Judul: Energy Balance and Life Cycle Assessment (LCA) Analysis for Bioethanol Production Cassava-Based (Manihot utilissima)
Abstrak: Bioetanol merupakan bahan bakar nabati alternatif untuk mengurangi penggunaan bensin. Perkembangan industri bioetanol di Indonesia semakin meningkat untuk mencapai target bauran energi dengan program Pertamax Green 95. Pemerintah juga mengoptimalkan keikutsertaan perusahaan terhadap kepedulian lingkungan melalui Program Penilaian Peringkat Kinerja Perusahaan dalam Pengelolaan Lingkungan Hidup (PROPER) dengan salah satu penilaiannya yaitu Life Cycle Assessment (LCA). Penelitian ini bertujuan untuk melakukan inventori, menganalisis neraca energi, mengkaji dampak, melakukan analisis sensitivitas, dan rekomendasi perbaikan pada daur hidup bioetanol berbahan baku singkong di Indonesia, khususnya di Jawa Barat. Penelitian ini menggunakan data sekunder terkait informasi aktual daur hidup bioetanol dengan batasan cradle to gate. Metode penilaian dampak yang digunakan yaitu Recipe 2016 Midpoint (H). Penelitian ini mengacu pada SNI ISO 14040:2016 dan 14044:2017 dengan kategori dampak Global Warming Potential (GWP), Stratospheric Ozone Depletion (SOD), Terrestrial Acidification (TAC), Freshwater Eutrophication (FEU), Terrestrial Ecotoxicity (TEC), dan Human Carcinogenic Toxicity (HCT). Berdasarkan perhitungan neraca energi dengan melibatkan embodied energy bahan baku, diperoleh nilai Net Energy Gain (NEG) dan Net Energy Ratio (NER) sebesar -59,79 MJ/L dan 0,365, serta energi spesifik sebesar 17,16 MJ/L. Potensi dampak lingkungan aktual per liter bioetanol dihasilkan GWP 11,88 kg CO2 eq; SOD 5,9x10-6 kg CFC11 eq; TAC 0,04 kg SO2 eq; FEU 0,01 kg P eq; TEC 41,60 kg 1,4-DCB; dan HCT 2,51 kg 1,4-DCB. Kontribusi terbesar (hotspot) terdapat pada proses pemurnian bioetanol yaitu distilasi dan dehidrasi. Analisis sensitivitas diantaranya skenario jarak kebun/industri chip ke industri bioetanol dan skenario pemanfaatan limbah menunjukkan neraca energi dan dampak lingkungan yang lebih baik., Bioethanol is an alternative biofuel to reduce gasoline consumption. Indonesia’s bioethanol industry development is increasing to achieve the energy mix target through Pertamax Green 95. The government also optimizes companies participation in environmental concerns through the Company Performance Rating Program in Environmental Management (PROPER) with one of it is Life Cycle Assessment (LCA). This research aims to conduct inventories, analyze energy balances, assess impacts, conduct sensitivity analysis and improvement recommendations of the life cycle bioethanol cassava-based in Indonesia, especially West Java. This research uses secondary data related to actual information by cradle to gate. The life cycle impact assessment method based on Recipe 2016 Midpoint (H). This research refers to SNI ISO 14040:2016 and 14044:2017 by analyzing Global Warming Potential (GWP), Stratospheric Ozone Depletion (SOD), Terrestrial Acidification (TAC), Freshwater Eutrophication (FEU), Terrestrial Ecotoxicity (TEC), and Human Carcinogenic Toxicity (HCT). Energy balance calculaion for Net Energy Gain (NEG) and Net Energy Ratio (NER) that involving embodied energy of raw materials are -59.79 MJ/L and 0.365, then the spesific energy consumption is 17,16 MJ/L. While the environmental impact per liter of bioethanol produced GWP 11.88 kg CO2 eq; SOD 5.9x10-6 kg CFC11 eq; TAC 0.04 kg SO2 eq; FEU 0.01 kg P eq; TEC 41.60 kg 1,4-DCB; dan HCT 2.51 kg 1,4-DCB. The biggest contribution (hotspot) is purifying bioethanol process, these are distillation and dehydration. The sensitivity analysis consists of distance from the farm/chip industry to the bioethanol industry scenario and waste utilization scenario showing improvement for energy balance and environmental impact.
Keyword: bioethanol, cassava, energy balance, life cycle assessment

Judul: Penilaian Daur Hidup (Life Cycle Assessment) Bioetanol Berbahan Baku Limbah Tanaman Jagung
Abstrak: Life Cycle Assessment (LCA) is the analysis system used in evaluating the environmental impacts of a product life cycle as a whole. LCA focuses on the factor to collect information and analyze the environmental impact caused by a product. This approach aims to avoid the mistakes of the outstanding environmental issues (UNEP, 1996; ISO, 1997. Ethanol or ethyl alcohol (familiar as “alcohol”, C2H5OH) is liquid has no colour with characteristic flamable, water soluble, biodegradable, and doesn’t give environmental impact if there’s contamination. Bioethanol is ethanol (alcohol), fermented from sugar, starches, and selullosic bimass (Demirbas, 2005). The purpose of this study were to identify the impact from life cycle of bioethanol made from corn stover with biological and chemical delignification stage and combination starter Zymomonas mobilis with Pichia stipitis and Saccharomyces cerevisiae with Pichia stipitis on stage fermentation and then determine the best process steps based on use of energy, raw materials, and pollution caused. The scope of this study include the transportation of raw materials; the use of boilers; electricity use; preparation of materials include mushroom breeding, starter, and demolition materials; preparation materials include delignification, hydrothermal I and II; Simultaneous Saccharification and Co-Fermentation (SSF) include pre-hydrolysis and fermentation; purification; and Waste Water Treatment Plant (WWTP). The use of LCA method conducted on eight specified design based delignification stage and the combination of starter during fermentation. Delignification of the R1 and R2 using Ca (OH) 2, R3 and R4 using white rot fungus Pleurotus ostreatus, R5 and R6 using Phanerochaete chrysosporium, whereas R7 and R8 use Tratemetes vercolor. Fermentation at R1, R3, R5, and R7 using Zymomonas mobilis and Pichia stipitis, while R2, R4, R6, R8 using Saccharomyces cerevisiae and Pichia stipitis. LCA method were performed, consist of inventory analysis and impact analysis. Inventory analysis, conducted by collected data related to the processes in the laboratory and the collection of literature related to energy demand and emissions generated. Impact analysis, done by created a matrix and flow chart the impact of significant impacts, where the assessment is based on inventory analysis has been done. The next stage is the selection of the best designs using Bayes method. Supplies of raw materials for the eighth design in produce 500 litre bioethanol 95% is 2,904.68 to 5,150.62 kg, energy demand 61,255.16 to 84,958.29 MJ, produce as much emissions 4,591.14 to 6,390.25 kg, solid waste 24,492.51 to 45,141.25 kg, and liquid waste 135,535.80 to 287,247.05 kg. Best design based on calculations used Bayes method is R7, the design with biological delignification used Trametes vercolor and fermentation used a combination starter Zymomonas mobilis dan Pichia stipitis. It is influenced by the ability to produce bioethanol by each design.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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