Dehydration of D-xylose and direct transformation of xylan into furfural were achieved by means of betaine-formic acid (HCOOH) catalytic system. All reactions were microwave-assisted and carried out in a CPME-water biphasic system. At 170 degrees C, in a pH range between 1.9 and 2.3, highest yields of 80% and 76% were obtained respectively for the pentose and the polysaccharide. Time dependence of the dehydration and influence of the temperature on the reaction kinetics were studied. Besides, at 190 degrees C, using the optimized condition of the reaction, rice husk was also employed as a source of furfural with a single stage reaction. (C) 2016 Elsevier B.V. All rights reserved.