This study has revealed that groundnut shell can be compacted to a stabled state with binding material. The densification of the groundnut shells aid in transporting and storing, making it more economically than is possible at unprocessed state. The effects of binder (cassava starch gel) show that the highest lateral and axial expansion was 1.91 and 6% respectively. Maximum density, relax density, relaxation ratio ranges between 411 to 441 kg/m , 201 to 202 kg/m , 2.03 to 2.19, respectively. Other results are durability in the 3 3 range of 69.89 to 93.52%, while the calorific value ranges between 19.82 to 21.97 MJ/kg. The overall, briquettes performances showed that 20% binder have the most outstanding resultin terms of durability. It was found that the amount of binder used have significant influence on the properties of the briquettes.

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Current energy shortage and environmental issues resulting from the use of fossil fuels have led to exploitation of renewable energy resources that includes municipal waste and agricultural residues. These residues are available, indigenous and are environmental friendly but some cannot be used directly in combustion process due high moisture content and low volumetric energy unless by briquetting. The study was undertaken to assess the combustion characteristic of binder-less briquettes produced from waste paper and groundnut shell. Combustion characteristics investigated were ignition time, burning time, calorific values, burning rate, specific fuel consumption, fuel efficiency and water boiling time. The calorific values of the briquettes ranged from 19.51-19.92 MJ/kg, while the thermal efficiency ranges between 13.75-21.64%, other results shows that the average burning rate between 0.511 and 1.133 kg/hr and the specific fuel consumption ranges between 0.087 and 0.131 J/g. The recorded boiling time values were between 17.5 and 30.0 minutes for cold start and 15.0 and 20.0 minutes for hot start. The results shows that waste paper and groundnut shell up to 25% in composition composite briquettes were found to have good combustion characteristics which qualify them as alternative to firewood for domestic and industrial energy. However, production of briquettes from waste paper and groundnut shell at mixing ratio of 85:15 was found to comparatively better from all experiment conducted.

Substituting Hydrofluorocarbons with natural refrigerants in domestic refrigerators will significantly reduce the direct contributions of fluorinated gases to global warming which will be of great environmental benefit. In this study, the performances of dimethyl-ether (RE170) and its azeotropic mixtures (R510A and R511A) in a refrigeration system were assessed theoretically and compare with that of conventional refrigerant. The study revealed that the three investigated alternative refrigerants exhibited significantly good heat transfer characteristics, low pressure ratio, high latent heat in the liquid phase which resulted in their high thermal conductivity and Volumetric Cooling Capacity (VCC). The thermal conductivity of the refrigerants reduces while the evaporating temperature rises and the value obtained for RE170 was the highest among the four refrigerants studied. The Coefficient of Performance (COP) for RE170, R510A and R511A were higher than that of R134a by 6.20, 10.06 and 3.02 % respectively while their power consumptions per ton of refrigeration were lower than that of R134a by 6.99, 11.04 and 1.47 % respectively. In conclusion, dimethyl-ether and its azeotropic mixtures performed better than R134a in that they have higher thermal conductivity, refrigerating effect, VCC, COP, lower power consumption per ton of refrigeration and hence, they can be considered as suitable replacements for R134a in domestic refrigerator.

The vast quantity of waste generated from industries is one of the serious outcomes of unplanned development, resulting into quantum of hazardous organic and inorganic waste generating daily. Proper waste management is a challenging issue that must be addressed adequately. This is, therefore, carried out with a view of assessing the energy and combustion quality of tannery solid waste with a view of converting them into briquettes for cooking, heating and small home industries and reducing the menace caused by tannery waste disposal. The results of the experiments showed that the combustion rate ranged between 0.171 and 0.217 g/min, the boiling time ranged between 27.78 to 34.11 minutes, the ignition time was found between 14.2 to 17.4 minutes. The durability test and humidity resistance test showed that the briquettes have durability ranged between 92.12 and 95.04 while the humidity resistance was between 95.34 and 97.95. The carbon content ranged between 40.79 and 45.15%. Other results showed that the fixed carbon ranged between 89.93 and 95.46%, volatile matter 1.61 to 4.56% and the calorific values were found between 18.03 and 21.86 MJ/kg. The fleshing has better quality than the other three wastes studied. AbstractPotensi Energi dari Briket yang Dihasilkan dari Limbah Padat Penyamakan Kulit Binatang Ternak. Jumlah limbah yang dihasilkan dari industri merupakan salah satu masalah serius dari perkembangan yang tidak direncanakan, yang mengakibatkan besarnya jumlah sampah organik dan anorganik yang tertimbun setiap hari. Pengelolaan limbah yang tepat merupakan tantangan yang harus ditangani secara benar. Pengelolaan ini dilakukan dengan berpandangan bahwa energi dan pembakaran dari limbah padat penyamakan kulit dapat diubah menjadi briket untuk memasak, memanaskan dan membantu industri rumahan kecil serta mengurangi ancaman yang diakibatkan oleh pembuangan limbah industri penyamakan kulit. Hasil percobaan menunjukkan bahwa laju pembakaran berkisar antara 0,171 dan 0,217 g/menit, waktu didih sekitar 27,78 sampai 34,11 menit, waktu pengapian sekitar 14,2 sampai 17,4 menit. Uji ketahanan dan uji resistansi kelembaban menunjukkan bahwa briket memiliki daya tahan sekitar 92,12 dan 95,04 sedangkan nilai resistansi kelembapan antara 95,34 dan 97,95. Kandungan karbon berkisar antara 40,79 dan 45,15%. Hasil lainnya menunjukkan bahwa karbon tetap berkisar antara 89,93 dan 95,46%, material volatil 1,61 sampai 4,56% dan nilai kalor ditemukan antara 18,03 dan 21,86 MJ/kg. Limbah dari tahap fleshing memiliki kualitas yang lebih baik daripada tiga limbah lainnya yang diuji.