عنوان مقاله [English]
Nowadays with regard to the need of upgrading the paper mill technology and give up the traditional processes and on the other hand, the possibility of using all wood parts, emerging technologies have been introduced. American Value Added Pulping (AVAP) is as new alternative to achieve these aims and sulfite cooking liquor is used in presence of alcohol. Addition of alcohol accelerates the pulping speed, while preserving the cellulose strength. Volatile cooking chemicals are stripped and reused in the cooking process. Energy can be obtained from precipitated lignosulfonates and hydrolyzed hemicelluloses converted to sugar. So that, up to 85.42 million litre of bioethanol are produced annually from sugar fermentation even more than the conventional system according to estimate done. Also, energy is obtained from residual biomass and this will finally results in a energy self sufficiency in production process. The results indicate that AVAP process plan have several benefits such as high yield (at a range of 41-58%), producing the pulp with improved bleachability and better refineability, lower operation and capital costs, the possibility of producing the more value-added byproducts (bioethanol and synthetic gases) lower energy consumption and the feasibility of planning a closed system as compared to traditional kraft and sulphite pulps. On the other hand, recovery system of cooking liquour is simpler and easier in AVAP because of the absence of sodium components.