• Energy Research

Traditional Cambodian food has higher nutrient balances and is environmentally sustainable compared to conventional diets. However, there is a lack of knowledge and evidence on nutrient intake and the environmental greenness of traditional food at different age distributions. The relationship between nutritional intake and environmental impact can be evaluated using carbon dioxide (CO2) emissions from agricultural production based on life cycle assessment (LCA). The objective of this study was to estimate the CO2 equivalent (eq) emissions from the traditional Cambodian diet using LCA, starting at each agricultural production phase. A one-year food consumption scenario with the traditional diet was established. Five breakfast (BF1–5) and seven lunch and dinner (LD1–7) food sets were consumed at the same rate and compared using LCA. The results showed that BF1 and LD2 had the lowest and highest emissions (0.3 Mt CO2 eq/yr and 1.2 Mt CO2 eq/yr, respectively). The food calories, minerals, and vitamins met the recommended dietary allowance. The country’s existing food production system generates CO2 emissions of 9.7 Mt CO2 eq/yr, with the proposed system reducing these by 28.9% to 6.9 Mt CO2 eq/yr. The change in each food item could decrease emissions depending on the type and quantity of the food set, especially meat and milk consumption.

Indonesia is the largest producer of palm oil; it is essential to manage its palm oil industry in a sustainable manner through swapping the oil palm plantation in peatland to mineral soil to reduce the greenhouse gas emissions. This study employed the latest spatial data using the ArcGIS software to analyze the potential area for the land swap option and to calculate the potential reduction in greenhouse gas emissions in Kalimantan, Indonesia. There are 1.08 million ha of oil palm in peatland, while 0.64 million ha of the area in mineral soil under the convertible production forest have the potential for land swapping. Via the land-swap option, emission reductions of 65.43% (from 979.05 MtCO2eq to 336.64 MtCO2eq) for the calculation period of 25 years and up to 61.19% (from 2147.81 MtCO2eq to 833.67 MtCO2eq) for that of 50 years is possible compared to the initial condition. The land swap will also increase the production of fresh fruit bunch (FFB) by 17.16% per year because the productivity of FFB in mineral soil is higher than that of the peatland. Considering that land swaps are costly, policymakers and stakeholders must collaborate to execute the land-swap option for the sustainability of Indonesian palm oil.

Most studies on honeycomb catalysts have been conducted using simulation models and exhaust experiments from automobiles. Very few monolithic catalyst studies have been applied to the agricultural sector, especially the catalyst exhaust system for flue purification from the biomass industry. The importance of exhaust gas purification and particulate removal from biomass power plants has become critical for evaluating the performance and environmental sustainability of biomass combustion. This is one of the first studies to investigate the performance of honeycomb catalysts for the oxidation of flue (PM2.5), (CO), and (SO2) from a rice husk briquette combustion system. The experimental setup comprised a fixed-bed electric furnace, the catalyst, an aerosol sampler, and a flue gas analyzer. Rice husk (0.1 g/mL density) and rice husk briquettes (0.8 g/mL density), were burned at 600–1000 °C for 3 min. From the results, the catalyst CO conversion rate was 100% at the optimum heated temperatures of 427.4–490.3 °C. At these temperatures, the inhibition effect of the chemisorbed CO was significantly minimized, enhancing the adsorption of oxygen, which reacted with CO to form CO2. However, SO2 oxidation was lower than that of CO because platinum-based catalysts are generally more attracted to CO in the presence of oxygen. The emission of PM2.5 decreased from its uncatalyzed-value (1169.9 mg/m3 and 1572.2 mg/m3) to its catalyzed values (18.9 mg/m3 and 170.1 mg/m3). This is a significant result in ensuring cleaner production of energy from rice husk.

A comparative evaluation of energy requirement and CO2 emission was performed for native polyculture microalgae oil production in a wastewater treatment plant (WWTP). The wastewater provided nutrients for algae growth. Datasets of microalgae oil production and their details were collected from the Minamisoma pilot plant. Environmental impact estimation from direct energy and material balance was analyzed using SimaPro® v8.0.4. in two scenarios: existing and algal scenarios. In the existing scenario, CO2 emission sources were from wastewater treatment, sludge treatment, and import of crude oil. In the algal scenario, CO2 emission with microalgae production was considered using wastewater treatment, CO2 absorption from growing algae, and hydrothermal liquefaction (HTL) for extraction, along with the exclusion of exhausted CO2 emission for growing algae and use of discharged heat for HTL. In these two scenarios, 1 m3 of wastewater was treated, and 2.17 MJ higher heating value (HHV) output was obtained. Consequently, 2.76 kg-CO2 eq/m3-wastewater in the existing scenario and 1.59 kg-CO2 eq/m3-wastewater in the algal scenario were calculated. In the HTL process, 21.5 MJ/m3-wastewater of the discharged heat energy was required in the algal scenario. Hence, the efficiency of the biocrude production system will surpass those of the WWTP and imported crude oil.

A comparative evaluation of economic efficiency was performed for native polyculture microalgae oil production in an oxidation ditch (OD) process wastewater treatment plant (WWTP). A cost function was developed for the process. The operational cost per 1 m3 of wastewater (w.w.) was 1.34 $/m3-w.w. in the existing scenario, 1.29 $/m3-w.w. in algal scenario A (no cost for CO2 and waste heat) and 1.36 $/m3-w.w. in algal scenario B (no cost for CO2). The conditions were set as follows: hydraulic retention time (HRT): 4 days, microalgal productivity: 0.148 g/L and daily treatment volume: 81.6 m3-w.w./d. The cost differences were related to the increase in polymer flocculants for algae separation (+0.23 $/m3-w.w), carbon credits from CO2 absorption (−0.01 $/m3-w.w), the sales of biocrude (−0.04 $/m3-w.w) and sludge disposal (−0.18 $/m3-w.w). Hence, the introduction of the algae scenario was the same cost-effective as the existing scenario. Microalgae oil production in an OD process WWTP can serve as a new energy system and reduce the environmental load in a society with a declining population.

Coffee is an important agricultural commodity that is branded according to its environmental criteria in the global market. Therefore, Indonesia’s coffee production system needs to be investigated to meet the demand for eco-labeling, which has become a consumer preference. This study aims to assess the comprehensive sustainability evaluation of coffee production nurtured by an organic fertilizing system (OFS), chemical-organic fertilizing system (COFS), and chemical fertilizing system (CFS) that focuses on the energy–environment–economic nexus. A life cycle assessment (LCA), life cycle cost analysis (LCC), and energy analysis were performed as methods to evaluate the environmental impact, economic performance, and energy requirement analysis. The results indicated that the OFS had superior performance in two sustainability aspects: resulting in the lowest environmental damage and generating the highest economic benefit. Simultaneously, COFS shows the highest sustainability performance as it consumes the least energy. In contrast, CFS indicated the lowest sustainability performance in all aspects: highest environmental impact, lowest economic benefit, and highest energy consumption. Therefore, OFS is strongly recommended to be applied broadly, considering its environmental and economic superiority. Consequently, massive OFS application was followed by higher energy consumption. Alternatively, COFS can be considered for application due to its higher energy performance, even though it can potentially result in higher environmental damage and lower economic benefit. However, the government should explicitly provide some effort for the broad application of OFS in financial and assistance support since the shifting process needs more time to adapt.

The demand for coffee in the local and global markets has encouraged massive production at upstream and downstream levels. The socioeconomic impact of coffee production still presents an issue, primarily related to the social benefit and economic value added for farmers. This study aims to identify the social impact of the coffee industry in rural areas in three different coffee industry management systems. Many coffee industries exist in rural areas, with various management systems: farmer group organizations, middlemen, and smallholder private coffee production. This study performed the social organization life cycle assessment to identify the social impact of the coffee industry in rural areas according to the management systems. The results indicated that the coffee industry managed by farmers is superior in providing a positive social impact to four stakeholders: workers, the local community, society, and suppliers, as indicated by the highest social impact scores of 0.46 for the workers, 0.8 for the local community, 0.54 for society, and 0.615 for the suppliers. The private coffee industry provides the highest social impact to consumers (0.43), and the middlemen were very loyal to the shareholders, with a total social impact score of 0.544. According to this social sustainability index analysis, the coffee industry managed by the farmer group has the highest endpoint of social impact at 0.64, which is categorized as the “sustainable” status. Meanwhile, the coffee industry managed by private companies and middlemen is categorized as “neutral or sufficient”. The coffee industry should implement improvement strategies to increase their social impact to all stakeholders in their business supply chain.

Palm oil mill effluent (POME) is a major concern as open lagoon technology is not environment-friendly. Therefore, the palm oil industry refers to a roundtable on sustainable palm oil (RSPO), Indonesian sustainable palm oil (ISPO), and Malaysian sustainable palm oil (MSPO) standards for POME treatment to reduce greenhouse gas emissions. An alternative POME treatment technology is the combination of open lagoon technology (COLT) with composting, biogas technology plus composting, biogas technology plus membrane, and biogas technology plus land application. The objective of this study is to analyze the life cycle assessment (LCA) result using a multi-criteria decision approach and to determine the implementation of POME treatment in the RSPO, ISPO, and MSPO standards. The LCA system boundary was considered from gate-to-gate and unit per ton of fresh fruit bunch as a functional unit. SimaPro® was used as the LCA analysis tool; Expert Choice® and Super Decision Software® were used to perform the analytic hierarchy process and analytic network process, respectively. In this study, COLT–Biogas plus composting technology had the maximum priority weight (0.470), according to the opinion of experts. The results could help palm oil mill decision-makers in choosing environment-friendly POME treatment technology.