A Method for Producing Microcrystalline Cellulose from Hemp Fibers

Abstract

Background. Obtaining from annually renewable plant raw materials, in particular from hemp fiber, microcrystalline cellulose (MCC), which is suitable for use in the chemical industry. Objective. The was aim of the paper is to develop a technology for obtaining MCC from hemp fibers to reduce the number of the technological process stages and to determine the optimum values of the main technological parameters of the chelating and hydrolysis processes of peracetic hemp pulp, in which the quality indicators of the obtained MCC will meet the requirements of regulatory documents. Methods. Peracetic cooking of hemp fibers was carried out at liquor to solid ratio 10: 1 and temperature of 90 ± 1 °C, ranging from 60 to 240 min. The process of chelating pulp by Trilon B was investigated at consumption from 5 to 30 % in acidic and alkaline environments. At the final stage of MCC preparation, the hemp pulp hydrolysis process was carried out by sulfate acid at its concentration of 0.5 to 2.0 %, liquor to solid ratio 15:1 and a temperature of 90 ± 1 °C for 90 min. The quality indices of the obtained microcrystalline cellulose were determined by standard methods. Results. The high efficiency of the peracetic method of pulp production from hemp fiber is shown. It has been experimentally proved that the chelating process of hemp pulp is expediently carried out in acid environment at a Trilon B consumption of 20 % from the the bone dry process weight. It is shown that the MCC can be obtained by the hydrolysis of peracetic hemp pulp with a solution of 1.5 % sulfuric acid at a temperature of 90 °С during 90 min that satisfies the requirements of regulatory documents. Conclusions. The proposed technology for the MCC production from hemp fibers reduces the cost of finished products by eliminating the bleaching stage of pulp as well as due to the use of domestic renewable plant raw materials, in particular hemp fibers compared with imported cotton or softwood pulp. The obtained MCC meets the requirements of technical conditions and can be used in the chemical industry as a sorbent or filler in the production of plastics and a water stabilizer for paints and emulsions.