بررسی تأثیر شرایط هیدرودینامیکی و نرخ انتقال جرم در آبکافت آنزیمی ریزجلبک مختلط

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی شیمی، دانشگاه صنعتی سهند

چکیده

ریزجلبک‌ها با داشتن ذخایر زیاد کربوهیدرات‌ها و سرعت بالای رشد، به‌‌عنوان یکی از
نوید بخش­ترین منابع برای تولید بیواتانول معرفی شده‌اند. در این تحقیق، بعد از کشت گونه‌های مختلط ریزجلبک در فتوبیوراکتور، برای افزایش
تجمع کربوهیدرات­ها در ریزجلبک از راهبرد قحطی نیتروژن استفاده شد. سپس، استخراج قندهای موجود در زیست‌توده با استفاده از فرایند آبکافت آنزیمی به‌وسیلۀ آنزیم سلولاز انجام شد. در این مقاله برای نخستین‌بار، فرایند آبکافت آنزیمی ریزجلبک با در نظرگرفتن شرایط هیدرودینامیکی سیال درون راکتور بررسی شد. نتایج نشان داد که افزایش همزدگی سامانه بیش از غلظت آنزیم، بر بازده آبکافت تأثیر می‌گذارد. در دورهای بالاتر از rpm 250 که رژیم جریان از آرام به متلاطم تغییر می‌کند، میزان قند آزادشده بسیار بیشتر از مقادیر در دورهای پایین همزن است. هم‌چنین، افزودن بافل با جلوگیری از تشکیل گردابه میزان انتقال جرم را و به‌تبع آن بازده آبکافت را افزایش می‌دهد؛ اما تغییر نوع همزن تأثیر قابل ملاحظه‌ای بر فرایند آبکافت ندارد. هم‌چنین در این تحقیق، تأثیر همزدگی در طول فرایند آبکافت از راه ارزیابی نرخ انتقال جرم بررسی شد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of the Hydrodynamic Condition Effects and Mass Transfer Rate on Enzymatic Hydrolysis of Mixed Microalgae

چکیده [English]

Microalgae with reserves of carbohydrates, high growth rate have been introduced as one of the most promising sources for bioethanol production. In this study, after culturing mixed microalgae species in photobioreactors, a nitrogen starvation strategy was used to increase the accumulation of carbohydrates in microalgae. Then, the sugars in the biomass were extracted using enzymatic hydrolysis by cellulase enzyme. For the first time, the enzymatic hydrolysis of microalgae is investigated by considering the dynamic conditions of the fluid inside the reactor. The results showed that increasing the system agitation more than the enzyme concentration affects the hydrolysis efficiency. At high speeds of 250 rpm, where the flow regime changes from slow to turbulent, the amount of sugar released is much higher than the values at low speeds of the stirrer. Also, adding baffle increases the mass transfer rate by preventing the formation of vortices and consequently increases the hydrolysis efficiency. But changing
the type of stirrer does not have a significant effect on
the hydrolysis process. Also in this study, the effect of agitation during the hydrolysis process was investigated by evaluating the mass transfer rate.

کلیدواژه‌ها [English]

  • Baffle
  • Mixed microalgae
  • Hydrodynamic Fluid Condition
  • stirrer
  • Enzymatic hydrolysis
  • Mass Transfer
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