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Study On The Technology And Reaction Kinetics Of Biomass Hydrolysis For Amino Acids Production In Subcritical Water

Posted on:2018-04-06Degree:MasterType:Thesis
Country:ChinaCandidate:R S ZhangFull Text:PDF
GTID:2381330518984430Subject:Environmental Science
Abstract/Summary:PDF Full Text Request
Biomass is one kind of green renewable energy,which is an important energy source to achieve sustainable development.This project mainly inspects the dying poultry and livestock(such as sick and dead pigs,animals' body,and rubbish).As well as the output of poultry and livestock in China with a great amount of production every year,whose keeps an increasing upward trend while a great deal of biomass waste is left.It is estimated that the nationwide wastes from the processing of livestock and poultry are about 5.612-7.331 × 107 tons.This kind of biomass waste contains many kinds of human body's essential amino acid and organic acid.Aimed at the wastes,the landfills,preservation and incineration are pointed as the optimal treatment,which not only causes the wastes of sources,but also the dead livestock and poultry are pathogenic,the microorganism that they carried induces the environmental pollution,finally results in the ecological destruction.Recently,acid hydrolysis,alkaline hydrolysis and enzymatic hydrolysis process are rapidly used in this area,but under the harsh processing condition,the amino acid is easily to be damaged during the production,and inadequate utilizing of biological solid causes the secondary pollution,which are the current bottlenecks to limit the development.How to reuse the waste of biomass reasonably and reduce the costing effectively,while refining the high added value product and easing environmental stress,which have always been the difficulty and keystone in research field.In those years,Supercritical and near-critical water is a new technology which has rapid development.Compared to the normal water,Supercritical and near-critical water has larger ion product and it also has acidic and alkaline catalytic effect to improve the rate of reaction.The density and dielectric constant can be controlled by temperature and pressure,which can meet the needs of various reaction media,and satisfy the demand of green chemistry.In the field of environmental conservation,in view of the fact that it can be used to decompose the high molecular weight organic pollutants into small molecules,such as H2O,CO2 and so on.Based on the study,the project attempts to make wastes pork as row materials,and using near critical water properties to test liquefaction experiments,exploring the hydrolysis of raw materials how to transform into amino acids,unsaturated fatty acids,and high value added oil industrial materials.Also,the influences of the reactant proportion and reacting condition on the area were studied,which aims to seek the optimum technological parameter.The study focuses on solving waste materials have not been fully developed and utilized,improving environment and increasing the benefits.Research purpose:1.Study of optimum technological conditions for hydrolysis of biomassThe paper relates to the experiment of the liquefaction of pork in the high pressure reactor with the condition of super/near critical water,and the product was transformed into high value-added industrial products,such as amino acids,unsaturated fatty acids,and oil so on.The different reaction temperature,reaction time,reaction pressure and the influence of material ratio on the hydrolysis product yield.The consequence shows that under different reaction conditions,hydrolyzed biomass change the amino acid content in regular way by the qualitative analysis of amino acids in the hydrolysate with the automatic amino acid analyzer,and the indene three ketone colorimetric method of quantitative determination of amino acids.Change of reaction temperature,reaction time,material ratio,reaction pressure,which all the factors will achieve the optimal amino acid hydrolysis yield of the process parameters by using orthogonal experiment and the analysis of the single factor experiment.The optimum experimental conditions are:reaction temperature 240 ?,pressure 2.0 MPa,reaction residence time of 40 min,1500 mL of solvent.The result shows that the order of magnitude of liquefaction amino acid yield was:reaction temperature>reaction pressure>reaction time>solvent amount.2.Study of the hydrolysis kinetics under the biomass supercritical water conditionIn order to overcome the difficulties of the determination of protein directly under the pork which is near to the critical water hydrolysis.The project measured the time points of the different hydrolysis reaction of amino acid and total yield of protein in the acid solution under the condition of the ratio of total yield of pork protein amino acids in liquefaction reaction hydrolysis rate,as well as establish the dynamic equation.The dynamics result shows that the order of reaction of pork protein under the Near-critical Water is 1.2437,as the temperature increase the reaction rate grows as well.The reaction rate constant at 0.0017,0.0044 and 0.0044 respectively under the temperatures 220 ?,240 ? and 220 ?.The activation energy is 96.7743 kJ/mol and the pre divisor is about 3.065 ×107.This experiment provides a new attempt for the study of biomass liquefaction reaction under the condition of super/sub critical water,which also provided the theoretical foundation and reference value to producing the beverage in industrialization.In this project,the innovation identity primarily reflected in two aspects:1.The achievement exists in that a new method which comes up with a new way to recycle the animal biomass resources harmlessly,and the method is also is simple,efficient and extremely easy to popularize.2.Using the hydrolytic amino acid yield to reverse the method of protein hydrolysis kinetics,which will supply the way for the study of the kinetics with near critical water biomass hydrolysis.
Keywords/Search Tags:Biomass, Amino acid productivity, Supercritical, Sub-Critical Water, Hydrolysis dynamics
PDF Full Text Request
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