Along with the times, the availability of fossil energy is decreasing, especially natural gas and coal, before using fossil energy, humans have used biomass as an energy source. Indonesia has many plantation commodities, one of which is coffee which is the fourth largest coffee producer in the world. Coffee grounds are the main waste produced by coffee shops and are usually only thrown away. The main ingredients in this study were arabica coffee grounds and robusta. By using robusta composition 60% arabica 40%, robusta 50% arabica 50% robusta 40% arabica 60%. In addition, briquettes are tested for hardness by making points on the surface of the briquettes using a durometer shore A tool of 30 points, then a calorimeter bomb test is carried out to obtain the calorific value content. The result obtained from the highest hardness value is briquettes with a robusta mixture of 50% arabica 50% with a value of 23.7 HA, while the highest calorific value is found in a robusta mixture of 60% arabica 40% with a value of 4526.85 cal / gram.

Briquettes are a type of alternative energy whose raw material source comes from agricultural waste such as coconut shells. Coconut shells are converted into charcoal which has a higher calorific value through the pyrolysis process. The aim of this research is to determine the effect of comparing particle size and printing pressure on the length of burning time and burning temperature, so as to obtain a briquette composition that is durable and produces high temperatures. In this research, the raw material used was shell waste with a drying process of 400°C and the particle size variations used were mesh 30, 150 and 250 mixed with 12 grams of starch adhesive. The briquette molding process uses 3 kg and 5 kg pressure, which are then dried using an oven at a temperature of 750°C for 3 hours. Tests were carried out on burning time, burning temperature, water content and ash content. From the research results, it was found that for the highest temperature, briquettes with a particle size of 250 mesh were produced with a pressure of 5 kg at 312°C, and the flame duration of the briquettes was 240 minutes.

One of the reasons the Sugar Factory failed to meet its sugar production target was due to damage to the machine components, particularly at the milling station, where the milling rollers are located. The milling rollers play a crucial role in extracting juice from sugar cane, separating the juice from the bagasse, and measuring the raw juice before it enters the purification process. This unit is designed to maximize raw juice yield while minimizing the amount of bagasse. The milling rollers are arranged in a triangular configuration of three mills, with a milling path between the front and rear rollers that can move forward and backward. Several common issues affect the milling rollers, including surface wear, damage from excessive loads, and wear from repeated friction between the rollers and the sugar cane. Sugar cane itself contributes to roller wear due to its composition, which includes water, sucrose, cellulose, lignin, hemicellulose, ash, and silica. These substances are highly corrosive, even to stainless steel, and act like abrasives against the rollers. The usual remedy at the factory is to weld stainless steel onto cast iron rollers. However, this method has only been moderately effective, as the rollers continue to experience wear after a short period. Based on field observations and literature reviews, some suggested solutions include more frequent cleaning and applying a tungsten coating to the roller surfaces.