Aluminium Industry Solution

1Sammo Energy Ltd - Q1 2012

The Issue

The Aluminium industry is a very energy intensive industry. It uses furnaces at very high temperatures to prepare the aluminium, either in primary or in secondary process.The most use process is Hall-Héroult process .

The new regulation on air pollutants will put an additional stress on this industry to maintain the NOx emissions below regulatory limits.

The industry is always looking for ways to reduce their energy costs, consumption, emissions and carbon footprint.

2Sammo Energy Ltd - Q1 2012

Our business model

Sammo Energy Ltd is proposing to bring a full solution for the issue of the industry.

Sammo Energy proposes to invest its own resources to bring the solutions to the industry using the following approach:

• Full solution implementation integrating power generation and batch preheating;• No investment needed from the industry, Sammo Energy makes all the necessary

investment from its own resources;• No adverse impact on the production process, the industry benefits only from the upsides;• A complete monitoring system documents the benefits and performances of the systems;• Using a long term power purchase agreement guarantees a price of energy lower than

the market price. The industry saves money from the very first day of operation of the system;• The basic principle is to share all side benefits such as carbon emission reduction

incentives, grants, etc. All those programs are managed by Sammo Energy in full transparency;

3Sammo Energy Ltd - Q1 2012

Principles

4Sammo Energy Ltd - Q1 2012

2 Heat recovery from the aluminum smelting process

2.1 Aluminum production

Primary aluminum production takes place in three major stages: Bauxite mining, alumina

refining and aluminum smelting (Figure 2-1). The primary aluminum is defined as “the weight

of liquid aluminum as tapped from the pots excluding the weight of any alloying materials as

well that of any metal produced from either returned scrap or remelted materials” (Plunkert

2004). The secondary aluminum production is the recycling of returned scrap or remelted

materials. Primary and secondary aluminum are cast, rolled or extruded before processed

further in various industrial processes.

Figure 2-1. Flow diagram of major steps in primary and secondary aluminum production, and aluminum processing (EMT c2004).

-5-

2.2 Energy balance of an aluminum reduction cell

Inherent to the operation of aluminum smelting cells is a considerable heat loss, which

amounts to approximately half of the primary energy input. Most of that heat loss is

unavoidable due to the delicate heat balance in the Hall-Héroult cell which must be maintained

for process reasons and protection of side lining. Excessive insulation of the cell would lead to

failures in the cell construction since the used materials for conducting the current to the

electrodes cannot withstand temperatures of 800 to 900°C indefinitely. In addition, the

formation of ledge on the inner side walls would be prevented and may lead to erosion and

early lining failure (Grjotheim and Kvande 1993).

Approximately 30-45% of the total waste heat is carried away by the exhaust gas which is

drawn from the cell (Grjotheim and Kvande 1993, Abbas et al. 2009). The remainder of the

cell´s waste heat is lost by heat transfer through the side walls (§ 35%), anode rods (§ 8%),

collector bar (§ 8%), deck (§ 7%), and bottom (§ 7%) of a typical cell as shown in Figure 2-6.

Recovering some of this thermal energy may be economically attractive.

�Figure 2-6. Typical Hall-Héroult cell loss distribution (Grjotheim and Kvande 1993).

-12-

Our Operational approach

5

Waste heat flow

220ºC1 000 000 m3/hr

220ºC

120ºCWaste heat flow

To the Filters

Power Generationabout 5950 kW

Thermal power ofwaste heat flow isabout 34500 kWth

Sammo Energy Ltd - Q1 2012

Based on Hall-Heroult process example from iceland

Our Operational approach

In Aluminium making industry, all furnaces uses high temperatures and release large quantities of heat into the atmosphere one way or another wasting precious energy.

Our approach is the following:•Make a survey of all waste heat sources available with temperature usable by conversion

solutions;•Evaluate the coordinated way of using those sources of waste heat;

Based on the quantity of waste heat and its temperature, the optimum set of technologies will be selected:

•Organic Rankine Cycle Turbines;•Steam Rankine Turbines;•Kalina Cycle Turbines;•Other specific technologies;

The technologies used and their suppliers must be industry grade and demonstrate sufficient track record.

6Sammo Energy Ltd - Q1 2012

Don’t hesitate to contact us for any complementary information you may need

7Sammo Energy Ltd - Q1 2012

Email: contact@sammoenergy.comWeb: www.sammoenergy.comLinkedin : http://www.linkedin.com/company/sammo-energy-england-blog : http://smartenergies.wordpress.com/