Ulva Lactuca is a fast-growing algae that can be utilized as a bioenergy source. However, the direct utilization of U. lactuca for energy applications still remains challenging due to its high moisture and inorganics content. Therefore, thermochemical processing such as slow pyrolysis to produce valuable added products, namely bio-oil and biochar, is needed. This study aims to conduct a thorough investigation of bio-oil and biochar production from U. lactuca to provide valuable data for its further valorization. A slow pyrolysis of U. lactuca was conducted in a batch-type reactor at a temperature range of 400–600 °C and times of 10–50 min. The results showed that significant compounds obtained in U. lactuca’s bio-oil are carboxylic acids (22.63–35.28%), phenolics (9.73–31.89%), amines/amides (15.33–23.31%), and N-aromatic compounds (14.04–15.68%). The ultimate analysis revealed that biochar’s H/C and O/C atomic ratios were lower than feedstock, confirming that dehydration and decarboxylation reactions occurred throughout the pyrolysis. Additionally, biochar exhibited calorific values in the range of 19.94–21.61 MJ kg⁻¹, which is potential to be used as a solid renewable fuel. The surface morphological analysis by scanning electron microscope (SEM) showed a larger surface area in U. lactuca’s biochar than in the algal feedstock. Overall, this finding provides insight on the valorization of U. lactuca for value-added chemicals, i.e., biofuels and biochar, which can be further utilized for other applications.

The physical properties of seed are required in designing an apparatus for handling, separation, drying, storage, and processing. The physical properties of white pepper seeds were determined as a function of moisture content in the range of 15,40 - 64,80 % dry basis (d.b.). The average height, length and width at a moisture content condition of 15,40 % (d.b.) were 4,11 ± 0,27 mm; 4,35 ± 0,34 mm and 4,35 ± 0,35 mm, respectively. In the range of moisture content 15,40 - 64,80 % (d.b.), the results of this study showed an increase linearly of the third axial dimension, the average diameter, the roundness from 0,969 to 0,977, the volume from 39,50 to 67,34 mm3, the surface area from 55,87 to 79,92mm2 and the thousand seed mass from 52,47 to 75,63 g. Bulk density and true density has a polynomial correlation with changes in moisture content.The porosity decreased from 45,01 % to 44,88 % with an increase in the moisture content range of 15,40 - 64,80 % (d.b.). ABSTRAK Sifat fisik biji-bijian diperlukan dalam merancang suatu peralatan untuk penanganan, pemisahan, pengeringan, penyimpanan dan pengolahannya. Sifat fisik biji lada putih ditentukan sebagai fungsi kadar air pada rentang 15,40 - 64,80 % basis kering (b.k.). Tinggi, panjang dan lebar rata-rata pada kondisi kadar air 15,40 % (b.k.) adalah 4,11 ± 0,27 mm; 4,35 ± 0,34 mm dan 4,35 ± 0,35 mm berturut-turut. Pada rentang kadar air 15,40 - 64,80 % b.k., hasil penelitian ini menunjukkan peningkatan secara linear pada ketiga dimensi aksial, diameter rata-rata, kebulatan dari 0,969 hingga 0,977, volume dari 39,50 hingga 67,34 mm3, luas permukaan dari 55,87 hingga 79,92 mm2 dan massa seribu biji dari 52,47 hingga 75,63 g. Bulk density dan true density memiliki hubungan polinomial dengan perubahan kadar air biji. Porositas menurun dari 45,01 % hingga 44,88 % dengan peningkatan kadar air pada rentang 15,40 - 64,80 % (b.k.).

Pembakaran adalah metode konversi energi dengan mereaksikan bahan bakar dan oksigen untuk menghasilkan panas. Saat ini batubara masih mendominasi sumber energi di Indonesia yang menyumbang lebih dari 50% emisi CO2 global. Upaya mengurangi emisi ini salah satunya dengan penggunaan energi terbarukan seperti biomassa, dimana energi biomassa yang sedang berpotensi saat ini adalah produk biomassa tanaman energi seperti kayu gamal dan sengon. Penggunaan tanaman energi tersebut sebagai penyedia termal melalui proses pembakaran masih belum pernah dikaji, sehingga paper ini akan membahas karakteristik termal pembakaran kayu gamal dan sengon secara teoritis melalui simulasi numerik pembakaran. Simulasi menggunakan model kesetimbangan pembakaran pada tungku adiabatik dengan kondisi stoikiometri, kelebihan udara (excess air), dan kelebihan bahan bakar (excess fuel) dengan perhitungan – perhitungan termodinamika yang nantinya akan divalidasi dengan data eksperimental. Hasil simulasi menunjukkan karakteristik termal pembakaran gamal lebih unggul dibandingkan sengon. Penambahan dan pengurangan udara dari kondisi optimum dapat mengurangi kualitas pembakaran, namun secara aktual penggunaan udara berlebih diperlukan untuk mengantisipasi faktor lingkungan yang mengganggu pembakaran stoikiometri teoritis. Kondisi optimum pembakaran dicapai pada saat rasio ekuivalen gamal dan sengon masing-masing 1,3. Hasil validasi menggunakan MAPE menunjukkan nilai error yang rendah (8,55%) sehingga model pembakaran yang digunakan mampu memprediksi karakteristik termal dengan sangat baik.

Cherry tomato production in tropical greenhouses requires intensive energy input to maintain optimal microclimatic conditions, particularly through evaporative cooling systems. This study presents an integrated life cycle assessment (LCA) and energy demand analysis of cherry tomato cultivation in a tropical evaporatively cooled greenhouse, using a gate-to-gate system boundary and a functional unit of 1 kg fresh cherry tomato. Environmental impacts were evaluated using the ReCiPe 2016 midpoint method, while energy performance was assessed through cumulative energy demand (CED) and specific energy consumption (SEC) based on the higher heating value (HHV). Inventory data were obtained from direct on-site measurements and supplemented with secondary data from the Ecoinvent database. The results show that the total cumulative energy demand was 38.98 MJ kg ⁻¹ , dominated by electricity consumption for evaporative cooling. The life cycle impact assessment per kg yielded a global warming potential (GWP) of 0.914 kg CO ₂ eq, stratospheric ozone depletion (SOD) of 7.8×10 ⁻⁷ kg CFC-11 eq, terrestrial acidification (TA) of 4.3×10 ⁻⁴ kg SO ₂ eq, freshwater eutrophication (FEU) of 8.4×10 ⁻⁵ kg P eq, human carcinogenic toxicity (HCT) of 8.09×10 ⁻² kg 1.4-DCB eq, and terrestrial ecotoxicity (TEC) of 3.177 kg 1.4-DCB eq. Key environmental hotspots were associated with electricity use, nutrient inputs (AB mix), and polybag materials. Scenario analysis confirmed that adaptive, temperature control of the evaporative cooling system is an effective strategy for improving sustainability.

Trichoderma sp. is a fungus used in oil palm plantations to control basal stem rot disease, which can reduce palm oil production by up to 80%. At PT. Bumitama Gunajaya Agro, the production of this fungus uses an autoclave, which can only produce 51 kg of Trichoderma sp. per day per unit. To meet the high demand for Trichoderma sp., a large-capacity sterilization tool called "stream" is needed for mass production. The optimal performance of the Stream shows that effective sterilization can be achieved in 20 min when the tool is operated for 45 min. The effectiveness of this sterilization time is proven by the Total Plate Count (TPC) test, which shows a bacterial count of 109×103 CFU/g and a fungal count of 35 CFU/g. The Trichoderma sp. product produced through this process has a conidium density of 8×108, 100% conidium viability, and an inhibition power of 54%, all of which exceed the standard values of SNI 8027.3:2014. Based on its production capacity, Stream can achieve production of up to 1 ton per day with quality not significantly different from Trichoderma sp. production using an autoclave. Keywords: Autoclave, Basal stem rot disease, Sterilization, TPC, Trichoderma sp.

The co-gasification of biomass and municipal solid waste (MSW) has high potential for sustainable energy generation and waste-to-energy applications. Calliandra calothyrsus (CC) and MSW pellets have complementary thermochemical properties, although there are few experimental studies on their co-gasification in downdraft reactors. This study analyzed the effect of the feedstock composition on the temperature distribution inside the reactor, the syngas composition, and the quality of syngas energy in a 1–2.5 kg/h downdraft gasifier during co-gasification. Six feedstock blend compositions were experimentally evaluated: they were 100 CC, 70 CC–30 MSW, 60 CC–40 MSW, 40 CC–60 MSW, 30 CC–70 MSW, and 100 MSW. The criteria considered for measuring include reactor temperature distribution, syngas composition (CO, H₂, CO₂, and C_nH_m), and lower heating value (LHV). The results indicated that the 70 CC–30 MSW blend had the best syngas performance with a higher oxidation-zone temperature, greater CO concentration, reasonably steady H₂ generation, lower C_nH_m concentration, and the highest syngas LHV compared to other feedstock compositions. In the gasification process, the increase in the proportion of CC was beneficial to char reactivity, oxidation–reduction reaction, and tar cracking. The increase in MSW fractions decreased syngas quality due to the increase in ash and moisture content. The results show that co-gasification of Calliandra calothyrsus and bio-dried MSW pellets can increase syngas quality and provide practical insight into the optimization of biomass–MSW blending for downdraft gasification systems.