Oil flax straw processing and utilization

Abstract

Flax (Linum usitatissimum) is widely used as a source of linen oil and fiber. As a rule, the flax varieties are suitable for either seeds and oil or stem fibers production. The “fiber” varieties bring low seed, while the “oil” ones have poor fibers. The straw of the oil flax is not suitable for the textile industry and has to be burned or degraded naturally in the field. However, it contains a low DP cellulose, which can be used at least for varnish production. The main challenge in the industrial application of the oil flax cellulose is separating the cellulose fibers and shive enriched in lignin. On the other hand, the relatively low cost of the final products restricts the set of tools allowing such separation. Here, we describe a machine designed for oil flax straw scutching having an efficiency of 500 kg/h at the power of 6.5 kW and producing fiber with the residual shive content of 15 % (tow yield $\sim 25$ %). We also suppose several ways to further convert the obtained tow into microcrystalline or fluff-like cellulose (WRV $\sim 9$ ). The suggested process runs below the water boiling point and atmospheric pressure and could be held in the plastic reactors.