Recyclables Collection Route Balancing Problem with Heterogeneous Fleet

Nowadays, robust and efficient solid waste collection is crucial to motivate citizens to participate in the circular economy by sorting recyclable solid waste. Vocational vehicles, including garbage trucks, contribute significantly to CO2 emissions; therefore, it is strongly recommended, and in the European Union it is mandatory, to replace conventional-fuel-based garbage trucks with electric ones. For providing sustainable and energy-efficient solid waste collection with a heterogeneous fleet, in-depth mathematical computations are needed to support solving complex decision-making problems, including crew rostering and vehicle routing, because the distance and capacity of electric garbage trucks differ from conventional-fuel-based ones. However, the literature on solid waste collection using electric garbage trucks is still relatively scarce. The main contribution of this paper is developing an optimization problem for balancing travel distance assigned to each garbage truck of a heterogeneous fleet. The problem is based on specific requirements of the Municipal Solid Waste Management in Cracow, Poland, where the working time of routes is balanced and the total time of collection service can be minimized. For the problem, an MIP program was developed to generate optimal crew schedules, so that the hitherto network of segregated solid waste pickup nodes can be served using a heterogeneous fleet in which the share of electric garbage trucks is up to 30%. We study the impact of the changed composition of the fleet on modifications in crew rostering due to the shorter range of an electric vehicle compared to a conventional-fuel-based one.

A comparative approach in the utilisation of rice husk and empty palm bunch in the biomass boiler

Growing world’s population has immense contribution towards world economy and energy utilisation. The enormous usage of conventional fuel has contributed many environmental problems such as greenhouse gas emission (GHG), world climate change, and deterioration of human health. Recent study focuses on the generated power from EPB compared with methane in a typical biomass boiler. Also, there are very limited studies on the Air to Fuel (ATF) ratios value in boiler operation. In this paper, empty palm bunch (EPB) and rice husk (RH) have been selected as biomass fuel in the biomass boiler. The same recommended parameters of boiler and turbine was chosen for both EPB and RH feedstocks from previous study. Overall, the study proven to produce about 33% and 25% of energy from EPB and RH of what a methane (CH4) can produce from the same amount of feeding rate, respectively, with EPB producing 13.31% of higher turbine power than RH. This directly contributes to the technical feasibility and adaptability of environmentally friendly elements by seizing the opportunity of carbon emission of conventional fuel and replacing it with natural resources such as EPB and RH which are part of the biomass fuel replacement regime. However, ATF ratio of RH is significantly minimal of what a CH4 and EPB utilised to burn 1 kg of fuel. Therefore, EPB and RH would be suitable for future renewable biomass feedstock in comparison with conventional fuel for power generation purposes.

Automated method of calculation of parameters for non-traditional heating technologies and conditioning of buildings

Purpose. Develop an automated method for calculating parameters for heat pump systems for heating, air conditioning and hot water supply, designed for use in domestic conditions with non-standard heat transfer flows. Methodology. Mathematical modeling of thermodynamic processes occurring in heating, air conditioning and hot water supply systems. Findings. The automated method of calculating the parameters of non-traditional technology, which uses standard heat pump equipment of the water heating system for the cooling mode of the air in the warm period of the year, and the discharge of heat dissipated into the ground, was substantiated and developed; and for the needs of hot water supply heat pump air-liquid, acting as a high-speed water heater. The estimation of technologies of the thermal energy utilization in buildings developed earlier by authors is executed. The first technology involved the use of a heat pump and heat accumulator scheme in the cold season, and halved the consumption of conventional fuel compared to a gas column for hot water at the same facility. The second technology involved heat recovery with the help of a heat accumulator in a complex system of air conditioning and hot water supply in the warm period, which saves from 74 to 82% of conventional fuel compared to the scheme with boiler and air conditioner without heat accumulator. Critical conclusions were drawn about the need to use additional dimensional equipment for these technologies and the excess amount of hot water received. Possibilities of realization of such scheme were analyzed. Analytically substantiated recommendations on the design (ribbing of heat exchange surfaces) of heating devices and parameters of their operating modes in the cold and warm periods of the year were given. The condition of invariance of heat exchange areas of heating devices and basic water consumption in the heating system was fulfilled. The need to regulate the air conditioning regime by changing the water flow in the system to maintain a constant indoor air temperature with fluctuations in outdoor air temperature was substantiated. Originality. For the first time, attention is paid to the study of non-traditional methods of using heat pump heating for heating, air conditioning and hot water supply of residential premises. The automated method for determining rational parameters for these technologies was developed. Practical value. The automated method of forming the control dependence of the mass flow of water in the system on the outside air temperature on the condition of constancy of the set comfortable indoor air temperature was developed. The use of air-liquid heat pump for hot water supply in the warm period was analyzed, a high energy conversion factor was noted (14 ... 22). The savings of conventional fuel from the application of the considered technology from 13% to 18% in comparison with the technology using a heat accumulator were substantiated.

Co-Pyrolysis of Biomass Solid Waste and Aquatic Plants

Reduction of conventional fuel has encouraged to find new sources of renewable energy. Oil produced from the pyrolysis method using biomass is considered as an emerging source of renewable energy. Pyrolytic oil produced in pyrolysis needs to be upgraded to produce bio-oil that can be used with conventional fuel. However, pyrolytic oil contains high amounts of oxygen that lower the calorific value of fuel, creates corrosion, and makes the operation unstable. On the other hand, the up-gradation process of pyrolytic oil involves solvent and catalyst material that requires a high cost. In this regard, the co-pyrolysis method can be used to upgrade the pyrolytic oil where two or more feedstock materials are involved. The calorific value and oil yield in the co-pyrolysis method are higher than pyrolytic oil. Also, the upgraded oil in the co-pyrolysis method contains low water that can improve the fuel property. Therefore, the co-pyrolysis of biomass waste is an emerging source of energy. Among different biomasses, solid waste and aquatic plants are significantly used as feedstock in the co-pyrolysis method. As a consequence, pressure on conventional fuel can be reduced to fulfill the demand for global energy. Moreover, the associated operating and production cost of the co-pyrolysis method is comparatively low. This method also reduces environmental pollution.