Pathways for hydrogen infrastructure development in China: Integrated assessment for vehicle fuels and a case study of Beijing

Abstract

This paper analyzes the technical, economic, and environmental characteristics of different pathways for supplying hydrogen to vehicles in China. A life-cycle accounting of “well-to-tank” hydrogen delivery for 11 different infrastructure pathways reveals different relative economic costs and environmental benefits. Coal-derived methanol as a hydrogen carrier appears particularly promising for China from an economic standpoint. The analysis considers three different infrastructure models: (1) “point-to-point” distribution from well to fueling station; (2) an “idealized city model” with radial and network distribution within a city grid; and (3) a model of Beijing infrastructure growth that evolves over time. The analytical results, the infrastructure models, and the practical case of Beijing provide policy-makers with new tools for hydrogen development strategies.

Introduction

Fifty years in the future, the total number of automotive vehicles in China will be 15 times the current amount [1]. It will increase the demand for liquid fuels and cause serious environmental pollution. Increased demand for fuel can even cause national energy security problems. To solve the problem, developing fuel cell vehicles (FCVs) will be a promising solution because FCVs, fueled by hydrogen, can realize nearly zero emissions, and hydrogen can be derived from diversified resources, such as fossil fuels and renewable energy resources.

In China, the research on hydrogen can be traced back to 1960s, which was highly related with China's space program, for instance, the production of rocket fuel (liquid hydrogen) and the development of rocket power sources (H₂/O₂ fuel cells). Over several decades, Chinese researchers have made great progress in hydrogen production, storage, and end-use technologies. But generally speaking, China still has a large gap in overall R&D capacities on hydrogen technology in comparison to industrialized countries, although some particular technologies have reached world-advanced level, such as mass production of hydride hydrogen storage material. Recently, China is implementing sustainable development strategies to promote the R&D and application of clean energy carriers such as hydrogen. And the key programs on hydrogen supported by the central government are mainly focusing on hydrogen vehicle technology. The most comprehensive R&D program on hydrogen vehicle technology initiated by the central government is the electric vehicle program under the National High Technology R&D Program (also called the 863 Program) for China's 10th 5-Year Plan period (2001–2005). In addition to tackling environmental and energy security issues, the Chinese government intends to use hydrogen technology to leapfrog past conventional vehicle technology and enhance the ability of China's auto industry to compete internationally. The national government was providing 880 million yuan (US$106 million), of which around US$12 million will be invested in a 3-year program highlighting proton exchange membrane fuel cell development and on hydrogen vehicle R&D and demonstrations [2]. Another key national program on hydrogen is included in the National Basic Research Program (also called the 973 Program), which was approved by the Chinese government in June 1997 and is organized and implemented by the Ministry of Science and Technology (MOST). The government invested around 30 million yuan (US$3.75 million) on the research of hydrogen storage materials, fuel cell membranes and catalysts during the 10th 5-Year Plan period. The purpose of the program was to provide domestic intellectual property holding technology bases for large-scale hydrogen development. Additionally, China has selected some cities and provinces as demonstration sites for fuel cell automobiles. The Global Environmental Fund (GEF) is funding the Demonstration of Fuel Cell Bus (FCB) Commercialization in China. This US$32 million co-funded project is intended to catalyze the cost reduction of FCBs for public transit applications in Chinese cities and stimulate technology transfer activities by supporting significant parallel demonstrations of FCBs and their hydrogen fueling infrastructures in Beijing and Shanghai. This project has been launched at an inception workshop in Beijing on March 27, 2003.

On the one hand, energy security issue and environmental challenges make Chinese decision makers hopeful that hydrogen can be a way to promote the automotive industry; on the other hand, the huge production cost of hydrogen vehicles and lack of required infrastructure are barriers to such development. Debates about when and how to introduce hydrogen technology are still ongoing. And this paper mainly focuses on the estimation and selection of different hydrogen infrastructure pathways for supplying hydrogen to vehicles in China.

Hydrogen can be generated by many pathways (or fuel chains), derived from both fossil fuels and renewable energy, located both centralized and onsite. Therefore, the question about which pathway might best meet the need of an FCV is a matter of much dispute. The development of hydrogen infrastructure is a time- and money-consuming project, so it needs comprehensive analysis of different hydrogen pathways before construction.

The life-cycle 3E (energy, environment, economy) analysis method acts as a powerful platform for this kind of estimation. In the past decades, several major studies [1], [3], [4], [5], [6], [7], [8], [9], [10], [11] have been performed to assess the fuel pathways of FCVs from well to wheel (WTW). However, the focuses of these completed studies are quite varied: some emphasize particularly on energy and emission impacts of FCVs in full life cycle; while others put their concentration on fuel economy and life-cycle cost analysis of FCVs. Although these WTW methodologies are generally similar, studies differ in terms of scope, timeframe, and geographic regions covered. As a result, different parametric assumptions regarding life-cycle 3E impacts of fuel pathways will be made. Among all the international literatures, only a few are specific to China. For instance, Feng [1] has developed an Excel-based spreadsheet model to assess the life-cycle 3E impacts of 11 feasible hydrogen pathways in Beijing during the 2008 Olympic period; Z Huang and X Zhang [3] applied the GREET model developed by Argonne National Laboratory to assess the energy and emissions impacts of 10 different hydrogen pathways in Shanghai's FCV development; and C Wang et al. [4] deals with the life-cycle 3E analysis of 10 hydrogen fuel chains of China with a timeframe of 5–10 years in the future. Since the objects of these studies are varied, the results are not always consistent.

Of all the literature related with hydrogen pathways analysis, few deal with the effect of delivery infrastructure model on final analysis result [12], rather, most of the published results are based on a particular delivery scenario set at the very beginning. So this paper renders some improvements over the previous studies, as it investigates the impacts of various delivery scenarios on the results.

Firstly, the “baseline” hydrogen pathways have been analyzed. Here, “baseline” means in one single pathway: it involves only one single production method, one single delivery method, though there may be combined methods used in reality, and also one single refueling method. And, different pathways have the same delivery distance, without distinguishing different delivery routes, just considering it as “point-to-point” delivery. The hydrogen demand area (hydrogen refueling stations) is concentrated on a single point. The purpose of this analysis is to find the potential and special points of each unique hydrogen pathway. Based on the first effort, a more sophisticated analysis will be done. An “idealized city model” is introduced to represent the hydrogen demand area, with a number of hydrogen refueling stations distributed spatially within the city. We consider complex delivery routes, which is an improvement on the “point-to-point” model. Finally, a Beijing case study of time-dependent hydrogen infrastructure development is discussed based on the previous efforts.

Based on current technology and market conditions, this paper analyzes 11 feasible hydrogen pathways for China in the near future. A life-cycle accounting of “well-to-tank” hydrogen delivery for these infrastructure pathways reveals different relative economic costs and environmental benefits. Besides the full consideration of Chinese energy structure (dominated by coal, lack of oil, and the potential for the further utilization of natural gas (NG)) during the pathways selection, what is more remarkable of this paper is that among all the analyzed hydrogen pathways, special attention is focused on using methanol as hydrogen carrier pathway, which may have economic advantages over hydrogen-delivery pathways, since its delivery cost is much lower than that of hydrogen delivery.

Hydrogen demand increases as more FCVs enter the markets, and analysis results rely on the scale of hydrogen demand [12]. At the starting stage with a few FCVs, China has a lot of hydrogen-rich waste gases and it is not worthwhile for setting up big dedicated facilities for the early small amount of hydrogen demand. Hence, except the Beijing case study with demand increasing, all the other hydrogen demands in the analysis are set to a medium to large scale of 150,000 kg H₂/day (the corresponding scale of single gasifier is already large enough currently), and the corresponding results are specific to this scale demand. When the hydrogen demand increases to more than this amount, we assume that several plants with same scale are applied, so the analysis result remains the same.

As for CO₂ issue, China is different from the countries that use oil or NG as major primary energy. China will depend on coal as primary energy for at least the next 50 years. In the future, more than half of coal will be used for power generation with large-scale units. These large units will be the major sources for CO₂ capture rather than small-scale, highly distributed facilities. The ratio of CO₂ emission in power generation sector and transportation sector is about 6:1 in 2003 [13], as a result, the carbon capture and sequestration (CCS) technology is not assumed in this transportation-based research work.