Potential depletion of fossil fuel and climate change have globally accelerated the demand in renewable and alternative energy. Most of the Southeast Asian countries have an abundance of biomass sources for the energy sector due to their agriculture-based economy and enormous forest resources. Therefore, the study aimed at highlighting an overview of biomass energy in the Southeast Asia countries to convey the environmental and economic benefits from the available biomass sources in the region. In order to achieve the aim, the study synthesized and evaluated the biomass sources, energy potential, utilization, and management in the region, based on the published research papers, review papers, and country reports. It was found that the major biomass sources in this region were fuelwood, wood residues, rice husk, rice straw, sugarcane residues, oil palm residues, and coconut residues. The total annual quantity of the biomass potential from agriculture and forest sector in the region was estimated at more than 500 million tons per year and equal to over 8000 million gigajoules of total energy potential. In order to implement the sustainable utilization of biomass sources, the study specified the barriers and challenges of biomass utilization in these countries and proposed a sustainable approach of biomass energy, by comparing the way of traditional biomass utilization.

Nowadays, drying methods for municipal solid waste quality improvement have been adopted in the developed and developing countries to valorize wastes for a renewable energy source, reduce dependency on fossil fuel and keep safer disposal at landfills. Among them, biodrying, biostabilization, thermal drying and solar drying are the most common. Drying of municipal solid waste could offer several environmental and economic benefits. Therefore, this review highlighted the drying methods for municipal solid waste quality improvement around the world and compared them based on the reduction of moisture, weight and volume of municipal solid wastes against drying temperature and time by using statistical analysis. It was observed that the drying temperature of different drying methods accounted for 115 ± 40°C for thermal drying, 59 ± 37°C for solar drying, 55 ± 15°C for biodrying and 58 ± 11°C for biostabilization. Among the drying methods, thermal drying provided the shortest drying time. The moisture reduction, weight reduction, volume reduction and heating value increase of municipal solid waste could vary with drying temperature and time. Finally, the benefits and drawbacks of different drying methods were specified, and recommendations were made for the future efficient drying.

Rapid urban population growth that boosts increased waste generation and electricity demand has led to a possible alternative waste-to-energy solution in Southeast Asia. Despite some issues related to the development of the waste-to-energy sector such as public perception, all stakeholder involvement, public–private partnerships, funding, and climate factors, some Southeast Asian countries have made a reasonably successful step toward the developed technologies. Therefore, this study aimed to highlight an overview of the waste-to-energy sector in Southeast Asian countries to specify the status, challenges, opportunities, and selection of the technologies suited for the specific country. In order to achieve this aim, the study collected, synthesized, and evaluated data about waste resources, current waste management, waste-to-energy utilization, and its potential in the region based on published research papers and policy reports. It was found that the major waste-to-energy technologies in the region are incineration, landfills with gas capture, and anaerobic digestion. The total quantity of the waste-to-energy capacity from landfill biogas plants, incineration plants, and other waste-to-energy practices in the region accounts for over 323 MW at present and is expected to grow to double its current size by 2022. Meanwhile, by 2030, the realizable generation potential from renewable municipal waste in six Southeast Asian countries (Indonesia, Malaysia, Philippines, Singapore, Thailand, and Vietnam) amounts to 17.26 terawatt-hours (TWh). The study also specifies the requirements and considerations for the selection of waste-to-energy technologies, as well as the dimensions related to the development of the technologies. Additionally, four major aspects—technical, financial, environmental, and social and political—regarding the challenges and opportunities for the development of these technologies are considered. The challenges and opportunities related to the development of waste-to-energy in the region reveal how to overcome the drawbacks and to grasp the benefits at present and in the near future. Finally, the study is concluded with suggestions for the selection of the technologies in the region.

Nowadays it is important to limit the use and combustion of fossil fuels such as oil and coal. There is a need to create environmentally acceptable projects that can reduce or even stop greenhouse gas emissions. In this article, we dealt with the objectives of energy policy with regard to environmental protection, waste utilization, and conservation of natural resources. The main objective of the research was to assess the possibility of the use of spent coffee grounds (SCG) as fuel. As a part of the solution, the processing of coffee waste in the form of pellets, analysis of calorific value and combustion in the boiler were proposed. The experiments were done with four samples of pellets. These samples were made from a mixture of wood sawdust and spent coffee grounds with ratio 30:70 (wood sawdust: spent coffee grounds), 40:60, 50:50 and 100% of spent coffee grounds. The calorific values were compared with wood sawdust pellets (17.15 MJ.kg⁻¹) and the best lower calorific value of 21.08 MJ.kg⁻¹ was measured for 100% of spent coffee grounds. This sample did not achieve the desired performance during the combustion in the boiler due to the low strength of the sample.