Research Of Preparing Methane By Crops Straw

Along with the crisis of the coal、oil and natural gas fossil energy, biomassenergy has been gradually intentioned by people, the methane is a new, clean biomassenergy. China is a large agricultural country, so it is imperative to use crops strawpreparing methane. According to process of the crops straw preparing methane bymeans of anaerobic fermentation. This paper does the research from the followingseveral aspects:(1) The influence of the anaerobic fermentation on different alkalipreteatmenting crops straw. In experiment we chooses NaOH、KOH、CO(NH3) as thepretreatment agent of the crops straw, the experimental research proceed in differentpretreatment dosage and different organic load rate, analysis and comparison theinfluence of the fermentation methane-producing ability, we found that NaOH is thebiggest influence of he fermentation methane-producing ability, so finally we choosethe NaOH as agent pretreatment the crops straw.(2) The optimization experiment on pretreatment agent NaOH.experiment frompretreatment agent dosage, pretreatment temperature and pretreatment time threeaspects NaOH preprocessing maize straw optimization experiment, the results of thestudy for：the dosage of the pretreatment agent: without NaOH preprocessing of thecorn straw compared, pretreatment of corn straw in Nissan volume, cumulative gasproduction, methane content has increased greatly, The comprehensive comparison ofvarious factors, we chooses2﹪NaOH dosage as appropriate pretreatment agent.(2)Pretreatment temperature: Pretreatment temperature is in the cases of the10℃and30℃, Maize straw anaerobic fermentation gas effect is good, and that there was noevident difference, But temperature is10℃, corn straw anaerobic fermentationdigestive efficiency higher, so we choose temperature10℃as appropriatepretreatment temperature.(3) Pretreatment time: The comprehensive comparison ofthe pretreatment3and6days of corn straw in various aspects of no significantdifference, But added NaOH in3days after basic was work out, so we choose threedays as the appropriate pretreatment time. So pretreatment agent NaOH optimizationparameters of2﹪dosage, temperature is10℃, pretreatment time is three days, organic load rate is65g·L-1.(3): the research of the crops straw on mechanism by NaOH pretreatment.Experiment use scanning electron microscopy(SEM) and Fourier infrared spectrumanalysis method,from straw microscopic physical structure, chemical structure andchemical composition three aspects2%NaOH preprocessing the maize straw,discusses the inner mechanism, found:(1) after pretreatment of corn straw, we use thescanning electron microscopy (SEM),it is known that2%NaOH preprocessing themaize straw, granulated, structure destruction obvious, and fine structure becomeloose, the emergence of a stratified, fall off phenomenon.(2) After pretreatment ofcorn straw, its chemical structure significantly changed, lignin-carbohydratescombined with a complex connect key was disrupted and fracture, Is cellulose andhemi cellulose in the parcel was released, improve the cellulose contact anaerobicfermentation bacteria opportunity, is maize straw anaerobic fermentation gas yieldimprovement of basic reasons.(3) After pretreatment of corn straw, the cellulose,hemi cellulose and lignin content had the very big change, Cellulose content from30.5%to25.4%, hemi cellulose content from the original28.2%to21.7%, the contentof lignin from the original12.5to10.5%, total content from the original71.2%to57.6%, Reduce the amplitude were20.08%,29.95%,19.05%,23.61%. After NaOHpreprocessing of the corn straw, physical structure and chemical structure andchemical composition of the three aspects of what happened the above change, ofcorn straw anaerobic fermentation gas yield increase played a decisive role, is also theNaOH preprocessing the inner mechanism of the corn straw.In this paper, the maize straw methanogenesis process research, to thecomprehensive utilization of the straw stalk, reduce pollution to the environment andthe development of new energy has an important meaning, the combination ofcontemporary China’s national conditions, in our promotion maize straw preparationprocess of methane has a very bright future.