Hydrogen from natural gas with CO2 capture can be a key transition technology to a low carbon energy system due to the abundance of natural gas and the possibility to increase the production capacity quickly. However, it is necessary to achieve both a high energy efficiency and a high CO2 capture ratio to be a viable option. The liquefaction of CO2 is one promising separation technology as it provides the captured CO2 in a transportable format. This paper therefore proposes a hydrogen production process with integrated CO2 liquefaction. Efficiencies of up to 84.7 % (Based on the higher heating value) and CO2 capture ratios of up to 97.2 % can be achieved. One advantage of the utilization of CO2 liquefaction as separation technology is furthermore the possibility to incorporate a partial recycle of the flue gas from the separation to the water–gas shift reaction, increasing both energy efficiency and carbon capture ratio.

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Novel integration of a hydrogen liquefaction process and cryogenic rectification of air is presented. The thermodynamics
analysis including the 2nd Law and sensitivity analysis regarding this process is conducted. The
proposed cryogenic process can produce 111.3 kg/s of nitrogen and 42 kg/s of oxygen with argon. In addition,
this process produces more than 132 × 103 tons of liquid hydrogen and 751 tons of crude neon per year.
Moreover, as the number of the used compressor is very fewer than of the conventional process, the required
power consumption of the proposed cryogenic plant is almost low. Based on the exergy analysis, using expanders,
providing the requested refrigeration condition by solar heat exchangers and proper streams, and integrating two
processes with similar operating conditions, the energetic efficiency of the cycle is more than 70 %. The
sensitivity analysis of operating parameters such as pressure, temperature, reflux ratio, and the number of stages
of colu... [more]

Cryogenic air separation is an efficient method to produce oxygen and nitrogen that
has been investigated extensively. However, the production of rare gas components of air
such as neon through air separation has not been explored enough. In this paper, a
cryogenic process to produce neon along with nitrogen and liquid oxygen from a two-column
air separation unit is proposed. Besides, energy, exergy, and sensitivity
analyses of the process are performed. Neon, nitrogen, and oxygen mole fractions
obtained were 0.206%, 98.75%, and 74.47% respectively. Results showed that
increasing the temperature of the feed streams and the reflux ratio of the columns have
a negative effect on the recovery of neon while increasing the feed’s pressure up to a point
improves the recovery. The overall exergy efficiency of the process was determined as 74.63%.

Carbon capture, transport, and storage (CCS) is an essential technology to mitigate global CO2 emissions from power and industry sectors. Despite the increasing recognition and interest in both the scientific community and stakeholders, current CCS deployment is far behind targeted ambitions. A key reason is that CCS is often perceived as too expensive to reduce CO2 emissions. The costs of CCS have however traditionally been looked at from the industrial plant point of view which does not necessarily reflect the end-user’s perspective. This paper addresses the incomplete view by investigating the impact of implementing CCS in industrial facilities on the overall costs and CO2 emissions of end-user products and services. As an example, this work examines the extent to which an increase in costs of raw materials (cement and steel) due to CCS impact the costs of building a bridge. Our results show that although CCS significantly increases the cost of cement and steel, the subsequent incre... [more]

The recognised urgency to achieve net-zero carbon dioxide (CO2) emissions by 2050, as first presented by the IPCC special report on 1.5 °C Global Warming, has spurred a renewed interest in hydrogen as a companion to electricity for widespread decarbonization of the economy. We present reflections on the estimation of future hydrogen demand, optimization of infrastructure for production, transport and storage, development of viable business cases, and environmental impact evaluations using life cycle assessments. We highlight challenges and opportunities that are common across studies of the business cases for hydrogen in Germany, the UK, the Netherlands, Switzerland and Norway. The use of hydrogen in the industry sector is an important driver and could incentivise large-scale hydrogen value chains. In the long-term hydrogen becomes important also for the transport sector. Hydrogen production from natural gas with capture and permanent storage of the produced CO2 (CCS) enables large-sc... [more]