Life Cycle Assessment for Bioethanol Production from Oil Palm Frond Juice in an Oil Palm Based Biorefinery

Abstract

A study was conducted to estimate the possible environmental impacts arising from the generation of bioethanol from oil palm frond sugar juice in a theoretical oil palm based biorefinery model. A life cycle assessment (LCA) with the gate-to-gate approach was performed with the aid of SimaPro version 8.0 whereby ten impact categories were evaluated. The scope included frond collection and transportation, frond sugar juice extraction, and bioethanol fermentation and purification. Evaluation on the processes involved indicated that fermentation contributed to the environmental problems the most, with a contribution range of 52% to 97% for all the impact categories. This was due to a substantial usage of nutrient during this process, which consumes high energy for its production thus contributing a significant burden to the surrounding. Nevertheless, the present system offers a great option for biofuel generation as it utilizes sugar juice from the readily available oil palm waste. Not only solving the issue of land utilization for feedstock cultivation, the enzymatic saccharification step, which commonly necessary for lignocellulosic sugar recovery could also be eliminated.

Life Cycle Analysis of the Bioethanol Production from Food Waste—A Review

“…Thus, the pretreatment stage is not very demanding in terms of energy (heat) or additional materials (acid, alkali, organic solvents etc.). The same is true for some industrial food wastes with high sugar content, for example, palm oil frond [13], banana waste [18], brewery waste [19] and fruit syrups [21], which can be utilized for the production of ethanol without energy-intensive pretreatment processes. Once the pretreatment step has been concluded, the hydrolysis step follows.…”

“…Other studies use as functional unit 1 TJ bioenergy [8], others 1MJ ethanol [9,10] or 1kg ethanol [11]. When the focus of the study is on the ethanol production technologies then a volumetric unit of ethanol (i.e., 1L or 1 ton) is prefered as the functional unit [12][13][14].…”

“…However, there are cases that present negative environmental impacts regarding the production of bioethanol from food waste. According to Yusof et al who studied the possibility of producing bioethanol from oil palm frond sugar juice in a theoretical biorefinery, the bottleneck of the process was the fermentation step because of the nutrients used [13]. This finding highlights the need for a careful selection of the feedstock used as well as for optimization in all the steps of a process.…”

“…Apart from the GHG emissions and the relevant impact categories, 50% of the studies assess midpoint impact categories such as AP, EP, TEP, MEP which allow a more detailed assessment of the system [9,[12][13][14][18][19][20]. These studies show strong evidence regarding the environmental benefits of the production of bioethanol from food waste.…”

Tropical agroindustrial biowaste revalorization through integrative biorefineries—review part I: coffee and palm oil by-products

“…Nevertheless, there are still many challenges that should be addressed to optimize and integrate a full process in the oil palm industry. These obstacles have been thoroughly described by others [85][86][87][88][89].…”