PORTABLE COFFEE LOG MACHINE

The escalating global demand for sustainable energy solutions has intensified research into alternative bio- mass fuels, particularly those utilizing waste streams. Among these innovations, coffee logs as combustible briquettes produced from recycled coffee grounds have emerged as a technologically and environmentally promising solution. Coffee logs are logs of compacted coffee grounds that can be burnt in wood burning and multi- fuel stoves as well as biomass boilers. The coffee grounds not only burn well when dried out, they supposedly burn hotter and longer than wooden logs and give off a subtle aroma too. These high-densi- ty logs are specifically engineered for optimal performance in wood-burning stoves, multi-fuel stoves, and biomass boilers, serving as a carbon-neutral alternative to conventional firewood. Thermogravimetric analysis reveals that desiccated coffee grounds exhibit superior combustion characteristics, including high- er ignition temperatures (280-320°C compared to 250-300°C for wood) and significantly prolonged burn durations (25-35% longer than equivalent hardwood logs). This enhanced performance is attributed to the residual oils in coffee grounds, which yield a higher energy density (18-22 MJ/kg versus 16-20 MJ/kg for wood) while emitting minimal particulate matter (PM2.5 emissions reduced by 40-45%). This study pres- ents a comprehensive investigation of the design, fabrication, and optimization of a novel portable coffee log production system. The purpose of this project is to design the portable coffee log machine by using Autodesk Inventor software to make the coffee logs with multi-size for the coffee industry and to reduce the air pollution. The prototype machine incorporates five interchangeable compression moulds (2, 3, 4, 5, and 6 mm diameters) to systematically evaluate the relationship between compaction density and combus- tion efficiency. The feedstock formulation consists of spent coffee waste (65±5%), shredded recycled paper (25±5%), and sawdust (10±2%), optimized through iterative testing to achieve optimal binder less cohesion. A comprehensive evaluation framework was implemented, by burn all the mixing material of mould to see the time lasting of burning process. The compression system operates at 8-10 MPa pressure, producing logs with bulk density of 1.1-1.3 g/cm3. Quality control testing demonstrated that the 2 mm diameter configu- ration achieved the most favourable combustion profile, with a burn time of ±12 minutes compared to ±10 minutes for conventional firewood of equivalent mass. The upgraded design with more suitable body frame included the base (where the location of the mould that can be adjust to align with the size of mould needed). Furthermore, it is easy to operate because it can operate by on top of the adjusted table. Other than that, the benefits of this project where the mould can be adjusted to align with jack to compress. In conclusion, this study establishes coffee logs as a technically viable, environmentally sustainable, and economically feasible biomass fuel alternative. The developed production system addresses critical barriers to adoption through its portability, efficiency, and product consistency. Future research directions should focus on scaling opti- mization, advanced emission control systems, and the development of regional supply chain models. This innovation aligns with multiple Sustainable Development Goals, particularly SDG 7 (Affordable and Clean Energy), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action), while offering a practical circular economy solution for the global coffee industry.