reasons. First, they can be readily obtained from biomass sources by different methods: 1,2-PD can be obtained either by bioglycerol Molecules 2020, 25, 1723; doi:10.3390/molecules25071723 www.mdpi.com/journal/molecules MoleculesMolecules 20202020, 25,, 25x , 1723 2 of2 27 of 26 readily obtained from biomass sources by different methods: 1,2-PD can be obtained either by bioglycerolhydrogenolysis hydrogenolysis [1,2] or by [1,2] microbial or by microbial production production starting fromstarti carbohydratesng from carbohydrates [3]. The [3]. process The of processcarbohydrate of carbohydrate biomass fermentation,biomass fermentation, which yields which 2,3-BD, yields is remarkable2,3-BD, is remarkable as it provides as ait relativelyprovides higha relativelydiol yield high as diol well yield as overall as well productivity as overall productivity along with aalong quite with low a energy quite low consumption. energy consumption. The low host Thetoxicity low host of 2,3-BD toxicity which of 2,3-BD is conducive which tois aconduc higherive possible to a producthigher possible titer in theproduct fermentation titer in brothsthe fermentationshould be also broths mentioned should [be4– 7also]. The mentioned direct microbial [4–7]. The conversion direct microbial route of CO conversion2 into 2,3-BD route is alsoof CO worth2 intomentioning 2,3-BD is also [8]. Hence,worth thementioning noted compounds [8]. Hence, are the of noted particular compounds interest asare renewable of particular feedstocks interest for as the renewableproduction feedstocks of chemicals. for the production of chemicals. TheThe majority majority of of studies studies on on 2,3- 2,3-BDBD conversion areare dedicated dedicated to to its its dehydrative dehydrative conversion conversion that that yields yieldsmethyl methyl ethyl ethyl ketone ketone (MEK) (MEK) and and isobutyraldehyde isobutyraldehyde [9 [9–12],–12], 3-butene-2-ol 3-butene-2-ol [ 10[10,13–15],,13–15], butenes butenes [[16–16–18] 18]and and 1,3-butadiene1,3-butadiene [[19–21].19–21]. Some Some 2,3-BD 2,3-BD derivati derivativesves have have been been previously previously considered considered as aspotential potential motormotor fuel fuel components components and and organic organic solvents. solvents. As Asfar faras asthis this aspect aspect is concerned, is concerned, one one should should note note the the recentrecent work work by byHarvey Harvey [22], [22 which], which has has arisen arisen intere interestst to the to the one-step one-step 2,3-BD 2,3-BD dehydrative dehydrative conversion conversion intointo a cyclic a cyclic ketal ketal by bycondensation condensation with with MEK MEK generated generated in situ in situ (Scheme (Scheme 1),1 previously), previously developed developed by by NeishNeish et al. et al.in 1945 in 1945 [23]. [23 ]. HO OH [H+] HO OH O [H+] H O 2 + + 2 O O + 2H2O 2,3-BD MEK ETMD heteroazeotropic removal heteroazeotropic SchemeScheme 1. One 1. One step-conversion step-conversion of 2,3- of 2,3-BDBD into into a cyclic a cyclic ketal. ketal. TheThe main main feature feature of of thethe abovementionedabovementioned approach approach to 2,3-BDto 2,3-BD conversion conversion is the is continuous the continuous stripping strippingof the reaction of the reaction products products (water (water and the and cyclic the ketal)cyclic outketal) of out the of reaction the reaction mixtures, mixtures, which which may provide may providefavorable favorable conditions conditions for driving for driving the reversiblethe reversible ketalization ketalization reaction reaction to completion.to completion. The The one-step one- stepconversion conversion might might also also be be partially partially combined combined with wi theth the drying drying of 2,3-BD,of 2,3-BD, since since some some water water content content in the in feedthe feed diol diol does does not decreasenot decrease the target the target product prod yield.uct yield. Nearly Nearly quantitative quantitative yields yields of the of ketal the could ketal be couldobtained be obtained in this processin this process by applying by applying a proper a combination proper combination of process of conditions process conditions such as temperature, such as temperature,pressure and pressure acid catalyst and acid concentration catalyst concentration [23]. [23]. TheThe cyclic cyclic ketal ketal derived derived from from 2,3-BD 2,3-BD — —2-et 2-ethyl-2,4,5-trimethyl-1,3-dioxolanehyl-2,4,5-trimethyl-1,3-dioxolane — —has has been been characterizedcharacterized as asa gasoline a gasoline component component and and an anorganic organic solvent solvent by byHarvey Harvey et etal. al.[22]. [22 As]. Asa gasoline a gasoline additive,additive, the the compound compound is issignificant significant for for its itsgood good miscibility miscibility with with fuel, fuel, high high lipophilicity, lipophilicity, and and acceptableacceptable boiling boiling point point (132–142 ◦C°C depending depending on on the isomericthe isomeric composition), composition), relatively relatively high antiknock high 1 1 antiknockperformance performance (RON/MON (RON/MON= 93.5/86.7) = 93.5/86.7) and calorific and calorific value (28.3 value MJ (28.3 L− versusMJ L−1 21.1versus MJ 21.1 L− MJfor L ethanol).−1 for ethanol).Although Although the use the of use ETMD of ETMD as a renewable as a renewable solvent solvent has been has been proposed, proposed, the existingthe existing data data is likely is likelyinsu insufficientfficient for understandingfor understanding itspotential. its potential. In addition,In addition, inthe in the aforementioned aforementioned study study by by Harvey Harvey et al., et someal., some properties properties of the of pure the compoundpure compound including including the neat the octane neat numbersoctane numbers were reported were withoutreported the withoutblending the octaneblending numbers octane andnumber withouts and any without detailed any data detailed on the data base on gasoline the base properties. gasoline properties. Some data on Somethe data diesel on fuel the blending diesel fuel properties blending of properties 2,3-BD acetals of 2,3-BD had also acetals been had reported also been earlier reported by Staples earlier et al. by [24 ]. StaplesThus, et a al. deeper [24]. Thus, investigation