Thermo-economic analysis of the potential for electricity generation by integrating a Rankine cycle with municipal solid waste incineration

Municipal Solid Wastes generated by human activities increase as the population grows; in Ocaña city, Norte de Santander, Colombia, these wastes reach a monthly production of about 2660 tons, made up of 65.6% waste food, 15.3% plastics, 9.9% toilet paper, 3.6% paperboard, 2.6% textile residues, 1.6% paper, 0.8% wood wastes, and 0.1% rubber. This work estimates the energy potential from municipal solid wastes for electricity generation and their production costs. A multicriteria decision analysis allowed selecting the best technology for the wastes processing based on their energy content. For the evaluated criteria, the incineration process showed priority. A model developed in the engineering equation solver software allowed calculating the electrical energy potential by integrating the incineration process with a Rankine cycle. By implementing a thermo-economic assessment, the electricity generation costs were determined, where the inversion, installation, operation, and maintenance costs were considered. 1974 KW of electrical power with generation costs of $300/KWh and a payback period of 2.5 years show the feasibility of this process.

Carbon Emission Reduction via HNGLRP CC&S Technology

The paper objective is to present the successful achievement by Saudi Aramco gas operations to reduce the carbon emission at Hawyiah NGL Recovery Plant (HNGLRP) after successful operation & maintainability of the newly state of the art Carbon Capture & Sequestration (CC&S) technology. This is in line with the Kingdom of Saudi Arabia (KSA) 2030 vision to increase the resources sustainability for future growth and part of Saudi Aramco circular economy in action examples. Saudi Aramco CC&S started in June 2015 at HNGLRP with main objective to capture the carbon dioxide (CO2) from Acid Gas Removal Units (AGRUs) and then inject an annual mass of nearly 750 Kton of carbon dioxide into oil wells for sequestration and enhanced oil recovery maintainability. This is to replace the typical acid gas incineration process after AGRUs operation to reduce carbon footprint. CC&S consists of the followings: integrally geared multistage compressor, standalone dehydration system using Tri-Ethylene Glycol (TEG), CO2 vapor recovery unit (VRU), Granulated Activated Carbon (GAC) to treat water generated from compression and dehydration systems for reuse purpose, and special dense phase pump that transfers the dehydrated CO2 at supercritical phase through 85 km pipeline to replace the typical sea water injection methodology in enhancing oil recovery. CC&S has several new technologies and experiences represented by the compressor capacity, supercritical phase fluid pumping, using mechanical ejector application to maximize carbon recovery, and CO2/TEG dehydration system as non-typical dehydration system. CC&S design considered the occupational health hazards generated from the compressor operation by installing engineering enclosure with proper ventilation system to minimize the noise hazard. CC&S helped HNGLRP to reduce the overall Greenhouse Gas (GHG) emission resulted from typical CO2 incineration process (thermal oxidizing). (2) The total GHG resulted from combustion sources at HNGLRP reduced by nearly 30% since CC&S technology in operation. The fuel gas consumption to run the thermal oxidizers in AGRUs reduced by 75% and sent as sales gas instead. The Energy Intensity Index (EII) reduced by 8% since 2015, water reuse index (WRI) increased by 12%. In conclusion, the project shows significant reduction in the carbon emission, noticeable increase in the production, and considerable water reuse.

Fault Detection in the MSW Incineration Process Using Stochastic Configuration Networks and Case-Based Reasoning

Fault detection in the waste incineration process depends on high-temperature image observation and the experience of field maintenance personnel, which is inefficient and can easily cause misjudgment of the fault. In this paper, a fault detection method is proposed by combining stochastic configuration networks (SCNs) and case-based reasoning (CBR). First, a learning pseudo metric method based on SCNs (SCN-LPM) is proposed by training SCN learning models using a training sample set and defined pseudo-metric criteria. Then, the SCN-LPM method is used for the case retrieval stage in CBR to construct the fault detection model based on SCN-CBR, and the structure, algorithmic implementation, and algorithmic steps are given. Finally, the performance is tested using historical data of the MSW incineration process, and the proposed method is compared with typical classification methods, such as a Back Propagation (BP) neural network, a support vector machine, and so on. The results show that this method can effectively improve the accuracy of fault detection and reduce the time complexity of the task and maintain a certain application value.

A Framework for Economically Optimal Operation of Explosive Waste Incineration Process to Reduce NOx Emission Concentration

Explosives, especially those used for military weapons, have a short lifespan and their performance noticeably deteriorates over time. These old explosives need to be disposed of safely. Fluidized bed incinerators (FBIs) are safe for disposal of explosive waste (such as TNT) and produce fewer gas emissions compared to conventional methods, such as the rotary kiln. However, previous studies on this FBI process have only focused on minimizing the amount of NOx emissions without considering the operating and unitality costs (i.e., total cost) associated with the process. It is important to note that, in general, a number of different operating conditions are available to achieve a target NOx emission concentration and, thus, it requires a significant computational requirement to compare the total costs among those candidate operating conditions using a computational fluid dynamics simulation. To this end, a novel framework is proposed to quickly determine the most economically viable FBI process operating condition for a target NOx concentration. First, a surrogate model was developed to replace the high-fidelity model of an FBI process, and utilized to determine a set of possible operating conditions that may lead to a target NOx emission concentration. Second, the candidate operating conditions were fed to the Aspen Plus™ process simulation program to determine the most economically competitive option with respect to its total cost. The developed framework can provide operational guidelines for a clean and economical incineration process of explosive waste.

The technology of wastewater sludge vitrification in comparison with other processing methods

Специалистами компании ООО «НТЦ «Экопромтех» разработана инновационная технология остеклования илового осадка сточных вод, позволяющая значительно сократить объем отходов и получить на выходе безопасный остеклованный материал для использования в строительстве. Приводится сравнение технологии остеклования с другими способами переработки осадка: депонированием, сбраживанием осадка в метантенках, сушкой, пиролизом, каталитическим и классическим сжиганием. В России более 90% образующихся иловых осадков депонируются. При сохранении этой тенденции неизбежен рост плеча перевозки осадка. Использование необработанного илового осадка в качестве удобрения повышает риск загрязнения почвы. Финансовые модели проектов с внедрением метантенков за счет продажи биогаза или электроэнергии не окупаются. В случае применения метода сушки для получения топлива из осадка расходуется практически столько же тепловой энергии, сколько содержится в конечном продукте. Поэтому себестоимость высушенного илового осадка как топлива не будет меньше стоимости природного газа, а с учетом других операционных затрат, включая доставку до потребителя, превысит стоимость газа в 2–3 раза. Пиролиз с получением ликвидных продуктов находится на стадии разработки, что потребует проведения большого количества исследований. Технология каталитического сжигания осадка без предварительной сушки не решает основные проблемы любого сжигания и приводит к определенным трудностям: риск эмиссии суперэкотоксикантов сохраняется, золу необходимо утилизировать, затруднено поддержание автотермического режима, катализатор изнашивается и требует замены. Технология остеклования имеет ряд преимуществ, готова к масштабированию и промышленному внедрению. The experts of Ekopromtekh R & D Centre, LLC have developed an innovative technology for vitrification of wastewater sludge that provides for reducing significantly the volume of wastes and obtaining a safe vitrified material to be used in construction. A comparison of the vitrification technology with other methods of sludge processing is given: depositing, sludge digestion in digesters, drying, pyrolysis, catalytic and classical incineration. In Russia, more than 90% of the generated sludge is landfilled. If this trend persists, an increase in the sludge hauling distance is inevitable. Using unprocessed sludge as fertilizer increases the risk of soil contamination. Financial models of projects that envisage using digesters and selling biogas or electricity do not pay off. In case of using the drying method to obtain fuel from sludge, almost the same amount of thermal energy is consumed as the final product contains. Therefore, the cost of dried sludge as a fuel will not be less than the cost of natural gas, and taking into account other operating costs, including delivery to the consumer, will exceed the cost of gas by 2–3 times. Pyrolysis to obtain marketable products is under development and involves a lot of research. The technology of catalytic incineration of sludge without preliminary drying does not solve the main problems of any incineration process and causes certain difficulties: the risk of emission of superecotoxicants remains; the ash must be disposed of, the autothermal regime is difficult to maintain, the catalyst wears out and requires replacement. The vitrification technology has a number of advantages, it is ready for scaling and industrial implementation.