The Hydrogen Economy

The following sections are included:

• Dedication
• Disclaimer
• Introduction, Preamble, Executive Summary
• Summary Observations
• Contents

The following sections are included:

• The Use of Hydrogen in the Process Industries
• Safety
• Oil Refineries
• Petrochemicals
• The Use of Hydrogen in the Chemicals Industry
• The Use of Hydrogen in Reducing Metal Ores
• Observations

In Chapter 1, we described the current large demand for hydrogen and this demand will only grow as a ‘Hydrogen Economy’ develops. Terrestrial hydrogen is sourced from either carbonaceous materials or water. Current manufacture is dominated by production from fossil fuels — coal, oil or gas. For this, to continue in a carbon-constrained world then carbon capture and storage is a necessity. If the use of fossil fuels is to be eliminated, then the major source will be water alone. This chapter discusses the production of hydrogen from carbonaceous sources and water.

Chapters 1 and 2 outlined the very large requirements for hydrogen in the hydrocarbon processing industries and outlined the methods of production of hydrogen to service this demand from fossil fuels, mainly coal and gas. This chapter addresses the cost of hydrogen production to fulfil the much-expanded demand to run a hydrogen economy. A focus of the chapter will be the cost of production on large-scale facilities to best fit the very large demand for an economy reliant on the use of hydrogen to fulfil transport and energy needs.

A central question for the use of fossil fuels to produce hydrogen is the emission of carbon dioxide to the atmosphere. If this is to be avoided, then the carbon dioxide either has to be used or disposed by burial underground, so called carbon geo-sequestration (CGS). Although there is some interest in the utility of carbon dioxide, few of the proposals would be able to realistically cope with the volumes of carbon dioxide produced. This leaves CGS as the only viable method for disposal. Consequently, a cost estimate for the production of hydrogen without CGS and with CGS will be developed. The approach and the methodology for generating the cost estimates are given in the Appendix.

One of the generally unstated aims of promoters of the hydrogen economy is that the hydrogen should be produced entirely by so-called renewable sources and in particular wind-generated electricity, hydropower, solar voltaic cells, renewable biomass etc. The purpose of this chapter is to review these methods and identify the hurdles and costs of implementation by these routes.

Although the generation of hydrogen on a large scale and export to a central fuel filling facility is an important objective there is also the objective of producing hydrogen on a small scale to fuel domestic requirements such as fuel cells for power generation. This is also considered in this chapter.

For the most part we are considering the use of renewable electricity as the source of hydrogen production by electrolysis so this is considered first.

The Chapter 4 discussed the methods of production and cost of producing hydrogen from various sources. Production is only the first part of the problem for a hydrogen-based economy. Of equal significance is the method and costs of hydrogen storage and transport. This chapter and the Chapter 6 will review the main methods and issues relating to hydrogen storage and transport from production facility to the end user.

Included in this discussion are the methods and cost of compression. For the most part hydrogen is produced at a low pressure when compared to the preferred delivery pressure for vehicles at 40 MPa–80 MPa (400–800 bar). The cost of compression of hydrogen from near atmospheric pressure to that required is significant in terms of both capital and the energy required.

One of the principal aims of this book concerning the hydrogen economy is the production and distribution of large volumes of hydrogen in advanced economies. If this comes to fruition, for a variety of reasons many economies will be unable to produce sufficient hydrogen within their borders and consequently may become major importers of hydrogen. For continental jurisdictions import by pipeline may be feasible, however, for many countries this will not be possible and it will become necessary to import hydrogen by ship. This raises the question of the manner of import either as gas (compressed gas) or liquid hydrogen — or by means of a carrier fluid. In the last-mentioned mode of transport a hydrogen-rich fluid is synthesised where the hydrogen is available and carried by ship to an importing region where the hydrogen is extracted from the carrier fluid. There are two main propositions for the carrier fluid — ammonia or a naphthene (cyclic hydrocarbon). This chapter will discuss the technologies and estimate the shipping costs as would be applied to various alternative scenarios.

The objective of most proposals to develop a hydrogen economy is to eliminate carbon emissions. In order to do this the current suite of fossil fuels needs to be replaced with hydrogen. This covers all aspects of the fuel supply. Of particular interest is the use of hydrogen fuel cells in vehicles to replace the current conventional fuels, particularly gasoline and diesel.

One of the issues for replacement of conventional fuels with hydrogen that will have to be addressed for vehicle fuels is tax. Most, if not all, major jurisdictions receive substantial tax revenue from the present conventional fuels. In the short term, when a hydrogen economy is small and developing, this problem can be largely ignored but in the longer term this loss of revenue will have to be addressed. When and how far a hydrogen economy will be subject to tax is a moot point.

The aim of this chapter is to analyse the competitive position of hydrogen versus conventional fossil fuels and in particular the competitive position of hydrogen fuel cells in vehicles versus conventional transport fuels. To try and analyse this, there is first a discussion of the current state of fuel cells, their operation and the estimation of their efficiency. This can then be used to estimate the cost advantages of hydrogen fuel cells over conventional fuels in a variety of scenarios.

This chapter aims to use the data developed in the Chapters 3,4,5 and 6 to evaluate various scenarios in a hydrogen economy and tease out pertinent issues, which will influence a specific location and approach to establishing a hydrogen fuelled solution.

The following sections are included:

• APPENDICES
  • Properties of Hydrogen
  • Comparison of Hydrogen to Other Fuels
  • Conversion Factors
  • Cost Indices
  • Location Factors
  • Relation of Delivered Equipment to Final Capital Cost
  • Methodology for Economic Analysis
  • Indexed Fuel and Construction Costs
  • Accuracy of Cost Estimates
  • Abbreviations
• INDEX