Haniif Prasetiawan

Indonesia’s energy demand continues to rise each year, while domestic oil reserves are steadily declining, highlighting the need for alternative energy sources such as bio-oil. Bio-oil, a dark-colored, combustible, acidic liquid with a smoky odor, can be produced through the pyrolysis of biomass. Pyrolysis is a thermal decomposition process where organic materials are converted into gas, liquid (bio-oil), and charcoal under oxygen-free conditions. This study investigated the impact of varying biomass waste compositions on the yields and properties of pyrolysis products. The primary feedstocks were sawdust and sugarcane bagasse, mixed in specific ratios. Pyrolysis experiments were conducted at 400, 500, and 600°C for 60 minutes. The results showed that the highest bio-oil yield, 27%, was achieved using 100% sugarcane bagasse at 400°C, with a calorific value of 5472.13 cal/g. These findings demonstrate the influence of biomass composition and pyrolysis temperature on bio-oil production, supporting its potential as a renewable energy source in Indonesia.

This study discusses modifying the geometric shape of the nozzle ring of the Vertical Roller Mill (VRM) to increase milling performance and energy efficiency. Computational Fluid Dynamics (CFD) and Discrete Phase Model (DPM) simulations are used to compare the design standard with the design modified, which is equipped with two water splitter elements in the form of a sickle. Simulation results show that modification produces a decline in peak speed gas flow up to 30%, reducing intensity turbulence by 14%, and increasing stability flow with the moving turbulent zone moving to the nearby area walls. In addition, the total energy consumption decreases by about 7%, extending the age of use components and allowing equipment to operate at its optimal efficiency. From the side performance particle, fraction “escaped” particles increase from 35.0% to 44.4%, indicating extension time stays and improves interaction with gas particles. Thus, this nozzle ring modification proved to increase the efficiency of transporting particles, stabilize the air flow, and reduce operational pressure. Because it is passive and modular, the design can be implemented without changing the existing structure of the channel air. Research. This recommends validating the field on the VRM scale industry and exploring alternative splitter forms to optimize performance further.

Durian peel waste in Ervin Duren, Jepara, has not been optimally utilized, despite its large amount and potential to pollute the environment. Therefore, this community service activity was conducted to empower local MSMEs through training in making candles from durian peel waste and business feasibility studies. The primary objective of this activity was to enhance product innovation skills and managerial capabilities of small business owners in the village. The method used in this activity involved hands-on training and group discussions to deepen participants' understanding of waste processing and business planning. The results show that participants successfully processed durian peel waste into quality candles, with approximately 75% of participants starting production. Additionally, participants’ understanding of business feasibility aspects significantly improved, particularly in market analysis and financial planning. This activity positively impacted the local economy while encouraging waste reduction in the environment. Overall, this community service demonstrated that product innovation and business management training can increase the competitiveness of local MSMEs and provide sustainable solutions for environmental issues.

The bio-oil production process from biomass waste can be carried out by using a pyrolysis reactor. Pyrolysis is a thermochemical decomposition process of organic materials through a heating process without oxygen, where the raw material will undergo a chemical structure breakdown into a gas phase. The nitrogen gas is needed to suppress or remove the oxygen during the pyrolysis process. Nitrogen flow in a good biomass pyrolysis reactor needs to pay attention to the speed of nitrogen without ignoring the volume of gas storage. For this reason, one thing that can be studied further is the geometry of the inlet of the biomass pyrolysis device. Inlet geometry can be varied based on several parameters, including variations in inlet shape that can affect flow pressure. Therefore, in this research, calculations will be carried out using computational fluid dynamics to obtain optimal outlet velocity and pressure drop results. The simulation will be carried out using inlet discharge data, namely 1 L/min, 2 L/min and 3 L/min which is converted into inlet velocity data. The results show that the modified inlet gas produces a flow rate with a lower pressure and also spreads the nitrogen gas more evenly inside the reactor compared to the unmodified inlet gas.

Bio-oil is a renewable fuel that can be obtained from biomass waste, such as empty palm fruit bunches, sugarcane bagasse, and rice husks. Within a biorefinery framework, bio-oil had not met the standards as a fuel due to the presence of impurities like corrosive phenol. Therefore, the separation of phenol from bio-oil is essential and can be achieved using the extraction method. In this study, biomass wastes (empty fruit bunches of oil palm, sugarcane bagasse, and rice husk) were pyrolyzed in a biorefinery framework to produce bio-oil, which was then refined through liquid-liquid extraction with a methanol-chloroform and ethyl acetate solvents to remove its phenolic compound. The extraction with methanol-chloroform solvent was carried out for 1 h at 50°C. Meanwhile, extraction with ethyl acetate solvent was carried out for 3 h at 70°C. Both extractions used the same variations, i.e., bio-oil: solvent ratio at 1:1, 1:2, 1:3, and 1:4, and stirring speeds of 150 rpm, 200 rpm, 250 rpm, and 300 rpm. The bio-oil obtained from this study contained complex chemical compounds and had characteristics such as a pH of 5, a density of 1.116 g/mL, and a viscosity of 29.57 cSt. The optimization results using response surface methodology (RSM) showed that the best yield for methanol-chloroform was 72.98% at a stirring speed of 250 rpm and a ratio of 1:3. As for ethyl acetate solvent, the highest yield obtained was 71.78% at a stirring speed of 237.145 rpm and a ratio of 1:2.

Aquaponics is an integrated and sustainable farming method that combines aquaculture and hydroponics in a recirculating water system. This system utilizes fish waste as a nutrient source for plants, and the plants act as biofilters to clean the water before it returns to the fish tank. A critical process in this system is nitrification, where ammonia is converted into nitrite and nitrate by beneficial bacteria, reducing toxicity to fish and providing nutrients for plants. This study investigates the efficiency of the nitrification process using four different biofilter media—rockwool, pumice stone, gravel, and zeolite—in a media-raised bed aquaponic system. Results showed that pumice stone provided the highest nitrate concentration (131.62 mg/L), indicating superior nitrification performance. The findings offer valuable insights for optimizing biofilter media selection in aquaponic systems, which is crucial not only for maintaining water quality but also for enhancing crop productivity. The study contributes to the development of more efficient and sustainable aquaponic designs, particularly in regions facing water scarcity and the need for integrated food production solutions.

This research aims to model and simulate the gas drilling mixing process with various conditions in the inlet gas flow. This mixing process is very crucial because it can affect the phase stability in the storage tank. Based on this, the gas that has been mixed must be ensured that it is in a perfectly mixed condition before entering the storage tank. The simulation method used in this research is Computational Fluid Dynamics (CFD) with ANSYS Fluent software. The data used as input in this simulation includes flow velocity, temperature, pressure and drilling gas composition. The simulation results are expected to show that flow velocity and pressure have a significant effect on the drilling gas mixing process in the pipe flow. In addition, the differences in the composition of the drilling gas also have an impact on the mixing process, where the more diverse the composition of the drilling gas, the more difficult it is to mix the gas homogeneously. However, by using baffle plates as a barrier and agitator in the pipe, the simulation results show that the mixing of drilling gas can be significantly increased.

Biodiesel, a third-generation bio-fuels, offering several advantages over regular diesel fuel. Waste cooking oil (WCO) emerges as an ideal feedstock due to its availability and easy accessibility. In this work, biodiesel is utilized from two different types of immobilized lipases: Rhizomucor miehei lipase (RMIM) and Candida antarctica lipase B (CALB). The impact of the molar ratio of oil to methyl acetate (1:3-1:12) was evaluated for both lipases, and the resultant biodiesel was tested in diesel engine. The enzymatic transesterification was carried out in ultrasonic assistance and the results showed that the greatest yield of 81.20% at 45℃, using CALB as a biocatalyst, 1.8% (w/v) lipase and oil to methyl acetate molar ratio of 1:12 within 3 hours. Triacetin, by-product was determined their concentration for each molar ratio and analyzed using FTIR range of 500cm-1 to 4000cm-1, revealing a significant absorption peak at 1238.90cm-1. Biodiesel was blended with commercial diesel fuel in varying quantities of 7, 10, and 20% by volume (B20). The results were compared to Industrial Diesel Fuel 7% (B7) and Commercial Diesel Fuel 10% (B10). NOx and CO2 emission drops as the percentage of diesel/biodiesel blends increases, supporting WCO as a cost-effective biodiesel feedstock with low petrol pollution.

Pyrolysis which is a technology that might become a solution for fishermen in the Jepara Coastal Village. Fish caught by fishermen can be preserved using natural ingredients that are safe and healthy, namely liquid smoke so that the fish remains fresh and safe for consumption even if it is stored for up to 3 weeks. The purpose of this activity is to provide added value economically since the fishermen can maintain high selling prices, especially when the fish they catch are abundant. With a special target, fishermen can make this natural preservative from the main ingredient which is also abundantly available in Jepara, namely coconut shell. The method of applying Appropriate Technology is divided into several stages. (1) Initial outreach to the target community by identifying fishermen's needs in preserving fish; (2) Training and practice on the use and maintenance of this technology for the production of liquid smoke. This community service activity that is a transfer of knowledge provides understanding to fishermen to use liquid smoke as a fish preservative and avoid using hazardous materials such as formaldehyde and borax. Fishermen partners in Pesisir Jepara Village have experienced increased skills and knowledge on how to make liquid smoke and how to use it on caught fish obtained from the sea. This natural preservation provides economic benefits by delaying sales but the condition of the fish is still fresh and can be consumed properly.

In the present study, biodiesel was produced via the enzymatic interesterification of Crude Palm Oil (CPO) and methyl acetate within ultrasonic condition. In contrast to alcohol, methyl acetate as an acyl acceptor does not inhibit lipase activity and can create triacetin as a useful byproduct. In this work, Immobilized lipase from Candida Antartica A (CaLA) was utilized as biocatalyst and the effect of using non-pretreated CPO and pre-treated CPO as feedstock were explored. The pre-treatment of CPO involves degumming with acid, washing with water, and bleaching. The enzymatic interesterification was conducted in three-neck flasks using an ultrasonic water bath at 45o C. Few parameter effects on biodiesel production were also investigated, including the effect of molar ratio of CPO to methyl acetate, the effect amount of lipase, and the reusability of immobilized lipase (CaLA) in the interesterification reaction. The highest average Biodiesel yield of 80.6% was obtained from pretreated CPO at a molar ratio of 1:9 with 100 mg (1% w/v) of Immobilized CaLA, after three hours of reaction. Further research on the reusability of immobilized CaLA revealed that the yield of biodiesel reduced significantly after the second run. The results of the present study also demonstrated that Immobilized CaLA performed well at low concentrations but had low stability, with productivity decreasing to 92% upon reuse after the initial run. In order to make Immobilized lipase economically viable, further research must be conducted to overcome its low stability in the reaction.