Article pubs.acs.org/EF
Development of an Integrated Oil Shale Refinery with Retorting Gas Steam Reforming for Hydrogen Production Siyu Yang, Jun Zhang, Qingchun Yang, and Yu Qian* School of Chemical Engineering, South China University of Technology, Guangzhou, Guangdong 510640, People’s Republic of China ABSTRACT: The conventional oil shale refinery suffers from inefficiency in resource use and poor economic performance. This is because that detrital oil shale and retorting gas are not properly used. Hydrogenation of crude shale oil is not cost-efficient with outsourcing hydrogen. Proposed in this paper is an integrated oil shale refinery with reforming of the retorting gas. The retorting gas is used to produce hydrogen, which is then supplied for the hydrogenation. Crude shale oil is upgraded to higher valued products, such as naphtha, diesel, and liquefied petroleum gas. The detrital oil shale is combusted to provide heat for the regeneration of CaO. Economic analysis is conducted by comparing to the conventional refinery process. Results show that the return on investment of the proposed process is 18.89%, much higher than the previous 10.53% of the conventional refinery process. operating experience.34 However, expensive hydrogen has to be outsourced, leading to high production cost. Proposed in this paper is an integrated oil shale refinery with retorting gas steam reforming for hydrogen production to solve the problems mentioned above. The sorption-enhanced reforming reaction is introduced to produce hydrogen.11,14,26 This hydrogen not only satisfies the need in the hydrogenation process but is also partially sold to improve the economic benefit. In addition, the heat needed for the CaCO3 calcination reaction is supplied by the combustion of the detrital oil shale. This heat integration raises energy efficiency of the proposed process. Followed in this paper, the process structure will be elaborated in section 2. It will be modeled and simulated in section 3. Economic analysis of the process will be conducted in section 4 in a comparison to the conventional refinery process.
1. INTRODUCTION With the limited reserve of oil and gas in China, various alternative energy resources have to be explored to meet the increasing demand for energy. Oil shale is one of the most promising alternatives, attracting increasing attention because of its rich reserve.10 According to the statistics, the total reserve of oil shale in China is about 500 000 billion t. It is distributed mainly in Fushun, Liaoning province, Huadian, Jilin province, and Maoming, Guangdong province.32 The gradual decrease in the reserves of conventional energy resources has motivated many countries, especially China, Estonia, and Brazil, to develop efficient and environmentally friendly processing technologies of oil shale.13,20 Ex situ retorting and in situ retorting are two promising technologies for oil shale exploitation. The in situ retorting technology is under investigation but not likely to be implemented at scale in the near future.9 The ex situ retorting technology is mainly applied in Fushun-type retort in China, Petrosix-type retort in Brazil, ATP-type retort in Australia, and Kiviter- and Galoter-type retort in Estonia.12,18,23 The conventional oil shale refinery technology suffers from three major problems: (i) The retorting gas is used only as fuel for boilers because of its relatively low heating value ranging from 3.3 to 4.0 MJ N−1 m−3.18 (ii) The detrital oil shale (
