Analysing the effect of thermal modification on the calorific values of Eucalyptus nitens wood

Gross and net calorific value of 13 samples of Eucalyptus nitens wood were determined at HAWK (Hochschule für Angewandte Wissenschaft und Kunst), Göttingen, Germany. Among 13 samples, 12 were thermally modified and one was unmodified. Calorific values of samples were determined by using a bomb calorimeter, and the wood components (cellulose, hemicellulose, lignin, and extractives) already analysed by Wentzel et al. (2019). After determination of the values, samples were statistically analysed by R studio to find the relations among the calorific value, temperature, and wood components. The gross calorific value and net calorific value of the untreated sample of Eucalyptus nitens were found to be 18.83 MJ/kg and 17.48 MJ/kg, and after thermal modification these increased up to 20.24 MJ/kg and 18.84 MJ/kg. Upon statistical analysis, the results for lignin showed a strong correlation with the temperature of thermal treatment and calorific value.

Efek Pemanasan Biosolar B30 Terhadap Kinerja Dan Pembakaran pada Mesin Diesel Type TV-1

Penelitian ini bertujuan untuk menganalisis kinerja mesin diesel dan pembakaran dari biosolar B30 yang dipanaskan sebelum diinjeksi ke dalam ruang bakar. Biosolar B30 yang dipasarkan oleh Pertamina sebelumnya diuji nilai kalor dengan bomb calorimeter. Biosolar B30 dialirkan ke ruang bakar dengan melewati tangki pemanas sampai temperatur biosolar mencapai 60 oC. Mesin diesel yang digunakan adalah type TV-1 (tipe vertikal) dengan spesifikasi mesin 1 silinder, 4 langkah, kapasitas 661 cc, Daya 3,5 kW pada 1500 rpm, dan rasio kompresi mesin 12:1 sampai 18:1. Pengujian dilakukan pada rasio kompresi 14:1, 16:1, dan 18:1 pada beban 3 kg dan 9 kg dengan membandingkan biosolar tanpa pemanasan dan dengan pemanasan 60 oC. Hasil yang diperoleh memperlihatkan bahwa biosolar B30 dengan pemanasan 60 oC menyebabkan SFC dan daya indikasi lebih rendah serta efisiensi mekanik yang lebih tinggi. Karakteristik pembakaran biosolar B30 dengan pemanasan 60 oC memperlihatkan SoC yang lambat dan proses pembakaran yang berlangsung lebih singkat, serta tekanan maksimum yang lebih tinggi dan nilai pelepasan panas yang menurun.

Analisa Pengaruh Ask Content Terhadap Nilai Kalor Batubara Pada PT. Tribhakti Inspektama Samarinda

Seiring dengan meningkatnya harga minyak dan gas bumi maka batubara sebagai bahan bakar alternatif sangat diharapkan dapat mengantisipasi kekurangan energi dengan meningkatkan pemanfaatannya untuk keperluan domestik, bahan bakar pembangkit tenaga listrik, dan lain sebagainya. Beberapa negara memiliki sistem klasifikasi batubara secara spesifik. Klasifikasi tersebut digunakan untuk menggolongkan batubara berdasarkan pemanfaatannya. Berdasarkan standar SNI 13-6011-1999 klasifikasi batubara di indonesia dibagi menjadi dua yaitu brown Coal dan hard coal. Umumnya, untuk mengetahui kualitas batubara dilakukan analisa kimia berupa analisis proksimat atau analisis ultimat. Tujuan dari penelitian ini adalah unuk mengetahui pengaruh kadar abu terhadap nilai kalor pada batubara. Indonesia sebelum mengekspor batubara ke negara-negara lain batubara terlebih dahulu diuji dan dianalisis untuk menentukan layak atau tidak untuk di berikan sesuai permintaan konsumenKadar abu merupakan kotoran yang tidak akan terbakar kandungannya berkisar 5%-40%. Oleh karena itu dilakukan analisis proximate untuk mengetahui pengaruh ash content. Metode yang digunakan dalam penelitian ini terdiri dari studi literatur, pengolahan sampel dan analisis data. Pengolahan sampel dengan cara menentukan Ash Content dan nilai kalor pada sampel batubara. Adapun cara menentukan Ash content yaitu dengan menimbang sampel batubara dengan berat tertentu kemudian dipanaskan hingga suhu 750?.dalam menentukan nilai kalor dampel batubara yang dianalisis menggunakan alat bomb calorimeter. Ash Content dan Nilai Kalor pada tujuh sampel yang di analisis yaitu sampel BB1 memiliki Ash Content 5,43 dengan nilai kalor 6007, sampel BB2 memiliki Ash Content 7,96 dengan nilai kalor 5752, sampel BB3 memiliki Ash Content 10,62 dengan nilai kalor 4780, sampel BB4 memiliki Ash Content 13,42 dengan nilai kalor 4712, sampel BB5 memiliki Ash Content 21,82 dengan nilai kalor 4154, sampel BB6 memiliki Ash Content 35.57 dengan nilai kalor 3218 dan sampel BB7 memiliki Ash Content 55,93 dengan nilai kalor 1921. Dapat disimpulkan bahwa nilai Ash Content sangat berpengaruh terhadap nilai kalor yang dihasilkan.

The Effect of Dolomite Addictive Ratio on Torrified Cassava Rhizome in the Biomass Combustion Process

This research studies on the effect of additive (Dolomite) on Biomass powder (Cassava rhizome) which passes Torrefied process and fixed bed at 250 degrees Celsius for one hour and a half. The gasifier with up-draft type was used in this experiment. Air pressure was fixed at 0.1 Bar. The useful heat (Quseful) and Low heating valves (LHV) was investigated by using an Automatic Bomb Calorimeter. Moreover, the dolomite was varied 0, 10 and 15% by weight mixed with Cassava rhizome achieved with Torrefied process. When Low heating valves (LHV) slightly decreases from 21.96±0.22 MJ/kg to 18.15±0.50 MJ/kg, Quseful heat from the burning from gasifier sharply increase when it is mixed with dolomite from 753.34±39.18 to 1,003.97±33.49KJ respectively. The loading of dolomite has significance affecting the useful heat. The present study reveals that low heating valves (LHV) decreases and Quseful heat increase result from dolomite which gives a clean gas product and the Tar molecule can be easily broken. The CO2 gas from the combustion process was absorbed by CaO, which is the main component in dolomite. The cost of mixing 8.9% of Dolomite with Cassava rhizome is the optimum ratio for the biomass combustion process.

Thermodynamic properties of the 2,4,6-triamine-1,3,5-triazine dodecahydro-closo-dodecaborate

Прямым сжиганием в бомбовом калориметре KL-5 экспериментально определена удельная теплота сгорания додекагидро-клозо-додекабората 2,4,6-триамино-1,3,5-триазина, из которой рассчитаны его стандартные теплоты сгорания и образования, равные –13 359 и –807 кДж/моль соответственно. By means of the direct burning in bomb calorimeter KL-5 was obtained experimentally specific combustion enthalpy of 2,4,6-triamino-1,3,5-triazine dodecahydro-closo-dodecaborate from which were calculated their standard combustion and formation enthalpies equal –13 359 and –807 kJ/mol, respectively.

Energy Potential of Solid Waste Generated in Landmark University, Omu- Aran, Kwara State Nigeria

This study aims at determining the energy content from campus wastes and estimation of electricity generation. Samples of solid wastes generated within Landmark University were collected, separated, classified, dried in the oven at 105°C till constant weight was attained, pulverized and sieved using a sieve size of 500 μm. The moisture contents of the waste samples were determined, in triplicates. The digital bomb calorimeter (C-200 Bomb Calorimeter) was used to determine the calorific value of the prepared waste samples. Correlation analysis was carried out to determine coefficients and significant levels; while regression equations were generated, using ANOVA to relate the dependent variable - Potential Electricity Generated (PEG) with independent variables- Total Energy Content (TEC) and Specific Energy Content (SEC). The moisture contents are plastic bottles (0.78%), water sachet (0.82%), and food packs (5.37%), wood wastes and ash (5.35%), food wastes (5.95%), and paper wastes (5.56%). Calorific values of plastic bottles, polythene products, Wood wastes and ash, food wastes, paper wastes and polystyrene (food pack) are 31,246.63, 29,084.24, 17,243.56, 14,360.49, 12,975.42 and 4575.10 kJ/kg, respectively. The total energy content from the campus wastes was estimated at 32,999.30 MJ/day. This implies a possibility of about 0.38MW of electricity generation from daily steam production. There was high level of correlation between the energy value parameters (R > 0.99) and significant at < 0.01. The energy content is expected to grow with the expansion of the campus.

Evaluasi Prediksi Higher Heating Value (HHV) Biomassa Berdasarkan Analisis Proksimat

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate

Measuring Heat Production from Burning Al/Zr and Al/Mg/Zr Composite Particles in a Custom Micro-Bomb Calorimeter

Al:Zr, Al-8Mg:Zr, and Al-38Mg:Zr nanocomposite particles fabricated by physical vapor deposition (PVD) and ball milling were reacted in 1 atm of pure O2 within a custom, highly-sensitive micro-bomb calorimeter. The heats of combustion were compared to examine the effect of particle size and composition on combustion efficiency under room temperature and in a fixed volume. All particles yielded ~60–70% of their theoretical maximum heat of combustion and exhibited an increase in heat over composite thin films of similar compositions, which is attributed to an increase in the surface area to volume ratio. The effect of particle size and geometry are mitigated owing to the sintering of the particles within the crucible, implying the importance of particle dispersion for enhanced performance. Vaporization of the metal species may transition between two diffusion flame species (Mg to Al). As Mg content is increased, more vaporization may occur at lower temperatures, leading to an additional stage of sintering. Physically intermixed Al and Mg oxides have been observed coating the surface of the particles, which implies a continuous transition of these vaporization processes. Such nano-oxides imply high vapor-flame combustion temperatures (>2700 K) and suggest viability for agent defeat applications.