Technology

1,3-Butadiene is an important monomer in the production of polymers such as polybutadiene, styrene-butadiene, and butadiene-methylstyrene rubber, nitrile rubber, butadiene-methyl vinylpyridine rubber, etc. In addition, butadiene is used in industry for production of synthetic latexes, adipodinitrile and sebacic acid. Currently over 95% of butadiene is produced by isolation from naphtha steam cracker fractions generated during ethylene production. However, growth of production of shale gas, which consists mostly of ethane, has led to a shift in feedstock composition for steam crackers. This leads to the decrease of butadiene yield and, therefore, the shortage of butadiene on the market, leading to the growth of interest to development of alternative butadiene synthesis processes. One of the most perspective sources for butadiene production is ethanol, which can be produced from carbohydrate biomass.

The concept of butadiene production from ethanol has been already confirmed in industrial scale. The one-step catalytic process to produce butadiene from ethanol had been developed by S. Lebedev and implemented in industry in the USSR in the beginning of the 1920s. Later on,the Carbide and Carbon Chemicals Corporation in the USA commercialized a two-stage process, featuring acetaldehyde as an intermediate product. However, as ethylene production facilities were put in operation, those processes lost their competitiveness, primarily due to high energy costs compared to butadiene extraction from naphtha cracker products, and all ‘ethanol-to-butadiene’ plants were stopped after the 1960th. Nowadays, despite the butadiene short supply on the market, the old process remains cost-ineffective due to high energy consumption and poor butadiene selectivity. Therefore, existing ‘ethanol-to-butadiene’ technologies require substantial improvement in particular, the development of novel catalystswith high activity and selectivity is of prime importance. However, even today the concept and the philosophy of butadiene synthesis from ethanol remain vital and up-to-date.

ETB CaT Process

Combined fundamental and applied approach used by ETB CaT R&D team allowed to design a novel one-step butadiene on-purpose production process based on conversion of ethanol over the polyfunctional heterogeneous catalyst.

The reaction chemistry includes the ethanol dehydrogenation into acetaldehyde, which transforms into C4 precursors, finally leading to butadiene. All of the above processes are governed by the single catalyst leading to extremely high conversion, selectivity, and stability. Mechanical properties and shape of catalyst pellets have been optimized to achieve best hydrodynamic regime inside the reactor, hence, improving heat and mass transfer.

Selectivity to target butadiene is over 82% (compared to 60% for the previous processes). The reaction runs at 320ᵒC (compared to previous400ᵒC) and under atmospheric pressure, which ensures energy saving.

Superior process designs, high-performance catalysts, and efficient equipment ensure significantly higher indicators while increasing plant availability. This features results in lower CAPEX and OPEX expenses with respect to the analogue solutions in the field of industrial large-capacity processes.

Advantages of our process

  • Use of renewable raw material, i.e. ethanol (unlike processes that run on hydrocarbon feedstock)
  • The highest selectivity to butadiene (over 80%) compared to the “Lebedev’s process” due to the decrease of side products formation
  • Low energy consumption