One kind of agriculture and forestry biomass cellulosic components of the whole fractionation method by the separation and preparation of fuel components and oligosaccharide alcohol

The invention discloses grading and separating of all components of forestry cellulose biomass and preparing of fuel alcohol and xylo-oligosaccharide by utilizing the separated components. The method comprises the following steps of: (a) crushing, immersing and filter pressing dry substances of the forestry cellulose biomass; (b) immersing the filter pressed solid phase part using an alkaline solution, adding an oxidizing agent, extracting and solidifying phase to form a cellulose crude product; (c) concentrating pressure filtrate through a nano-filtration membrane, adding alcohol with the final concentration of above 50% to the concentrated solution, filtering or centrifugally separating after standing to obtain precipitate and supernatant, wherein the precipitate is a hemi-cellulose crude product; and (d) adjusting the supernatant obtained in the step (c) to be acid, and filtering, separating and precipitating to obtain a lignin crude product. According to the method disclosed by the invention, the resource utilization is maximized; the independence on imported oil in our country can be reduced; the environment pollution is reduced; establishment of a new energy industry and a biological chemical industry can also be promoted; the economic growth pattern in our country is changed; and social and economic sustainable development can be realized.