PPT 2.6MB - Energy Efficiency Opportunities

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Energy Efficiency

Opportunities

Presentation

September 2011

Bruce Philpott

Energy Champion

Simcoa Operations Pty Ltd

Presentation Overview

Background on Simcoa

Silicon production process

Simcoa’s energy profile

EEO Opportunities – 2 examples

Evaluation of the EEO process

Simcoa Operations Pty Ltd

Silicon Production

Simcoa Operations Pty Ltd

Simcoa is a fully integrated silicon smelting operation located in the

Kemerton Industrial Park

Australia’s only silicon producer

The site consists of a sawmill, two charcoal retorts, two 27MVA submerged arc furnaces, a filter house , a product handling plant and baghouse as well as site services, laboratory, administration and maintenance areas.

Kemerton Silicon Smelter

The Silicon Industry

• Silicon is used in both chemical and metallurgical processes, ultimately producing a range of high-tech products

• The majority of the world’s silicon is produced in China, Europe and South

America.

The Silicon Industry

• Silicon is produced by the reduction of quartz at 3000 - 4000°C using a carbon reductant

• SiO2 + C

Si + CO2

• Particularly carbon and energy intensive

• International benchmark in process efficiency

Silicon Products

• PV Solar Cells

• Silicone rubber

• Synthetic oil

• Optical fibre

• High strength aluminum alloys

• Silicon chips

• Synthetic quartz

Energy Profile

Energy

Inputs

Electricity

Natural Gas

Diesel

LPG

GJ

(Approx)

1,400,000

70,000

12,000

500

Total energy use at the Kemerton site is approximately 1.5 PJ per year.

The submerged arc furnaces use about 90% of the site’s electrical power with a load of 41 MW

The process is highly endothermic requiring approx 11 MWh/tonne of silicon

The furnaces are currently operating at worlds best practice levels in terms of electrical efficiencies, so opportunities for improvement are limited

.

Energy Efficiency Initiatives

• Considerable scope for projects that can capture and use waste heat from the smelting process or minimize furnace downtime.

• Projects that recover energy (waste heat) are normally only feasible if considered at the design stage.

Energy Savings through EEO

• Assessment identified 10 opportunities with a total energy saving of 41,000 GJ

• 4 of these opportunities have been implemented, 4 are to be implemented,

1 is under investigation and 1 not to be implemented.

Example Opportunity

Replacement of steel contact pads with copper pads

Energy saving calculated as ~10,000 GJ.

Example Opportunity

Optimize use of ladle pre-heater Natural Gas

Historically spare ladles heated under gas fueled pre-heaters so that they could be immediately called into service

– with better planning they can be maintained at a lower temperature, which is increased before use

Energy saving calculated as ~8,400 GJ.

Examination of the EEO process

• Being one of the first participants it was difficult to estimate resources needed – in hindsight probably underresourced

• Identified savings that did not require significant expenditure (for example ladle preheating)

• Use of energy bandwidths, while sometimes necessary, can be confusing

• Lack of continuity of staff makes reporting difficult

• Second cycle will provide an opportunity to apply the knowledge and skills learnt from networking, workshops etc

• Short payback period does not make opportunities a sure thing i.e. other variables such as technical risk, cash flow, other strategic priorities etc will influence decision making

For new plant – EEO evaluation at design phase would be helpful – for example new silicon furnace is designed for future energy recovery

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