Upgrading existing ammonia plants with heat exchange reforming to improve energy efficiency and boost production

摘要

The fertilizer market has become increasingly competitive and this puts additional pressure on ammonia plants to improve efficiency and produce more from less. Existing plants especially in areas with high feedstock prices meet fierce competition from new plants in low gas cost areas. In order to survive, it is necessary to minimize energy consumption, maximize feedstock utilization, and optimize plant operation. This can be achieved by working together with the best engineering partners and taking benefit from the latest technological advances. Limited access to natural gas is another challenge to the ammonia industry. In areas having abundant reserves of coal (or other available fuels) and high natural gas prices, the conversion of an ammonia plant to use alternative fuels to substitute part of the natural gas will in general provide a good business case. This paper will describe various scenarios foreseen for implementing heat exchange reforming both as a revamp feature and for new grassroots ammonia plants. In general, the implementation of heat exchange reforming offers multiple benefits for ammonia producers such as lower production costs and better utilization of available alternative fuels such as coal. Higher production capacity is also a possibility and will improve the economics of the entire complex. For existing plants, the Haldor Topsoe Exchange Reformer (HTER) offers a very compact revamp option that can increase reforming capacity with up to 25%. Moreover, the natural gas consumption in the ammonia plant can be minimized by saving fuel, and thereby also reduce emissions from the reformer. By introducing heat exchange reforming, steam generation from the ammonia plant will be reduced as well, so this is an attractive way to minimize or avoid steam export from the ammonia plant. Industrial case stories describing the implementation of heat exchange reforming in an ammonia plant will also be presented.