Decentralized Power Generation Research Articles

Contribution of the wood-processing industry for sustainable power generation: Viability of biomass-fuelled cogeneration in Sub-Saharan Africa

Energy access in Sub-Saharan Africa (SSA) remains a challenging issue at the midway point to the United Nations’ development goals. From the perspective of energy efficiency and diversification of power-generation sources, this paper investigates the capacity of the wood-processing industry to contribute to the decentralised power generation by performing a techno-economic analysis of the use of wood residues for cogeneration. Using a survey performed in Cameroon as a case study, a biomass-fuelled cogeneration scheme and a model analysing its viability are proposed for the specific context of SSA. A sensitivity analysis indicates for a given process efficiency of the industry, the attractiveness of cogeneration as the processing capacity and feed-in tariffs of electricity increase. More specifically, the threshold of feed-in tariffs ensuring the economic viability of CHP in the sub-region is estimated at $0.15 per kWh for mills where the output capacities of sawn timber products are of 5000 cubic metre per annum and more. The power-generation potential from the primary processing of timbers in the sub-region is about 388 kWh per cubic metre of sawn wood, while the energy intensity of the sawing process is estimated at 132 kWh per cubic metre. Therefore, the industry can generate up to 2472 GWh of electricity in the three sub-regions of East, West and Central Africa if a total of US$ 2.5 billion is invested, allowing a substantial increase of 1% of the current electricity-generation capacity for the geographic location which has the most important forestry resources on the continent.

Low pressure direct injection strategies effect on a small SI natural gas two-stroke engine’s energy distribution and emissions

This paper examines methods to simultaneously improve efficiency and reduce emissions from a 34 cc air-cooled two-stroke engine configured to operate on natural gas, using tuned intake plus exhaust resonators designed from Helmholtz resonance theory to promote effective scavenging. The engine was developed for novel application in a small, free piston engine for decentralized power generation. Operation occurred at wide-open-throttle at a speed of 5400 RPM for both port injection (PI) and low-pressure direct injection (LPDI). In both cases, the electronic ignition timing was adjusted for maximum brake torque, while the fuel was adjusted such that both rich and lean combustion were examined. The LPDI engine was then operated over a variety of engine speeds. An energy balance was completed for both PI and LPDI operation, which quantified all energy pathways, as engine operating regimes changed. Results showed that exhaust chemical energy (ECE) for LPDI was reduced significantly when compared to PI, mostly due to less fuel slip. The fuel slip rate ranged from 35 to 40% for PI operation while it was in the range of 6–20% for LPDI operation. However, mixture stratification with LPDI operation increased carbon monoxide emissions. The start-of-injection (SOI) was also examined, targeting a SOI to provide the highest trapping efficiency and most stable combustion. For LPDI operation, trapping efficiency, which is function of engine speed, showed significant effects on overall efficiency and fuel slip. Air volumetric efficiency increased due to the absence of gaseous fuel within the intake manifold. It was shown that, relative to PI, the overall engine indicated efficiency increased by 90% to a maximum indicated efficiency of 30% for LPDI operation with a SOI of 180 CAD BTDC.

Impacts of Decentralized Power Generation on Distribution Networks: a Statistical Typology of European Countries

The development of decentralized sources of power out of renewable sources of energies has been triggering far-reaching consequences for Distribution System Operators over the past decade in Europe. Our paper benchmarks across 23 European countries the impact of the development of renewables on the physical characteristics of power distribution networks and on their investments. It builds on a large spectrum of databases of quantitative indicators about the dynamics of installed capacity of renewable energy resources and the power generation out of them, electricity independence, quality of electricity distribution, smart grids investments, Network System Operators capital expenditures, length of the distribution networks, overall costs of power networks paid by private agents, and electricity losses, all in relation with the development of decentralized generation. The heterogeneity of these indicators across Europe appears to be wide notably because of physical constraints, historic legacies, or policy and regulatory choices. A cluster analysis allows for deriving six groups of countries that display statistically homogenous characteristics. Our results may provide decision makers and regulators with a tool helping them to concentrate on the main issues specific to their countries as compared to the European median, and to look for possible solutions in the experience of other clusters which are shown to perform better for some indicators.

Conceptual design and life cycle assessment of decentralized power generation by HT-PEMFC system with sorption enhanced water gas shift loop

In this work, the decentralized power generation system consisting of a biomass gasifier, high-temperature proton exchange membrane fuel cells (HT-PEMFCs), and a sorption enhanced water gas shift reactor (SE-WGS) is investigated. With very low CO2 and CO concentrations in the reformate gas, the unconsumed fuel at the anode outlet stream of HT-PEMFC is possibly recirculated to the sorption enhanced water gas shift reactor to improve the performance and overall system efficiency without an increase in the problematic CO poisoning. The effects of CaO/C ratio, fuel utilization, and anode split ratio are analysed. With the anode recirculation, the operation at higher fuel utilization and anode split ratio improves the hydrogen efficiency and the system efficiency. The environmental impacts of the biomass gasification integrated with the SE-WGS and HT-PEMFCs are analysed and compared to the different decentralized HT-PEMFC systems fuelled by biomass using life cycle assessment methodology. The CaO production process is found to be the main cause of global warming impact and damage to human health and ecosystem quality, and no negative effect on resource depletion is observed for all studied power generation systems fuelled by biomass. The implementation of CO2 capture into the decentralized HT-PEMFC systems to enhance the hydrogen purity and efficiency significantly increases the environmental impact of the systems. Compared to the Thai Mixed Electricity Grid, better global warming impact of power generation from all studied HT-PEMFC systems is observed due to the environmental benefit obtained from the electricity produced from biomass.

A novel strategy of periodic dosing of soy-lecithin as additive during long term test of diesel engine fueled with straight vegetable oil

The vegetable oil has become a frontier area of research in rural and remote areas for small or decentralized power generation applications. However, the biggest challenge in use of straight vegetable oil (SVO) in a diesel engine is the problem of injector deposits. Soy-lecithin has been identified as bio-additive to overcome the deposits problem due to its natural surfactant and emulsifying properties. Though short-term performance test using soy-lecithin as bio-additive with non-edible karanj oil showed quite good results, its effect on engine performance during long-term test needs to be experimentally investigated for its reliability. The key objective of the current work is to examine the performance of diesel engine operated with karanj oil (Pongamia pinnata) by adopting a novel strategy of periodic dosing of bio-additive during a long-term test. This study also intends to focus on lubricating oil analysis to evaluate the effectiveness of soy-lecithin as bio-additive with karanj oil. Long-term engine test was performed on a Cummins DXP, direct injection diesel genset at a constant speed and load for 130 h. A test was conducted by adopting a novel strategy of periodic dosing of bio-additive in karanj oil in a repeated cycle during engine running condition. Experimental results showed that immediately switched over to additive improved the performance of engine but its continuous use lead to degradation of engine performance. Thus, running of engine continuously with either additive or w/o additive independently would lead to degradation of the engine performance but with periodic dosing of soy-lecithin as bio-additive improved the performance of the engine. The present work suggests the strategy of running the engine with bio-additive in discreet dosages for 2 h after every 7–8 h of engine run without additive in a repeated cycle. This approach would lead to smooth running of the engine which is an improvement over the baseline performance of karanj oil either with or without soy-lecithin alone. The lubricating oil analysis revealed the normal physicochemical properties and normal wear metal level within the discarding limit after 130 h of the long run test. The information coming out of this research would be helpful to researchers working with SVO to overcome the engine problems for its long-term durability or endurance test by adding an additive in a strategic manner.

Techno-Economic Study of Photovoltaics and Dish Stirling Engines for Decentralised Power Generation in Sudan: Part 1: Overview and Methodology

Mohamed Atta ElManan Bakhit Alhaj Hamad bin Khalifah University, Education City, Doha PO Box 5825 Qatar Email: mohbakhitalhaj@hbku.edu.qa Kamaruzzaman Sopian Solar Energy Research Institute SERI, Universiti Kebangsaan Malaysia, Bangi PO Box 43600 Malaysia Email: ksopian@ukm.edu.my DOI: 10.47556/J.IJSR.8.1.2018.2 Purpose: This paper presents an overview of the power generation market in Sudan, solar energy potential, introduction to photovoltaics […]

A Technical-economic Analysis of Wood Gasification for Decentralized Power Generation in Colombian Forest Cores

This work presents a technical-economic analysis of several biomass gasification-based power plants for decentralized generation. The major aim is to make a preliminary evaluation of their feasibility in the Colombian context by means of the cost of electricity (COE). The analysis was conducted using information provided directly by power plant manufacturers from several continents. A silvicultural analysis of the major commercial forest plantations in Colombia allowed to determine suitable forest crops for energy projects, with energy potentials ranging from 500 kWe to 2000 kWe. Results from the study show that COE varies from 10.2 cUSD/kWe-h to 40.8 cUSD/kWe-h depending on the technology used. For lower cost plants, the share of investment cost in COE is of 45-50%, whereas for more expensive technologies it is of 63-67%. The methodology used provides technical, economic, and energy support to make informed decisions regarding the best technology for small-medium power applications using biomass.

SOLIDpower produces 1000th BlueGEN SOFC generator

Solid oxide fuel cell manufacturer SOLIDpower recently manufactured the 1000th BlueGEN SOFC generator, at its production facility in Heinsberg, Germany. This is a major milestone in the short history of the globally operating company, which offers a sustainable alternative for decentralised power generation with its micro combined heat and power (CHP) systems.

Hybrid Renewable Power Systems for Generation of Own Power by Small and Medium-Scale Enterprises

Decentralized power generation, from renewables, is an attractive option for the future energy transition. Through a case study, the techno-economic feasibility to produce own power from distributed renewable to de-carbonize the operations of the Small and Medium Scale Enterprises (SMEs) was critically analysed. The case study was performed on one of the leading printing outfits of Sri Lanka. Solar photovoltaic (PV) and biomass gasification systems are the most cost-efficient and easy to operate technologies for grid-connected, small-scale power generation, at present, for the context. Grid integration has been found as a major challenge, in both technical and economic parameters of the project. The low capacity factor of solar PV and complexity of the supply chain for biomass power systems are critical to the respective technologies. A hybrid Solar PV-Biomass gasification power plant would have superior techno-economic performances with lower environmental impact than stand-alone systems. An equal share of the net power capacity between the technologies was obtained as the most suitable combination for the proposed hybrid power plant. A net carbon dioxide reduction of more than eighty percent of the operations of the SMEs is feasible. Socio-political factors also have a high impact on overall viability of such small-scale systems.

Making the World More Sustainable: Enabling Localized Energy Generation and Distribution on Decentralized Smart Grid Systems

Smart grid is an idea of upgradation of the traditional electric grid infrastructure. The efficiency of the existing electrical grid can be automated by integrating with innovative technical equipment such as: high-tech forecasting system, digital sensors, advanced two-way communication and two-way power flow systems. Smart grid establishes an interface between utility and consumer which helps to use energy, based on the preferences of price, eco-friendly and without technical system issues. It empowers the grid to be more secure, reliable and efficient. The peer-reviewed articles and published government reports have been reviewed, based on the analysis of technical characteristics of power generation systems, eco-friendly sources of power generations, cost reduction, functionality and design of traditional grid versus smart grid. Furthermore, the innovative technologies that enable the grid to integrate with decentralized power generation system efficiently have been considered. This paper claims that in this modern era, it is arduous for traditional grid to fulfill the rising demand of electricity, along with sustainable, eco-friendly and stable power supply, as it cannot be efficiently integrated with decentralized and localized power generation systems and renewable energy sources. The result of this paper shows that decentralized and localized power generation systems are located close to end-users which decrease the transmission and supply cost of electricity. Innovative technologies allow the decentralized and localized power generation systems to be integrated with renewable energy sources which help to reduce the cost of utility services and provide clean energy. Moreover, technological advancement played a decisive role in enabling the electrical system to be more efficient. Electrical reliability can be improved, greenhouse gas emissions can be reduced, renewable energy sources can efficiently be integrated, and rising demand for electricity can be met by embedding advanced applications and technological equipment in the electrical grid.

Thermochemical Biomass Conversion for Decentralized Power Generation with the Inverse Brayton Cycle

AbstractBiomass is an important energy source for decentralized power generation. The combination of a two‐stage thermochemical conversion unit with an inverse Brayton cycle (IBC) is the subject of current research activities. Several advantages are expected compared to commercially available concepts. A commercially proven turbocharger from the automotive industry is used for the IBC unit. No cost‐intensive gas cleaning is required due to an almost dust‐ and tar‐free biomass conversion. The influence of the feedstock characteristics on the thermochemical conversion, the emissions, and the overall plant performance is subject to process optimization studies. Furthermore, validation of the concept is the target of a demonstration phase planned for a later stage of the research activities.

Influence of soy-lecithin as bio-additive with straight vegetable oil on CI engine characteristics

This research has embarked on capitalizing the potential sources of domestic renewable energy. Among various alternative fuel sources for compression ignition (CI) engine, vegetable oil has gained attention in rural and remote areas for stationary decentralized power generation applications, where diesel is not easily available. However, use of straight vegetable oil (SVO) causes various issues like formation of carbon deposits, injector coking, poor atomization, cold starting, etc. This could adversely affect the engine performance and exhaust emissions. Use of an appropriate fuel additive in a fuel is an attractive option in the existing diesel engines to overcome the deposits problem and to lower airborne pollution. It is one of the simplest and easiest methods as it does not require any hardware modifications. Although a wide variety of fuel additives have been developed for diesel fuel and bio-diesel fuel or blended fuel, no special additive for SVO has been developed yet. The present study is therefore undertaken on using naturally available soy-lecithin as a bio-additive with SVO to overcome the problems related to engine performance. Soy-lecithin is well known for its surfactant and emulsifying properties. The main objective of this study is to investigate the influence of soy-lecithin with non-edible karanj oil (Pongamia pinnata) on the performance, combustion and emission characteristics of a CI engine during short term test. The optimization of dosages of soy-lecithin for karanj oil was done through critical micelle concentrations (CMC) method. This study also shed light on the influence of soy-lecithin on physical properties of karanj oil and Sauter mean diameter (SMD). The detailed structural and chemical analysis of soy-lecithin was done through GC-MS, FTIR and NMR spectroscopy. This study also focuses on the influence of soy-lecithin on injector deposits. The test was conducted on a Cummins DXP 15-5, two cylinders, DI unmodified diesel engine at a constant speed by varying brake load. The test results demonstrated that addition of soy-lecithin in karanj oil significantly reduced NOx and CO emissions as compared to karanj oil without additive with no penalty of brake specific fuel consumption. The addition of soy-lecithin in karanj oil remarkably reduced cylinder pressure, HRR, ignition delay and mean gas temperature in comparison to karanj oil without additive whereas increased mechanical efficiency throughout the load range. Soy-lecithin was found very effective in drastic reduction of injector deposits.

Techno-economic analysis of novel working fluid pairs for the Kalina cycle

The organic Rankine cycle (ORC) and the Kalina cycle (KC) are well established thermodynamic concepts for decentralized power generation based on waste heat at low and medium temperature level. In a previous exergetic analysis, it has been shown that second law efficiency of KC can be increased by applying alcohol/alcohol mixtures as working fluid instead of ammonia/water. The aim of this work is to provide a detailed evaluation of operational parameters of a novel ethanol/hexanol mixture as a working fluid for the KC. Therefore, process simulations in ASPEN PLUS V8.0 are conducted. As a benchmark the KC with standard working fluid ammonia/water and the ORC are examined. Next to thermodynamic aspects, a techno-economic evaluation of the KC and the ORC is conducted. For 200 °C, 300 °C and 400 °C heat source temperature the pressure, power output, heat exchange capacity and the size parameter are analyzed. Compared to ammonia/water alcohol/alcohol mixtures offer an up to 1.5 times higher power output, an up to 66.6 % lower pressure and heat exchange capacity, but lead to 5.6 times higher size parameters. Compared to the KC, the subcritical ORC leads to an up to 3.4 % lower power output. The heat exchange capacity is at least 33.3 % and the size parameter up to 6.3 times lower. For the considered concepts, ammonia/water leads to the lowest specific cost with 619.4 €/kW. However, the cost estimation for the KC is related to several uncertainties. Therefore, the pure fluid ORC should be preferred in terms of techno-economic considerations.To sum up, the results show that the pure fluid ORC should be preferred in terms of techno-economic considerations.

The role of thermo-catalytic reforming for energy recovery from food and drink supply chain wastes

Disposal of food and drink wastes, including packaging wastes, has a significant cost and environmental impact. All carbon containing wastes have an energy potential and the food industry should focus on recovering that energy to offset their reliance on fossil-fuel derived energy sources. This paper focuses on the novel use of intermediate pyrolysis for decarbonizing the food chain, through the treatment of food and packaging waste, to recover energy. The TCR is a versatile technology which overcomes many of the traditional problems associated with fast pyrolysis and can thermo-chemically convert a range of different feedstocks, including inaccessible lignin and some inorganic, recalcitrant materials. The feedstocks are converted into new fuel sources; char, bio-oil (thermally stable) and permanent gases, for further electrical and heat generation. Ultimately with the use of the TCR technology, the food production industry could look to using decentralized power generation located on-site of large food processing facilities to optimize their energy efficiencies.

NOTA TÉCNICA: CAMA DE FRANGO E RESÍDUO MOVELEIRO: ALTERNATIVA ENERGÉTICA PARA A ZONA DA MATA MINEIRA

Objetivou-se discutir as possibilidades de utilização da cama de frango e do resíduo moveleiro do Polo de Ubá, associados ou não, e propor alternativas energéticas sustentáveis para a região da Zona da Mata Mineira. Para tal, foi feito um levantamento da quantidade de resíduos produzidos por essas atividades e extrapolação descritiva do potencial energético baseado em literaturas publicadas. Estimou-se que o volume de cama de frango gerado foi de 78.624 ton/ano. Já o Polo moveleiro de Ubá produz em média 480 ton/ano. Estes resíduos são dispostos no meio ambiente de forma aleatória, sendo caracterizados como passivos ambientais. Em virtude das características de composição da cama de frango e do resíduo moveleiro e da necessidade de se produzir de maneira sustentável pode-se adotar estas biomassas como alternativas energéticas locais para geração de energia descentralizada. Isto pode ocorrer através da produção de briquetes e de pellets mistos e nos seus diversos processos de aproveitamento (combustão, gaseificação, co-geração) em alguns setores produtivos da região. No entanto, faz-se necessário o desenvolvimento de estudos futuros para avaliar a emissão dos poluentes atmosféricos nocivos que possam vir a ser gerados durante seu aproveitamento energético.

Assessment of Environmental Impacts of Tar Releases from a Biomass Gasifier Power Plant for Decentralized Electricity Generation

Abstract: Biomass gasification systems may be relevant for decentralized power generation from recoverable agricultural and wood residues available in rural areas. Although they have many positive effects, these systems can also affect environment and human health. Indeed, during the process of biomass gasification, tars are produced and generally discharged in the local environment. This work deals with the analysis of the environmental impacts of a biomass gasifier power plant project. It compares the impacts of tar releases from the conversion of two biomasses: cotton stalks and rice husks, and that of two disposal modes (into water or on soil). The gate-to-gate environmental impacts are assessed through Life Cycle Assessment (LCA) approach. The results of this study indicate that the environmental impacts of electricity production from cotton stalks are higher than that of from rice husks. Results also show that the impact levels are high when tars are dumped into water comparatively to their discharge on soil. For environmental research, these results represent a significant step of a global environmental assessment of the studied systems.

Experimental and economic study of small-scale CHP installation equipped with downdraft gasifier and internal combustion engine

This paper concerns the experimental and numerical analysis of a combined heat and power (CHP) installation equipped with a biomass downdraft gasifier, gas purification system and gas piston engine. The numerical studies were aimed at identifying waste heat in the CHP installation for further utilisation. In turn, a new innovative method of heat recovery inside the gasifier was proposed and subsequently applied in the experimental CHP installation. The newly developed facility is able to produce up to 75kWe of electrical power. An extensive parametric study was performed under the steady and unsteady facility operation and was supplemented by economic analysis of the process. The main objective of the study was to examine the possibility of sewage sludge gasification and the impact of produced syngas quality on gas engine performance. During the investigation a number of different types of biomass were investigated including wood pellets, sewage sludge and their blends. The results showed a stable operation of the CHP facility in terms of produced syngas load, calorific value and content – even when dried sewage sludge was used alone. Results indicate that a 40/60% blend of wood pellets with sewage sludge is recommended, which allowed the lower heating value (LHV) of 4.45MJ/Nm3. Additionally, it was confirmed that the fixed bed gasifier is able to self-adjust to temporary changes in gasifier agent load.The economic analysis was performed taking into account policies and regulations in the Polish energy market sector. The study showed that it is more profitable to use the generated electricity and heat for its self-consumption rather than selling it on the market. Even with the supporting policies the payback time is not less than about eight years. Taking into account calorific value and limited local biomass availability, it seems justified that the described CHP installation is suitable for decentralised power generation such as small farms or horticultural businesses, where the produced electricity and heat can be sufficiently utilised. This technology also contributes to reduction of CO2 emissions into the atmosphere, which is one of the most problematic issues for energy sector today.

Effects of varying composition of biogas on performance and emission characteristics of compression ignition engine using exergy analysis

Growing energy demands and environmental degradation with uncontrolled exploitation of fossil fuels have compelled the world to look for the alternatives. In this context, biogas is a promising candidate, which can easily be utilized in IC engines for vehicular as well as decentralized power generation applications. Primary constituents of raw biogas are methane (CH4) that defines its heating value, and carbon dioxide (CO2) that acts like a diluent. This dilution effect reduces the flame speed and heating value of biogas, eventually deteriorating the engine performances. Present article focuses on experimental evaluation and quantification of these variations of the engine performance. Three compositions of biogas: BG93, BG84 and BG75 (containing 93%, 84% and 75% of CH4 by volume respectively) were studied on a small CI engine in dual fuel mode. Moreover, to evaluate individual process inefficiencies, exergy analysis based on second-law of thermodynamics is implemented. Exergy balances for different compositions of biogas are presented. Biogas dual fuel operation showed 80–90% diesel substitution at lower engine loads. At higher loads, total irreversibility of the engine was increased from 59.56% for diesel operation to 61.44%, 64.18% and 64.64% for BG93, BG84 and BG75 biogas compositions respectively. Furthermore, combustion irreversibility was found to be decreasing with higher CO2 concentrations in biogas. BG93 showed comparable results to that of diesel operation with 26.9% and 27.4% second-law efficiencies respectively.

On the Mathematical Modelling of Adaptive Darrieus Wind Turbine

Darrieus wind turbines are experiencing a renewed interest for their application in decentralized power generation and urban installation. Much attention and research efforts have been dedicated in the past to develop as an efficient standalone Darrieus turbine. Despite these efforts, these vertical axis turbines are still low in efficiency compared to the horizontal axis counterparts. The current architecture of the turbine and their inherent characteristics limit their application in low wind speed areas as confirmed experimentally and computationally by past research. To enable and extend their operation for weak wind flows, a novel design of Adaptive Darrieus Wind Turbine (ADWT) is proposed. The hybrid Darrieus Savonius rotor with dynamically varying Savonius rotor diameter based on the wind speed enables the turbine to start, efficiently operate and stop the turbine at high winds. As the wake of Savonius rotor has a profound impact on the power performance of the combined rotor, the wake of two buckets Savonius rotor in open and closed configuration is reviewed. The current study aims to develop an analytical model to predict the power coefficient and the influence of other design parameters on the proposed design. The formulated analytical model is coded in python, and the results are obtained for the 10 kW rotor. Parametric analysis on the chord length and the diameter of the closed Savonius rotor is performed in search of an optimized diameter to maximize the annual energy output. Blade torque and the rotor torque are evaluated with respect to azimuthal angle and compared with conventional Darrieus rotor. The computed results show that peak power coefficient of ADWT is 13% lower than the conventional Darrieus rotor at the rated wind speed of 10 m/s.

Second law analysis of novel working fluid pairs for waste heat recovery by the Kalina cycle

The organic Rankine cycle (ORC) and the Kalina cycle (KC) are potential thermodynamic concepts for decentralized power generation from industrial waste heat at a temperature level below 500 °C. The aim of this work is to investigate in detail novel zeotropic mixtures as working fluid for the KC and compare to sub- and supercritical ORC based on second law efficiency. Heat source temperature is varied between 200 °C and 400 °C. The results show that second law efficiency of KC can be increased by applying alcohol/alcohol mixtures as working fluid instead of ammonia/water mixtures; especially for heat source temperatures above 250 °C. Efficiency increase is in the range of 16% and 75%. Despite this efficiency improvements, ORC with zeotropic mixtures in sub- and supercritical operation mode proves to be superior to KC in the examined temperature range. Second law efficiency is up to 13% higher than for KC. A maximum second law efficiency of 59.2% is obtained for supercritical ORC with benzene/toluene 36/64 at 400 °C heat source temperature. The higher level of efficiency and the lower complexity of ORC in comparison to KC indicate that ORC with zeotropic mixtures offers the greater potential for waste heat recovery.