Carbon capture for decarbonisation of energy-intensive industries:a comparative review of techno-economic feasibility of solid looping cycles

Carbon capture and storage will play a crucial role in industrial decarbonisation.However,the current literature presents a large variability in the techno-economic feasibility of CO_(2)capture technologies.Consequently,reliable pathways for carbon capture deployment in energyintensive industries are still missing.This work provides a comprehensive review of the state-of-the-art CO_(2)capture technologies for decarbonisation of the iron and steel,cement,petroleum refining,and pulp and paper industries.Amine scrubbing was shown to be the least feasible option,resulting in the average avoided CO_(2)cost of between 62.7∈t_(CO_(2))^(-1)for the pulp and paper and 104.6∈t_(CO_(2))^(-1)for the iron and steel industry.Its average equivalent energy requirement varied between 2.7(iron and steel)and 5.1MJ_(th)·kg_(CO_(2))^(-1)(cement).Retrofits of emerging calcium looping were shown to improve the overall viability of CO_(2)capture for industrial decarbonisation.Calcium looping was shown to result in the average avoided CO_(2)cost of between 32.7(iron and steel)and 42.9(cement).Its average equivalent energy requirement varied between 2.0(iron and steel)and 3.7(pulp and paper).Such performance demonstrated the superiority of calcium looping for industrial decarbonisation.Further work should focus on standardising the techno-economic assessment of technologies for industrial decarbonisation.

Environmental life-cycle assessment of waste-coal pellets production

Industrial decarbonization is crucial to keeping the global mean temperature<1.5°C above pre-industrial levels.Although unabated coal use needs to be phased out,coal is still expected to remain an important source of energy in power and energy-intensive industries until the 2030s.Decades of coal exploration,mining and processing have resulted in~30 billion tonnes of waste-coal tailings being stored in coal impoundments,posing environmental risks.This study presents an environmental life-cycle assessment of a coal-processing technology to produce coal pellets from the waste coal stored in impoundments.It has been shown that the waste-coal pellets would result in the cradle-to-gate global warming of 1.68-3.50 kgCO_(2,eq)/G_(Jch),depending on the source of electricity used to drive the process.In contrast,the corresponding figure for the supply of conventional coal in the US was estimated to be 12.76 kgCO_(2,eq)/G_(Jch).Such a reduction in the global-warming impact confirms that waste-coal pellets can be a viable source of energy that will reduce the environmental impact of the power and energy-intensive industries in the short term.A considered case study showed that complete substitution of conventional coal with the waste-coal pellets in a steelmaking plant would reduce the greenhouse-gas emissions from 2649.80 to 2439.50 kgCO_(2,eq)/t_(steel).This,in turn,would reduce the life-cycle greenhouse-gas emissions of wind-turbine manufacturing by≤8.6%.Overall,this study reveals that the use of waste-coal pellets can bring a meaningful reduction in industrial greenhouse-gas emissions,even before these processes are fully decarbonized.

Integration of solid-oxide fuel cells and absorption refrigeration for efficient combined cooling,heat and power production

Combined cooling,heating and power(CCHP)systems are characterized by a substantially higher energy-utilization efficiency compared to standalone systems.In this study,an integrated system comprising a solid-oxide fuel cell(SOFC),hot-water storage tank(HWST)and absorption refrigeration(AR)cycle is considered.The SOFC model was developed in Aspen Plus®.It was used to determine the thermodynamic properties of the exhaust gas that was then used to provide heat for the HWST and to drive the AR cycle.Thermodynamic models for the AR cycles were developed in Engineering Equation Solver,considering LiBr-H2O and NH3-H2O as working fluids.The sensitivity analysis of a number of SOFC output parameters has been carried out.The most optimal case was characterized with the coefficient of performance(COP)and CCHP efficiency of 0.806 and 85.2%for the LiBr-H2O system,and 0.649 and 83.6%for the NH3-H2O system,respectively.Under such optimal operating conditions,the SOFC was characterized by the net electrical efficiency of 57.5%and the net power output of 123.66 kW.Data from the optimal solution were used to perform the thermodynamic study and sensitivity analysis to assess the influence of different absorption cycle operating conditions and to identify possible applications for the considered integrated systems.