generate steam for process heating in the food, brewing, sprits distillation, paper making and chemicals sectors. An HTIHP requires a heat sink at a temperature of between 60°C and 120°C to generate steam. Waste heat is widely available from many processes at these temperatures. From a sustainability perspective, HTIHPs are attractive for steam generation because they do not create CO 2 greenhouse gas emissions for boiler operation. This is because the combustion of fossil fuels is not required. However, the heat pump must be supplied with renewable electrical power for the full environmental benefits to be realised. The electrification of industrial processes will only be climate neutral if the power is generated using renewable technologies. Wind, solar, and hydro-electric power dominate here. Geothermal and biomass-based power generation are also relevant. So-called ‘green’ hydrogen can be produced through the electrolysis of water using renewable power. Reforming of biogas or gasification of biomass can also yield ‘green’ or renewable hydrogen. There is the possibility that renewable power generation in the future will far exceed the total level of electricity production today. Imagine that all existing power from all sources is produced by renewables, plus a similar amount of power is used to generate hydrogen, and an additional third of the total is used to drive CO 2 and methane reduction equipment. For example, DAC technology to reverse the damage of the past and return the air to sustainable levels of these greenhouse gases.
5(ish)% residual CO 2 emissions from ATR and CCS for blue hydrogen can be offset in some way (e.g. BECC or DAC). Furthermore, of great interest to the downstream sector, production of e-fuels could be a major application of CO 2 from DAC in the future. In the simplest case, captured CO 2 and hydrogen from an electrolyser are synthesised to methanol. Methanol acts as a hydrogen carrier and remains liquid under ambient pressure and temperature. Thus, the storage and transport of methanol is much easier and cheaper than liquid or compressed hydrogen distribution. Whilst several commercial DAC technologies for atmospheric CO 2 removal exist, there is not yet one that has been implemented for methane capture from the air. It would be a good idea to capture these gases in parallel, since a major energy consumer in the system is the power requirement to drive the fan that moves air through the equipment. Using this power once to remove both gases would perhaps be the most efficient way to reverse the historical damage that has been done from CO 2 and methane emissions. Electrification of industrial processes will play a leading role Heat pumps are common for space heating. They use ambient air or soil as a heat sink and produce heat at about 50°C, which is ideal for heating buildings. High temperature industrial heat pumps (HTIHPs) are based on a similar operating principle and have been recognised for their potential to
Vapour
Vapour
Compressor
Fan
Evaporator
Heat from ambient air
Heat for warmth and hot water
Condensor
Refrigerant gas recirculates within the system
1kW of electrical power applied to the fan and compressor can yield between 3 and 5 times the amount of heat energy
Liquid and vapour
Liquid
Expansion valve
Heat pumps can generate warmth for space heating from ambient air, or higher temperatures for steam generation from waste process heat
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