(337b) Biomass Conversion to Acrylonitrile Monomer-Precursor for Production of Carbon Fibers

Jadid E. Samad, Lindsey Chatterton, Govedarica Zora and Amit Goyal

Energy and Environment Division

Southern Research, Durham, NC 27712

Over the last few years, the global demand for carbon fibers has been growing at an impressive rate. With newer applications in the horizon and the major consumers (e.g., aerospace, defense, automotive, construction) already gearing towards more use, this trend is projected to continue in the foreseeable future [1]. Of the several types of carbon fibers, Polyacrylonitrile (PAN) based fibers are of particular interest for its specific mechanical properties (250 ksi tensile strength and 25 Msi Youngâ??s modulus) required for automotive applications.

Acrylonitrile (ACN), a monomer of PAN is commercially produced from fossil sources (e.g., propylene). This process has come under scrutiny due to volatile propylene price and non-sustainable nature of petroleum based feedstock. An alternative production route using biomass derived starting materials e.g., glycerol has gained steam of late. This route enables high selectivity to ACN with an array of valuable byproducts but is limited to purified glycerol obtained from biodiesel production. As a result, although promising, this route has yet to become economically attractive [2].

Southern Research is developing a biomass to ACN (B2ACN) process under a cooperative agreement with the Department of Energy [3]. The goal of this work is to pursue a cost effective process for ACN production at mild condition using biomass derived sugars as raw materials. From sugar to ACN, the entire B2ACN process consists of multiple catalytic reaction steps. In the first reaction step, several novel multi-functional catalysts have been used to convert sugar to. The produced oxygenates are converted to a gas phase intermediate (acrolein) which will be converted to acrylonitrile in the subsequent step. Based on preliminary results significantly reduced cost (~15-22%) as well as greenhouse gas (GHG) emissions (~37%) compared to typical ACN processes have been forecasted. The work is currently at lab scale development/testing phase. A scaled up integrated bench-scale reactor system will be designed and demonstrated after successful completion of this phase.

In the previous paper, results of catalyst development and optimization from the first reaction (sugars to oxygenates) has been discussed. This paper will primarily focus on the results obtained from the second reaction (oxygenates to acrolein) involving oxygenate conversion. Several catalyst candidates have been identified and tested for optimum catalytic performance in this part of the study.

[1] Mark Holmes, Global carbon fiber market remains on upward trend, Reinforced Plastics, Volume 58, Issue 6, Novemberâ??December 2014, Pages 38-45

[2] M. Olga Guerrero-Pérez, Miguel A. Bañares, Metrics of acrylonitrile: From biomass vs. petrochemical route, Catalysis Today, Volume 239, 1 January 2015, Pages 25-30

[3] http://energy.gov/eere/articles/energy-department-announces-11-million-a...