System for preparing xylose liquid by continuously hydrolyzing hemicellulose and method thereof

A system for preparing xylose liquid by continuously hydrolyzing hemicellulose, comprising a neutralizing unit, an acid-adjusting unit, a feeding unit, a liquefaction ejecting unit, a feed and discharge heat-exchanging unit and a discharge controlling unit, wherein:

• the neutralizing unit comprises a raw material tank, a neutralizing concentrated sulfuric acid pump and a neutralizing pipeline mixer,
• the acid-adjusting unit comprises an acid-adjusting concentrated sulfuric acid pump, an acid-adjusting pipeline mixer and an acid-adjusting tank,
• the feeding unit comprises a feed tank,
• the liquefaction ejecting unit comprises a liquefaction ejector and a liquefaction maintainer,
• the feed and discharge heat-exchanging unit comprises a plate-type feed and discharge heat exchanger and a first discharge temperature sensor, and
• the discharge controlling unit comprises a discharge valve and a reflux valve, wherein:
• the raw material tank is configured to store a hemicellulose alkaline liquid,
• the neutralizing pipeline mixer is configured to perform a neutralization reaction of the hemicellulose alkaline liquid with sulfuric acid from the neutralizing concentrated sulfuric acid pump to obtain a hemicellulose liquid raw material,
• the acid-adjusting pipeline mixer is configured to mix the hemicellulose liquid raw material with sulfuric acid from the acid-adjusting concentrated sulfuric acid pump to obtain an acid-adjusted hemicellulose liquid,
• the acid-adjusting tank is configured to collect the acid-adjusted hemicellulose liquid,
• the feed tank is configured to receive hemicellulose liquid overflowing from the acid-adjusting tank,
• the plate-type feed and discharge heat exchanger is configured to exchange heat between feed of the acid-adjusted hemicellulose liquid from the feed tank and a xylose liquid obtained by hydrolysis,
• the liquefaction ejector is configured to mix the heat-exchanged hemicellulose liquid with an external high-pressure vapor and eject the heat-exchanged hemicellulose liquid and the high-pressure vapor together into the liquefaction maintainer,
• the liquefaction maintainer is configured to perform a hydrolysis reaction for the hemicellulose liquid and high-pressure vapor to obtain the xylose liquid,
• the first discharge temperature sensor is configured to sense a temperature of the xylose liquid obtained by the hydrolysis reaction, and
• the first discharge temperature sensor is interlocked with the discharge valve and the reflux valve to control a flow direction of the xylose liquid obtained by hydrolysis.