欢迎来到麦多课文档分享! | 帮助中心 海量文档,免费浏览,给你所需,享你所想!
麦多课文档分享
全部分类
  • 标准规范>
  • 教学课件>
  • 考试资料>
  • 办公文档>
  • 学术论文>
  • 行业资料>
  • 易语言源码>
  • ImageVerifierCode 换一换
    首页 麦多课文档分享 > 资源分类 > PPT文档下载
    分享到微信 分享到微博 分享到QQ空间

    THE SCIENCE BEHIND ANAEROBIC DIGESTION.ppt

    • 资源ID:373103       资源大小:937.50KB        全文页数:24页
    • 资源格式: PPT        下载积分:2000积分
    快捷下载 游客一键下载
    账号登录下载
    微信登录下载
    二维码
    微信扫一扫登录
    下载资源需要2000积分(如需开发票,请勿充值!)
    邮箱/手机:
    温馨提示:
    如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
    如需开发票,请勿充值!如填写123,账号就是123,密码也是123。
    支付方式: 支付宝扫码支付    微信扫码支付   
    验证码:   换一换

    加入VIP,交流精品资源
     
    账号:
    密码:
    验证码:   换一换
      忘记密码?
        
    友情提示
    2、PDF文件下载后,可能会被浏览器默认打开,此种情况可以点击浏览器菜单,保存网页到桌面,就可以正常下载了。
    3、本站不支持迅雷下载,请使用电脑自带的IE浏览器,或者360浏览器、谷歌浏览器下载即可。
    4、本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰。
    5、试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。

    THE SCIENCE BEHIND ANAEROBIC DIGESTION.ppt

    1、,THE SCIENCE BEHIND ANAEROBIC DIGESTION,Dr Joseph C. Akunna Reader in Water & Environmental Engineering +44 1382 308141 j.akunnaabertay.ac.uk Dundee, 4th Sept 2013,Biofuels Series: Anaerobic Digestion Industry Engagement Event,CONTENTS,Introduction Factors affecting process efficiency Process monito

    2、ring and control Technological options: Examples Conclusions,INTRODUCTION,Process fundamentals,Typical biogas composition: 50-70 %CH4; 30-50%CO2,Main stages - simplified,SOLUBLE ORGANIC MATTER,Organic Acids, CO2, H2,Biogas: CH4 + CO2,Hydrolysis,PARTICULATE ORGANIC MATTER,Acid production Optimum pH:

    3、6.0,Methane production Optimum pH: 7.0,Biogas yield of common feedstocks,Manure: Biogas yield = 200-500 m3/t (dry solids) Cow: 200-400 m3/t VS; Pig and Chicken: 350-550 m3/t VS* Wastes: Biogas yield = 400-800 m3/t (dry solids) Household = 100-200 m3/t VS Green (vegetable/garden/parks): 400-500 m3/t

    4、(dry solids) Sewage sludge 500 m3/t (dry solids) Farm residuals (e.g. Corn, grass, maize, barely, sorghum, wheat silage): Biogas yield = 500-900 m3/t (dry solids),*VS, Volatile Solids, is a measure of the organic content,FACTORS AFFECTING PROCESS EFFICIENCY,Process conditions,Mixed culture of anaero

    5、bic micro-organisms Where possible, use active seed inoculum from operational anaerobic digesters Anaerobic conditions Ensure absence of oxygen/air, nitrogen oxides (i.e., nitrates and nitrites)Moisture contentWet Digestion: less than 16% dry solids; Dry Digestion: 22-40% dry solids Temperature Psyc

    6、hrophilic: 5 - 20C Mesophilic: 20 - 45C (optimum: 35C) - most common Thermophilic: 45 - 70C (optimum: 55C),Effect of temperature on anaerobic digestion process (Mata-Alvarez 2003),Process conditions (Contd),Hydraulic Retention Time (HRT) Reaction Time Values depend on feedstock characteristics, proc

    7、ess technology, temperature, Solids Retention time (SRT) Time microorganisms remain in a digester Organic loading rate (OLR) Amount of organic matter fed per m3 of digester Values depend on feedstock characteristics, temperature, Consistent operating conditions e.g. HRT, SRT, OLR, TC, ,Process condi

    8、tions (contd),Nutrient requirementsMinimum C/N/P ratio: 100/5/1 Trace elements: nickel, cobalt, etc pH: Optimum between 6.5 and 7.5 Alkalinity: High level reduce excessive pH fluctuations Toxic compounds (NH3, H2S, O2, NO2/NO3, antibiotics, disinfectants, etc) Mixing, prevention of pressure build-up

    9、, increase in microorganism-substrate contact, etc Feedstock preparation (removal of inorganics, plastics, solid size reduction, pH/nutrient correction, etc),Process conditions (contd),Nature of substrate (type, solid content and size, etc),rate of degradation,retention time,sugars (mono/disaccharid

    10、es),starch,proteins,hemicellulose,lignin,waxes,Effect of the nature of organic matter on reaction rates (Eder and Schulz 2006),rate of degradation,retention time,sugars (mono/disaccharides),starch,proteins,hemicellulose,lignin,waxes,Effect of the nature of organic matter on reaction rates (Eder and

    11、Schulz 2006),Common methods for enhancing process efficiency,Increasing hydrolysis rates by pre-treatment:Enzymatic treatmentUltra-sound treatmentAcid treatmentAlkaline treatmentHeat treatment, etcCombination of some of the above Phase-separation Multi-stage systems,Digestion phases,PROCESS MONITORI

    12、NG & CONTROL,Key parameters,Influent/Feedstock characteristics VS, COD, N, P, pH, sulphates, metals HRT, OLR Temperature Biogas Quantity and Composition (CH4, CO, CO2, H2, H2S) Treated effluent quality Volatile fatty acids (total and constituents) COD, ammonia, total N, pH, VS,Summary of major chall

    13、enges of AD process,Delicate process; requires skilled manpowerDifficult to resurrect when process fails Long start-up timesPost aerobic polishing is usually necessary before discharge of treated effluent or digestate into the water or soil environment,TECHNOLOGICAL OPTIONS: EXAMPLES,Options for liq

    14、uid organic residues/slurries,Chemical-assistedsolids reduction+ pH and nutrientcorrection,Anaerobic Digester,pH and nutrient correction,Anaerobic Digester,pH and nutrientcorrection,Anaerobic Digester 2,Anaerobic Digester 1,Hydrolytic treatment + pH and nutrientcorrection,Anaerobic Digester,Aerobic

    15、polishing,Aerobic polishing,Aerobic polishing,Aerobic polishing,1,2,3,4,Solids for further treatment and/or disposal,Options for solid/semi-solid organic residues,Compost,CONCLUSIONS,1. MOST ANAEROBIC DIGESTIONS SYSTEMS CAN WORK PROPERLY IF WELL OPERATED,2. PROCESS MONITORING AND CONTROL ARE SOME OF THE MOST IMPORTANT COMPONENTS OF SUCCESSFUL DIGESTION APPLICATION3. EARLY DETECTION IS KEY TO EFFECTIVE RESOLUTION OF PROCESS RELATED PROBLEMS,Thank you for listening,Any Questions?,


    注意事项

    本文(THE SCIENCE BEHIND ANAEROBIC DIGESTION.ppt)为本站会员(medalangle361)主动上传,麦多课文档分享仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文档分享(点击联系客服),我们立即给予删除!




    关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服 - 联系我们

    copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
    备案/许可证编号:苏ICP备17064731号-1 

    收起
    展开