Waste fibers from papermaking are often rejected due to quality and production issues. Since the rejected fibers also known as 'fines' are discharged as solid waste placing significant strain on landfills, bioconversion into sugars by hydrolysis of their cellulosic content can be very attractive to the paper industry. The present work presents a method for process intensification of the hydrolysis of waste fines by integrating membrane separation for enzymes and recycle along with hydrolysis in a separation hydrolysis reactor. The performance of the reactor is analyzed and compared with experimental data on hydrolysis.