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Abstract: This paper presents a thermoeconomic analysis aimed at the optimization of a novel zero-CO2 and other emissions and high-efficiency power and refrigeration cogeneration system, COOLCEP-S (Patent pending), which uses the liquefied natural gas (LNG) coldness during its revaporization. It was predicted that at the turbine inlet temperature (TIT) of 900°C, the energy efficiency of the COOLCEP-S system reaches 59%. The thermoeconomic analysis determines the specific cost, the cost of electricity, the system payback period and the total net revenue. The optimization started by performing a thermodynamic sensitivity analysis, which has shown that for a fixed TIT and pressure ratio, the pinch point temperature difference in the recuperator, ΔT p1, and that in the condenser, ΔT p2 are the most significant unconstrained variables to have a significant effect on the thermal performance of novel cycle. The payback period of this novel cycle (with fixed net power output of 20MW and plant life of 40years) was ∼5.9years at most, and would be reduced to ∼3.1years at most when there is a market for the refrigeration byproduct. The capital investment cost of the economically optimized plant is estimated to be about 1000$/kWe, and the cost of electricity is estimated to be 0.34–0.37CNY/kWh (∼0.04$/kWh). These values are much lower than those of conventional coal power plants being installed at this time in China, which, in contrast to COOLCEP-S, do produce CO2 emissions at that. [Copyright &y& Elsevier]

Emissions reduction in industrial processes, i.e. clean production, is an essential requirement for sustainable development. Fossil fuel combustion is the main emission source for gas pollutants, such as NOX, SO2 and CO2, and coal is now a primary energy source used worldwide with coal combustion being the greatest atmospheric pollution source in China. This paper analyzes flue gas cleaning by ammonia scrubbing (FGCAS) for power plants to remove gaseous pollutants, such as NOX, SO2 and CO2, and presents the conceptual zero emission design for power plants. The byproducts from the FGCAS process can be used in agriculture or for gas recovery. Experimental results presented for SO2 removal from the simulated flue gas in a continuous flow experiment, which was similar to an actual flue gas system, showed that the effectiveness of the ammonia injection or scrubbing depends on the temperature. The FGCAS process can effectively remove SO2, but the process temperature should be below 60 °C or above 80 °C for SO2 reduction by NH3 scrubbing. [Copyright &y& Elsevier]

• A systematic method is proposed to evaluate seawater heat pump potential in China assisted by spatial analysis. • Techno-economic, environmental and geographical key performance indicators are calculated. • Seawater heat pump is more feasible in north cities based on current status. • In the future seawater heat pump can be more feasible in south China. Fossil fuel based building space heating and cooling contribute to more than 10% total final energy consumption in China. Consequent carbon dioxide and air pollutants emissions bring about atmospheric pressure and associated respiratory diseases. Seawater heat pumps as a candidate sustainable building space heating and cooling solution can alleviate such environmental pressure since China has a long coastline and many coastal cities have the possibility for seawater heat pump implementation. However, stakeholders are still suffering from insufficient understanding of seawater heat pumps feasibility in different coastal cities of China from techno-economic, environmental and geographical perspectives. This paper proposes a systematic method to evaluate seawater heat pump potential in different locations of China considering various local spatial parameters in the source and sink side of the energy system. A key performance indicator system is introduced to quantitatively analyze the relative advantages and disadvantages of applying seawater heat pumps compared with status-quo systems. Quantitative evaluation results show that seawater heat pumps have a higher potential in north Chinese coastal cities from techno-economic point of view when compared with existing heating and cooling systems. Environmentally, seawater heat pumps have to reach a critical seasonal coefficient of performance value to guarantee its potential in carbon emissions saving. In south Chinese coastal cities, seawater heat pumps have to reach a more satisfactory system efficiency and a more competitive system cost in order to exploit its full advantages over status-quo systems from techno-economic perspectives. Environmentally, seawater heat pumps are more attractive than competing technologies in south cities. Also, north Chinese cities are geographically more feasible for seawater heat pumps applications compared with south cities. [ABSTRACT FROM AUTHOR]