Economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry

Flavia Melo Menezes,José Celio Andrade,Armando Hirohumi Tanimoto,Maria Fátima Góes,Ricardo Araújo Kalid

doi:10.14807/ijmp.v8i4.672

Abstract

The burning of fossil fuels majorly contributes to the increase in global warming, and it represents 93% of greenhouse gases emissions in the chemical industry. Most of the energy demand in this sector is associated with steam systems, where 1/3 of the energy efficiency opportunities are located in its distribution system. However, most of the literature focuses on the design of new systems. Those that deal with existing systems, not always use simple and available methods. Furthermore, they address energy losses of steam systems only due to thermal insulation, ignoring those due to leakages of traps. Given this context, the purpose of this paper is to determine the economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry, located in the metropolitan region of Salvador, Brazil. First, the energy lost in the steam distribution system through heat insulation and steam traps was estimated by applying thermodynamic principles, and technic consulting, respectively. Then, investments were estimated using commercial prices for new thermal insulation and steam traps. Finally, an economic evaluation of the improvement project was made, through the construction of a cash flow, and calculation of economic indicators: payback time, net present value (NPV), and internal rate of return (IRR). Economic indicators showed that the project is economically viable. The NPV and IRR reached approximately 5 million reais, and 66% per year, respectively. Additionally, this project also had social and environmental benefits, such as a reduction in greenhouse gases emissions, and increased local water availability.

Highlights

The delivery of high quality thermal energy in large quantities is essential in many processes of manufacturing goods and services
Steam systems generally provide this thermal energy, and it is largely derived from the burning of fossil fuels (CEB; FUPAI/ EFFICENTIA, 2005a)
The purpose of this paper is to determine the economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry

Summary

Introduction

The delivery of high quality thermal energy in large quantities is essential in many processes of manufacturing goods and services. Steam systems generally provide this thermal energy, and it is largely derived from the burning of fossil fuels (CEB; FUPAI/ EFFICENTIA, 2005a). This is worrying, as its burning is a major factor that contributes to increase in global warming. The Intergovernmental Panel on Climate Change (IPCC) states that anthropic climate warming is unquestionable, and if current pace is maintained, irreversible environmental damages to the planet may occur (IPCC, 2014). At the 21st Conference of Parties (COP-21) of the United Nations Framework Convention on Climate Change (UNFCCC), countries agreed to restrict greenhouse gas emissions (GHG) as soon as possible, and make major reductions by 2050, in order to limit the global temperature increase well below 2°C (UNFCCC, 2015). Analysts suggest that a reduction in emissions should be done initially by decreasing the amount of burning of fossil fuels (WYNN, 2015)

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