Effect of Chemical Pre-treatments on Bioethanol Production from Chlorella minutissima

Abstract

In recent years, algal bioethanol production comes into prominence as a trend towards sustainable development. Due to being sustainable energy source and environmental friendly, bioethanol production from algae is becoming increasingly popular all over the world. However, yield of bioethanol production from algae is lower than first generation feedstock's currently, and needs to be improved. In order to increase bioethanol yield, pre-treatments should be performed as cell disruption process on algal biomass. For this reason, researchers investigate the most appropriate pre-treatment method and its parameters for high yield bioethanol production from algae. In this study, cultivated Chlorella minutissima was utilized for bioethanol production. Effects of pre-treatment method (dilute acid and alkaline), chemical concentration, pre-treatment temperature and pre-treatment time on bioethanol yield were investigated. It was found that, the highest bioethanol yield was obtained as 18.52% with acid pre-treatment at pre-treatment temperature of 100 °C and pre-treatment time of 60 minutes.

Optimization of chemical pre-treatment methods for production of bioethanol from dry fallen Neem leaves

“…Moreover, comparatively dilute acids effectively remove hemicellulose as dissolved sugars, and due to the removal of hemicellulose the glucose yield from cellulose also increases resulting in an enhanced yield of sugars [19]. The results suggest that with increase in temperature there is a simultaneous increase in the sugar content which is in agreement with the literature reports [2,3]. For temperature higher than 120 °C, the yield of reducible sugar is found to decrease.…”

“…of 1N and reaction time of 60 min. The results of the study are shown in Fig 5.The results suggest that with increase in temperature there is a simultaneous increase in the sugar content which is in agreement with the literature reports[2,3]. For temperature higher than 120 °C, the yield of reducible sugar is found to decrease.…”

“…After that the fermented broth was distillated with the round bottom distillation column enclosed with a running tap water and the temperature was set up to 78.3°C. Then, the distillate was collected in the other end of the distillation column Characterization of powdered neem leaves was carried out to analyse the total carbohydrate (cellulose and hemicelluloses content), moisture and ash content using a similar procedure reported elsewhere [3]. Besides the biomass sample was also characterized by FTIR spectroscopy for analyzing the presence of various functional groups along with lignin content in the samples [12].…”

“…The increase in global green house emissions due to extensive use of fossil fuels has become a major concern. Thus development and use of alternate renewable source of energy with negligible carbon footprint is the need of the day [2,3,4,5]. Recently energy derived from biomass is grabbing the attention worldwide as a potential renewable energy source.…”

“…The biological pretreatment causes the degradation of lignin and reduces the degree of polymerization in both cellulose and hemicellulose. The chemical pre-treatment step is easy to perform and highly efficient [3,12]. Following the pretreatment step, the cellulose and hemicellulose are hydrolyzed either enzymatically or chemically producing simple fermentable carbohydrates/sugars [12].…”