Chemocatalytic Conversion of Ethanol into Butadiene and Other Bulk Chemicals

Abstract

The development of new and improved processes for the synthesis of bio-based chemicals is one of the scientific challenges of our time. These new discoveries are not only important from an environmental point of view, but also represent an important economic opportunity, provided that the developed processes are selective and efficient. Bioethanol is currently produced from renewable resources in large amounts and, in addition to its use as biofuel, holds considerable promise as a building block for the chemical industry. Indeed, further improvements in production, both in terms of efficiency and feedstock selection, will guarantee availability at competitive prices. The conversion of bioethanol into commodity chemicals, in particular direct 'drop-in' replacements is, therefore, becoming increasingly attractive, provided that the appropriate (catalytic) technology is in place. The production of green and renewable 1,3-butadiene is a clear example of this approach. The Lebedev process for the one-step catalytic conversion of ethanol to butadiene has been known since the 1930s and has been applied on an industrial scale to produce synthetic rubber. Later, the availability of low-cost oil made it more convenient to obtain butadiene from petrochemical sources. The desire to produce bulk chemicals in a sustainable way and the availability of low-cost bioethanol in large volumes has, however, resulted in a renaissance of this old butadiene production process. This paper reviews the catalytic aspects associated with the synthesis of butadiene via the Lebedev process, as well as the production of other, mechanistically related bulk chemicals that can be obtained from (bio)ethanol.

Recent updates on lignocellulosic biomass derived ethanol - A review

“…Although, novel biochemical, thermo-catalytic, and hybrid routes are being developed to produce drop-in fuels and fuel additives to meet the infrastructure and other requirements (Huber et Figure 1 shows that ethanol derived from cellulosic biomass can also be used to produce other fuel candidates such as butanol, gasoline, hydrogen, diesel, and others (Whitcraft et al, 1983;Costa et al, 1985;Deluga et al, 2004;Narula et al, 2015;Riittonen et al, 2015). Moreover, ethanol can also serve as a precursor for several other chemicals and intermediates that are currently derived from non-renewable resources (Angelici et al, 2013;Sun and Wang, 2014). …”

Ethanol to 1,3‐Butadiene Conversion by using ZrZn‐Containing MgO/SiO2 Systems Prepared by Co‐precipitation and Effect of Catalyst Acidity Modification

“…As expected, an increase in reaction temperature increased ethene selectivity, Figure 2(a), and decreased DEE selectivity, Figure 2(b), ethanol dehydration to ethene is endothermic and to DEE is exothermic. [7,38] Even though the mechanism of DEE formation is still discussed in the literature, for instance, regarding whether it involves acid-base pairs, [39,40] Brønsted acid sites and/or Lewis acid sites, [40] it is understood that DEE formation should involve the reaction of the two nearest chemisorbed ethanol moieties. [41] On the other hand, ethene formation should occur through a concerted mechanism, where the methyl hydrogen of the ethoxide species, chemisorbed on a Lewis [41] or Brønsted acid site, [42] is abstracted by the adjacent Brønsted basic site.…”

“…The effect of calcination steps removal was further investigated through 7 Li MAS NMR spectroscopy. Figure S9(a) shows spectra for samples 1.2-Li/ZrZn/MgO-SiO 2-1 and 1.2-Li/ZrZn/MgO-SiO2-1 prepared with only 1 calcination step after ZrO2 and ZnO addition.…”

“…[3,4] Besides environmental concerns as a result of the use of petroleumderived hydrocarbons, the need for a new route to 1,3-BD is further exacerbated due to the possible future shortfall in supply due to the changes of feedstock from naphtha to ethane in the U.S. [5,6] The catalytic conversion of ethanol into 1,3-BD is an attractive alternative, due to the availability of bioethanol which is expected to significantly increase over the next few years from fermentation of sugar rich waste materials (second generation bioethanol). [1,5,7,8] For example in Brazil alone, 23.4 billion litres of bioethanol were produced in 2014. [9] The route most widely accepted to account for 1,3-BD production from ethanol involves five consecutive reactions.…”

Olefins from Biomass Intermediates: A Review

“…C4H6 is also a by product of C2H4 production through cracking of hydrocarbons. C4H6 production from bio ethanol is a promising alternative that has been industrially implemented prior to the installation of naphtha cracking technologies; ethanol to C4H6 processes have been used since 1920, constituting the main production practice until the end of World War II [22,100]. Main routes of this process include dehydrogenation, dehydration, and condensation over suitable catalysts, either in one step (i.e., Lebedev approach) (Scheme 5) or two step processes (i.e., Ostromisslenski C 4 H 6 is also a by-product of C 2 H 4 production through cracking of hydrocarbons.…”