THE CASE FOR HYDROGEN ECONOMY

The time for the hydrogen economy is opportune for India. But are we prepared for it and what needs to be done? Hydrogen economy has a great potential for boosting India's energy security and alleviating the greenhouse gases (GHG) emissions. Simply stated, hydrogen can be employed as a fuel in a variety of applications, including fuel cell power generation and fuel cell vehicles. It combusts cleanly producing only water and no other obnoxious gases, and it can used as fuel in conventional IC engines to produce mechanical or electrical power. Above all, the overall energy efficiency is higher than IC engines that run with conventional fuels such as petrol or diesel. The hydrogen IC engine is said to be about 38%, 8% higher than petrol IC engine, while the fuel cell is 2–3 times more efficient than an IC engine.

Energy and the environment are thoroughly connected and the crude oil-based economy for the manufacture of fuels, chemicals and materials will not have a sustainable future. By the mid-2050s, there may not be a viable source of crude oil by using the current means of production and hence alternate sources must be tapped. Even otherwise, the over-use of oil products over last century has done a great harm to the environment, ultimately culminating into the Paris Agreement of 2015. Can hydrogen be the saviour of the environment and how? In the realm of renewable energy across the world, it is estimated that the share of the renewable energy will increase from current ~27% to ~51% by 2035 to ~73% by 2050 totaling 49000 terrawatt-hour (TWh). The contribution of solar, wind and hydro will be more than 50% in the renewable energy sources which will be 73% of the total; coal will still play a role. The European Union, the Hydrogen Council and Bloomberg New Energy Finance (BNEF) have reported that hydrogen could grow from 2% of the global energy mix in 2018 to 13–24% by 2050, at about 8% CAGR at the mid-point. The Hydrogen Council predicts investment of USD 150 billion by 2030. For the hydrogen economy to be a reality, hydrogen must be produced cheaply and in an ecofriendly manner, and it should serve as the commercial fuel that would provide a substantial portion of the country's energy demand and services. The reason might not so obvious to the public but in the so-called net-(carbon)-zero economy, green hydrogen will have to play a dominant role, not only in achieving the objective of converting carbon dioxide into fuels and chemicals such as methanol, dimethyl ether, formic acid, hydrocarbons, polymers, ammonia, etc. but also transforming (waste) biomass including waste plastics into fuels and chemicals. Carbon dioxide, the GHG and hydrogen are linked together in more than one way for protection of environment and provision of future stocks of chemicals and energy.

Hydrogen should be manufactured using local resources using indigenously developed technologies. It can be manufactured via a variety of processes which are coupled with a broad range of emissions, depending on the type technology and energy source used, thereby having different costs consequences and material needs. Hydrogen production technologies are broadly and simplistically categorized into three types such as grey hydrogen, blue hydrogen, and green hydrogen. The main difference among the grey, blue, and green hydrogen is that the hydrogen is produced using fossil fuels, non-renewable energy, and renewable energy, respectively. Electrolysis of water using clean electricity from wind, solar, hydro, or nuclear energy sources will give green hydrogen which is the gold standard because it produces zero GHG emissions. Steam reforming of biomass, biogas, biooil, or natural gas also gives hydrogen called blue hydrogen giving the other carbon portion in the feedstock as carbon dioxide. Authorities estimate that this process captures up to 90% of the carbon having low to moderate carbon intensity. Whereas the steam reforming of fossil sources similarly gives grey hydrogen coupled with co-generation of carbon dioxide; and this method is the most common technology which is increasingly unpalatable because of the emissions of carbon dioxide.

Green hydrogen can be used as a feedstock, a fuel or an energy carrier and storage, and has numerous potential applications across different industries, transport, power, and buildings sectors. Most importantly, it does not emit carbon dioxide and almost no air pollution when used. It thus provides a key to decarbonise industrial processes and economic sectors where reducing carbon emissions, which is both important and challenging to achieve. This is part of the so-called net zero carbon policy by 2050 in consonance with the Paris Agreement while working towards zero pollution. However, hydrogen represents a modest fraction of the global energy mix and is still largely produced as grey hydrogen from fossil fuels, notably from natural gas or coal, resulting in the release of tons carbon dioxide annually in the EU. The reduction of carbon dioxide emissions of ~35 gigatons in 2020 to ~10 gigatons will contain the global temperature to within 1.5 oC in 2050. For hydrogen to contribute to mitigate climate change and climate neutrality, it ought to attain much larger scale and its production must become fully from water splitting using green technologies. During November 2019-March 2020, the list of planned global investments increased from 3.2 GW to 8.2 GW of electrolysers by 2030 of which 57% in Europe. The Hydrogen Council founded in 2017 by 13 companies has now 109 companies as members from more than 20 countries, bringing together an even broader range of sectors along with the complete hydrogen value chain. However, the transition to a hydrogen economy encounters many challenges that must be surmounted, including large-scale infrastructures for refilling stations of hydrogen akin to those of petrol, diesel and natural gas, and the cost of hydrogen production, transport, and storage. These challenges can be overcome collectively by multi-partnership among companies, nations, and continued research across institutions, and above all local government policies. Today, the fossil-fuel based grey hydrogen is much cheaper than the green or blue hydrogen. The EU report estimates that the costs today for fossil-based hydrogen are ~1.83 USD/kg for the EU, highly dependent on natural gas prices, and disregarding the cost of carbon dioxide. Projected costs today for fossil-based hydrogen with carbon capture and storage (CCS) are around 2.44 USD/kg, and renewable hydrogen 3.05-6.71 USD/kg. Further, the fossil-based hydrogen with carbon capture can become competitive only if the carbon prices are in the range of 70-110 USD/ton of carbon dioxide. The electrolyser costs have gone down during the past decade by about 60% and will further reduce by half by 2030 due to the economies of scale. In other words, the cost of hydrogen must be below 1.5-2 USD/kg to make a practical commercial sense for the hydrogen economy. Incidentally, the cost of hydrogen production by using water splitting in conjunction with solar energy is less than USD 1/kg for the process developed by the author in collaboration with OEC; we have named it as ICT-OEC hydrogen production technology. I hope the Ministry pays attention to it.

Some other costs and life cycle analysis (LCA) must be mentioned here for the planners to take cognizance of this article. The EU is way ahead in planning for the hydrogen economy. According to the International Energy Agency, IEA (2019), the well-to-gate greenhouse gas emissions for renewable hydrogen from renewable electricity are close to zero. The well-to-gate greenhouse gas emissions of steam reforming of natural gas are 9 kg carbon dioxide equivalent per kg of hydrogen. The same figures for the well-to-gate greenhouse gas emissions of steam reforming of natural gas with CCS with 90% and 56 % respectively are 1 are and 4. In this analysis the natural gas prices for the EU are taken as 26.8 USD/MWh, electricity prices from 43-106 USD/MWh, and capacity costs of USD 730/kW. Based on cost assessments of IEA, the International Renewable Energy Agency (IRENA), and BNEF, the electrolyser costs will decline from 1100 USD/kW to 550 USD/kW or less after the year 2030, and 220 USD/kW after the year 2040. Costs of CCS increases the costs of steam reforming of natural gas from 990 USD/kWh to 1850/kWh. On the basis of current electricity and gas prices, low-carbon fossil-based hydrogen is projected to cost in 2030 from 2.5-3.0 USD in the EU, and renewable hydrogen are projected to cost from USD 1.3-2.9/kg according to IEA, IRENA and BNEF. The target for solar electricity is to be cost competitive with the current fossil-fueled system. If the cost of installed PV power can be reduced from the present cost of about USD 5/W installed to about USD1/W installed, the cost of solar electricity is predicted to reach USD 0.10/kWh.

One of the issues using carbon based, whether renewable or fossil, is the emission of carbon dioxide associated with hydrogen production. That co-product carbon dioxide can be valorized by using hydrogen into a few products enumerated earlier, such as methane and higher hydrocarbons, methanol, dimethyl ether (DME), formic acid, formates, urea, carbonates, etc. DME is the cleanest, colorless, non-toxic, non-corrosive, non-carcinogenic and environmentally friendly chemical that is mainly used today as an aerosol propellant in various spray cans, replacing CFC. Due to its high cetane rating of 55-60, compared with 40-55 for conventional diesel fuel, much higher than that of methanol, DME can be effectively used in diesel engines. Like methanol, it is a clean-burning fuel and produces no soot and black smoke. DME is the best substitute for propane and butane in LPG as a cooking fuel and the well-established LPG industry infrastructure can be used for DME. The worldwide demand for DME is currently only about 150,000 tons/year, which could be considerably increased if large quantities of DME are needed as fuel.

There are many points to advocate hydrogen economy for India's transition to clean and green energy. Renewable electricity will lead the decarbonization or net-zero effort across the globe by 2050. Meanwhile hydrogen can serve as a vector for renewable energy storage in conjunction with batteries, and transport, guaranteeing as a backup for seasonable variation. Hydrogen can substitute fossil fuels in some carbon intensive industrial processes, such as steel and chemical and allied industry, lowering GHGs and further bolstering global competitiveness for those industries. It can present solutions for difficult to abate parts of the transport system, in addition to what can be accomplished through electrification and other renewable and low-carbon fuels. India can learn a lot from countries like the US, the EU, Japan, and China, and from their policies to promote the hydrogen economy. It was heartening to note that the IndianOil has planned to purchase 15 polymer electrolyte membrane (PEM) fuel cell buses that can run on hydrogen fuel and is also setting up a facility to produce hydrogen to run the buses. The Ministry of Natural Gas and Petroleum must be applauded for creating the hydrogen corpus fund. The renewable energy resources like solar and wind, and other types are environment-friendly alternatives to produce electricity to be applied for hydrogen production. The potential of solar energy for producing sustainable electric power (solar PV or solar heat), or by direct use of solar heat to produce hydrogen for fuel cell power generation and as fuel for ICEs merits attention. However, the high capital cost of fuel cell, about USD 5,500/kW, is one of the major hurdles of its development that must be surmounted before commercialization.

As fuel cell technology becomes mature and economical, fuel cells and fuel cell vehicles will gain substantial market share vis-à-vis conventional power generation sources and transportation vehicles. In that way, the entire world would benefit from lower dependence on oil and coal as the major sources of energy and cleaner environment through lower carbon emissions. What we need in the future are the integrated plant for hydrogen production from water splitting and its use in controlling environmental pollution and climate change as well as production of many chemicals (the carbon dioxide refineries). Also, we need a novel, realistic rethinking of the energy policy—from transitioning from coal to petroleum to gas and eventually to electrification of transport, to carbon pricing and a focus on new technologies. Why and how the energy and material policies should consider (renewable) carbon for chemicals and materials with non-carbon renewable sources of energy should be abundantly clear now. However, before this vision is turned into a reality and the transition to the Hydrogen economy happens, many technical, social, and policy challenges must be conquered. The Government of India should make the first move, sooner than later, in consonance with its grand objectives, the 5 trillion-dollar economy notwithstanding.

Emeritus Professor of Eminence & J.C. Bose National Fellow.

Former Vice Chancellor & R.T. Mody Distinguished Professor & Tata Chemicals Darbari Seth Distinguished Professor of Leadership & Innovation

INSTITUTE OF CHEMICAL TECHNOLOGY, MUMBAI