• Energy Research

Abstract Rural electrification challenges in Iran are the most important obstacle to achieve electricity access for the entire population. The current study focuses on finding an optimal renewable energy system to meet the load of a small village by renewable resources. This village faces frequent power outages, common in many far-off villages in Iran. A hybrid photovoltaics/wind turbine/biogas generator/fuel cell renewable energy system is proposed and analyzed for both stand-alone and on-grid application. Fuel cells are used alongside a hydrogen tank, batteries, and a reformer or an electrolyzer, to act as storage devices and backup component. The main goal is to find an optimal configuration that can meet the electricity demand and be satisfactory from both an economic and environmental point of view. The results indicated that using solar, wind and biogas is the most affordable method and that adding fuel cell to this configuration would increase costs by 33–37%, but also improve system flexibility. Using a reformer is more efficient and about 6% less costly, but also creates more pollution. The cost of energy for a stand-alone system with reformer was calculated to be 0.164 to 0.233 $/kWh, while the on-grid system cost of energy was 0.096–0.125 $/kWh.

The main purpose of this paper is to study the thermodynamic, economic, and environmental aspects of a integrated system combined cooling, heating, and power generation system empowered by biomass and natural gas. Eco-Indicator 99 method is utilized to quantify the environmental impact. The proposed system consists of four main subsystems producing power, heating, and cooling. Natural gas is mixed with the syngas to enhance its heating value. The results indicate that the exergy efficiency of system is 39.45%, the products cost per exergy unit is 9.71 $ h−1, and the products environmental impact per exergy unit is 4422 mpt GJ−1. Also, when the natural gas mass flow rate-to-syngas mass flow rate ratio increases from 0 to 0.5, the exergy efficiency is found to improve by 71.97%, whereas the products cost per exergy unit and environmental impact per exergy unit of total products are seen to decline by 70.75 and 64.09%, correspondingly. Additionally, the exergy efficiency enhances by 19.48%, while the cost and environmental impact per exergy unit of the total products drop by 13.39 and 13.02%, respectively, as the splitter separation ratio increases from 0 to1.

Carbon capture and utilization (CCU) may offer a response to climate change mitigation from major industrial emitters. CCU can turn waste CO2 emissions into valuable products such as chemicals and fuels. Consequently, attention has been paid to petrochemical industries as one of the best options for CCU. The largest industrial CO2 removal monoethanol amine-based plant in Iran has been simulated with the aid of a chemical process simulator, i.e., Aspen HYSYS® v.10. The thermodynamic properties are calculated with the acid gas property package models, which are available in Aspen HYSYS®. The results of simulation are validated by the actual data provided by Kermanshah Petrochemical Industries Co. Results show that there is a good agreement between simulated results and real performance of the plant under different operational conditions. The main parameters such as capture efficiency in percent, the heat consumption in MJ/kg CO2 removed, and the working capacity of the plant are calculated as a function of inlet pressure and temperature of absorber column. The best case occurred at the approximate temperature of 40 to 42 °C and atmospheric pressure with CO2 removal of 80.8 to 81.2%; working capacity of 0.232 to 0.233; and heat consumption of 4.78 MJ/kg CO2.