Near Critical Water Liquefaction Biomass And Its Application

In order to create a green ecological recycling model suitable for rural areas and agriculture of cold regions in the north,the study under the guidance of the concept of “combination of cultivating and breeding” was conducted.It was combined with the technical status of rural areas and was associated with the development concepts and technologies of international advanced agriculture.The study on application technology of preparing organic fertilizer to improve saline-alkali soil by near-critical water liquefaction biomass was carried out on the basis of the technology of conversion and extraction of bio-oil from cornstalk by near-critical water.The general idea is to prepare organic fertilizers by using the near-critical water technology from the agricultural wastes,such as biomass-rich straw and livestock excrement.Then the obtained organic fertilizers are applied into the improvement of organic matter in soil and the treatment and restoration of saline-alkali soil.Finally,we aim to construct no pollution circulative agriculture and to achieve closed-loop production of modern agriculture.The application research on the biomass liquefaction in near-critical water:(1)The application research on conversion and extraction of bio-oil from cornstalk by near-critical water.The extraction method and conversion between cornstalk and bio-oil was established under the condition of lower transition temperature and short constant temperature time without using any catalyst and organic solvent.The experiments of transformation of cornstalk in different shapes showed that application of rod-shaped cornstalk was beneficial to obtain more bio-oil in near-critical water.The water-soluble oil was extracted by n-hexane and analyzed by GC-MS.The results indicated that the main liquefied products were phenolic compounds followed by a small amount of n-alkanes,aromatic ketones,alcohols,alkylbenzenes and several compounds containing sulfur and nitrogen.(2)The application research on organic fertilizer prepared with biomass liquefaction in near-critical water.Without using any catalyst or organic solvent,the organic fertilizer and plant nutrient solution were prepared from cornstalk-animal excrement and cornstalk liquefaction in near-critical water,respectively.The electromagnetic induction pilot and small-scale production equipment with high heating efficiency and good economic efficiency were designed and optimized for biomass liquefaction in near-critical water.Moreover,the reasonable production processes and technical parameters were confirmed respectively.The study showed that biomass converted rapidly without any chemical addition.The composition of liquid product were mainly phenols,aldehydes and ketones,and there are abundant N,P,K and trace elements such as Ca,Mn,Fe,Zn,B,S,Mg,Mo in the liquid product which can promote the growth of plant.The liquefied product have a pH value of 3.5-4.2 and its component is close to the humic acid which is the product of the natural decay biomass.The research can not only provide theoretical basis and technical support for the preparation of organic fertilizers from biomass,but also provide technical reference for the practical application of scale industrialization of energy conversion such as treatment of manure in large-scale farm and liquefaction of cornstalks and livestock excrements in near-critical water for the preparation of natural gas.(3)The effect of biomass liquefaction in near-critical water on the improvement of saline-alkali soil for planting wheat was explored.Under the support of the special fund for poverty alleviation of JilinUniversity,the technology of biomass liquefaction in near-critical was carried out in Tongyu County of Jilin Province for the filed trial of corn and sorghum in saline-alkali soil.Through the evaluation of crop growth and seed yield,it is proved that the biomass liquefaction in near-critical water has a certain role for promoting plant growth and improving soil and provides a scientific basis for widely applying biomass to improve saline-alkali soil.(4)Demonstration projects were carried out,and Tongyu base of the JilinProvince biomass-modified saline-alkali soil and the modern green agricultural engineering research center were established.Through the economic efficiency of using organic fertilizer and comprehensive improvement of soil quality,farmers' enthusiasm and internal motivation that they use organic fertilizer to improve saline-alkali soil were motivated.The improvement of saline-alkali soil in the central and western of Jilin Province and the improvement of organic matter in the black soil region of northeast China were promoted effectively.The innovation of this study are as follow:(1)Without using any catalysts or chemical reagents,the feasibility of liquefying cornstalk and liquefying cornstalk-livestock excreta with near-critical water was explored.A method for preparing organic fertilizer by biomass such as cornstalk and cornstalk-livestock excrement in near-critical water was established.It provides a simple and green technology for the recycling of cornstalk and renewable resources.(2)A high temperature and pressure reactor suitable for the pilot(200L)and small-scale industrial production(1000L)of the liquefaction of biomass in near-critical water was designed and manufactured.Without using any catalysts or chemical reagents,the small-scale tests,pilot-scale tests and small-scale production of biomass applications are realized in the experimental base of Tongyu County,Jilin Province.The liquefaction of rod-shaped cornstalk and cornstalk-livestock excrement in near-critical water was conducted at low-temperature and in short-time.The work has rarely been reported in China.(3)The measure of using near-critical water to liquefy cornstalk-pig manure-sheep manure and other biomass to prepare solid and liquid organic fertilizer was proposed innovatively.The whole process is environmentally friendly without secondary pollution,it realizes returning cornstalk and cornstalk-livestock excrement to field in a simple,clean and fast way.Compared with other technologies for preparing organic fertilizers from agriculture wastes such as cornstalk and livestock excrement,the production cycle of the study is greatly shortened,and the investment and floor space of the study are small.The production capacity of the liquid manure can be set according to the scale of the farm and the manure could be processed completely on the same day,realizing large-scale industrial production in the true sense.(4)Using the organic fertilizer prepared from waste biomass,the soil improvement experiment of the saline-alkali field and the plant planting impact evaluation test were carried out in the experimental base of Tongyu County,Jilin Province.By comparing the growth and yield of sorghum and corn,it is proved that the prepared organic fertilizer has obvious effects on crop growth and soil improvement.It provides a new idea for the preparation of organic fertilizer and saline-alkali land for agricultural and livestock waste.