Steam Generator from Waste Heat

THE CONCEPT

Many industries need heat at relatively low temperatures (100-140* C) for process requirements. Normally, low-pressure steam boilers are used to provide steam as a heat source for such process heat duty

If the steam boiler uses liquid fuel or gas as a fossil fuel energy source, the cost of such heat supply tends to be quite high and industries shift to using alternates like coal, lignite and agro waste aggregates to reduce the costs. This trend results in increasing Green House Gas (GHG) emissions apart from increasing other air pollutant emissions (sulphur, nitrogen oxides, particulates) and solid wastes. Use of solid fossil fuels also increases problems of general housekeeping and dust pollution in industrial premises

In order to address the issue, we have partnered with Ahmedabad Ethical Energy Consultants who have designed a unique system wherein we can help industries in generating low pressure steam without burning any fossil fuel. The system works on the technical concept of 'HEAT PUMP' and uses grid supplied or onsite generated electricity, in a highly efficient manner, to generate steam

POWERED BY TECHNOLOGY

The system is based on proven technology modules related to the heat pump as well as the unique steam compression technology available from our OEM partner. The steam generation scheme involves the following major technology modules:



The waste heat source could be anything, including the cooling water system. Thus, one can easily envisage the use of cooling water return from process to be used as the heat source for generating steam. Moreover, this unique system also helps in reducing or eliminating the heat rejection load on cooling towers. We also provide necessary process guarantees and warrantees on the system

SYSTEM SPECIFICATIONS
Based on available size and capacity of steam compressors from our OEM partner, we can offer steam generators starting with minimum capacity of 1500 kgs/hr, although higher capacities are also possible. The maximum steam pressure that can be generated in our system is 6 kg/sq.cm.A, while steam generation pressure ranges from 1.2-6 kg/sq.cm.A

SAVINGS AND ECONOMICS
Let us consider the example of Maharashtra, India where power cost is approximately Rs. 7 per unit. The cost of steam generated in our system is related to the pressure at which steam is required. Power required would be in the range of 0.15-0.3 kwh/kg of steam depending upon the pressure. The fuel cost in a liquid fuel based boiler would be in the range of INR 4-4.5 per kg of steam. When compared with the cost of power required to generate 1 kg of steam at 0.30kwh which equates to Rs. 2, our steam generator could offer attractive paybacks where steam requirement of 1500 kgs/hr or more is observed for more than 5000 hours in a year. Additionally, our steam generator helps in generating steam in a clean, cost effective manner, thereby enabling reduction in GHG emissions. Fuels such as Furnace Oil not only contaminate the environment, but also cause maintenance problems and pollution

IMPORTANT POINTS
The heat pump works on the principle of upgrading low level heat to a higher temperature level. Hence, adequate low temperature heat should be available to generate the required quantity of steam. The steam compressor power requirement depends on two main parameters - final steam pressure and temperature level of waste heat available. Depending on the main source of waste heat, power requirement would then depend on final steam pressure required