بررسی تاثیر دما و کودگاوی بر تولید بیوگاز از باگاس نیشکر

نوع مقاله: کاربردی

نویسندگان

1 دانش آموخته مهندسی مکانیک بیوسیستم، دانشگاه شهید چمران اهواز

2 استادیار گروه مهندسی بیوسیستم، دانشگاه شهید چمران اهواز

10.22055/agen.2020.29932.1497

چکیده

به دلیل مشکلات زیست­محیطی و افزایش تقاضا برای انرژی، استفاده از انرژی­های پاک و تجدیدپذیر مانند بیوگاز به یک ضرورت تبدیل شده است. در این پژوهش، تاثیر درصد کود گاوی در ترکیب با باگاس نیشکر و دمای محیط درون بیوراکتور­ها بر حجم بیوگاز تولیدی مورد مطالعه قرار گرفت. آزمایش­ها در دو دمای 35 درجه سلسیوس (T1) و 45 درجه سلسیوس (T2) و در چهار ترکیب با نسبت درصد وزنی مختلف از کود به باگاس B5،  B10، B15 و B20 و در سه تکرار در قالب طرح فاکتوریل بر پایه کاملاً تصادفی انجام شد. حجم گاز تولید شده بر حسب ارتفاع ستون آب (برحسب سانتی­متر) اندازه گیری شد. نتایج نشان داد که در سطح یک درصد اثر دما و نسبت کود به باگاس بر مقدار بیوگاز تولید شده اختلاف معنی­داری داشت. همچنین با افزایش دما از T1 به T2 میزان بیوگاز تولید شده در ترکیبات B5، B10، B15 و  B20 به ترتیب 82/36، 50/22، 80/15 و 80/8 درصد  افزایش یافت. با افرایش درصد کود گاوی از  B5به B20 در دمای T1  و  T2 میزان بیوگاز تولیدی به ترتیب 27/68 و 81/31 درصد افزایش یافت، بطوری که بیشترین میزان بیوگاز تولیدی تجمعی برحسب ماده آلی فرارm3.kg.VS-1 33/0 در تیمار B20T2 بدست آمد.

کلیدواژه‌ها


عنوان مقاله [English]

The effect of temperature and cow manure on biogas production from sugarcane bagasse

نویسندگان [English]

  • M.J. Malekzadeh 1
  • M. Kiani Dehkiani 2
  • M. Sajadiyeh 2
1 M.Sc. Student, Department of Biosystems Engineering, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
2 Assistant Professor, Department of Biosystems Engineering, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
چکیده [English]

Introduction The limitation of fossil fuels and environmental pollution by using them have encouraged researchers toward renewable fuels.  The most important renewable fuels are bioethanol, biodiesel and biogas. Biogas is a gas that is produced from biodegradable fermentation, agricultural products and wastes, animal waste and urban waste by anaerobic digestion.  One of the products that has a significant amount of waste is sugar cane. This plant is widely cultivated in Khuzestan Province and annually produces a lot of waste which is currently not useful. One of the most important wastes is bagasse. Bagasse is the solid residues after crushing sugar cane and extracting it. Bagasse is composed of cellulose (45%), humiculus (27%), lignin (21%), extract (5%) and a small amount of inorganic salts (2%). A lot of bagasse is produced in sugar cane production process (about 240 kg with a moisture content of 50% per ton of sugar cane). Every year, a lot of bagasse is wasted. One of the most useful ways is to convert it into biogas and provide the percentage of the required thermal and electrical energy of the plant. Therefore, in this study, the effect of temperature and percentage of cow manure as an additive on biogas production from bagasse sugar cane was investigated.
 
Materials and Methods The used bagasse in this research was provided from Farabi industry and Cultivation, located 48 km from Ahwaz, and a cow manure was provided from a livestock farm in Hamidieh, Ahwaz. In order to increasing the production efficiency of biogas, sugar cane bagasse was milled. Batch reactors of 4 liters was used to produce biogas from sugar cane bagasse.  To control and maintain the working temperature, the reactors were placed in a water bath and the temperature of the bath was kept constant by using the thermal element and the thermostat. Cow manure was used to provide source of microorganisms. Cow manure with 5, 10, 15 and 20% weight percentages (B5, B10, B15 and B20) was blended with bagasse (numeric index of B indicates the percentage of cow manure in the blends). Sodium bicarbonate was used to control the pH of the reactors. Stirring was carried out manually in order to homogenize the materials and prevent the formation of hard layer at the top of the reactors. The amount of produced biogas was daily measured by water displacement method. Another measured parameter was the total Solid Index (TS), which represents the percentage of organic and inorganic matter for materials of the reactors. The experiments were carried out by using eight reactors for 30 days and the results were analyzed by completely randomized factorial design.
Results and Discussion The results of variance analysis of biogas production in terms of bagasse to cow manure ratio and temperature changes showed that they had a significant effect at 1% level on biogas production. Considering the interaction effects of temperature and bagasse to cow manure ratios have a significant effect on the produced biogas at a 1% level. The results showed that with increasing in the percentage of cow manure in the materials, the amount of biogas production increased at both temperatures, so that by increasing the ratio of cow manure in the blends from 5 to 20% at 35 and 45 ° C, the produced biogas increased by 27.78% and 81.83%, respectively. By increasing the percentage of cow manure in the blends, the number of microorganisms in the digestion increased, and as a result of their activity, the amount of produced biogas increased. It was also observed that with increasing the temperature of digestion from 35 ° C to 45 ° C, the biogas production for B5, B10, B15 and B20 blends increased by 19.82%, 22.5%, 15.85% and 80.8%, respectively. The highest amount of cumulative production of biogas was obtained 0.3 m3.kg.VS-1 for 45 ° C and 20% cow manure to bagasse ratio.
Conclusion In this research, the effect of cow manure in blend of sugar cane bagasse and temperature on produced biogas was investigated. The experiments were carried out at two temperatures of 35 and 45 ° C, and four blends with different weight percentages from cow manure to bagasse (5, 10, 15 and 20 percent). The results showed that with increasing the percentage of cow manure in blends, the amount of biogas production increased. Also, with increasing temperatures from 35 ° C to 45 ° C, the production of biogas in all blends increased.

کلیدواژه‌ها [English]

  • Biogas
  • Sugarcane Bagasse
  • Cow manure
  • methane