Solar Steam Generation at JTI
Pioneering solar steam generation in the tobacco industry
In 2017, we helped Japan Tobacco International (JTI)’s Jordan factory become the first tobacco factory to use solar steam generation. In April 2016, JTI and Industrial Solar signed an agreement to advance the unprecedented task of building a commercially viable solar steam generator for process heating and cooling to meet the energy requirements of JTI’s Jordan facility.
JTI & path to solar steam generation
JTI, operating in Jordan since 1999, decided to significantly reduce its carbon footprint by using solar steam generation to cover its thermal energy demands and convert a part of the solar heat into cold. The solar system on the factory roof covers 85% of the factory’s annual steam consumption. This reduces costs and significantly diminishes dependency on Liquefied Petroleum Gas (LPG), used for steam generation.
The system’s major components are the solar collector field, a steam drum, and an absorption chiller that converts the solar steam not used by the production plant into cold.
How it works
The Fresnel collector is a linear concentrating solar technology. The uniaxially tracked primary mirrors and the secondary reflector focus the irradiation onto an absorber tube. The flowing fluid absorbs the heat and transfers it to the industrial production processes.
Water is pumped through the collector field and partly evaporates due to the concentrated solar irradiation. Afterward, the fluid enters the steam drum, where steam accumulates at the top and water at the bottom. The produced steam is conducted to the JTI’s steam network, where a part is used to supply the absorption chiller to generate space cooling. The water is continuously recirculated through the collector field. The steam drum also provides 1 hour of storage that compensates for short variations in the solar irradiation due to clouds. When steam is released into the factory, feed water is pumped into the steam drum to maintain mass balance. The existing boiler automatically produces steam when the sunshine is insufficient.
JTI solar steam generation system components
The 11 rows of primary mirrors of the Fresnel Collector have high reflectivity, are slightly curved and individually track the sun to concentrate the irradiation onto the absorber tube. This tube is composed of a metallic pipe encapsulated by a glass vacuum tube, which increases the system’s thermal efficiency. The main advantages of Industrial Solar Linear Fresnel collectors for providing industrial process heat are:
The steam drum is an insulated vessel that receives the mixture of steam and superheated water produced by the Fresnel collectors. This mixture is separated in the steam drum, in which the accumulated steam at the top of the vessel is discharged by a control valve to JTI’s steam network. The hot water at the bottom is recirculated to the Fresnel collectors. This reservoir runs at a higher pressure and temperature, providing up to one hour of storage, compensating for fluctuations in the demand or eventual shading in the collector field.
The absorption chiller has 4 main components: evaporator, absorber, generator, and condenser. In each step, the refrigerant changes phase and is conducted to the next step. The steam produced by the Fresnel collectors provides the heat needed to regenerate the refrigerant in the generator. The evaporator performs cold production where the refrigerant at low pressure absorbs heat from the environment to be cooled. The principle is like a conventional cooling system, but instead of using a compressor, it uses the generator/absorber to drive the refrigeration cycle.
The direct solar steam generation system installed at JTI provides heat at the specified pressure and temperature to be used directly in the factory. The steam drum provides seamless integration to JTI’s network, accumulating and regulating the collector thermal power and flow. The backup boiler remains parallel to the steam drum and provides additional steam when needed.